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Sample records for proximal limb muscles

  1. Fatigue-related firing of distal muscle nociceptors reduces voluntary activation of proximal muscles of the same limb.

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    Kennedy, David S; McNeil, Chris J; Gandevia, Simon C; Taylor, Janet L

    2014-02-15

    With fatiguing exercise, firing of group III/IV muscle afferents reduces voluntary activation and force of the exercised muscles. These afferents can also act across agonist/antagonist pairs, reducing voluntary activation and force in nonfatigued muscles. We hypothesized that maintained firing of group III/IV muscle afferents after a fatiguing adductor pollicis (AP) contraction would decrease voluntary activation and force of AP and ipsilateral elbow flexors. In two experiments (n = 10) we examined voluntary activation of AP and elbow flexors by measuring changes in superimposed twitches evoked by ulnar nerve stimulation and transcranial magnetic stimulation of the motor cortex, respectively. Inflation of a sphygmomanometer cuff after a 2-min AP maximal voluntary contraction (MVC) blocked circulation of the hand for 2 min and maintained firing of group III/IV muscle afferents. After a 2-min AP MVC, maximal AP voluntary activation was lower with than without ischemia (56.2 ± 17.7% vs. 76.3 ± 14.6%; mean ± SD; P muscle afferents from the hand decreased voluntary drive and force of AP. Moreover, this effect decreased voluntary drive and torque of proximal unfatigued muscles, the elbow flexors. Fatigue-sensitive group III/IV muscle nociceptors act to limit voluntary drive not only to fatigued muscles but also to unfatigued muscles within the same limb.

  2. Latissimus dorsi fine needle muscle biopsy: a novel and efficient approach to study proximal muscles of upper limbs.

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    Paoli, Antonio; Pacelli, Quirico F; Toniolo, Luana; Miotti, Danilo; Reggiani, Carlo

    2010-12-01

    The muscle biopsy based on the Bergström needle has been widely used for more than 40 y for diagnosis and experimental studies on muscle. More recently, thinner needles and tru-cut needles have also been introduced. Such techniques have been largely tested on various muscles, including the quadriceps, with few studies on upper limb muscles like deltoid, and no studies on latissimus dorsi muscle (LDM). In this study, we implemented and validated a protocol to collect samples of LDM for experimental purposes, causing minimal discomfort to volunteers. Two main problems were considered: the anatomical localization of the biopsy site and the selection of an appropriate needle. A strict protocol of palpatory anatomy was adopted and validated with ultrasonography to localize the biopsy site in LDM in subjects with various degrees of muscle development. A 14 gauge tru-cut needle was selected as the smallest and still effective device for sampling. Biopsy sampling was performed in 18 subjects without any complications, or complains of pain or functional limitations. Approximately 4 mg of tissue were recovered from each introduction of the inner notched cannula of the needle. With three consecutive samplings, an amount of tissue sufficient to prepare proteins for gel electrophoresis and Western blot and to dissect single fiber segment for functional experiments, was obtained. Taken together, the results suggest that this biopsy technique opens to experimental studies muscles until now never considered accessible. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Proximal Limb Weakness Reverting After CSF Diversion In Intracranial Hypertension

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    Sinha S

    2005-01-01

    Full Text Available We report about two young girls who developed progressive visual failure secondary to increased intracranial pressure and had significant proximal muscle weakness of limbs. Patients with elevated intracranial pressure (ICP may present with "false localizing signs", besides having headache, vomiting and papilledema. Radicular pain as a manifestation of raised ICP is rare and motor weakness attributable to polyradiculopathy is exceptional. Two patients with increased intracranial pressure without lateralizing signs′ had singnificant muscle weakness. Clinical evaluation and laboratory tests did not disclose any other cause for weakness. Following theco-peritoneal shunt, in both patients, there was variable recovery of vision but the proximal weakness and symptoms of elevated ICP improved rapidly. Recognition of this uncommon manifestation of raised ICP may obviate the need for unnecessary investigation and reduce morbidity due to weakness by CSF diversion procedure.

  4. Muscle Selection for Focal Limb Dystonia

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    Barbara Illowsky Karp

    2017-12-01

    Full Text Available Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this article, we discuss approaches to selecting upper and lower extremity muscles for chemodenervation treatment of limb dystonia.

  5. Muscle Selection for Focal Limb Dystonia.

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    Karp, Barbara Illowsky; Alter, Katharine

    2017-12-29

    Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this article, we discuss approaches to selecting upper and lower extremity muscles for chemodenervation treatment of limb dystonia.

  6. Muscle Selection for Focal Limb Dystonia

    OpenAIRE

    Barbara Illowsky Karp; Katharine Alter

    2017-01-01

    Selection of muscles for botulinum toxin injection for limb dystonia is particularly challenging. Limb dystonias vary more widely in the pattern of dystonic movement and involved muscles than cervical dystonia or blepharospasm. The large variation in how healthy individuals perform skilled hand movements, the large number of muscles in the hand and forearm, and the presence of compensatory actions in patients with dystonia add to the complexity of choosing muscles for injection. In this artic...

  7. Method to measure tone of axial and proximal muscle.

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    Gurfinkel, Victor S; Cacciatore, Timothy W; Cordo, Paul J; Horak, Fay B

    2011-12-14

    The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention.

  8. Method to Measure Tone of Axial and Proximal Muscle

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    Gurfinkel, Victor S.; Cacciatore, Timothy W.; Cordo, Paul J.; Horak, Fay B.

    2011-01-01

    The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs1, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention. PMID:22214974

  9. Characteristic MRI Findings of upper Limb Muscle Involvement in Myotonic Dystrophy Type 1.

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    Kazuma Sugie

    Full Text Available The objective of our study was to evaluate the relation between muscle MRI findings and upper limb weakness with grip myotonia in patients with myotonic dystrophy type 1 (DM1. Seventeen patients with DM1 were evaluated by manual muscle strength testing and muscle MRI of the upper limbs. Many DM1 patients presenting with decreased grasping power frequently showed high intensity signals in the flexor digitorum profundus (FDP muscles on T1-weighted imaging. Patients presenting with upper limb weakness frequently also showed high intensity signals in the flexor pollicis longus, abductor pollicis longus, and extensor pollicis muscles. Disturbances of the distal muscles of the upper limbs were predominant in all DM1 patients. Some DM1 patients with a prolonged disease duration showed involvement of not only distal muscles but also proximal muscles in the upper limbs. Muscle involvement of the upper limbs on MRI strongly correlated positively with the disease duration or the numbers of CTG repeats. To our knowledge, this is the first study to provide a detailed description of the distribution and severity of affected muscles of the upper limbs on MRI in patients with DM1. We conclude that muscle MRI findings are very useful for identifying affected muscles and predicting the risk of muscle weakness in the upper limbs of DM1 patients.

  10. Characteristic MRI Findings of upper Limb Muscle Involvement in Myotonic Dystrophy Type 1.

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    Sugie, Kazuma; Sugie, Miho; Taoka, Toshio; Tonomura, Yasuyo; Kumazawa, Aya; Izumi, Tesseki; Kichikawa, Kimihiko; Ueno, Satoshi

    2015-01-01

    The objective of our study was to evaluate the relation between muscle MRI findings and upper limb weakness with grip myotonia in patients with myotonic dystrophy type 1 (DM1). Seventeen patients with DM1 were evaluated by manual muscle strength testing and muscle MRI of the upper limbs. Many DM1 patients presenting with decreased grasping power frequently showed high intensity signals in the flexor digitorum profundus (FDP) muscles on T1-weighted imaging. Patients presenting with upper limb weakness frequently also showed high intensity signals in the flexor pollicis longus, abductor pollicis longus, and extensor pollicis muscles. Disturbances of the distal muscles of the upper limbs were predominant in all DM1 patients. Some DM1 patients with a prolonged disease duration showed involvement of not only distal muscles but also proximal muscles in the upper limbs. Muscle involvement of the upper limbs on MRI strongly correlated positively with the disease duration or the numbers of CTG repeats. To our knowledge, this is the first study to provide a detailed description of the distribution and severity of affected muscles of the upper limbs on MRI in patients with DM1. We conclude that muscle MRI findings are very useful for identifying affected muscles and predicting the risk of muscle weakness in the upper limbs of DM1 patients.

  11. Lower limb muscle volumes in bilateral spastic cerebral palsy.

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    Noble, Jonathan J; Fry, Nicola R; Lewis, Andrew P; Keevil, Stephen F; Gough, Martin; Shortland, Adam P

    2014-04-01

    Muscle weakness is a feature of individuals with spastic cerebral palsy (SCP) but there are few reports in the literature of muscle volume in this group. This study compares muscle volumes in adolescents and young adults with SCP with those of their typically developing (TD) peers. Measurements of the volumes of nine major lower limb muscles in 19 independently ambulant subjects with SCP (mean age 14.2 years (sd 2.7), 11 male, GMFCS I (n=5); GMFCS II (n=14)), 19 TD subjects (mean age 16.5 years (sd 3.0), 11 male) were made using magnetic resonance imaging. Lower limb muscles were smaller in the SCP group (p≤0.023 in all muscles) than the TD group with the exception of the vastii (lateralis+intermedius; p=0.868) and gluteus maximus (p=0.056). Average muscle volume deficit was 27.9%. Muscle volume deficits were significantly greater for distal muscles than proximal muscles (phistory of sarcopenia in adulthood may contribute to the early loss of mobility of adults with SCP. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  12. Effect of limb immobilization on skeletal muscle

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    Booth, F. W.

    1982-01-01

    Current knowledge and questions remaining concerning the effects of limb immobilization on skeletal muscle is reviewed. The most dramatic of these effects is muscle atrophy, which has been noted in cases of muscles fixed at or below their resting length. Immobilization is also accompanied by a substantial decrease in motoneuronal discharges, which results in the conversion of slow-twitch muscle to muscle with fast-twitch characteristics. Sarcolemma effects include no change or a decrease in resting membrane potential, the appearance of extrajunctional acetylcholine receptors, and no change in acetylcholinesterase activity. Evidence of changes in motoneuron after hyperpolarization characteristics suggests that the muscle inactivity is responsible for neuronal changes, rather than vice versa. The rate of protein loss from atrophying muscles is determined solely by the first-order rate constant for degradation. Various other biochemical and functional changes have been noted, including decreased insulin responsiveness and protein synthesis. The model of limb immobilization may also be useful for related studies of muscle adaptation.

  13. Origin of directionally tuned responses in lower limb muscles to unpredictable upper limb disturbances

    OpenAIRE

    Forghani, Ali; Milner, Theodore E.

    2017-01-01

    Unpredictable forces which perturb balance are frequently applied to the body through interaction between the upper limb and the environment. Lower limb muscles respond rapidly to these postural disturbances in a highly specific manner. We have shown that the muscle activation patterns of lower limb muscles are organized in a direction specific manner which changes with lower limb stability. Ankle muscles change their activity within 80 ms of the onset of a force perturbation applied to the h...

  14. Neck muscle fatigue alters upper limb proprioception.

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    Zabihhosseinian, Mahboobeh; Holmes, Michael W R; Murphy, Bernadette

    2015-05-01

    Limb proprioception is an awareness by the central nervous system (CNS) of the location of a limb in three-dimensional space and is essential for movement and postural control. The CNS uses the position of the head and neck when interpreting the position of the upper limb, and altered input from neck muscles may affect the sensory inputs to the CNS and consequently may impair the awareness of upper limb joint position. The purpose of this study was to determine whether fatigue of the cervical extensors muscles (CEM) using a submaximal fatigue protocol alters the ability to recreate a previously presented elbow angle with the head in a neutral position. Twelve healthy individuals participated. CEM activity was examined bilaterally using surface electromyography, and kinematics of the elbow joint was measured. The fatigue protocol included an isometric neck extension task at 70 % of maximum until failure. Joint position error increased following fatigue, demonstrating a significant main effect of time (F 2, 18 = 19.41, p ≤ 0.0001) for absolute error. No significant differences were found for variable error (F 2, 18 = 0.27, p = 0.76) or constant error (F 2, 18 = 1.16 of time, p ≤ 0.33). This study confirms that fatigue of the CEM can reduce the accuracy of elbow joint position matching. This suggests that altered afferent input from the neck subsequent to fatigue may impair upper limb proprioception.

  15. Proximal and distal muscle fatigue differentially affect movement coordination.

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    Cowley, Jeffrey C; Gates, Deanna H

    2017-01-01

    Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p fatigue caused small but significant changes in trunk angles (2°, p fatigue protocols (p fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks.

  16. Proximal and distal muscle fatigue differentially affect movement coordination

    Science.gov (United States)

    Cowley, Jeffrey C.

    2017-01-01

    Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p fatigue caused small but significant changes in trunk angles (2°, p fatigue protocols (p fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks. PMID:28235005

  17. Modified Vertical Rectus Abdominis Musculocutaneous Flap for Limb Salvage Procedures in Proximal Lower Limb Musculoskeletal Sarcomas

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    Haitham H. Khalil

    2008-01-01

    Full Text Available Introduction and aim. Management of complicated wounds after tumor extipiration of pelvic and proximal lower limb musculoskeletal sarcoma represents an essential component in the outcome of these patients. The authors present modified vertical rectus abdominis musculocutaneous (VRAM flap techniques to reconstruct extensive defects after debridment of these complicated wounds. Material and Methods. Over a period of 4 years (2002–2005, 5 men and 2 women were managed. Median age was 21 years (range 15–49. The patients were managed for complicated lower trunk, groin, and upper thigh wounds after resection of three pelvic chondrosarcomas as well as two pelvic and two proximal femur osteosarcomas. The modifications included a VRAM flap with lateral and tongue-like extension design of the skin paddle (5 cases or a delayed extended VRAM flap (2 cases. Results. All flaps showed complete survival and healing with no ischemic events providing stable coverage. All patients were ambulant with good limb functions in terms of walking and gait after adequate rehabilitation, 2 needed support with crutches. Conclusion. The modified VRAM flaps offer reliable reconstructive tools for coverage of complex groin and thigh defects by providing larger well-vascularized soft tissue with acceptable donor site.

  18. A novel MYH7 mutation with prominent paraspinal and proximal muscle involvement.

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    Park, Jin-Mo; Kim, Ye Jin; Yoo, Jeong Hyun; Hong, Young Bin; Park, Ji Hoon; Koo, Heasoo; Chung, Ki Wha; Choi, Byung-Ok

    2013-07-01

    Laing distal myopathy (LDM) is caused by mutations in the MYH7 gene, and known to have muscle weakness of distal limbs and neck flexors. Through whole exome sequencing, we identified a novel p.Ala1439Pro MYH7 mutation in a Korean LDM family. This missense mutation is located in more N-terminal than any reported rod domain LDM mutations. In the early stage of disease, the present patients showed similar clinical patterns to the previously described patients of LDM. However, in the later stage, fatty replacement and atrophy of paraspinal or proximal leg muscles was more severely marked than lower leg muscles, and asymmetric atrophies were observed in trapezius, subscapularis and adductor magnus muscles. Distal myopathy like LDM showed marked and predominant fatty infiltrations in paraspinal or proximal leg muscles with marked asymmetry. These observations expand the clinical spectrum of LDM with the MYH7 mutation. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Proximal and distal muscle fatigue differentially affect movement coordination

    OpenAIRE

    Cowley, Jeffrey C.; Gates, Deanna H.

    2017-01-01

    Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proxim...

  20. Fibre operating lengths of human lower limb muscles during walking.

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    Arnold, Edith M; Delp, Scott L

    2011-05-27

    Muscles actuate movement by generating forces. The forces generated by muscles are highly dependent on their fibre lengths, yet it is difficult to measure the lengths over which muscle fibres operate during movement. We combined experimental measurements of joint angles and muscle activation patterns during walking with a musculoskeletal model that captures the relationships between muscle fibre lengths, joint angles and muscle activations for muscles of the lower limb. We used this musculoskeletal model to produce a simulation of muscle-tendon dynamics during walking and calculated fibre operating lengths (i.e. the length of muscle fibres relative to their optimal fibre length) for 17 lower limb muscles. Our results indicate that when musculotendon compliance is low, the muscle fibre operating length is determined predominantly by the joint angles and muscle moment arms. If musculotendon compliance is high, muscle fibre operating length is more dependent on activation level and force-length-velocity effects. We found that muscles operate on multiple limbs of the force-length curve (i.e. ascending, plateau and descending limbs) during the gait cycle, but are active within a smaller portion of their total operating range.

  1. Myogenic capacity of muscle progenitor cells from head and limb muscles.

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    Grefte, Sander; Kuijpers, Mette A R; Kuijpers-Jagtman, Anne M; Torensma, Ruurd; Von den Hoff, Johannes W

    2012-02-01

    The restoration of muscles in the soft palate of patients with cleft lip and/or palate is accompanied by fibrosis, which leads to speech and feeding problems. Treatment strategies that improve muscle regeneration have only been tested in limb muscles. Therefore, in the present study the myogenic potential of muscle progenitor cells (MPCs) isolated from head muscles was compared with that of limb muscles. Muscle progenitor cells were isolated from the head muscles and limb muscles of rats and cultured. The proliferation of MPCs was analysed by DNA quantification. The differentiation capacity was analysed by quantifying the numbers of fused cells, and by measuring the mRNA levels of differentiation markers. Muscle progenitor cells were stained to quantify the expression of paired box protein Pax 7 (Pax-7), myoblast determination protein 1 (MyoD), and myogenin. Proliferation was similar in the head MPCs and the limb MPCs. Differentiating head and limb MPCs showed a comparable number of fused cells and mRNA expression levels of myosin-1 (Myh1), myosin-3 (Myh3), and myosin-4 (Myh4). During proliferation and differentiation, the number of Pax-7(+), MyoD(+), and myogenin(+) cells in head and limb MPCs was equal. It was concluded that head and limb MPCs show similar myogenic capacities in vitro. Therefore, in vivo myogenic differences between those muscles might rely on the local microenvironment. Thus, regenerative strategies for limb muscles might also be used for head muscles. © 2012 Eur J Oral Sci.

  2. Proximal and distal muscle fatigue differentially affect movement coordination.

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    Jeffrey C Cowley

    Full Text Available Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor or distal (finger flexor muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p < 0.005 in trunk lean and velocity, reduced humeral elevation (11°, p < 0.005, and increased elbow flexion (4°, p < 0.01. In contrast, distal fatigue caused small but significant changes in trunk angles (2°, p < 0.05, increased velocity of wrench movement relative to the hand (17°/s, p < 0.001, and earlier wrist extension (4%, p < 0.005. Movement variability increased at proximal joints but not distal joints after both fatigue protocols (p < 0.05. Varying movements at proximal joints may help people adapt to fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks.

  3. Core muscle activation during dynamic upper limb exercises in women.

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    Tarnanen, Sami P; Siekkinen, Kirsti M; Häkkinen, Arja H; Mälkiä, Esko A; Kautiainen, Hannu J; Ylinen, Jari J

    2012-12-01

    Although several everyday functions and sporting activities demand controlled use of the abdominal and back muscles while working with the upper limbs, the activity of core muscles during dynamic upper limb exercises in the standing position has not been studied extensively. The purpose of this cross-sectional study was to examine abdominal and back muscle activity during dynamic upper limb exercises while standing and to evaluate whether dynamic exercises are appropriate for strengthening muscles. The activation of the rectus abdominis, obliquus externus abdominis, longissimus, and multifidus muscles during dynamic bilateral or unilateral shoulder exercises with or without fixation of the pelvis was measured in 20 healthy women using surface electromyography. Trunk muscle activation during isometric maximum contraction was used as a comparative reference. With bilateral shoulder extension and unilateral shoulder horizontal adduction, abdominal muscle activity was >60% of activity during reference exercises. With unilateral shoulder horizontal abduction and shoulder extension exercises, back muscle activity was >60% of the activity level reference exercise. Muscle activation levels were 35-64% lower during shoulder horizontal adduction and abduction without fixation compared with exercises with fixation. The results indicate that upper limb exercises performed in the standing position are effective for activating core muscles. Bilateral and unilateral shoulder extension and unilateral shoulder horizontal abduction and adduction with the pelvis fixed elicited the greatest activity of the core muscles.

  4. X-rays computed tomographic scans of lower limb and trunk muscles in facioscapulohumeral muscular dystrophy

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    Horikawa, Hirosei; Mano, Yukio; Takayanagi, Tetsuya (Nara Medical Univ., Kashihara (Japan)); Takahashi, Keiichi; Nishio, Hisahide

    1992-10-01

    X-rays computed tomographic (CT) scans of muscles of the lower limbs and the trunk in 14 patients with facioscapulohumeral muscular dystrophy (FSH) were studied. The CT scans showed that the affected muscles were decreased in density and size. The laterality of muscular involvement was sometimes observed. The muscular lesions in the lower limbs showed proximal distribution. In the thigh, the hamstrings were affected first, the adductor muscles second, and then the muscular involvement progressed to the quadriceps femoris muscle. In the lower leg, the gastrocnemius and soleus muscles were relatively spared as compared with the tibialis anterior muscle. In the lumbar girdle, the abdominal muscles were involved first, the gluteal muscles second, the back muscles third, and the psoas major muscle were relatively spared. The muscular weakness of this distribution exacerbated lumbar lordosis. The neck muscles were less affected than those of the lumbar girdle. The CT scans in FSH demonstrated the characteristic pattern of muscular involvement, which differed from the inherited muscular diseases such as Duchenne muscular dystrophy, myotonic dystrophy, and others. (author).

  5. Limb-sparing surgery in a dog with osteosarcoma of the proximal femur.

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    Liptak, Julius M; Pluhar, G Elizabeth; Dernell, William S; Withrow, Stephen J

    2005-01-01

    To report successful limb-sparing surgery in a dog with a proximal femoral osteosarcoma (OSA) using a composite allograft-prosthetic technique. Case report. Client-owned dog. A stage IIB OSA of the proximal aspect of the femur was resected in accordance with oncologic and limb-sparing principles. The osseous defect was reconstructed with a proximal femoral allograft and cemented, long-stemmed femoral prosthesis. Soft tissue reconstruction was achieved by suturing host tendons to their respective allogeneic tendons on the allograft. Coxofemoral joint function was preserved using standard total hip arthroplasty techniques. Limb-sparing surgery of the proximal aspect of the femur using a composite allograft-prosthetic technique resulted in excellent limb function. Postoperative complications included aseptic loosening of the femoral composite graft and allograft nonunion, which required revision, traumatic implant luxation, and local tumor recurrence. Limb function was excellent after surgical stabilization of the allograft nonunion but deteriorated after implant luxation 270 days postlimb-sparing surgery. Pulmonary and skeletal metastases were diagnosed and local tumor recurrence suspected 596 and 650 days postoperatively, respectively. The dog was euthanatized 688 days after limb-sparing surgery as a result of progressive local and metastatic disease. Limb-sparing surgery for dogs with primary bone tumors of the proximal aspect of the femur is feasible with good functional results.

  6. Coactivation of Lower Limb Muscles during Gait in Patients with Multiple Sclerosis.

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    Boudarham, Julien; Hameau, Sophie; Zory, Raphael; Hardy, Alexandre; Bensmail, Djamel; Roche, Nicolas

    2016-01-01

    Coactivation of agonist and antagonist lower limb muscles during gait stiffens joints and ensures stability. In patients with multiple sclerosis, coactivation of lower limb muscles might be a compensatory mechanism to cope with impairments of balance and gait. The aim of this study was to assess coactivation of agonist and antagonist muscles at the knee and ankle joints during gait in patients with multiple sclerosis, and to evaluate the relationship between muscle coactivation and disability, gait performance, dynamic ankle strength measured during gait, and postural stability. The magnitude and duration of coactivation of agonist-antagonist muscle pairs at the knee and ankle were determined for both lower limbs (more and less-affected) in 14 patients with multiple sclerosis and 11 healthy subjects walking at a spontaneous speed, using 3D-gait analysis. In the patient group, coactivation was increased in the knee muscles during single support (proximal strategy) and in the ankle muscles during double support (distal strategy). The magnitude of coactivation was highest in the patients with the slowest gait, the greatest motor impairment and the most instability. Increased muscle coactivation is likely a compensatory mechanism to limit the number of degrees of freedom during gait in patients with multiple sclerosis, particularly when postural stability is impaired.

  7. Upper and lower limb muscle activation is bidirectionally and ipsilaterally coupled.

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    Huang, Helen J; Ferris, Daniel P

    2009-09-01

    There are neural connections between the upper and lower limbs of humans that enable muscle activation in one limb pair (upper or lower) to modulate muscle activation in the other limb pair (lower or upper, respectively). The aims of this study were to extend previous findings regarding submaximal exercise to maximal effort exercise and determine whether there is an ipsilateral or contralateral bias to the neural coupling during a rhythmic locomotor-like task. We measured upper and lower limb muscle activity, joint kinematics, and limb forces in neurologically intact subjects (n = 16) as they performed recumbent stepping using different combinations of upper and lower limb efforts. We found increased muscle activation in passive lower limbs during active upper limb effort compared with passive upper limb effort. Likewise, increased muscle activation in passive upper limbs occurred during active lower limb effort compared with passive lower limb effort, suggesting a bidirectional effect. Maximal muscle activation in the active lower limbs was not different between conditions with active upper limb effort and conditions with passive upper limb movement. Similarly, maximal muscle activation in the active upper limbs was not different between conditions with active lower limb effort and conditions with passive lower limb movement. Further comparisons revealed that neural coupling was primarily from active upper limb muscles to passive ipsilateral lower limb muscles. These findings indicate that interlimb neural coupling affects muscle recruitment during maximal effort upper and lower limb rhythmic exercise and provides insight into the architecture of the neural coupling.

  8. Co-activation of upper limb muscles during reaching in post-stroke subjects: an analysis of the contralesional and ipsilesional limbs.

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    Silva, Cláudia C; Silva, Augusta; Sousa, Andreia; Pinheiro, Ana Rita; Bourlinova, Catarina; Silva, Ana; Salazar, António; Borges, Carla; Crasto, Carlos; Correia, Miguel Velhote; Vilas-Boas, João Paulo; Santos, Rubim

    2014-10-01

    The purpose of this study was to analyze the change in antagonist co-activation ratio of upper-limb muscle pairs, during the reaching movement, of both ipsilesional and contralesional limbs of post-stroke subjects. Nine healthy and nine post-stroke subjects were instructed to reach and grasp a target, placed in the sagittal and scapular planes of movement. Surface EMG was recorded from postural control and movement related muscles. Reaching movement was divided in two sub-phases, according to proximal postural control versus movement control demands, during which antagonist co-activation ratios were calculated for the muscle pairs LD/PM, PD/AD, TRIlat/BB and TRIlat/BR. Post-stroke's ipsilesional limb presented lower co-activation in muscles with an important role in postural control (LD/PM), comparing to the healthy subjects during the first sub-phase, when the movement was performed in the sagittal plane (plimb showed in general an increased co-activation ratio in muscles related to movement control, comparing to the healthy subjects. Our findings demonstrate that, in post-stroke subjects, the reaching movement performed with the ipsilesional upper limb seems to show co-activation impairments in muscle pairs associated to postural control, whereas the contralesional upper limb seems to have signs of impairment of muscle pairs related to movement. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. First Neuromuscular Contact Correlates with Onset of Primary Myogenesis in Rat and Mouse Limb Muscles.

    Directory of Open Access Journals (Sweden)

    Bradley Hurren

    Full Text Available Skeletal muscle development has been the focus of intensive study for many decades. Recent advances in genetic manipulation of the mouse have increased our understanding of the cell signalling involved in the development of muscle progenitors which give rise to adult skeletal muscles and their stem cell populations. However, the influence of a vital tissue type - the peripheral nerve-has largely been ignored since its earliest descriptions. Here we carefully describe the timing in which myogenic progenitors expressing Pax3 and Pax7 (the earliest markers of myogenic cells enter the limb buds of rat and mouse embryos, as well as the spatiotemporal relationship between these progenitors and the ingrowing peripheral nerve. We show that progenitors expressing Pax3 enter the limb bud one full day ahead of the first neurites and that Pax7-expressing progenitors (associated with secondary myogenesis in the limb are first seen in the limb bud at the time of nerve entry and in close proximity to the nerve. The initial entry of the nerve also coincides with the first expression of myosin heavy chain showing that the first contact between nerves and myogenic cells correlates with the onset of myogenic differentiation. Furthermore, as the nerve grows into the limb, Pax3 expression is progressively replaced by Pax7 expression in myogenic progenitors. These findings indicate that the ingrowing nerve enters the limb presumptive muscle masses earlier than what was generally described and raises the possibility that nerve may influence the differentiation of muscle progenitors in rodent limbs.

  10. Arterial supply of the soleus muscle: anatomical study of fifty lower limbs.

    Science.gov (United States)

    Raveendran, S S; Kumaragama, K G J L

    2003-05-01

    Soft tissue defects of the lower limb are a formidable challenge to the plastic surgeon but a soleus muscle flap often provides the solution. Various types of soleus muscle flap have been described, based mainly on the vascular supply. The arterial blood supply of the soleus muscle was studied in 50 cadaveric lower limbs. The blood vessels and their branches to the muscle were dissected. The distance of the origin of the perforators was measured from fixed bony landmarks. Branches of the popliteal artery trunk, the posterior tibial artery, and the peroneal artery supplied the soleus muscle. The number of branches to the soleus muscle from these main arteries were analyzed. The medial part of the muscle was supplied throughout its length by perforators arising from the posterior tibial artery. This constant feature makes the medial part of the muscle reliable as a proximally or distally based flap. The average distances of the lower perforators arising from the posterior tibial artery were 6.5 cm, 11.6 cm, and 16.8 cm from the medial malleolus. The branches of the peroneal artery were mostly distributed in the upper half of the muscle. These large pedicles allow a composite transfer of the soleus muscle with the fibula. Lower perforators were demonstrated to arise from the peroneal artery in 60% of the limbs but the scarcity of perforators in this region limits the clinical usefulness of an inferiorly based lateral hemisoleus flap. The study demonstrates the distribution of arteries entering the soleus muscle and how the information may be used in the design of soleus muscle flaps. The average numbers of the perforators arising from the vessels and their distribution have been highlighted. Copyright 2003 Wiley-Liss, Inc.

  11. Muscle MRI STIR signal intensity and atrophy are correlated to focal lower limb neuropathy severity

    Energy Technology Data Exchange (ETDEWEB)

    Deroide, N.; Mambre, L.; Kubis, Nathalie [Service de Physiologie Clinique-Explorations Fonctionnelles, AP-HP, Hopital Lariboisiere, Paris (France); Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); Bousson, V.; Laredo, J.D. [Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); Radiologie Osteo-articulaire, AP-HP, Hopital Lariboisiere, Paris (France); Vicaut, E. [Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); URC, AP-HP, Hopital Lariboisiere, Paris (France)

    2014-09-26

    The objective is to determine if muscle MRI is useful for assessing neuropathy severity. Clinical, MRI and electromyography (EMG) examinations were performed in 17 patients with focal lower limb neuropathies. MRI Short Tau Inversion Recovery (STIR) signal intensity, amyotrophy, and muscle fatty infiltration measured after T1-weighted image acquisition, EMG spontaneous activity (SA), and maximal voluntary contraction (MVC) were graded using semiquantitative scores and quantitative scores for STIR signal intensity and were correlated to the Medical Research Council (MRC) score for testing muscle strength. Within this population, subgroups were selected according to severity (mild versus severe), duration (subacute versus chronic), and topography (distal versus proximal) of the neuropathy. EMG SA and MVC MRI amyotrophy and quantitative scoring of muscle STIR intensity were correlated with the MRC score. Moreover, MRI amyotrophy was significantly increased in severe, chronic, and proximal neuropathies along with fatty infiltration in chronic lesions. Muscle MRI atrophy and quantitative evaluation of signal intensity were correlated to MRC score in our study. Semiquantitative evaluation of muscle STIR signal was sensitive enough for detection of topography of the nerve lesion but was not suitable to assess severity. Muscle MRI could support EMG in chronic and proximal neuropathy, which showed poor sensitivity in these patients. (orig.)

  12. An anatomical and histological study of the structures surrounding the proximal attachment of the hamstring muscles.

    Science.gov (United States)

    Pérez-Bellmunt, Albert; Miguel-Pérez, Maribel; Brugué, Marc Blasi; Cabús, Juan Blasi; Casals, Martí; Martinoli, Carlo; Kuisma, Raija

    2015-06-01

    The proximal attachment of hamstring muscles has a very high incidence of injuries due to a wide number of factors and its morphology may be one of the underlying factors as scientific literature points out. The connective tissue component of the attachment of hamstring muscles is not well known. For this reason the aim of this study is to describe the anatomy and histology surrounding the proximal attachment of the hamstring muscles (PAHM) and its direct anatomic relations. Forty-eight cryopreserved lower limbs have sequentially been studied by means of dissection, anatomical sections and histology. All specimens studied presented an annular connective tissue structure that resembles a retinaculum, which covers and adapts to the attachment of hamstring muscles on the ischial tuberosity. The results show how this retinaculum is continuous with the long head of biceps femoris muscle, however there is a layer of loose connective tissue between the retinaculum and the semitendinosus muscle. Furthermore, this structure receives expansions of the anterior epimysium of the gluteus maximus muscle (GIM). Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Activity modulations of trunk and lower limb muscles during impact-absorbing landing.

    Science.gov (United States)

    Iida, Yoshiaki; Kanehisa, Hiroaki; Inaba, Yuki; Nakazawa, Kimitaka

    2011-08-01

    This study aimed to investigate the activity patterns of trunk and lower limb muscles during impact-absorbing landing. Electromyogram activities of the trunk and lower limb muscles along with kinematic and ground reaction forces were measured while subjects (n=17) performed 10 landings from a height of 35 cm. Landing motions were divided into three phases: 100 ms preceding ground contact (GC) (PRE phase), from GC through 100 ms (ABSORPTION phase), and from the end of the ABSORPTION phase until the vertical position of the center of mass was minimized (BRAKING phase). During the PRE phase, the rectus abdominis, external oblique, and medial gastrocnemius were highly activated. Upon GC, the hip and knee joints were in a flexed position; the ankle joints, in a plantarflexed position. After GC, peak timings of muscle activities and lower limb joint rotations were characterized by distal-to-proximal sequential patterns. The peak vertical ground reaction force in the ABSORPTION phase relative to body weight positively correlated with the activity levels of the vastus lateralis and gluteus maximus in the PRE phase and that of rectus abdominis in the ABSORPTION phase. These findings indicate that the intensities and peak timings of muscle activities in the trunk and lower limb are coordinated to absorb landing impact. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Origin of directionally tuned responses in lower limb muscles to unpredictable upper limb disturbances.

    Directory of Open Access Journals (Sweden)

    Ali Forghani

    Full Text Available Unpredictable forces which perturb balance are frequently applied to the body through interaction between the upper limb and the environment. Lower limb muscles respond rapidly to these postural disturbances in a highly specific manner. We have shown that the muscle activation patterns of lower limb muscles are organized in a direction specific manner which changes with lower limb stability. Ankle muscles change their activity within 80 ms of the onset of a force perturbation applied to the hand which is earlier than the onset of changes in ground reaction force, ankle angle or head motion. The latency of the response is sensitive to the perturbation direction. However, neither the latency nor the magnitude of the response is affected by stiffening the arm even though this alters the magnitude and timing of motion of the body segments. Based on the short latency, insensitivity of the change in ankle muscle activation to motion of the body segments but sensitivity to perturbation direction we reason that changes in ankle muscle activation are most likely triggered by sensory signals originating from cutaneous receptors in the hand. Furthermore, evidence that the latency of changes in ankle muscle activation depends on the number of perturbation directions suggests that the neural pathway is not confined to the spinal cord.

  15. Origin of directionally tuned responses in lower limb muscles to unpredictable upper limb disturbances.

    Science.gov (United States)

    Forghani, Ali; Milner, Theodore E

    2017-01-01

    Unpredictable forces which perturb balance are frequently applied to the body through interaction between the upper limb and the environment. Lower limb muscles respond rapidly to these postural disturbances in a highly specific manner. We have shown that the muscle activation patterns of lower limb muscles are organized in a direction specific manner which changes with lower limb stability. Ankle muscles change their activity within 80 ms of the onset of a force perturbation applied to the hand which is earlier than the onset of changes in ground reaction force, ankle angle or head motion. The latency of the response is sensitive to the perturbation direction. However, neither the latency nor the magnitude of the response is affected by stiffening the arm even though this alters the magnitude and timing of motion of the body segments. Based on the short latency, insensitivity of the change in ankle muscle activation to motion of the body segments but sensitivity to perturbation direction we reason that changes in ankle muscle activation are most likely triggered by sensory signals originating from cutaneous receptors in the hand. Furthermore, evidence that the latency of changes in ankle muscle activation depends on the number of perturbation directions suggests that the neural pathway is not confined to the spinal cord.

  16. Origin of directionally tuned responses in lower limb muscles to unpredictable upper limb disturbances

    Science.gov (United States)

    Forghani, Ali; Milner, Theodore E.

    2017-01-01

    Unpredictable forces which perturb balance are frequently applied to the body through interaction between the upper limb and the environment. Lower limb muscles respond rapidly to these postural disturbances in a highly specific manner. We have shown that the muscle activation patterns of lower limb muscles are organized in a direction specific manner which changes with lower limb stability. Ankle muscles change their activity within 80 ms of the onset of a force perturbation applied to the hand which is earlier than the onset of changes in ground reaction force, ankle angle or head motion. The latency of the response is sensitive to the perturbation direction. However, neither the latency nor the magnitude of the response is affected by stiffening the arm even though this alters the magnitude and timing of motion of the body segments. Based on the short latency, insensitivity of the change in ankle muscle activation to motion of the body segments but sensitivity to perturbation direction we reason that changes in ankle muscle activation are most likely triggered by sensory signals originating from cutaneous receptors in the hand. Furthermore, evidence that the latency of changes in ankle muscle activation depends on the number of perturbation directions suggests that the neural pathway is not confined to the spinal cord. PMID:29095888

  17. Skeletal muscle responses to lower limb suspension in humans

    Science.gov (United States)

    Hather, Bruce M.; Adams, Gregory R.; Tesch, Per A.; Dudley, Gary A.

    1992-01-01

    The morphological responses of human skeletal muscle to unweighting were assessed by analyzing multiple transaxial magnetic resonance (MR) images of both lower limbs and skeletal muscle biopsies of the unweighted lower limb before and after six weeks of unilaterial (left) lower limb suspension (ULLS). Results indicated that, as a results of 6 weeks of unweighting (by the subjects walking on crutches using only one limb), the cross sectional area (CSA) of the thigh muscle of the unweighted left limb decreased 12 percent, while the CSA of the right thigh muscle did not change. The decrease was due to a twofold greater response of the knee extensors than the knee flexors. The pre- and post-ULLS biopsies of the left vastus lateralis showed a 14 percent decrease in average fiber CSA due to unweighting. The number of capillaries surrounding the different fiber types was unchanged after ULLS. Results showed that the adaptive responses of human skeletal muscle to unweighting are qualitatively, but not quantitatively, similar to those of lower mammals and not necessarily dependent on the fiber-type composition.

  18. Protein Turnover and Cellular Stress in Mildly and Severely Affected Muscles from Patients with Limb Girdle Muscular Dystrophy Type 2I

    DEFF Research Database (Denmark)

    Hauerslev, Simon; Sveen, Marie-Louise; Vissing, John

    2013-01-01

    Patients with Limb girdle muscular dystrophy type 2I (LGMD2I) are characterized by progressive muscle weakness and wasting primarily in the proximal muscles, while distal muscles often are spared. Our aim was to investigate if wasting could be caused by impaired regeneration in the proximal...... highly increased in severely affected muscles compared to mildly affected muscles. Our results indicate that alterations in the protein turnover and myostatin levels could progressively impair the muscle mass maintenance and/or regeneration resulting in gradual muscular atrophy....

  19. Effects of proximal and distal robot-assisted upper limb rehabilitation on chronic stroke recovery.

    Science.gov (United States)

    Mazzoleni, Stefano; Sale, Patrizio; Franceschini, Marco; Bigazzi, Samuele; Carrozza, Maria Chiara; Dario, Paolo; Posteraro, Federico

    2013-01-01

    To evaluate the effects of add-on distal upper limb robot-assisted treatment on the outcome of proximal regions. 64 chronic stroke patients divided into two groups participated in the study. Group A was assigned to the proximal robot-assisted rehabilitation, Group B to the proximal and distal. Shoulder/elbow subsection of Fugl-Meyer Assessment scale was collected for Group A, whereas for Group B wrist subsection was also collected. Motricity Index was used and a set of kinematic parameters was computed for both groups. A decrease in impairment after the treatment in both groups of patients (Group A: Shoulder/elbow FM p robot-assisted treatment in both groups; group B showed a greater improvement in velocity. Robotic treatment is effective to reduce motor impairment in chronic stroke patients even if distal training added to proximal segments in the Group B does not provide any incremental benefit to the proximal segments. It remains unclear if the effectiveness of robot-assisted treatment is directly related to the upper limb segment specifically treated and which order may lead to better outcome. Our study suggests that kinematic parameters should be computed in order to better clarify the role of distal training (wrist) on proximal segments (shoulder/elbow) as well.

  20. Comparative anatomy and muscle architecture of selected hind limb muscles in the Quarter Horse and Arab.

    Science.gov (United States)

    Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wakeling, J M; Wilson, A M; Payne, R C

    2008-02-01

    The Quarter Horse (bred for acceleration) and the Arab (bred for endurance) are situated at either end of the equine athletic spectrum. Studies into the form and function of the leg muscles in human sprint and endurance runners have demonstrated that differences exist in their muscle architecture. It is not known whether similar differences exist in the horse. Six Quarter Horse and six Arab fresh hind limb cadavers were dissected to gain information on the muscle mass and architecture of the following muscles: gluteus medius; biceps femoris; semitendinosus; vastus lateralis; gastrocnemius; tibialis cranialis and extensor digitorum longus. Specifically, muscle mass, fascicle length and pennation angle were quantified and physiological cross-sectional area (PCSA) and maximum isometric force were estimated. The hind limb muscles of the Quarter Horse were of a significantly greater mass, but had similar fascicle lengths and pennation angles when compared with those of the Arab; this resulted in the Quarter Horse hind limb muscles having greater PCSAs and hence greater isometric force potential. This study suggests that Quarter Horses as a breed inherently possess large strong hind limb muscles, with the potential to accelerate their body mass more rapidly than those of the Arab.

  1. Neural effects of muscle stretching on the spinal reflexes in multiple lower-limb muscles.

    Science.gov (United States)

    Masugi, Yohei; Obata, Hiroki; Inoue, Daisuke; Kawashima, Noritaka; Nakazawa, Kimitaka

    2017-01-01

    While previous studies have shown that muscle stretching suppresses monosynaptic spinal reflex excitability in stretched muscles, its effects on non-stretched muscles is still largely unknown. The purpose of this study was to examine the effects of muscle stretching on monosynaptic spinal reflex in non-stretched muscles. Ten healthy male subjects participated in this study. Muscle stretching of the right triceps surae muscle was performed using a motor torque device for 1 minute. Three different dorsiflexion torques (at approximately 5, 10, and 15 Nm) were applied during muscle stretching. Spinal reflexes evoked by transcutaneous spinal cord stimulation were recorded in both the lower-limb muscles before, during, and at 0 and 5 min following muscle stretching. The amplitudes of the spinal reflexes in both the stretched and non-stretched muscles in the right (ipsilateral) leg were smaller during stretching compared to before, and at 0 and 5 min after stretching. Furthermore, the degree of reduction in the amplitude of the spinal reflexes in the right (ipsilateral) leg muscles increased significantly as the dorsiflexion torque (i.e., stretching of the right triceps surae muscles) increased. In contrast, reduction in the amplitude of the spinal reflexes with increasing dorsiflexion torque was not seen in the left (contralateral) leg muscles. Our results clearly indicate that muscle stretching has inhibitory effects on monosynaptic spinal reflexes, not only in stretched muscles, but also in non-stretched muscles of the ipsilateral leg.

  2. Protein turnover and cellular stress in mildly and severely affected muscles from patients with limb girdle muscular dystrophy type 2I.

    Science.gov (United States)

    Hauerslev, Simon; Sveen, Marie L; Vissing, John; Krag, Thomas O

    2013-01-01

    Patients with Limb girdle muscular dystrophy type 2I (LGMD2I) are characterized by progressive muscle weakness and wasting primarily in the proximal muscles, while distal muscles often are spared. Our aim was to investigate if wasting could be caused by impaired regeneration in the proximal compared to distal muscles. Biopsies were simultaneously obtained from proximal and distal muscles of the same patients with LGMD2I (n = 4) and healthy subjects (n = 4). The level of past muscle regeneration was evaluated by counting internally nucleated fibers and determining actively regenerating fibers by using the developmental markers embryonic myosin heavy chain (eMHC) and neural cell adhesion molecule (NCAM) and also assessing satellite cell activation status by myogenin positivity. Severe muscle histopathology was occasionally observed in the proximal muscles of patients with LGMD2I whereas distal muscles were always relatively spared. No difference was found in the regeneration markers internally nucleated fibers, actively regenerating fibers or activation status of satellite cells between proximal and distal muscles. Protein turnover, both synthesis and breakdown, as well as cellular stress were highly increased in severely affected muscles compared to mildly affected muscles. Our results indicate that alterations in the protein turnover and myostatin levels could progressively impair the muscle mass maintenance and/or regeneration resulting in gradual muscular atrophy.

  3. Lower limb asymmetry in mechanical muscle function

    DEFF Research Database (Denmark)

    Jordan, M J; Aagaard, Per; Herzog, W

    2015-01-01

    Due to a high incidence of anterior cruciate ligament (ACL) re-injury in alpine ski racers, this study aims to assess functional asymmetry in the countermovement jump (CMJ), squat jump (SJ), and leg muscle mass in elite ski racers with and without anterior cruciate ligament reconstruction (ACL......-R). Elite alpine skiers with ACL-R (n = 9; 26.2 ± 11.8 months post-op) and uninjured skiers (n = 9) participated in neuromuscular screening. Vertical ground reaction force during the CMJ and SJ was assessed using dual force plate methodology to obtain phase-specific bilateral asymmetry indices (AIs...... as a part of a multifaceted approach for improving outcome following ACL-R in elite ski racers....

  4. Targeted muscle reinnervation a neural interface for artificial limbs

    CERN Document Server

    Kuiken, Todd A; Barlow, Ann K

    2013-01-01

    Implement TMR with Your Patients and Improve Their Quality of Life Developed by Dr. Todd A. Kuiken and Dr. Gregory A. Dumanian, targeted muscle reinnervation (TMR) is a new approach to accessing motor control signals from peripheral nerves after amputation and providing sensory feedback to prosthesis users. This practical approach has many advantages over other neural-machine interfaces for the improved control of artificial limbs. Targeted Muscle Reinnervation: A Neural Interface for Artificial Limbs provides a template for the clinical implementation of TMR and a resource for further research in this new area of science. After describing the basic scientific concepts and key principles underlying TMR, the book presents surgical approaches to transhumeral and shoulder disarticulation amputations. It explores the possible role of TMR in the prevention and treatment of end-neuromas and details the principles of rehabilitation, prosthetic fitting, and occupational therapy for TMR patients. The book also describ...

  5. Effect of maturation on muscle quality of the lower limb muscles in adolescent boys.

    Science.gov (United States)

    Fukunaga, Yuko; Takai, Yohei; Yoshimoto, Takaya; Fujita, Eiji; Yamamoto, Masayoshi; Kanehisa, Hiroaki

    2014-09-19

    The purpose of this study was to clarify the effect of maturation on the muscle quality of the lower limb muscles around puberty. Subjects were 117 Japanese boys age 12 to 15 years. The maturity status was assessed by using a self-assessment of stage of pubic hair development based on the criteria of Tanner. On the basis of the criteria, subjects were divided into the prepubescent or pubescent group. Muscle thickness of knee extensors and plantar flexors were measured by a B-mode ultrasound. Muscle volume index (MV) was calculated from muscle thickness and limb length. Maximal voluntary isometric joint toques (TQ) of knee extension and ankle plantar flexion were measured using a myometer. Muscle quality was derived from dividing TQ by MV (TQ/MV). In both muscles, TQ-MV relationships were also similar between the prepubescent and pubescent groups, and there was no significant difference in TQ/MV between the two groups when chronological age was statistically adjusted. The current results indicate that, for adolescent boys, the muscle quality of the lower limb muscles is not significantly influenced by maturation.

  6. Pneumatic Muscle Actuated Rehabilitation Equipment of the Upper Limb Joints

    Science.gov (United States)

    Deaconescu dr. eng. habil., Andrea, Prof.

    2017-06-01

    Rehabilitation equipment of the upper limb joints holds a key role in passive physical therapy. Within this framework, the paper presents two such pieces of equipment developed for the rehabilitation of elbow and of wrist and knuckles, respectively. The presented and discussed equipment is actuated by pneumatic muscles, its benefits being a low cost, simple and robust construction, as well as short response time to commands.

  7. Influence of muscle groups' activation on proximal femoral growth tendency.

    Science.gov (United States)

    Yadav, Priti; Shefelbine, Sandra J; Pontén, Eva; Gutierrez-Farewik, Elena M

    2017-12-01

    Muscle and joint contact force influence stresses at the proximal growth plate of the femur and thus bone growth, affecting the neck shaft angle (NSA) and femoral anteversion (FA). This study aims to illustrate how different muscle groups' activation during gait affects NSA and FA development in able-bodied children. Subject-specific femur models were developed for three able-bodied children (ages 6, 7, and 11 years) using magnetic resonance images. Contributions of different muscle groups-hip flexors, hip extensors, hip adductors, hip abductors, and knee extensors-to overall hip contact force were computed. Specific growth rate for the growth plate was computed, and the growth was simulated in the principal stress direction at each element in the growth front. The predicted growth indicated decreased NSA and FA (of about [Formula: see text] over a four-month period) for able-bodied children. Hip abductors contributed the most, and hip adductors, the least, to growth rate. All muscles groups contributed to a decrease in predicted NSA ([Formula: see text]0.01[Formula: see text]-0.04[Formula: see text] and FA ([Formula: see text]0.004[Formula: see text]-[Formula: see text]), except hip extensors and hip adductors, which showed a tendency to increase the FA ([Formula: see text]0.004[Formula: see text]-[Formula: see text]). Understanding influences of different muscle groups on long bone growth tendency can help in treatment planning for growing children with affected gait.

  8. Reliability of EMG normalisation methods for upper-limb muscles.

    Science.gov (United States)

    Rota, Samuel; Rogowski, Isabelle; Champely, Stéphane; Hautier, Christophe

    2013-01-01

    The study investigated different electromyographic (EMG) normalisation methods for upper-limb muscles. This assessment aimed at comparing the EMG amplitude and the reliability of EMG values obtained with each method. Eighteen male tennis players completed isometric maximal voluntary contractions and dynamic strength exercises (push-ups and chin-ups) on three separate test sessions over at least 7 days. Surface EMG activity of nine upper body muscles was recorded. For each muscle, an analysis of variance for repeated measures was used to compare maximal EMG amplitudes between test conditions. The intra-class correlation coefficient, the coefficient of variation and the standard error of measurement were calculated to determine the EMG reliability of each condition. On the basis of a compromise between maximal EMG amplitude and high reliability, the chin-ups appeared to be the optimal normalisation method for M. latissimus dorsi, M. posterior deltoid, M. biceps brachii, M. flexor carpi radialis and M. extensor carpi radialis. The push-ups seemed relevant to normalise M. anterior deltoid and M. triceps brachii activity, while isometric maximal voluntary contraction remained the most appropriate method for M. pectoralis major and M. middle deltoid. Thus, original methods are proposed to normalise EMG signal of upper-limb muscles.

  9. Muscle activation patterns when passively stretching spastic lower limb muscles of children with cerebral palsy.

    Science.gov (United States)

    Bar-On, Lynn; Aertbeliën, Erwin; Molenaers, Guy; Desloovere, Kaat

    2014-01-01

    The definition of spasticity as a velocity-dependent activation of the tonic stretch reflex during a stretch to a passive muscle is the most widely accepted. However, other mechanisms are also thought to contribute to pathological muscle activity and, in patients post-stroke and spinal cord injury can result in different activation patterns. In the lower-limbs of children with spastic cerebral palsy (CP) these distinct activation patterns have not yet been thoroughly explored. The aim of the study was to apply an instrumented assessment to quantify different muscle activation patterns in four lower-limb muscles of children with CP. Fifty-four children with CP were included (males/females n = 35/19; 10.8 ± 3.8 yrs; bilateral/unilateral involvement n =  32/22; Gross Motor Functional Classification Score I-IV) of whom ten were retested to evaluate intra-rater reliability. With the subject relaxed, single-joint, sagittal-plane movements of the hip, knee, and ankle were performed to stretch the lower-limb muscles at three increasing velocities. Muscle activity and joint motion were synchronously recorded using inertial sensors and electromyography (EMG) from the adductors, medial hamstrings, rectus femoris, and gastrocnemius. Muscles were visually categorised into activation patterns using average, normalized root mean square EMG (RMS-EMG) compared across increasing position zones and velocities. Based on the visual categorisation, quantitative parameters were defined using stretch-reflex thresholds and normalized RMS-EMG. These parameters were compared between muscles with different activation patterns. All patterns were dominated by high velocity-dependent muscle activation, but in more than half, low velocity-dependent activation was also observed. Muscle activation patterns were found to be both muscle- and subject-specific (pmuscles into activation patterns (pmuscles with different patterns react differently to treatment.

  10. Pneumatic Muscles Actuated Lower-Limb Orthosis Model Verification with Actual Human Muscle Activation Patterns

    Directory of Open Access Journals (Sweden)

    Dzahir M.A.M

    2017-01-01

    Full Text Available A review study was conducted on existing lower-limb orthosis systems for rehabilitation which implemented pneumatic muscle type of actuators with the aim to clarify the current and on-going research in this field. The implementation of pneumatic artificial muscle will play an important role for the development of the advanced robotic system. In this research a derivation model for the antagonistic mono- and bi-articular muscles using pneumatic artificial muscles of a lower limb orthosis will be verified with actual human’s muscle activities models. A healthy and young male 29 years old subject with height 174cm and weight 68kg was used as a test subject. Two mono-articular muscles Vastus Medialis (VM and Vastus Lateralis (VL were selected to verify the mono-articular muscle models and muscle synergy between anterior muscles. Two biarticular muscles Rectus Femoris (RF and Bicep Femoris (BF were selected to verify the bi-articular muscle models and muscle co-contraction between anterior-posterior muscles. The test was carried out on a treadmill with a speed of 4.0 km/h, which approximately around 1.25 m/s for completing one cycle of walking motion. The data was collected for about one minute on a treadmill and 20 complete cycles of walking motion were successfully recorded. For the evaluations, the mathematical model obtained from the derivation and the actual human muscle activation patterns obtained using the surface electromyography (sEMG system were compared and analysed. The results shown that, high correlation values ranging from 0.83 up to 0.93 were obtained in between the derivation model and the actual human muscle’s model for both mono- and biarticular muscles. As a conclusion, based on the verification with the sEMG muscle activities data and its correlation values, the proposed derivation models of the antagonistic mono- and bi-articular muscles were suitable to simulate and controls the pneumatic muscles actuated lower limb

  11. Estimation of changes in volume of individual lower-limb muscles using magnetic resonance imaging (during bed-rest).

    Science.gov (United States)

    Belavý, D L; Miokovic, T; Rittweger, J; Felsenberg, D

    2011-01-01

    Muscle size in the lower limb is commonly assessed in neuromuscular research as it correlates with muscle function and some approaches have been assessed for their ability to provide valid estimates of muscle volume. Work to date has not examined the ability of different measurement approaches (such as cross-sectional area (CSA) measures on magnetic resonance (MR) imaging) to accurately track changes in muscle volume as a result of an intervention, such as exercise, injury or disuse. Here we assess whether (a) the percentage change in muscle CSA in 17 lower-limb muscles during 56 days bed-rest, as assessed by five different algorithms, lies within 0.5% of the muscle volume change and (b) the variability of the outcome measure is comparable to that of muscle volume. We find that an approach selecting the MR image with the highest muscle CSA and then a series of CSA measures, the number of which depended upon the muscle considered, immediately distal and proximal, provided an acceptable estimate of the muscle volume change. In the vastii, peroneal, sartorius and anterior tibial muscle groups, accurate results can be attained by increasing the spacing between CSA measures, thus reducing the total number of MR images and hence the measurement time. In the two heads of biceps femoris, semimembranosus and gracilis, it is not possible to reduce the number of CSA measures and the entire muscle volume must be evaluated. Using these approaches one can reduce the number of CSA measures required to estimate changes in muscle volume by ~60%. These findings help to attain more efficient means to track muscle volume changes in interventional studies.

  12. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

    OpenAIRE

    Huang, Stephanie; Ferris, Daniel P

    2012-01-01

    Abstract Background Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. Methods We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocne...

  13. Proximal major limb amputations – a retrospective analysis of 45 oncological cases

    Directory of Open Access Journals (Sweden)

    Goertz Ole

    2009-02-01

    Full Text Available Abstract Background Proximal major limb amputations due to malignant tumors have become rare but are still a valuable treatment option in palliation and in some cases can even cure. The aim of this retrospective study was to analyse outcome in those patients, including the postoperative course, survival, pain, quality of life, and prosthesis usage. Methods Data of 45 consecutive patients was acquired from patient's charts and contact to patients, and general practitioners. Patients with interscapulothoracic amputation (n = 14, shoulder disarticulation (n = 13, hemipelvectomy (n = 3 or hip disarticulation (n = 15 were included. Results The rate of proximal major limb amputations in patients treated for sarcoma was 2.3% (37 out of 1597. Survival for all patients was 42.9% after one year and 12.7% after five years. Survival was significantly better in patients with complete tumor resections. Postoperative chemotherapy and radiation did not prolong survival. Eighteen percent of the patients with malignant disease developed local recurrence. In 44%, postoperative complications were observed. Different modalities of postoperative pain management and the site of the amputation had no significant influence on long-term pain assessment and quality of life. Eighty-seven percent suffered from phantom pain, 15.6% considered their quality of life worse than before the operation. Thirty-two percent of the patients who received a prosthesis used it regularly. Conclusion Proximal major limb amputations severely interfere with patients' body function and are the last, albeit valuable, option within the treatment concept of extremity malignancies or severe infections. Besides short survival, high complication rates, and postoperative pain, patients' quality of life can be improved for the time they have remaining.

  14. A diagnostic fluorescent marker kit for six limb girdle muscular dystrophies

    NARCIS (Netherlands)

    Richard, I.; Bourg, N.; Marchand, S.; Alibert, O.; Eymard, B.; van der Kooi, A. J.; Jackson, C. E.; Garcia, C.; Burgunder, J. M.; Legum, C.; de Visser, M.; Fardeau, M.; Beckmann, J. S.

    1999-01-01

    The autosomal progressive muscular dystrophies which are grouped together under the term limb girdle muscular dystrophies (LGMD) are diseases characterized by a progressive impairment of the proximal limb muscles and myopathic changes on electromyogram and muscle biopsy. Eight independent purely

  15. Determination of muscle effort at the proximal femur rotation osteotomy

    Science.gov (United States)

    Sachenkov, O.; Hasanov, R.; Andreev, P.; Konoplev, Yu

    2016-11-01

    The paper formulates the problem of biomechanics of a new method for treatment of Legg-Calve-Perthes disease. Numerical calculations of the rotational flexion osteotomy have been carried out for a constructed mathematical model of the hip joint, taking into account the main set of muscles. The work presents the results of the calculations and their analysis. The results have been compared with the clinical data. The calculations of the reactive forces arising in the acetabulum and the proximal part of the femur allowed us to reveal that this reactive force changes both in value and direction. These data may be useful for assessing the stiffness of an external fixation device used in orthopedic intervention and for evaluating the compression in the joint.

  16. Unilateral hip osteoarthritis: Its effects on preoperative lower limb muscle activation and intramuscular coordination patterns.

    Science.gov (United States)

    Schmidt, André; Stief, Felix; Lenarz, Katharina; Froemel, Dara; Lutz, Frederick; Barker, John; Meurer, Andrea

    2016-03-01

    The objective of this study was to test if patients with unilateral hip osteoarthritis (OA) show greater muscle activity asymmetry between their affected and non-affected limbs than healthy controls between their left and right limbs. Seventeen patients with unilateral hip OA (7 females, 10 males) and 17 age-matched healthy controls (7 females, 10 males) participated in this study. Both groups performed instrumented gait analysis at comparable speeds. Muscle activity was recorded simultaneously for the tibialis anterior (TA), gastrocnemius medialis (GM), vastus lateralis (VL), semitendinosus (ST), tensor fasciae latae (TFL), and gluteus medius (GLM) muscles. In hip OA patients, EMG data showed greater activity of the TA muscle in the non-affected limb, and greater TFL muscle activity in the affected limb. Compared to healthy controls, greater asymmetries between paired limbs were observed for the TA and GM muscles. Finally, the TFL muscle of the affected limb contributed more to the total limb muscle activity than did the non-affected limb. The observed alterations in TA and GM muscle activity in hip OA patients may be due to the greater peak braking and peak vertical forces measured in the non-affected limb. Contrary to this, greater TLF muscle activity of the affected limb indicates the demands put on stabilizing the hip during stance phase. Further studies are necessary to test whether leg length discrepancy affects muscle activation alterations between the affected and non-affected limb in unilateral hip OA patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Muscle activation patterns when passively stretching spastic lower limb muscles of children with cerebral palsy.

    Directory of Open Access Journals (Sweden)

    Lynn Bar-On

    Full Text Available The definition of spasticity as a velocity-dependent activation of the tonic stretch reflex during a stretch to a passive muscle is the most widely accepted. However, other mechanisms are also thought to contribute to pathological muscle activity and, in patients post-stroke and spinal cord injury can result in different activation patterns. In the lower-limbs of children with spastic cerebral palsy (CP these distinct activation patterns have not yet been thoroughly explored. The aim of the study was to apply an instrumented assessment to quantify different muscle activation patterns in four lower-limb muscles of children with CP. Fifty-four children with CP were included (males/females n = 35/19; 10.8 ± 3.8 yrs; bilateral/unilateral involvement n =  32/22; Gross Motor Functional Classification Score I-IV of whom ten were retested to evaluate intra-rater reliability. With the subject relaxed, single-joint, sagittal-plane movements of the hip, knee, and ankle were performed to stretch the lower-limb muscles at three increasing velocities. Muscle activity and joint motion were synchronously recorded using inertial sensors and electromyography (EMG from the adductors, medial hamstrings, rectus femoris, and gastrocnemius. Muscles were visually categorised into activation patterns using average, normalized root mean square EMG (RMS-EMG compared across increasing position zones and velocities. Based on the visual categorisation, quantitative parameters were defined using stretch-reflex thresholds and normalized RMS-EMG. These parameters were compared between muscles with different activation patterns. All patterns were dominated by high velocity-dependent muscle activation, but in more than half, low velocity-dependent activation was also observed. Muscle activation patterns were found to be both muscle- and subject-specific (p<0.01. The intra-rater reliability of all quantitative parameters was moderate to good. Comparing RMS-EMG between

  18. The relationship between lower limb muscle strength and lower extremity function in HIV disease

    OpenAIRE

    Peter C. Mhariwa; Hellen Myezwa; Mary L. Galantino; Douglas Maleka

    2017-01-01

    Background: Human immunodeficiency virus (HIV) negatively impacts muscle strength and function. This study aimed to establish the relationship between lower limb muscle strength and lower extremity function in HIV disease.Method: A cross-sectional study was undertaken with a sample of 113 HIV-positive participants. Lower limb muscle strength and self-reported function were established using dynamometry and the Lower Extremity Functional Scale (LEFS), respectively. Muscle strength and function...

  19. Disinhibition of upper limb motor area by voluntary contraction of the lower limb muscle.

    Science.gov (United States)

    Tazoe, Toshiki; Endoh, Takashi; Nakajima, Tsuyoshi; Sakamoto, Masanori; Komiyama, Tomoyoshi

    2007-03-01

    It is well known that monosynaptic spinal reflexes and motor evoked potentials following transcranial magnetic stimulation (TMS) are reinforced during phasic and intensive voluntary contraction in the remote segment (remote effect). However, the remote effect on the cortical silent period (CSP) is less known. The purpose of the present study is to determine to what extent the CSP in the intrinsic hand muscle following TMS is modified by voluntary ankle dorsiflexion and to elucidate the origin of the modulation of CSP by the remote effect. CSP was recorded in the right first dorsal interosseous while subjects performed phasic dorsiflexion in the ipsilateral side under self-paced and reaction-time conditions. Modulation of the peripherally-induced silent period (PSP) induced by electrical stimulation of the ulnar nerve was also investigated under the same conditions. In addition, modulation of the CSP was investigated during ischemic nerve block of the lower limb and during application of vibration to the tibialis anterior tendon. The duration of CSP was significantly shortened by phasic dorsiflexion, and the extent of shortening was proportional to dorsiflexion force. Shortening of the CSP duration was also observed during tonic dorsiflexion. In contrast, the PSP duration following ulnar nerve stimulation was not altered during phasic dorsiflexion. Furthermore, the remote effect on the CSP duration was seen during ischemic nerve block of the lower limb and the pre-movement period in the reaction-time paradigm, but shortening of the CSP was not observed during tendon vibration. These findings suggest that phasic muscle contraction in the remote segment results in a decrease in intracortical inhibitory pathways to the corticospinal tract innervating the muscle involved in reflex testing and that the remote effect on the CSP is predominantly cortical in origin.

  20. Spinal μ-opioid receptor-sensitive lower limb muscle afferents determine corticospinal responsiveness and promote central fatigue in upper limb muscle.

    Science.gov (United States)

    Sidhu, Simranjit K; Weavil, Joshua C; Venturelli, Massimo; Garten, Ryan S; Rossman, Matthew J; Richardson, Russell S; Gmelch, Benjamin S; Morgan, David E; Amann, Markus

    2014-11-15

    We investigated the influence of group III/IV lower limb muscle afferents on the development of supraspinal fatigue and the responsiveness of corticospinal projections to an arm muscle. Eight males performed constant-load leg cycling exercise (80% peak power output) for 30 s (non-fatiguing) and to exhaustion (∼9 min; fatiguing) both under control conditions and with lumbar intrathecal fentanyl impairing feedback from μ-opioid receptor-sensitive lower limb muscle afferents. Voluntary activation (VA) of elbow flexors was assessed via transcranial magnetic stimulation (TMS) during maximum voluntary contraction (MVC) and corticospinal responsiveness was monitored via TMS-evoked potentials (MEPs) during a 25% MVC. Accompanied by a significant 5 ± 1% reduction in VA from pre- to post-exercise, elbow flexor MVC progressively decreased during the fatiguing trial (P muscle afferents, MVC and VA remained unchanged during fatiguing exercise (P > 0.3). MEPs decreased by 36 ± 6% (P lower corticospinal responsiveness during this short bout (P muscle fatigue, group III/IV-mediated leg muscle afferents facilitate responsiveness of the motor pathway to upper limb flexor muscles. By contrast, in the presence of cycling-induced leg fatigue, group III/IV locomotor muscle afferents facilitate supraspinal fatigue in remote muscle not involved in the exercise and disfacilitate, or inhibit, the responsiveness of corticospinal projections to upper limb muscles.

  1. Electromyographic Analysis of the Lower Limb Muscles in Low- and High-Handicap Golfers

    Science.gov (United States)

    Marta, Sérgio; Silva, Luís; Vaz, João R.; Castro, Maria António; Reinaldo, Gustavo; Pezarat-Correia, Pedro

    2016-01-01

    Purpose: The aim of this study was to compare the electromyographic patterns of the lower limb muscles during a golf swing performed by low- and high-handicap golfers. Method: Ten golfers (5 low- and 5 high-handicap) performed 8 swings using a 7-iron. Surface electromyography (EMG) was recorded for the following lower limb muscles on both sides:…

  2. Dissociation between distal and proximal left limb agraphia and agraphesthesia in a patient with a callosal disconnection syndrome.

    Science.gov (United States)

    Bachoud-Lévi, A C; Ergis, A M; Cesaro, P; Degos, J D

    2000-06-01

    A few neuropsychological studies have suggested the existence of bilateral hemispheric representations for the proximal parts of the limbs in humans. We report the case of a patient who presented with a callosal disconnection syndrome, which at a later stage of disease became restricted to left agraphia, left agraphesthesia and left auditory extinction. The anomic character of the agraphesthesia was demonstrated. Tactile naming was normal, which allows us to conclude that separate callosal pathways related to the left language areas transmit information for graphesthesia and tactile naming. Agraphia and agraphesthesia were not observed when the proximal part of the left upper limb was utilized. These observations support the conclusion that writing and graphesthesia with the proximal part of the limb can be mediated by the ipsilateral cortex.

  3. Muscle fatigue changes cutaneous suppression of propriospinal drive to human upper limb muscles.

    Science.gov (United States)

    Martin, P G; Gandevia, S C; Taylor, J L

    2007-04-01

    Some voluntary drive reaches human upper limb muscles via cervical propriospinal premotoneurones. Stimulation of the superficial radial nerve can inhibit these premotoneurones selectively and the resultant suppression of voluntary drive to motoneurones changes on-going electromyographic (EMG) activity. We investigated whether muscle fatigue changes this cutaneous-induced suppression of propriospinal drive to motoneurones of upper limb muscles. EMG was recorded from the extensors and flexors of the wrist and elbow. In the first study (n = 10 subjects), single stimuli (2 x perception threshold; 2PT) to the superficial radial nerve were delivered during contraction of the wrist extensors, before and after sustained fatiguing contractions of wrist extensors. In the second study (n = 10), similar stimuli were applied during elbow extension, before and during fatigue of elbow extensors. In the final study (n = 10), trains of three stimuli (2PT) were delivered during contractions of wrist extensors, before and while they were fatigued. With fatigue of either the wrist or elbow extensors, EMG suppression to single cutaneous stimuli increased significantly (by approximately 75%) for the fatigued muscle (P muscles, which were coactivated but not principally involved in the task, inhibition decreased or facilitation increased. Trains of stimuli produced greater suppression of on-going wrist extensor EMG than single stimuli and this difference persisted with fatigue. A control study of the H reflex in extensor carpi radialis showed that the mechanism responsible for the altered EMG suppression in fatigue was not at a motoneurone level. The findings suggest that the proportion of descending drive mediated via the disynaptic propriospinal pathway or the excitability of inhibitory interneurones projecting to propriospinal neurones increases substantially to fatigued muscles, but decreases to other active muscles. This pattern of changes may maintain coordination during

  4. Reversal of lower limb edema by calf muscle pump stimulation.

    Science.gov (United States)

    Goddard, Ayana A; Pierce, Carolyn S; McLeod, Kenneth J

    2008-01-01

    Peripheral edema (PE) is commonly coupled with heart failure, restrictive cardiomyopathy, nephrotic syndrome, renal failure, and hypoproteinemia. Diuretics and/or limb elevation, although commonly prescribed to treat PE, are often insufficient to remove sufficient fluid to prevent complications. We assessed the ability of the calf muscle pump (CMP) stimulation to reverse PE. Fluid volume was evaluated by air plethysmography in the right legs of 54 adult women (mean age 46.7 +/- 1.5 years) following venous status assessment. Change in calf volume was assessed during 30 minutes of quiet sitting, followed by 30 minutes of sitting with CMP stimulation via micromechanical stimulation of the plantar surface. Leg volume changes demonstrated a bimodal distribution. Leg volume decreased during quiet sitting in 56% of the study group, whereas in 44% of the group, significant lower leg fluid pooling was evident (increase in calf volume of 14.0 +/- 0.3 mL/h). CMP stimulation reversed the fluid pooling in the edematous group (-2.7 +/- 0.1 mL/h) and was able to accelerate fluid removal in the nonedematous group. Approximately two fifths of adult women experience substantial pooling when their lower limbs are maintained in a dependent position. Lower-extremity edema exhibited by these women may primarily be due to inadequate calf muscle tone because exogenous stimulation of the CMP was sufficient to halt and reverse fluid pooling. Whether CMP stimulation would provide a means to treat PE in individuals with edema-related health complications, such as congestive heart failure, merits further investigation.

  5. Prevalence of adult Pompe disease in patients with proximal myopathic syndrome and undiagnosed muscle biopsy.

    Science.gov (United States)

    Golsari, Amir; Nasimzadah, Arzoo; Thomalla, Götz; Keller, Sarah; Gerloff, Christian; Magnus, Tim

    2017-12-07

    We examined patients with limb-girdle muscle weakness and/or hyper-CKaemia and undiagnosed muscle biopsy for late onset Pompe disease (LOPD). Patients with an inconclusive limb-girdle muscle weakness who presented at our neuromuscular centre between 2005 and 2015 with undiagnosed muscle biopsies were examined by dry blood spot testing (DBS) including determination of the enzyme activity of acid alpha-glucosidase (GAA). In the case of depressed enzyme activity, additional gene testing of the GAA gene was carried out. Of the 340 evaluated muscle biopsies, 69 patients fulfilled the inclusion criteria and were examined with DBS. Among those patients, 76% showed a limb-girdle muscle weakness and 14% showed a hyper-CKaemia. A diagnosis of LOPD could be established in the case of two patients (2.9%) with reduced GAA enzyme activity and proof of mutations in the GAA gene. One of the two patients presents in the muscle biopsy suggestive features of Pompe disease including vacuoles with positive acid phosphatase reaction. In summary, our results show that a muscle biopsy can be helpful in identifying LOPD patients, but vacuolation with glycogen storage can also be absent. An inconspicuous muscle biopsy does not rule out Pompe disease. Consequently, all patients with limb-girdle muscle weakness should be examined by DBS before conducting a muscle biopsy. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Fatigue-related firing of muscle nociceptors reduces voluntary activation of ipsilateral but not contralateral lower limb muscles.

    Science.gov (United States)

    Kennedy, David S; Fitzpatrick, Siobhan C; Gandevia, Simon C; Taylor, Janet L

    2015-02-15

    During fatiguing upper limb exercise, maintained firing of group III/IV muscle afferents can limit voluntary drive to muscles within the same limb. It is not known if this effect occurs in the lower limb. We investigated the effects of group III/IV muscle afferent firing from fatigued ipsilateral and contralateral extensor muscles and ipsilateral flexor muscles of the knee on voluntary activation of the knee extensors. In three experiments, we examined voluntary activation of the knee extensors by measuring changes in superimposed twitches evoked by femoral nerve stimulation. Subjects attended on 2 days for each experiment. On one day a sphygmomanometer cuff occluded blood flow of the fatigued muscles to maintain firing of group III/IV muscle afferents. After a 2-min extensor contraction (experiment 1; n = 9), mean voluntary activation was lower with than without maintained ischemia (47 ± 19% vs. 87 ± 8%, respectively; P fatiguing exercise, activity in group III/IV muscle afferents reduces voluntary activation of the fatigued muscle and nonfatigued antagonist muscles in the same leg. However, group III/IV muscle afferents from the fatigued left leg had no effect on the unfatigued right leg. This suggests that any "crossover" of central fatigue in the lower limbs is not mediated by group III/IV muscle afferents. Copyright © 2015 the American Physiological Society.

  7. An investigation into the bilateral functional differences of the lower limb muscles in standing and walking

    Directory of Open Access Journals (Sweden)

    Shengyun Liang

    2016-08-01

    Full Text Available To date, most studies use surface electromyographic (sEMG signals as the control source on active rehabilitation robots, and unilateral data are collected based on the gait symmetry hypothesis, which has caused much controversy. The purpose of this study is to quantitatively evaluate the sEMG activity asymmetry of bilateral muscles in lower extremities during functional tasks. Nine participants were instructed to perform static and dynamic steady state tests. sEMG signals from the tibialis anterior, soleus, medial gastrocnemius and lateral gastrocnemius muscles of bilateral lower extremities were recorded in the experiments. Muscle activities are quantified in terms of sEMG amplitude. We investigated whether characteristics of left limb and the one of the right limb have the same statistical characteristics during functional tasks using The Wilcoxon rank-sum test, and studied dynamic signal irregularity degree for sEMG activities via sample entropy. The total of muscle activities showed significant differences between left limb and right limb during the static steady state (p = 0.000. For dynamic steady states, there were significant differences for most muscle activities between left limb and right limb at different speeds (p = 0.000. Nevertheless, there was no difference between the lateral gastrocnemius for bilateral limb at 2.0 kilometers per hour (p = 0.060. For medial gastrocnemius, differences were not found between left limb and right limb at 1.0 and 3.0 kilometers per hours (p = 0.390 and p = 0.085, respectively. Similarly, there was no difference for soleus at 3.0 kilometers per hour (p = 0.115. The importance of the differences in muscle activities between left limb and right limb were found. These results can potentially be used for evaluating lower limb extremity function of special populations (elderly people or stroke patients in an objective and simple method.

  8. An investigation into the bilateral functional differences of the lower limb muscles in standing and walking.

    Science.gov (United States)

    Liang, Shengyun; Xu, Jiali; Wang, Lei; Zhao, Guoru

    2016-01-01

    To date, most studies use surface electromyographic (sEMG) signals as the control source on active rehabilitation robots, and unilateral data are collected based on the gait symmetry hypothesis, which has caused much controversy. The purpose of this study is to quantitatively evaluate the sEMG activity asymmetry of bilateral muscles in lower extremities during functional tasks. Nine participants were instructed to perform static and dynamic steady state tests. sEMG signals from the tibialis anterior, soleus, medial gastrocnemius and lateral gastrocnemius muscles of bilateral lower extremities were recorded in the experiments. Muscle activities are quantified in terms of sEMG amplitude. We investigated whether characteristics of left limb and the one of the right limb have the same statistical characteristics during functional tasks using The Wilcoxon rank-sum test, and studied dynamic signal irregularity degree for sEMG activities via sample entropy. The total of muscle activities showed significant differences between left limb and right limb during the static steady state (p = 0.000). For dynamic steady states, there were significant differences for most muscle activities between left limb and right limb at different speeds (p = 0.000). Nevertheless, there was no difference between the lateral gastrocnemius for bilateral limb at 2.0 kilometers per hour (p = 0.060). For medial gastrocnemius, differences were not found between left limb and right limb at 1.0 and 3.0 kilometers per hours (p = 0.390 and p = 0.085, respectively). Similarly, there was no difference for soleus at 3.0 kilometers per hour (p = 0.115). The importance of the differences in muscle activities between left limb and right limb were found. These results can potentially be used for evaluating lower limb extremity function of special populations (elderly people or stroke patients) in an objective and simple method.

  9. Frequency response of vestibular reflexes in neck, back, and lower limb muscles.

    Science.gov (United States)

    Forbes, Patrick A; Dakin, Christopher J; Vardy, Alistair N; Happee, Riender; Siegmund, Gunter P; Schouten, Alfred C; Blouin, Jean-Sébastien

    2013-10-01

    Vestibular pathways form short-latency disynaptic connections with neck motoneurons, whereas they form longer-latency disynaptic and polysynaptic connections with lower limb motoneurons. We quantified frequency responses of vestibular reflexes in neck, back, and lower limb muscles to explain between-muscle differences. Two hypotheses were evaluated: 1) that muscle-specific motor-unit properties influence the bandwidth of vestibular reflexes; and 2) that frequency responses of vestibular reflexes differ between neck, back, and lower limb muscles because of neural filtering. Subjects were exposed to electrical vestibular stimuli over bandwidths of 0-25 and 0-75 Hz while recording activity in sternocleidomastoid, splenius capitis, erector spinae, soleus, and medial gastrocnemius muscles. Coherence between stimulus and muscle activity revealed markedly larger vestibular reflex bandwidths in neck muscles (0-70 Hz) than back (0-15 Hz) or lower limb muscles (0-20 Hz). In addition, vestibular reflexes in back and lower limb muscles undergo low-pass filtering compared with neck-muscle responses, which span a broader dynamic range. These results suggest that the wider bandwidth of head-neck biomechanics requires a vestibular influence on neck-muscle activation across a larger dynamic range than lower limb muscles. A computational model of vestibular afferents and a motoneuron pool indicates that motor-unit properties are not primary contributors to the bandwidth filtering of vestibular reflexes in different muscles. Instead, our experimental findings suggest that pathway-dependent neural filtering, not captured in our model, contributes to these muscle-specific responses. Furthermore, gain-phase discontinuities in the neck-muscle vestibular reflexes provide evidence of destructive interaction between different reflex components, likely via indirect vestibular-motor pathways.

  10. The influence of motor cortical stimulus intensity on the relaxation rate of human lower limb muscles

    NARCIS (Netherlands)

    McNeil, C.J.; Bredius, M.S.; Molenaar, J.P.F.; Gandevia, S.C.

    2013-01-01

    Transcranial magnetic stimulation (TMS) allows an in vivo assessment of the rate of muscle relaxation during a voluntary contraction. It is unknown if this method can be applied to lower limb muscles, and the effect of stimulus intensity on relaxation rate has not been investigated in any muscle

  11. Cancer cachexia decreases specific force and accelerates fatigue in limb muscle

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, B.M. [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States); Frye, G.S.; Ahn, B.; Ferreira, L.F. [1864 Stadium Road, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32610 (United States); Judge, A.R., E-mail: arjudge@phhp.ufl.edu [1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610 (United States)

    2013-06-07

    Highlights: •C-26 cancer cachexia causes a significant decrease in limb muscle absolute force. •C-26 cancer cachexia causes a significant decrease in limb muscle specific force. •C-26 cancer cachexia decreases fatigue resistance in the soleus muscle. •C-26 cancer cachexia prolongs time to peak twitch tension in limb muscle. •C-26 cancer cachexia prolongs one half twitch relaxation time in limb muscle. -- Abstract: Cancer cachexia is a complex metabolic syndrome that is characterized by the loss of skeletal muscle mass and weakness, which compromises physical function, reduces quality of life, and ultimately can lead to mortality. Experimental models of cancer cachexia have recapitulated this skeletal muscle atrophy and consequent decline in muscle force generating capacity. However, more recently, we provided evidence that during severe cancer cachexia muscle weakness in the diaphragm muscle cannot be entirely accounted for by the muscle atrophy. This indicates that muscle weakness is not just a consequence of muscle atrophy but that there is also significant contractile dysfunction. The current study aimed to determine whether contractile dysfunction is also present in limb muscles during severe Colon-26 (C26) carcinoma cachexia by studying the glycolytic extensor digitorum longus (EDL) muscle and the oxidative soleus muscle, which has an activity pattern that more closely resembles the diaphragm. Severe C-26 cancer cachexia caused significant muscle fiber atrophy and a reduction in maximum absolute force in both the EDL and soleus muscles. However, normalization to muscle cross sectional area further demonstrated a 13% decrease in maximum isometric specific force in the EDL and an even greater decrease (17%) in maximum isometric specific force in the soleus. Time to peak tension and half relaxation time were also significantly slowed in both the EDL and the solei from C-26 mice compared to controls. Since, in addition to postural control, the oxidative

  12. Gait Performance and Lower-Limb Muscle Strength Improved in Both Upper-Limb and Lower-Limb Isokinetic Training Programs in Individuals with Chronic Stroke

    OpenAIRE

    Marie-Hélène Milot; Sylvie Nadeau; Denis Gravel; Daniel Bourbonnais

    2013-01-01

    Background. Limited improvement in gait performance has been noted after training despite a significant increase in strength of the affected lower-limb muscles after stroke. A mismatch between the training program and the requirements of gait could explain this finding. Objective. To compare the impact of a training program, matching the requirements of the muscle groups involved in the energy generation of gait, to a control intervention, on gait performance and strength. Methods. 30 individ...

  13. Frequency response of vestibular reflexes in neck, back, and lower limb muscles

    NARCIS (Netherlands)

    Forbes, P.A.; Dakin, C.J.; Vardy, A.N.; Happee, R.; Siegmund, G.P.; Schouten, Alfred Christiaan; Blouin, J.S.

    2013-01-01

    Vestibular pathways form short-latency disynaptic connections with neck motoneurons, whereas they form longer-latency disynaptic and polysynaptic connections with lower limb motoneurons. We quantified frequency responses of vestibular reflexes in neck, back, and lower limb muscles to explain

  14. Acute compartment syndrome in the pelvic limb of a cow following biopsy of a skeletal muscle-associated hemangiosarcoma.

    Science.gov (United States)

    Vogel, Susan R; Desrochers, André; Lanthier, Isabelle; Strina, Marion; Babkine, Marie

    2012-02-15

    A 6-year-old Holstein cow was examined because of chronic lameness and swelling near the stifle joint of the left pelvic limb. A mass was palpated in the soft tissues lateral to the proximal aspect of the left tibia. Multiple attempts to obtain a biopsy specimen of the mass resulted in acute compartment syndrome of the femoral compartment (tensor fasciae latae and biceps femoris muscles) and lateral tibial compartment (cranial tibial and peroneus tertius muscles) with associated sciatic nerve paralysis. Surgical decompression via tensor fasciae latae and biceps femoris incision resolved the sciatic nerve paralysis. On the fifth day following surgery, the cow began to develop signs of increased respiratory effort. Thoracic radiography revealed a pulmonary metastatic micronodular pattern. The cow was euthanized because its condition deteriorated. Metastatic hemangiosarcoma was confirmed at necropsy, and the primary tumor was the mass that was lateral to the tibia and within the biceps femoris muscle. Hemangiosarcoma should be considered a differential diagnosis for lameness in cattle when no orthopedic cause can be identified. Close patient surveillance is strongly recommended in the event that a vascular tumor is present because catastrophic consequences are possible. To our knowledge, this is the first report of acute compartment syndrome in a pelvic limb of a bovine patient and the only report of hemangiosarcoma in the skeletal muscle of cattle.

  15. Mechanisms underlying the sparing of masticatory versus limb muscle function in an experimental critical illness model.

    Science.gov (United States)

    Aare, Sudhakar; Ochala, Julien; Norman, Holly S; Radell, Peter; Eriksson, Lars I; Göransson, Hanna; Chen, Yi-Wen; Hoffman, Eric P; Larsson, Lars

    2011-12-16

    Acute quadriplegic myopathy (AQM) is a common debilitating acquired disorder in critically ill intensive care unit (ICU) patients that is characterized by tetraplegia/generalized weakness of limb and trunk muscles. Masticatory muscles, on the other hand, are typically spared or less affected, yet the mechanisms underlying this striking muscle-specific difference remain unknown. This study aims to evaluate physiological parameters and the gene expression profiles of masticatory and limb muscles exposed to factors suggested to trigger AQM, such as mechanical ventilation, immobilization, neuromuscular blocking agents, corticosteroids (CS), and sepsis for 5 days by using a unique porcine model mimicking the ICU conditions. Single muscle fiber cross-sectional area and force-generating capacity, i.e., maximum force normalized to fiber cross-sectional area (specific force), revealed maintained masseter single muscle fiber cross-sectional area and specific-force after 5 days' exposure to all triggering factors. This is in sharp contrast to observations in limb and trunk muscles, showing a dramatic decline in specific force in response to 5 days' exposure to the triggering factors. Significant differences in gene expression were observed between craniofacial and limb muscles, indicating a highly complex and muscle-specific response involving transcription and growth factors, heat shock proteins, matrix metalloproteinase inhibitor, oxidative stress responsive elements, and sarcomeric proteins underlying the relative sparing of cranial vs. spinal nerve innervated muscles during exposure to the ICU intervention.

  16. A finite element model of the lower limb during stance phase of gait cycle including the muscle forces.

    Science.gov (United States)

    Diffo Kaze, Arnaud; Maas, Stefan; Arnoux, Pierre-Jean; Wolf, Claude; Pape, Dietrich

    2017-12-07

    Results of finite element (FE) analyses can give insight into musculoskeletal diseases if physiological boundary conditions, which include the muscle forces during specific activities of daily life, are considered in the FE modelling. So far, many simplifications of the boundary conditions are currently made. This study presents an approach for FE modelling of the lower limb for which muscle forces were included. The stance phase of normal gait was simulated. Muscle forces were calculated using a musculoskeletal rigid body (RB) model of the human body, and were subsequently applied to a FE model of the lower limb. It was shown that the inertial forces are negligible during the stance phase of normal gait. The contact surfaces between the parts within the knee were modelled as bonded. Weak springs were attached to the distal tibia for numerical reasons. Hip joint reaction forces from the RB model and those from the FE model were similar in magnitude with relative differences less than 16%. The forces of the weak spring were negligible compared to the applied muscle forces. The maximal strain was 0.23% in the proximal region of the femoral diaphysis and 1.7% in the contact zone between the tibia and the fibula. The presented approach based on FE modelling by including muscle forces from inverse dynamic analysis of musculoskeletal RB model can be used to perform analyses of the lower limb with very realistic boundary conditions. In the present form, this model can be used to better understand the loading, stresses and strains of bones in the knee area and hence to analyse osteotomy fixation devices.

  17. Isokinetic strength and endurance in proximal and distal muscles in patients with peripheral artery disease.

    Science.gov (United States)

    Câmara, Lucas Caseri; Ritti-Dias, Raphael Mendes; Menêses, Annelise Lins; D'Andréa Greve, Júlia Maria; Filho, Wilson Jacob; Santarém, José Maria; Forjaz, Cláudia Lúcia de Moraes; Puech-Leão, Pedro; Wolosker, Nelson

    2012-11-01

    The objective of this study was to analyze the muscle strength and endurance of the proximal and distal lower-extremity muscles in peripheral artery disease (PAD) patients. Twenty patients with bilateral PAD with symptoms of intermittent claudication and nine control subjects without PAD were included in the study, comprising 40 and 18 legs, respectively. All subjects performed an isokinetic muscle test to evaluate the muscle strength and endurance of the proximal (knee extension and knee flexion movements) and distal (plantar flexion and dorsiflexion movements) muscle groups in the lower extremity. Compared with the control group, the PAD group presented lower muscle strength in knee flexion (-14.0%), dorsiflexion (-26.0%), and plantar flexion (-21.2%) movements (P strength in knee extension movements (P > 0.05). The PAD patients presented a 13.5% lower knee flexion/extension strength ratio compared with the control subjects (P lower muscle endurance in dorsiflexion (-28.1%) and plantar flexion (-17.0%) movements (P muscle endurance in knee flexion and knee extension movements was similar between PAD patients and the control subjects (P > 0.05). PAD patients present lower proximal and distal muscle strength and lower distal muscle endurance than control patients. Therefore, interventions to improve muscle strength and endurance should be prescribed for PAD patients. Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.

  18. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface.

    Science.gov (United States)

    Huang, Stephanie; Ferris, Daniel P

    2012-08-10

    Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user's nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee's nervous system.

  19. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

    Directory of Open Access Journals (Sweden)

    Huang Stephanie

    2012-08-01

    Full Text Available Abstract Background Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. Methods We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. Results We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Conclusion Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee’s nervous system.

  20. Accelerated growth plate mineralization and foreshortened proximal limb bones in fetuin-A knockout mice.

    Directory of Open Access Journals (Sweden)

    Jong Seto

    Full Text Available The plasma protein fetuin-A/alpha2-HS-glycoprotein (genetic symbol Ahsg is a systemic inhibitor of extraskeletal mineralization, which is best underscored by the excessive mineral deposition found in various tissues of fetuin-A deficient mice on the calcification-prone genetic background DBA/2. Fetuin-A is known to accumulate in the bone matrix thus an effect of fetuin-A on skeletal mineralization is expected. We examined the bones of fetuin-A deficient mice maintained on a C57BL/6 genetic background to avoid bone disease secondary to renal calcification. Here, we show that fetuin-A deficient mice display normal trabecular bone mass in the spine, but increased cortical thickness in the femur. Bone material properties, as well as mineral and collagen characteristics of cortical bone were unaffected by the absence of fetuin-A. In contrast, the long bones especially proximal limb bones were severely stunted in fetuin-A deficient mice compared to wildtype littermates, resulting in increased biomechanical stability of fetuin-A deficient femora in three-point-bending tests. Elevated backscattered electron signal intensities reflected an increased mineral content in the growth plates of fetuin-A deficient long bones, corroborating its physiological role as an inhibitor of excessive mineralization in the growth plate cartilage matrix--a site of vigorous physiological mineralization. We show that in the case of fetuin-A deficiency, active mineralization inhibition is a necessity for proper long bone growth.

  1. Accelerated Growth Plate Mineralization and Foreshortened Proximal Limb Bones in Fetuin-A Knockout Mice

    Science.gov (United States)

    Gupta, Himadri S.; Schäfer, Cora; Krauss, Stefanie; Dunlop, John W. C.; Masic, Admir; Kerschnitzki, Michael; Zaslansky, Paul; Boesecke, Peter; Catalá-Lehnen, Philip; Schinke, Thorsten; Fratzl, Peter; Jahnen-Dechent, Willi

    2012-01-01

    The plasma protein fetuin-A/alpha2-HS-glycoprotein (genetic symbol Ahsg) is a systemic inhibitor of extraskeletal mineralization, which is best underscored by the excessive mineral deposition found in various tissues of fetuin-A deficient mice on the calcification-prone genetic background DBA/2. Fetuin-A is known to accumulate in the bone matrix thus an effect of fetuin-A on skeletal mineralization is expected. We examined the bones of fetuin-A deficient mice maintained on a C57BL/6 genetic background to avoid bone disease secondary to renal calcification. Here, we show that fetuin-A deficient mice display normal trabecular bone mass in the spine, but increased cortical thickness in the femur. Bone material properties, as well as mineral and collagen characteristics of cortical bone were unaffected by the absence of fetuin-A. In contrast, the long bones especially proximal limb bones were severely stunted in fetuin-A deficient mice compared to wildtype littermates, resulting in increased biomechanical stability of fetuin-A deficient femora in three-point-bending tests. Elevated backscattered electron signal intensities reflected an increased mineral content in the growth plates of fetuin-A deficient long bones, corroborating its physiological role as an inhibitor of excessive mineralization in the growth plate cartilage matrix - a site of vigorous physiological mineralization. We show that in the case of fetuin-A deficiency, active mineralization inhibition is a necessity for proper long bone growth. PMID:23091616

  2. Assessment of Lower Limb Muscle Strength and Power Using Hand-Held and Fixed Dynamometry: A Reliability and Validity Study.

    Directory of Open Access Journals (Sweden)

    Benjamin F Mentiplay

    Full Text Available Hand-held dynamometry (HHD has never previously been used to examine isometric muscle power. Rate of force development (RFD is often used for muscle power assessment, however no consensus currently exists on the most appropriate method of calculation. The aim of this study was to examine the reliability of different algorithms for RFD calculation and to examine the intra-rater, inter-rater, and inter-device reliability of HHD as well as the concurrent validity of HHD for the assessment of isometric lower limb muscle strength and power.30 healthy young adults (age: 23±5 yrs, male: 15 were assessed on two sessions. Isometric muscle strength and power were measured using peak force and RFD respectively using two HHDs (Lafayette Model-01165 and Hoggan microFET2 and a criterion-reference KinCom dynamometer. Statistical analysis of reliability and validity comprised intraclass correlation coefficients (ICC, Pearson correlations, concordance correlations, standard error of measurement, and minimal detectable change.Comparison of RFD methods revealed that a peak 200 ms moving window algorithm provided optimal reliability results. Intra-rater, inter-rater, and inter-device reliability analysis of peak force and RFD revealed mostly good to excellent reliability (coefficients ≥ 0.70 for all muscle groups. Concurrent validity analysis showed moderate to excellent relationships between HHD and fixed dynamometry for the hip and knee (ICCs ≥ 0.70 for both peak force and RFD, with mostly poor to good results shown for the ankle muscles (ICCs = 0.31-0.79.Hand-held dynamometry has good to excellent reliability and validity for most measures of isometric lower limb strength and power in a healthy population, particularly for proximal muscle groups. To aid implementation we have created freely available software to extract these variables from data stored on the Lafayette device. Future research should examine the reliability and validity of these variables in

  3. Assessment of Lower Limb Muscle Strength and Power Using Hand-Held and Fixed Dynamometry: A Reliability and Validity Study.

    Science.gov (United States)

    Mentiplay, Benjamin F; Perraton, Luke G; Bower, Kelly J; Adair, Brooke; Pua, Yong-Hao; Williams, Gavin P; McGaw, Rebekah; Clark, Ross A

    2015-01-01

    Hand-held dynamometry (HHD) has never previously been used to examine isometric muscle power. Rate of force development (RFD) is often used for muscle power assessment, however no consensus currently exists on the most appropriate method of calculation. The aim of this study was to examine the reliability of different algorithms for RFD calculation and to examine the intra-rater, inter-rater, and inter-device reliability of HHD as well as the concurrent validity of HHD for the assessment of isometric lower limb muscle strength and power. 30 healthy young adults (age: 23±5 yrs, male: 15) were assessed on two sessions. Isometric muscle strength and power were measured using peak force and RFD respectively using two HHDs (Lafayette Model-01165 and Hoggan microFET2) and a criterion-reference KinCom dynamometer. Statistical analysis of reliability and validity comprised intraclass correlation coefficients (ICC), Pearson correlations, concordance correlations, standard error of measurement, and minimal detectable change. Comparison of RFD methods revealed that a peak 200 ms moving window algorithm provided optimal reliability results. Intra-rater, inter-rater, and inter-device reliability analysis of peak force and RFD revealed mostly good to excellent reliability (coefficients ≥ 0.70) for all muscle groups. Concurrent validity analysis showed moderate to excellent relationships between HHD and fixed dynamometry for the hip and knee (ICCs ≥ 0.70) for both peak force and RFD, with mostly poor to good results shown for the ankle muscles (ICCs = 0.31-0.79). Hand-held dynamometry has good to excellent reliability and validity for most measures of isometric lower limb strength and power in a healthy population, particularly for proximal muscle groups. To aid implementation we have created freely available software to extract these variables from data stored on the Lafayette device. Future research should examine the reliability and validity of these variables in clinical

  4. Relationships of 35 lower limb muscles to height and body mass quantified using MRI.

    Science.gov (United States)

    Handsfield, Geoffrey G; Meyer, Craig H; Hart, Joseph M; Abel, Mark F; Blemker, Silvia S

    2014-02-07

    Skeletal muscle is the most abundant tissue in the body and serves various physiological functions including the generation of movement and support. Whole body motor function requires adequate quantity, geometry, and distribution of muscle. This raises the question: how do muscles scale with subject size in order to achieve similar function across humans? While much of the current knowledge of human muscle architecture is based on cadaver dissection, modern medical imaging avoids limitations of old age, poor health, and limited subject pool, allowing for muscle architecture data to be obtained in vivo from healthy subjects ranging in size. The purpose of this study was to use novel fast-acquisition MRI to quantify volumes and lengths of 35 major lower limb muscles in 24 young, healthy subjects and to determine if muscle size correlates with bone geometry and subject parameters of mass and height. It was found that total lower limb muscle volume scales with mass (R(2)=0.85) and with the height-mass product (R(2)=0.92). Furthermore, individual muscle volumes scale with total muscle volume (median R(2)=0.66), with the height-mass product (median R(2)=0.61), and with mass (median R(2)=0.52). Muscle volume scales with bone volume (R(2)=0.75), and muscle length relative to bone length is conserved (median s.d.=2.1% of limb length). These relationships allow for an arbitrary subject's individual muscle volumes to be estimated from mass or mass and height while muscle lengths may be estimated from limb length. The dataset presented here can further be used as a normative standard to compare populations with musculoskeletal pathologies. © 2013 Published by Elsevier Ltd.

  5. Age factor and proximate compositions of the muscle of ...

    African Journals Online (AJOL)

    Signiicant decreases (P < 005) in the EE content of the fish muscle could be attributed to the harmful effects of petroleum-relatedaromatic compound (ACs) on animals. These ACs might have caused decreases in the muscle triglycerides of the total lipid (EE) content of thethree age groups of the fish. Significant increases (P ...

  6. Changes in muscle contractile characteristics and jump height following 24 days of unilateral lower limb suspension

    NARCIS (Netherlands)

    Horstman, A.M.; de Ruiter, C.J.; van Duinhoven, N.T.L.; Hopman, M.T.E.; de Haan, A.

    2012-01-01

    We measured changes in maximal voluntary and electrically evoked torque and rate of torque development because of limb unloading. We investigated whether these changes during single joint isometric muscle contractions were related to changes in jump performance involving dynamic muscle contractions

  7. Changes in muscle contractile characteristics and jump height following 24 days of unilateral lower limb suspension.

    NARCIS (Netherlands)

    Horstman, A.M.; Ruiter, C.J. de; Duijnhoven, N.T.L. van; Hopman, M.T.E.; Haan, A. de

    2012-01-01

    We measured changes in maximal voluntary and electrically evoked torque and rate of torque development because of limb unloading. We investigated whether these changes during single joint isometric muscle contractions were related to changes in jump performance involving dynamic muscle contractions

  8. A portable device for the clinical assessment of upper limb motion and muscle synergies

    NARCIS (Netherlands)

    Murgia, A.; Kerkhofs, V.; Savelberg, H.; Meijer, K.

    2010-01-01

    We present a device for recording and analyzing upper limb movements and muscle activities in a single unit. The device's outputs are related to aspects of clinical assessment such as joint coordination, fatigue and muscle synergies. A comparison with an optoelectronic motion capture system was also

  9. Muscle coordination is key to the power output and mechanical efficiency of limb movements.

    Science.gov (United States)

    Wakeling, J M; Blake, O M; Chan, H K

    2010-02-01

    The purpose of this study was to determine which features of muscle mechanics and muscle coordination affect the power output from a limb during locomotion. Eight subjects were tested while cycling at maximum exertion for 25 min on a stationary dynamometer. Cadence and load were varied to span a range of power outputs and myoelectric activity was measured from 10 muscles in the leg. Cycle-by-cycle variations in muscle coordination, cadence and power output were observed and the EMG intensity across all muscles was used as an estimate of the metabolic cost for each cycle. Data for the cycles at greatest power output were separated into three groups: maximum power, 80% power but lower EMG intensity and 80% power and higher EMG intensity. Torque-angular velocity relations were determined for the ankle and knee joints. During cycling at maximum power output the ankle joint was not extending at the velocity necessary for maximum power output; thus, maximum limb power occurs when some of the individual muscles cannot be generating maximum power output. Increases in EMG intensity occurred with no increase in power output from the limb: these corresponded to decreases in the efficiency and changes in coordination. Increases in power were achieved that were not matched by equivalent increases in EMG intensity, but did occur with changes in coordination. It is proposed that the power output from the limb is limited by the coordination pattern of the muscles rather than the maximum power output from any one muscle itself.

  10. Muscle involvement in limb-girdle muscular dystrophy with GMPPB deficiency (LGMD2T)

    DEFF Research Database (Denmark)

    Oestergaard, S T; Stojkovic, T; Dahlqvist, Julia Rebecka

    2016-01-01

    OBJECTIVE: In this study, muscle involvement assessed by MRI and levels of GMPPB and glycosylation of α-dystroglycan expression in muscle were examined in patients with limb-girdle muscular dystrophy (LGMD) type 2T. METHODS: Six new patients with genetically verified mutations in GMPPB were studied...

  11. Role of the coordinated activities of trunk and lower limb muscles during the landing-to-jump movement.

    Science.gov (United States)

    Iida, Yoshiaki; Kanehisa, Hiroaki; Inaba, Yuki; Nakazawa, Kimitaka

    2012-06-01

    This study aimed to clarify how the activities of trunk and lower limb muscles during a landing-to-jump (L-J) movement are coordinated to perform the task effectively. Electromyography (EMG) activities of trunk and lower limb muscles as well as kinematic and ground reaction force data were recorded while 17 subjects performed 5 L-Js from a height of 35 cm. The L-J was divided into four phases: PRE phase, 100 ms preceding ground contact; ABSORPTION phase, from ground contact through 100 ms; BRAKING phase, from the end of the ABSORPTION phase to the time of the lowest center of mass position; and PROPULSION phase, from the end of the BRAKING phase to takeoff. The trunk extensor and flexors showed reciprocal activation patterns through the L-J. In the PROPULSION phase, the timings when the EMG activities of the extensor muscles peaked were characterized as a sequential proximal-to-distal pattern. Furthermore, the peak vertical ground reaction force in the ABSORPTION phase relative to body mass negatively correlated to the jump height of the L-J movement and positively correlated with the magnitude of the EMG activities of the soleus in the PRE phase and those of the soleus and rectus abdominis in the ABSORPTION phase. These findings indicate that the intensities and peak timings of muscle activities in the trunk and lower limb are coordinated during the L-J movement and, the coordinated activities would play functional roles such as impact absorption, braking against the descent of body and force generation and direction control for jumping.

  12. Proximal Limb Weakness in a Patient with Celiac Disease: Copper Deficiency, Gluten Sensitivity, or Both as the Underlying Cause?

    Directory of Open Access Journals (Sweden)

    J. David Avila

    2016-01-01

    Full Text Available Celiac disease has been associated with several neurologic disorders which may result from micronutrient deficiencies, coexisting autoimmune conditions, or gluten sensitivity. Copper deficiency can produce multiple neurologic manifestations. Myeloneuropathy is the most common neurologic syndrome and it is often irreversible, despite copper replacement. We report the case of a 55-year-old man who presented with progressive proximal limb weakness and weight loss in the setting of untreated celiac disease without gastrointestinal symptoms. He had anemia, neutropenia, and severe hypocupremia. The pattern of weakness raised the suspicion that there was an underlying myopathy, although this was not confirmed by electrodiagnostic studies. Weakness and hematologic abnormalities resolved completely within 1 month of total parenteral nutrition with copper supplementation and a gluten-free diet. Myopathy can rarely occur in patients with celiac disease, but the mechanism is unclear. Pure proximal limb weakness has not been previously reported in copper deficiency. We propose that this may represent a novel manifestation of hypocupremia and recommend considering copper deficiency and gluten sensitivity in patients presenting with proximal limb weakness.

  13. ANATOMICAL DESCRIPTION OF MUSCLES IN THE HIND LIMB AND TAIL OF CEBUS ALBIFRONS

    OpenAIRE

    Quevedo U., Miriam; Laboratorio de Anatomía y Fauna Silvestre, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Cisneros S., Jannet; Laboratorio de Anatomía y Fauna Silvestre, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Navarette Z., Miluska; Laboratorio de Anatomía y Fauna Silvestre, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Torres G., Juan Pablo; Laboratorio de Anatomía y Fauna Silvestre, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Sato S., Alberto; Laboratorio de Anatomía y Fauna Silvestre, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima

    2012-01-01

    The objective of this study was to perform the anatomic description of the muscles located in the hind limb and tail of Cebus albifrons. Four adult monkeys older than 3 years of age and castrated were used. The animals were euthanized and embalmed; then, after six days, the dissection of the hind limb and tail was carried out. Muscles were described in comparison with the Rhesus monkey (Maccaca mullata). The pelvis and thigh, leg and foot region presented 18, 12 and 11 muscles respectively. P...

  14. The relationship between lower limb muscle strength and lower extremity function in HIV disease

    Directory of Open Access Journals (Sweden)

    Peter C. Mhariwa

    2017-02-01

    Full Text Available Background: Human immunodeficiency virus (HIV negatively impacts muscle strength and function. This study aimed to establish the relationship between lower limb muscle strength and lower extremity function in HIV disease.Method: A cross-sectional study was undertaken with a sample of 113 HIV-positive participants. Lower limb muscle strength and self-reported function were established using dynamometry and the Lower Extremity Functional Scale (LEFS, respectively. Muscle strength and functional status were established in a subset of 30 HIV-negative participants to determine normative values.Results: Muscle strength for participants with HIV ranged from an ankle dorsiflexion mean of 9.33 kg/m2 to 15.79 kg/m2 in hip extensors. In the HIV-negative group, ankle dorsiflexors recorded 11.17 kg/m2, whereas hip extensors were the strongest, generating 17.68 kg/m2. In the HIV-positive group, linear regression showed a positive relationship between lower limb muscle strength and lower extremity function (r = 0.71, p = 0.00. Fifty per cent of the changes in lower extremity function were attributable to lower limb muscle strength. A simple linear regression model showed that lower limb ankle plantar flexors contributed the most to lower extremity function in this cohort, contrary to the literature which states that hip and trunk muscles are the most active in lower limb functional activities.Conclusion: Lower extremity strength impacts perceived function in individuals stabilised on antiretroviral therapy for HIV disease. These findings demonstrate that ankle plantar flexors produce more force over hip flexors. Careful attention should be paid to the implications for strength training in this population.

  15. Subject-specific modelling of lower limb muscles in children with cerebral palsy.

    Science.gov (United States)

    Oberhofer, K; Stott, N S; Mithraratne, K; Anderson, I A

    2010-01-01

    Recent studies suggest that the architecture of spastic muscles in children with cerebral palsy is considerably altered; however, only little is known about the structural changes that occur other than in the gastrocnemius muscle. In the present study, Magnetic Resonance Imaging (MRI) and subject-specific modelling techniques were used to compare the lengths and volumes of six lower limb muscles between children with cerebral palsy and typically developing children. MRI scans of the lower limbs of two children with spastic hemiplegia cerebral palsy, four children with spastic diplegia cerebral palsy (mean age 9.6 years) and a group of typically developing children (mean age 10.2 years) were acquired. Subject-specific models of six lower limb muscles were developed from the MRI data using a technique called Face Fitting. Muscle volumes and muscle lengths were derived from the models and normalised to body mass and segmental lengths, respectively. Normalised muscle volumes in the children with cerebral palsy were smaller than in the control group with the difference being 22% in the calf muscles, 26% in the hamstrings and 22% in the quadriceps, respectively. Only the differences in the hamstrings and the quadriceps were statistically significant (P=0.036, P=0.038). Normalised muscle lengths in the children with cerebral palsy were significantly shorter (Pmuscle in either group. The present results show that lower limb muscles in ambulatory children with cerebral palsy are significantly altered, suggesting an overall mechanical deficit due to predominant muscle atrophy. Further investigations of the underlying causes of the muscle atrophy are required to better define management and treatment strategies for children with cerebral palsy.

  16. The muscle activation patterns of lower limb during stair climbing at different backpack load.

    Science.gov (United States)

    Yali, Han; Aiguo, Song; Haitao, Gao; Songqing, Zhu

    2015-01-01

    Stair climbing under backpack load condition is a challenging task. Understanding muscle activation patterns of lower limb during stair climbing with load furthers our understanding of the factors involved in joint pathology and the effects of treatment. At the same time, stair climbing under backpack load requires adjustments of muscle activations and increases joint moment compared to level walking, which with muscle activation patterns are altered as a result of using an assistive technology, such as a wearable exoskeleton leg for human walking power augmentation. Therefore, the aim of this study was to analyze lower limb muscles during stair climbing under different backpack load. Nine healthy volunteers ascended a four-step staircase at different backpack load (0 kg, 10 kg, 20 kg, 30 kg). Electromyographic (EMG) signals were recorded from four lower limb muscles (gastrocnemius, tibialis anterior, hamstring, rectus femoris). The results showed that muscle activation amplitudes of lower limb increase with increasing load during stair climbing, the maximum RMS of gastrocnemius are greater than tibialis anterior, hamstring and rectus femoris whether stair climbing or level walking under the same load condition. However, the maximum RMS of hamstring are smaller than gastrocnemius, tibialis anterior and rectus femoris. The study of muscle activation under different backpack load during stair climbing can be used to design biomechanism and explore intelligent control based on EMG for a wearable exoskeleton leg for human walking power augmentation.

  17. Motor patterns of distal hind limb muscles in walking turtles: Implications for models of limb bone loading.

    Science.gov (United States)

    Schoenfuss, Heiko L; Roos, John D; Rivera, Angela R V; Blob, Richard W

    2010-12-01

    Previous studies of limb bone loading in walking turtles indicate that the ground reaction force exerts a flexor moment at the ankle during stance, requiring extensor muscle activity to maintain joint equilibrium. Of four proposed ankle extensors in turtles, two (gastrocnemius medialis, pronator profundus) originate on the tibia and fibula, respectively, while the other two (flexor digitorum longus, gastrocnemius lateralis) originate from the distal femur, crossing the flexor aspect of the knee and potentially eliciting compensatory forces from antagonist knee extensor muscles that could contribute to femoral stress. Published bone stress models assume all four proposed ankle extensors are active during stance in turtles. However, if only the ankle extensors that cross the knee were active then femoral stresses might be higher than predicted by published models, whereas if only extensors that do not cross the knee were active then femoral stresses might be lower than predicted. We analyzed synchronized footfall and electromyographic activity patterns in slider turtles (Trachemys scripta) and found that all four proposed ankle extensors were active during at least part of stance phase in most individuals, corroborating bone stress models. However, activation patterns were complex, with multiple bursts in many ankle extensors that frequently persisted into swing phase. In addition, two hypothesized ankle flexors (tibialis anterior, extensor digitorum communis) were frequently active during stance. This might increase the joint moment that ankle extensors must counter, elevating the forces they transfer across the knee joint and, thereby, raising femoral stress. Recognition of these activity patterns may help reconcile differences between evaluations of loads on turtle limbs based on force platform versus in vivo strain studies. Moreover, while some variation in motor patterns for the distal hind limbs of turtles may reflect functional compartmentalization of muscles

  18. Muscle fatigue evaluation of astronaut upper limb based on sEMG and subjective assessment

    Science.gov (United States)

    Zu, Xiaoqi; Zhou, Qianxiang; Li, Yun

    2012-07-01

    All movements are driven by muscle contraction, and it is easy to cause muscle fatigue. Evaluation of muscle fatigue is a hot topic in the area of astronaut life support training and rehabilitation. If muscle gets into fatigue condition, it may reduce work efficiency and has an impact on psychological performance. Therefore it is necessary to develop an accurate and usable method on muscle fatigue evaluation of astronaut upper limb. In this study, we developed a method based on surface electromyography (sEMG) and subjective assessment (Borg scale) to evaluate local muscle fatigue. Fifteen healthy young male subjects participated in the experiment. They performed isometric muscle contractions of the upper limb. sEMG of the biceps brachii were recorded during the entire process of isotonic muscle contraction and Borg scales of muscle fatigue were collected in certain times. sEMG were divided into several parts, and then mean energy of each parts were calculated by the one-twelfth band octave method. Equations were derived based on the relationship between the mean energy of sEMG and Borg scale. The results showed that cubic curve could describe the degree of local muscle fatigue, and could be used to evaluate and monitor local muscle fatigue during the entire process.

  19. Analysis and control of a parallel lower limb based on pneumatic artificial muscles

    Directory of Open Access Journals (Sweden)

    Feilong Jiang

    2016-12-01

    Full Text Available Most robots that are actuated by antagonistic pneumatic artificial muscles are controlled by various control algorithms that cannot adequately imitate the actual muscle distribution of human limbs. Other robots in which the distribution of pneumatic artificial muscle is similar to that of human limbs can only analyze the position of the robot using perceptual data instead of rational knowledge. In order to better imitate the movement of a human limb, the article proposes a humanoid lower limb in the form of a parallel mechanism where muscle is unevenly distributed. Next, the kinematic and dynamic movements of bionic hip joint are analyzed, where the joint movement is controlled by an observer-based fuzzy adaptive control algorithm as a whole rather than each individual pneumatic artificial muscle and parameters that are optimized by a neural network. Finally, experimental results are provided to confirm the effectiveness of the proposed method. We also document the role of muscle in trajectory tracking for the piriformis and musculi obturator internus in isobaric processes.

  20. Upper and lower limb muscles in patients with COPD: similarities in muscle efficiency but differences in fatigue resistance.

    Science.gov (United States)

    Miranda, Eduardo Foschini; Malaguti, Carla; Marchetti, Paulo Henrique; Dal Corso, Simone

    2014-01-01

    Peripheral muscle dysfunction is a common finding in patients with COPD; however, the structural adaptation and functional impairment of the upper and lower limb muscles do not seem to be homogenous. We compared muscle fatigue and recovery time between 2 representative muscles: the middle deltoid and the quadriceps femoris. Twenty-one subjects with COPD (FEV1 46.1 ± 10.3% of predicted) underwent maximal voluntary isometric contraction and an endurance test (60% of maximal voluntary isometric contraction, to the limit of tolerance). The maximal voluntary isometric contraction test was repeated after 10 min, 30 min, 60 min, and 24 hours for both the quadriceps femoris and middle deltoid. Surface electromyography was recorded throughout the endurance test. Maximal voluntary isometric contraction significantly decreased only for the middle deltoid between 10 and 60 min after the endurance test. A significant increase of the root mean square and a greater decline in median frequency throughout the endurance test occurred for the middle deltoid, compared with the quadriceps femoris. When dyspnea and fatigue scores were corrected by endurance time, higher values were observed for the middle deltoid (0.07 and 0.08, respectively) in relation to the quadriceps femoris (0.02 and 0.03, respectively). Subjects with COPD had a higher fatigability of a representative upper limb muscle (middle deltoid) than a lower limb muscle (quadriceps femoris).

  1. Comparison of Lower Limb Segments Kinematics in a Taekwondo Kick. An Approach to the Proximal to Distal Motion

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    Estevan Isaac

    2015-09-01

    Full Text Available In taekwondo, there is a lack of consensus about how the kick sequence occurs. The aim of this study was to analyse the peak velocity (resultant and value in each plane of lower limb segments (thigh, shank and foot, and the time to reach this peak velocity in the kicking lower limb during the execution of the roundhouse kick technique. Ten experienced taekwondo athletes (five males and five females; mean age of 25.3 ±5.1 years; mean experience of 12.9 ±5.3 years participated voluntarily in this study performing consecutive kicking trials to a target located at their sternum height. Measurements for the kinematic analysis were performed using two 3D force plates and an eight camera motion capture system. The results showed that the proximal segment reached a lower peak velocity (resultant and in each plane than distal segments (except the peak velocity in the frontal plane where the thigh and shank presented similar values, with the distal segment taking the longest to reach this peak velocity (p < 0.01. Also, at the instant every segment reached the peak velocity, the velocity of the distal segment was higher than the proximal one (p < 0.01. It provides evidence about the sequential movement of the kicking lower limb segments. In conclusion, during the roundhouse kick in taekwondo inter-segment motion seems to be based on a proximo-distal pattern.

  2. Similarity of muscle synergies extracted from the lower limb including the deep muscles between level and uphill treadmill walking.

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    Saito, Akira; Tomita, Aya; Ando, Ryosuke; Watanabe, Kohei; Akima, Hiroshi

    2018-01-01

    This study aimed to examine muscle synergies involving the deeper muscles of the lower limb during level and uphill treadmill walking. Seven men and five women walked on a treadmill at three speeds (60, 80, and 100m/min) and two grades (level and 10% grade). Surface electromyographic (EMG) signals were recorded from 10 muscles of the lower limb, including vastus intermedius, adductor magnus, and adductor longus. Muscle synergies were extracted applying non-negative matrix factorization, and the relative co-activation across muscles and the temporal information of synergy recruitment were identified by the muscle synergy vector and synergy activation coefficient, respectively. Correlation coefficients between a pair of synergy vectors during level and uphill walking were analyzed as a similarity index, with the similarity criterion at r=0.76. Changes in synergy activation coefficients between the walking conditions were evaluated by cross-correlation analysis. The mean number of synergies ranged from 3.8 to 4.0 across all conditions, and they were not significantly different between level and uphill walking conditions. Similarity between walking conditions was high (r>0.76) for three muscle synergies, but not for one synergy that mainly consisted of the quadriceps femoris. The inter-condition similarity of the synergy activation coefficients was high for the four synergies, and a significant lag time for synergy 2, which consisted mainly of the activity of medial gastrocnemius, was found at 60 and 80m/min. The muscle synergies extracted from the lower limb involving the deeper muscles appear to be consistent during level and uphill treadmill walking. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Lower-limb pain, disease, and injury burden as determinants of muscle strength deficit after hip fracture

    NARCIS (Netherlands)

    Portegijs, Erja; Rantanen, Taina; Kallinen, Mauri; Heinonen, Ari; Alen, Markku; Kiviranta, Ilkka; Sipilä, Sarianna

    2009-01-01

    BACKGROUND: Hip fracture may result in an asymmetrical lower-limb strength deficit. The deficit may be related to the trauma, surgical treatment, pain, or disuse of the fractured limb. However, disease and injury burden or musculoskeletal pain in the other limb may reduce muscle strength on that

  4. Regulation of motility of myogenic cells in filling limb muscle anlagen by Pitx2.

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    Adam L Campbell

    Full Text Available Cells of the ventrolateral dermomyotome delaminate and migrate into the limb buds where they give rise to all muscles of the limbs. The migratory cells proliferate and form myoblasts, which withdraw from the cell cycle to become terminally differentiated myocytes. The myogenic lineage colonizes pre-patterned regions to form muscle anlagen as muscle fibers are assembled. The regulatory mechanisms that control the later steps of this myogenic program are not well understood. The homeodomain transcription factor Pitx2 is expressed specifically in the muscle lineage from the migration of precursors to adult muscle. Ablation of Pitx2 results in distortion, rather than loss, of limb muscle anlagen, suggesting that its function becomes critical during the colonization of, and/or fiber assembly in, the anlagen. Microarrays were used to identify changes in gene expression in flow-sorted migratory muscle precursors, labeled by Lbx1(EGFP/+, which resulted from the loss of Pitx2. Very few genes showed changes in expression. Many small-fold, yet significant, changes were observed in genes encoding cytoskeletal and adhesion proteins which play a role in cell motility. Myogenic cells from genetically-tagged mice were cultured and subjected to live cell-tracking analysis using time-lapse imaging. Myogenic cells lacking Pitx2 were smaller, more symmetrical, and had more actin bundling. They also migrated about half of the total distance and velocity. Decreased motility may prevent myogenic cells from filling pre-patterned regions of the limb bud in a timely manner. Altered shape may prevent proper assembly of higher-order fibers within anlagen. Pitx2 therefore appears to regulate muscle anlagen development by appropriately balancing expression of cytoskeletal and adhesion molecules.

  5. Effects of step length and step frequency on lower-limb muscle function in human gait.

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    Lim, Yoong Ping; Lin, Yi-Chung; Pandy, Marcus G

    2017-05-24

    The aim of this study was to quantify the effects of step length and step frequency on lower-limb muscle function in walking. Three-dimensional gait data were used in conjunction with musculoskeletal modeling techniques to evaluate muscle function over a range of walking speeds using prescribed combinations of step length and step frequency. The body was modeled as a 10-segment, 21-degree-of-freedom skeleton actuated by 54 muscle-tendon units. Lower-limb muscle forces were calculated using inverse dynamics and static optimization. We found that five muscles - GMAX, GMED, VAS, GAS, and SOL - dominated vertical support and forward progression independent of changes made to either step length or step frequency, and that, overall, changes in step length had a greater influence on lower-limb joint motion, net joint moments and muscle function than step frequency. Peak forces developed by the uniarticular hip and knee extensors, as well as the normalized fiber lengths at which these muscles developed their peak forces, correlated more closely with changes in step length than step frequency. Increasing step length resulted in larger contributions from the hip and knee extensors and smaller contributions from gravitational forces (limb posture) to vertical support. These results provide insight into why older people with weak hip and knee extensors walk more slowly by reducing step length rather than step frequency and also help to identify the key muscle groups that ought to be targeted in exercise programs designed to improve gait biomechanics in older adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Bioelectrical activity of limb muscles during cold shivering of stimulation of the vestibular apparatus

    Science.gov (United States)

    Kuzmina, G. I.

    1980-01-01

    The effects of caloric and electric stimulation of the vestibular receptors on the EMG activity of limb muslces in anesthetized cats during cold induced shivering involved flexor muscles alone. Both types of stimulation suppressed bioelectrical activity more effectively in the ipsilateral muscles. The suppression of shivering activity seems to be due to the increased inhibitory effect of descending labyrinth pathways on the function of flexor motoneurons.

  7. Muscle perfusion of posterior trunk and lower-limb muscles at rest and during upper-limb exercise in spinal cord-injured and able-bodied individuals.

    Science.gov (United States)

    Zafeiridis, A; Vasiliadis, A V; Doumas, A; Galanis, N; Christoforidis, T; Kyparos, A; Nikolaidis, M G; Dipla, K; Vrabas, I S

    2012-11-01

    Nonrandomized-controlled trial. To assess muscle perfusion at rest and during arm-cranking exercise (ACE) in upper and lower posterior trunk and vastus lateralis (VL) muscles in individuals with spinal cord injury (SCI) and controls (C). Exercise Physiology-Biochemistry Laboratory. Eight SCI with thoracic lesion and eight C received injections of radioactive tracer to trapezius (TRAP), latissimus dorsi (LAT) and VL. Radioactive counts were recorded with a γ-camera for 10 min at rest and during ACE (60% VO(2max) for 20 min). Time-count curves were generated and the isotope clearance rate, expressed as half-life time (T(1/2),min), was calculated to assess muscle perfusion. Resting T(1/2) was lower in TRAP and LAT vs VL (Pmuscles in C. Arm-cranking increased (Pmuscles. Resting muscle perfusion was reduced in the paralyzed limbs of SCI compared with C, whereas there was no evidence of impaired microcirculation in upper and lower back muscles in SCI. Although ACE did not induce a hyperemic response in VL, it increased hyperemia in upper and lower posterior trunk muscles in SCI, suggesting beneficial effects of this type of activity on muscle microvasculature in this region.

  8. Adaptations in limb muscle function following pulmonary rehabilitation in patients with COPD – a review

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    André Nyberg

    2016-11-01

    Full Text Available Even though chronic obstructive pulmonary disease (COPD is primarily a disease of the respiratory system, limb muscle dysfunction characterized by muscle weakness, reduced muscle endurance and higher muscle fatigability, is a common secondary consequence and a major systemic manifestation of the disease. Muscle dysfunction is especially relevant in COPD because it is related to important clinical outcomes such as mortality, quality of life and exercise intolerance, independently of lung function impairment. Thus, improving muscle function is considered an important therapeutic goal in COPD management. Pulmonary rehabilitation (PR is a multidisciplinary, evidence-based and comprehensive approach used to promote better self-management of the disease, minimize symptom burden, optimize functional status, and increase participation in activities of daily life. Exercise training, including cardiovascular and muscle exercises, is the cornerstone of PR and is considered the best available strategy to improve exercise tolerance and muscle function among patients with COPD. This paper addresses the various components of exercise training within PR used to improve limb muscle function in COPD, providing clinicians and health-care professionals with an overview and description of these various exercise modalities and of their effects on limb muscle function. Guidance and recommendations to help design optimal limb muscle training regimens for these patients are also presented. Keywords: COPD, Exercise, Muscle function, Limb muscle dysfunction, Pulmonary rehabilitation, Resistance training, Aerobic exercises

  9. Muscle edema of the lower limb determined by MRI in Asian hypokalaemic periodic paralysis patients.

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    Jia, Bai-Xue; Yang, Qi; Li, Sheng-Yun; Wan, Min; Wang, Han; Huo, Lin-Yu; Zhao, Ethan; Ding, Yu-Chuan; Ji, Xun-Ming; Guo, Xiu-Hai

    2015-03-01

    To determine the pattern of muscle edema occurring in the lower limb muscles of Asian hypokalaemic periodic paralysis (hypoPP) patients using magnetic resonance imaging (MRI). Specifically, the relationship between muscle edema and muscle activity during daily use was examined by comparing the lower limb muscle MRI of healthy subjects following exercise and hypoPP patients. Twenty Asian patients (mean age: 29·3±7·53 years) clinically diagnosed with hypoPP were enrolled in the present study. Ten healthy subjects were also enrolled. Direct automated DNA sequencing of the S4 regions of CACNA1S and SCN4A in all hypoPP patients was performed. The upper and lower legs of all hypoPP patients during the time interval between attacks and healthy subjects pre- and post-exercise were examined on a 3 T system with T2-weighted fat saturation sequence. Images were evaluated by means of a region of interest analysis. A scoring from 0 to 3 was used to compare the degree of muscle edema among individual muscles. Three hypoPP patients were identified with mutations in the screened genes: R1239H and R900S of CACNA1S and R672H of SCN4A. The lower leg muscles of both hypoPP patients and healthy subjects after exercise displayed significantly higher MRI signal intensities compared to healthy subjects before exercise (P muscle signal intensities of hypoPP patients and healthy subjects following exercise compared to pre-exercise healthy subjects (P  =  0·7598 and P  =  0·9651, respectively). In the hypoPP patient group, high signal intensity in the upper leg muscles was seen only in the patient with the R1239H mutation. In the lower legs, muscle edema was most frequently seen in the gastrocnemius lateralis, soleus, and gastrocnemius medialis in the hypoPP patient group. Furthermore, the degree of muscle edema was the greatest in these muscles. This similar pattern of muscle edema was also seen in healthy subjects after exercise. In Asian hypoPP patients, muscle edema as well

  10. Unilateral strength training leads to muscle-specific sparing effects during opposite homologous limb immobilization.

    Science.gov (United States)

    Andrushko, Justin W; Lanovaz, Joel L; Björkman, Kelsey M; Kontulainen, Saija A; Farthing, Jonathan Peter

    2017-12-14

    Cross-education (CE) occurs after unilateral training whereby performance of the untrained contralateral limb is enhanced. A handful of studies have shown that CE can spare the strength and size of an opposite immobilized limb, but specificity (i.e., trained homologous muscle and contraction type) of these effects is unknown. The purpose was to investigate specificity of CE "sparing" effects with immobilization. The non-dominant forearm of 16 participants was immobilized with a cast and participants were randomly assigned to a resistance training (eccentric wrist flexion, 3 times/week) or control group for four weeks. Pre- and post-testing involved wrist flexors and extensors muscle thickness (via ultrasound), eccentric, concentric and isometric maximal voluntary contractions (via dynamometer), and forearm muscle cross-sectional area (MCSA, via peripheral quantitative computed tomography). Only the training group showed strength preservation across all contractions in the wrist flexors of the immobilized limb (Training: -2.4% vs. -21.6%; P =0.04), and increased wrist flexors strength of the non-immobilized limb (Training: 30.8% vs. -7.4%; P =0.04). Immobilized arm MCSA was preserved for the training group only (Training: 1.3% vs. -2.3%; P =0.01). Muscle thickness differed between groups for the immobilized (Training: 2.8% vs. -3.2%; P =0.01) and non-immobilized wrist flexors (Training: 7.1% vs. -3.7%; P =0.02). Strength preservation was non-specific to contraction type (P =0.69, η p 2 =0.03), yet specific to the trained flexors muscle. These findings suggest that eccentric training of the non-immobilized limb can preserve size of the immobilized contralateral homologous muscle and strength across multiple contraction types.

  11. Reliable protocol for shear wave elastography of lower limb muscles at rest and during passive stretching.

    Science.gov (United States)

    Dubois, Guillaume; Kheireddine, Walid; Vergari, Claudio; Bonneau, Dominique; Thoreux, Patricia; Rouch, Philippe; Tanter, Mickael; Gennisson, Jean-Luc; Skalli, Wafa

    2015-09-01

    Development of shear wave elastography gave access to non-invasive muscle stiffness assessment in vivo. The aim of the present study was to define a measurement protocol to be used in clinical routine for quantifying the shear modulus of lower limb muscles. Four positions were defined to evaluate shear modulus in 10 healthy subjects: parallel to the fibers, in the anterior and posterior aspects of the lower limb, at rest and during passive stretching. Reliability was first evaluated on two muscles by three operators; these measurements were repeated six times. Then, measurement reliability was compared in 11 muscles by two operators; these measurements were repeated three times. Reproducibility of shear modulus was 0.48 kPa and repeatability was 0.41 kPa, with all muscles pooled. Position did not significantly influence reliability. Shear wave elastography appeared to be an appropriate and reliable tool to evaluate the shear modulus of lower limb muscles with the proposed protocol. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  12. Electromyographic analysis of lower limb muscles during the golf swing performed with three different clubs.

    Science.gov (United States)

    Marta, Sérgio; Silva, Luís; Vaz, João Rocha; Castro, Maria António; Reinaldo, Gustavo; Pezarat-Correia, Pedro

    2016-01-01

    The aim of this study was to describe and compare the EMG patterns of select lower limb muscles throughout the golf swing, performed with three different clubs, in non-elite middle-aged players. Fourteen golfers performed eight swings each using, in random order, a pitching wedge, 7-iron and 4-iron. Surface electromyography (EMG) was recorded bilaterally from lower limb muscles: tibialis anterior, peroneus longus, gastrocnemius medialis, gastrocnemius lateralis, biceps femoris, semitendinosus, gluteus maximus, vastus medialis, rectus femoris and vastus lateralis. Three-dimensional high-speed video analysis was used to determine the golf swing phases. Results showed that, in average handicap golfers, the highest muscle activation levels occurred during the Forward Swing Phase, with the right semitendinosus and the right biceps femoris muscles producing the highest mean activation levels relative to maximal electromyography (70-76% and 68-73% EMG(MAX), respectively). Significant differences between the pitching wedge and the 4-iron club were found in the activation level of the left semitendinosus, right tibialis anterior, right peroneus longus, right vastus medialis, right rectus femuris and right gastrocnemius muscles. The lower limb muscles showed, in most cases and phases, higher mean values of activation on electromyography when golfers performed shots with a 4-iron club.

  13. Lower limb muscle activation during the sit-to-stand task in subjects who have had a stroke.

    Science.gov (United States)

    Prudente, Cecília; Rodrigues-de-Paula, Fátima; Faria, Christina D C M

    2013-08-01

    The aim of this study was to compare electromyographic activities between and within the paretic and nonparetic lower limb muscles during the sit-to-stand (STS) task in subjects with hemiparesis as a result of stroke. This is a cross-sectional study. All monitored muscles of both lower limbs remained active during most of the sit-to-stand task; the muscles were activated before the seat-off and reached the maximum peak of electromyographic activity after the seat-off (P limb, the nonparetic limb exhibited earlier activation of the hamstrings (P muscles of the nonparetic lower limb (P ≥ 0.053), whereas the tibialis anterior of the paretic lower limb was activated before the hamstring and the soleus (P ≤ 0.015). These results illustrate that muscle activation of both limbs during the sit-to-stand task was impaired but in a higher level in the paretic side. Neuromuscular coordination abnormalities were observed in both lower limbs. The paretic limb was unable to recruit the muscles at the proper time and to achieve the amplitude for executing the sit-to-stand task, whereas significant compensations occurred on the nonparetic side.

  14. The effect of arm weight support on upper limb muscle synergies during reaching movements.

    Science.gov (United States)

    Coscia, Martina; Cheung, Vincent C K; Tropea, Peppino; Koenig, Alexander; Monaco, Vito; Bennis, Caoimhe; Micera, Silvestro; Bonato, Paolo

    2014-03-04

    Compensating for the effect of gravity by providing arm-weight support (WS) is a technique often utilized in the rehabilitation of patients with neurological conditions such as stroke to facilitate the performance of arm movements during therapy. Although it has been shown that, in healthy subjects as well as in stroke survivors, the use of arm WS during the performance of reaching movements leads to a general reduction, as expected, in the level of activation of upper limb muscles, the effects of different levels of WS on the characteristics of the kinematics of motion and of the activity of upper limb muscles have not been thoroughly investigated before. In this study, we systematically assessed the characteristics of the kinematics of motion and of the activity of 14 upper limb muscles in a group of 9 healthy subjects who performed 3-D arm reaching movements while provided with different levels of arm WS. We studied the hand trajectory and the trunk, shoulder, and elbow joint angular displacement trajectories for different levels of arm WS. Besides, we analyzed the amplitude of the surface electromyographic (EMG) data collected from upper limb muscles and investigated patterns of coordination via the analysis of muscle synergies. The characteristics of the kinematics of motion varied across WS conditions but did not show distinct trends with the level of arm WS. The level of activation of upper limb muscles generally decreased, as expected, with the increase in arm WS. The same eight muscle synergies were identified in all WS conditions. Their level of activation depended on the provided level of arm WS. The analysis of muscle synergies allowed us to identify a modular organization underlying the generation of arm reaching movements that appears to be invariant to the level of arm WS. The results of this study provide a normative dataset for the assessment of the effects of the level of arm WS on muscle synergies in stroke survivors and other patients who could

  15. The effect of arm weight support on upper limb muscle synergies during reaching movements

    Science.gov (United States)

    2014-01-01

    Background Compensating for the effect of gravity by providing arm-weight support (WS) is a technique often utilized in the rehabilitation of patients with neurological conditions such as stroke to facilitate the performance of arm movements during therapy. Although it has been shown that, in healthy subjects as well as in stroke survivors, the use of arm WS during the performance of reaching movements leads to a general reduction, as expected, in the level of activation of upper limb muscles, the effects of different levels of WS on the characteristics of the kinematics of motion and of the activity of upper limb muscles have not been thoroughly investigated before. Methods In this study, we systematically assessed the characteristics of the kinematics of motion and of the activity of 14 upper limb muscles in a group of 9 healthy subjects who performed 3-D arm reaching movements while provided with different levels of arm WS. We studied the hand trajectory and the trunk, shoulder, and elbow joint angular displacement trajectories for different levels of arm WS. Besides, we analyzed the amplitude of the surface electromyographic (EMG) data collected from upper limb muscles and investigated patterns of coordination via the analysis of muscle synergies. Results The characteristics of the kinematics of motion varied across WS conditions but did not show distinct trends with the level of arm WS. The level of activation of upper limb muscles generally decreased, as expected, with the increase in arm WS. The same eight muscle synergies were identified in all WS conditions. Their level of activation depended on the provided level of arm WS. Conclusions The analysis of muscle synergies allowed us to identify a modular organization underlying the generation of arm reaching movements that appears to be invariant to the level of arm WS. The results of this study provide a normative dataset for the assessment of the effects of the level of arm WS on muscle synergies in stroke

  16. A Novel AGRN Mutation Leads to Congenital Myasthenic Syndrome Only Affecting Limb-girdle Muscle

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2017-01-01

    Conclusions: This study reports a Chinese pedigree in which all three children carried the same novel AGRN mutation have CMS only affecting limb-girdle muscle. These findings might expand the spectrum of mutation in AGRN and enrich the phenotype of CMS.

  17. Relationship between lower limb muscle strength and 6-minute walk test performance in stroke patients.

    Science.gov (United States)

    Pradon, Didier; Roche, Nicolas; Enette, Lievyn; Zory, Raphaël

    2013-01-01

    The aim of this study was to determine if lower limb muscle strength and/or spasticity are related to performance in the 6-min walk test (6MWT) in stroke patients. A total of 24 patients (12 males and 12 females) participated in the study. Muscle strength (Medical Research Council (MRC) scale) and spasticity (modified Ashworth scale) were assessed prior to the 6MWT. Heart rate was recorded at rest and during the 6MWT. Subjects were divided into two groups: (i) those with a high MRC sum score, and (ii) those with a low MRC sum score. The relationship between the 6MWT distance and the other parameters was analysed using a Spearman's rank correlation coefficient. There was a significant and positive relationship between 6MWT distance and lower limb muscle strength (p = 0.001), whereas no significant correlations were found between the 6MWT distance and spasticity, resting heart rate and heart rate during the 6MWT. The 6MWT distance may be a good indicator of lower limb muscle strength, and lower limb strengthening may improve gait capacity in stroke patients.

  18. Increase in corticospinal excitability of limb and trunk muscles according to maintenance of neck flexion.

    Science.gov (United States)

    Fujiwara, Katsuo; Tomita, Hidehito; Kunita, Kenji

    2009-09-25

    The effect of maintenance of neck flexion on corticospinal excitability of limb and trunk muscles was investigated using transcranial magnetic stimulation (TMS). Nine healthy young subjects participated in this experiment. Every measurement was performed with subjects sitting on a chair. Target muscles were the first dorsal interosseous (FDI), biceps brachii (BB), triceps brachii (TB), rectus abdominis (RA), erector spinae (ES), rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius (GcM) on the right side. TMS was applied to the left primary motor cortex, and motor evoked potential (MEP) was measured from the muscles listed above. Optimal stimulus location and resting motor threshold (RMT) were identified for each target muscle, and stimulus intensity used was 120% of RMT. MEPs of the target muscle were recorded with the chin resting on a chin support (chin-on condition) with neck in 20 degrees of flexion, and with voluntary maintenance of the neck flexion posture (chin-off condition). Amplitude and latency of MEP and background activity of target muscles were analyzed. For FDI, BB, TB, ES, and RF, amplitude of MEP increased and latency shortened in the chin-off compared with the chin-on condition. No significant difference in background activity of each target muscle was found between the two conditions. Corticospinal excitability of limb and trunk muscles was selectively enhanced while neck flexion was maintained.

  19. Contribution of oxidative stress to pathology in diaphragm and limb muscles with Duchenne muscular dystrophy.

    Science.gov (United States)

    Kim, Jong-Hee; Kwak, Hyo-Bum; Thompson, LaDora V; Lawler, John M

    2013-02-01

    Duchenne muscular dystrophy (DMD) is a degenerative skeletal muscle disease that makes walking and breathing difficult. DMD is caused by an X-linked (Xp21) mutation in the dystrophin gene. Dystrophin is a scaffolding protein located in the sarcolemmal cytoskeleton, important in maintaining structural integrity and regulating muscle cell (muscle fiber) growth and repair. Dystrophin deficiency in mouse models (e.g., mdx mouse) destabilizes the interface between muscle fibers and the extracellular matrix, resulting in profound damage, inflammation, and weakness in diaphragm and limb muscles. While the link between dystrophin deficiency with inflammation and pathology is multi-factorial, elevated oxidative stress has been proposed as a central mediator. Unfortunately, the use of non-specific antioxidant scavengers in mouse and human studies has led to inconsistent results, obscuring our understanding of the importance of redox signaling in pathology of muscular dystrophy. However, recent studies with more mechanistic approaches in mdx mice suggest that NAD(P)H oxidase and nuclear factor-kappaB are important in amplifying dystrophin-deficient muscle pathology. Therefore, more targeted antioxidant therapeutics may ameliorate damage and weakness in human population, thus promoting better muscle function and quality of life. This review will focus upon the pathobiology of dystrophin deficiency in diaphragm and limb muscle primarily in mouse models, with a rationale for development of targeted therapeutic antioxidants in DMD patients.

  20. Muscle dependency of corticomuscular coherence in upper and lower limb muscles and training-related alterations in ballet dancers and weightlifters.

    Science.gov (United States)

    Ushiyama, Junichi; Takahashi, Yuji; Ushiba, Junichi

    2010-10-01

    It has been well documented that the 15- to 35-Hz oscillatory activity of the sensorimotor cortex shows coherence with the muscle activity during weak to moderate steady contraction. To investigate the muscle dependency of the corticomuscular coherence and its training-related alterations, we quantified the coherence between electroencephalogram (EEG) from the sensorimotor cortex and rectified electromyogram (EMG) from five upper limb (first dorsal interosseous, flexor carpi radialis, extensor carpi radialis, biceps brachii, triceps brachii) and four lower limb muscles (soleus, tibialis anterior, biceps femoris, rectus femoris), while maintaining a constant force level at 30% of maximal voluntary contraction of each muscle, in 24 untrained, 12 skill-trained (ballet dancers), and 10 strength-trained (weightlifters) individuals. Data from untrained subjects demonstrated the muscle dependency of corticomuscular coherence. The magnitude of the EEG-EMG coherence was significantly greater in the distally located lower limb muscles, such as the soleus and tibialis anterior, than in the upper or other lower limb muscles in untrained subjects (P muscles, according to the functional role of each muscle. In addition, the ballet dancers and weightlifters showed smaller EEG-EMG coherences than the untrained subjects, especially in the lower limb muscles (P muscles and that this neural adaptation may lead to finer control of muscle force during steady contraction.

  1. Decline in voluntary activation contributes to reduced maximal performance of fatigued human lower limb muscles.

    Science.gov (United States)

    Mileva, K N; Sumners, D P; Bowtell, J L

    2012-12-01

    In upper limb muscles, altered corticospinal excitability and reduction in neural drive are observed in parallel with peripheral fatigue during prolonged and/or repeated contractions. However, the fatigue-induced adaptations of central and peripheral elements and their relative contribution to lower limb muscle performance are yet to be fully explored. In the present study, corticospinal excitability and peripheral contractility of ankle flexor muscles were quantified before, during and after repeated brief unilateral maximal dorsiflexions to fatigue in eleven healthy volunteers. Transcranial magnetic stimulation of the motor cortex area related to lower limb muscles was performed, and the evoked twitch and EMG responses in tibialis anterior (TA) and soleus (SOL) were measured. The motor evoked potentials (MEPs) in fatigued TA during post-exercise maximal dorsiflexions were smaller (-20 ± 6 %, p = 0.026) and remained depressed for at least 5 min. Post-exercise MEPs in fatigued SOL and silent periods in TA and SOL were not different compared to pre-exercise. These changes were accompanied by lower voluntary torque (-8 ± 3 %, p = 0.013), estimated resting twitch (-36 ± 5 %, p = 0.003) and voluntary activation (-17 ± 9 %, p = 0.021) versus pre-exercise. During last versus first maximal contraction in the fatiguing protocol lower voluntary torque (-40 ± 4 %, p = 0.003), higher MEP amplitudes (>+49 %, p +24 %, p muscles. Decreased corticospinal excitability contributes significantly to the reduced maximal performance of fatigued lower limb muscles. During prolonged intermittent maximal dorsiflexions the performance of ankle muscles declines despite enhanced corticospinal excitability presumably due to deficient descending drive and/or spinal motoneuron responsiveness to the cortical drive.

  2. Heterogeneous atrophy occurs within individual lower limb muscles during 60 days of bed rest.

    Science.gov (United States)

    Miokovic, Tanja; Armbrecht, Gabriele; Felsenberg, Dieter; Belavý, Daniel L

    2012-11-01

    To better understand disuse muscle atrophy, via magnetic resonance imaging, we sequentially measured muscle cross-sectional area along the entire length of all individual muscles from the hip to ankle in nine male subjects participating in 60-day head-down tilt bed rest (2nd Berlin BedRest Study; BBR2-2). We hypothesized that individual muscles would not atrophy uniformly along their length such that different regions of an individual muscle would atrophy to different extents. This hypothesis was confirmed for the adductor magnus, vasti, lateral hamstrings, medial hamstrings, rectus femoris, medial gastrocnemius, lateral gastrocnemius, tibialis posterior, flexor hallucis longus, flexor digitorum longus, peroneals, and tibialis anterior muscles (P ≤ 0.004). In contrast, the hypothesis was not confirmed in the soleus, adductor brevis, gracilis, pectineus, and extensor digitorum longus muscles (P ≥ 0.20). The extent of atrophy only weakly correlated (r = -0.30, P muscles (P muscles recovered to their baseline size between 14 and 90 days after bed rest, but flexor hallucis longus, flexor digitorum longus, and lateral gastrocnemius required longer than 90 days before recovery occurred. On the basis of findings of differential atrophy between muscles and evidence in the literature, we interpret our findings of intramuscular atrophy to reflect differential disuse of functionally different muscle regions. The current work represents the first lower-limb wide survey of intramuscular differences in disuse atrophy. We conclude that intramuscular differential atrophy occurs in most, but not all, of the muscles of the lower limb during prolonged bed rest.

  3. Alterations in upper limb muscle synergy structure in chronic stroke survivors

    Science.gov (United States)

    Rymer, William Z.; Perreault, Eric J.; Yoo, Seng Bum; Beer, Randall F.

    2013-01-01

    Previous studies in neurologically intact subjects have shown that motor coordination can be described by task-dependent combinations of a few muscle synergies, defined here as a fixed pattern of activation across a set of muscles. Arm function in severely impaired stroke survivors is characterized by stereotypical postural and movement patterns involving the shoulder and elbow. Accordingly, we hypothesized that muscle synergy composition is altered in severely impaired stroke survivors. Using an isometric force matching protocol, we examined the spatial activation patterns of elbow and shoulder muscles in the affected arm of 10 stroke survivors (Fugl-Meyer muscle synergies were identified using non-negative matrix factorization. In both groups, muscle activation patterns could be reconstructed by combinations of a few muscle synergies (typically 4). We did not find abnormal coupling of shoulder and elbow muscles within individual muscle synergies. In stroke survivors, as in controls, two of the synergies were comprised of isolated activation of the elbow flexors and extensors. However, muscle synergies involving proximal muscles exhibited consistent alterations following stroke. Unlike controls, the anterior deltoid was coactivated with medial and posterior deltoids within the shoulder abductor/extensor synergy and the shoulder adductor/flexor synergy in stroke was dominated by activation of pectoralis major, with limited anterior deltoid activation. Recruitment of the altered shoulder muscle synergies was strongly associated with abnormal task performance. Overall, our results suggest that an impaired control of the individual deltoid heads may contribute to poststroke deficits in arm function. PMID:23155178

  4. Limb skeletal muscle adaptation in athletes after training at altitude

    DEFF Research Database (Denmark)

    Mizuno, M; Juel, C; Bro-Rasmussen, Thomas

    1990-01-01

    Morphological and biochemical characteristics of biopsies obtained from gastrocnemius (GAS) and triceps brachii muscle (TRI), as well as maximal O2 uptake (VO2 max) and O2 deficit, were determined in 10 well-trained cross-country skiers before and after a 2-wk stay (2,100 m above sea level) and t...

  5. Ambulatory Versus In-Hospital Treatment of Proximal Lower-Limb Deep Vein Thrombosis in Adults: A Retrospective Cohort Study.

    Science.gov (United States)

    Mausbach, Lisa S; Avnery, Orli; Ellis, Martin H

    2017-10-01

    Complications of deep vein thrombosis (DVT) are related to adequacy of initial anticoagulant therapy. In this study, we analyze consecutive patients with lower-limb proximal DVT and compare the characteristics, treatment, and clinical outcomes of patients receiving entirely ambulatory treatment versus those hospitalized for initial treatment. This was a retrospective study of consecutive patients with a first proximal lower-limb DVT during a 2-year period. Patients were followed for 90 days. Major end points were all-cause mortality, bleeding requiring hospitalization, and recurrent venous thromboembolism (VTE). Events were determined for patients who were hospitalized versus those treated on an entirely ambulatory basis. A total of 236 patients were included in the study. Of these, 147 patients were hospitalized and 89 patients received ambulatory treatment. There were 20 fatalities-18 in-hospital and 2 in-ambulatory patients ( P = .008). By multivariable Cox regression analysis, the presence of active cancer (hazard ratio [HR] = 5.44; confidence interval [CI]: 2.16-13.7; P = .001), age (HR = 1.06; CI: 1.02-1.1; P = .001), and hospitalization (HR = 5.73; CI: 1.33-24.69; P = .019) were associated with death. Eight hospitalized and 2 ambulatory patients required readmission because of bleeding. Age was the only variable associated with bleeding (HR = 1.10; CI: 1.03-1.18; P = .004). There were no recurrent VTE events. In this study of routine management of proximal DVT, we demonstrate that patients suitable for ambulatory care are adequately identified by physicians and may be treated with equal safety and efficacy to hospitalized patients.

  6. On the potential of lower limb muscles to accelerate the body's centre of mass during walking.

    Science.gov (United States)

    Correa, Tomas A; Pandy, Marcus G

    2013-01-01

    Quantification of lower limb muscle function during gait or other common activities may be achieved using an induced acceleration analysis, which determines the contributions of individual muscles to the accelerations of the body's centre of mass. However, this analysis is reliant on a mathematical optimisation for the distribution of net joint moments among muscles. One approach that overcomes this limitation is the calculation of a muscle's potential to accelerate the centre of mass based on either a unit-force or maximum-activation assumption. Unit-force muscle potential accelerations are determined by calculating the accelerations induced by a 1 N muscle force, whereas maximum-activation muscle potential accelerations are determined by calculating the accelerations induced by a maximally activated muscle. The aim of this study was to describe the acceleration potentials of major lower limb muscles during normal walking obtained from these two techniques, and to evaluate the results relative to absolute (optimisation-based) muscle-induced accelerations. Dynamic simulations of walking were generated for 10 able-bodied children using musculoskeletal models, and potential- and absolute induced accelerations were calculated using a perturbation method. While the potential accelerations often correctly identified the major contributors to centre-of-mass acceleration, they were noticeably different in magnitude and timing from the absolute induced accelerations. Potential induced accelerations predicted by the maximum-activation technique, which accounts for the force-generating properties of muscle, were no more consistent with absolute induced accelerations than unit-force potential accelerations. The techniques described may assist treatment decisions through quantitative analyses of common gait abnormalities and/or clinical interventions.

  7. The influence of motor cortical stimulus intensity on the relaxation rate of human lower limb muscles.

    Science.gov (United States)

    McNeil, Chris J; Bredius, Marlous S; Molenaar, Joery P; Gandevia, Simon C

    2013-07-01

    Transcranial magnetic stimulation (TMS) allows an in vivo assessment of the rate of muscle relaxation during a voluntary contraction. It is unknown if this method can be applied to lower limb muscles, and the effect of stimulus intensity on relaxation rate has not been investigated in any muscle group. The present study sought to address these unknowns. A secondary aim was to test the sensitivity of the method to a change in muscle length by comparing the relaxation rate of the plantar flexor muscles with the gastrocnemius at short and long lengths. Seven subjects performed 21 maximal voluntary isometric contractions (MVCs) of the dorsiflexors (DF) and plantar flexors with a knee angle of either 90° or 180° (PF90 and PF180, respectively). TMS intensity ranged from 40 to 100% stimulator output in intervals of 10%. Relaxation rates increased with stimulus intensity but were equivalent to maximal output at 50 (DF and PF90) or 60% (PF180). MVC torque was greater, and the rate of relaxation was faster for PF180 compared to PF90. The main findings are that TMS can be used to measure relaxation rates of lower limb muscles, and these rates are robust provided the stimulus intensity is above a critical threshold. The dependency of plantar flexor relaxation rate on the length of the fast-twitch gastrocnemius fibers reinforces published temperature and fatigue data which show that the method is sensitive to the contractile properties of the muscle fibers which are actively contributing to torque production.

  8. High-frequency submaximal stimulation over muscle evokes centrally generated forces in human upper limb skeletal muscles.

    Science.gov (United States)

    Blouin, Jean-Sébastien; Walsh, Lee D; Nickolls, Peter; Gandevia, Simon C

    2009-02-01

    Control of posture and movement requires control of the output from motoneurons. Motoneurons of human lower limb muscles exhibit sustained, submaximal activity to high-frequency electrical trains, which has been hypothesized to be partly triggered by monosynaptic Ia afferents. The possibility to trigger such behavior in upper limb motoneurons and the potential unique role of Ia afferents to trigger such behavior remain unclear. Subjects (n = 9) received high-frequency trains of electrical stimuli over biceps brachii and flexor pollicis longus (FPL). We chose to study the FPL muscle because it has weak monosynaptic Ia afferent connectivity and it is involved in fine motor control of the thumb. Two types of stimulus trains (100-Hz bursts and triangular ramps) were tested at five intensities below painful levels. All subjects exhibited enhanced torque in biceps and FPL muscles after both types of high-frequency train. Torques also persisted after stimulation, particularly for the highest stimulus intensity. To separate the evoked torques that resulted from a peripheral mechanism (e.g., muscle potentiation) and that which resulted from a central origin, we studied FPL responses to high-frequency trains after complete combined nerve blocks of the median and radial nerves (n = 2). During the blocks, high-frequency trains over the FPL did not yield torque enhancements or persisting torques. These results suggest that enhanced contractions of central origin can be elicited in motoneurons innervating the upper limb, despite weak monosynaptic Ia connections for FPL. Their presence in a recently evolved human muscle (FPL) indicates that these enhanced contractions may have a broad role in controlling tonic postural outputs of hand muscles and that they may be available even for fine motor activities involving the thumb.

  9. Prophylactic knee bracing alters lower-limb muscle forces during a double-leg drop landing.

    Science.gov (United States)

    Ewing, Katie A; Fernandez, Justin W; Begg, Rezaul K; Galea, Mary P; Lee, Peter V S

    2016-10-03

    Anterior cruciate ligament (ACL) injury can be a painful, debilitating and costly consequence of participating in sporting activities. Prophylactic knee bracing aims to reduce the number and severity of ACL injury, which commonly occurs during landing maneuvers and is more prevalent in female athletes, but a consensus on the effectiveness of prophylactic knee braces has not been established. The lower-limb muscles are believed to play an important role in stabilizing the knee joint. The purpose of this study was to investigate the changes in lower-limb muscle function with prophylactic knee bracing in male and female athletes during landing. Fifteen recreational athletes performed double-leg drop landing tasks from 0.30m and 0.60m with and without a prophylactic knee brace. Motion analysis data were used to create subject-specific musculoskeletal models in OpenSim. Static optimization was performed to calculate the lower-limb muscle forces. A linear mixed model determined that the hamstrings and vasti muscles produced significantly greater flexion and extension torques, respectively, and greater peak muscle forces with bracing. No differences in the timings of peak muscle forces were observed. These findings suggest that prophylactic knee bracing may help to provide stability to the knee joint by increasing the active stiffness of the hamstrings and vasti muscles later in the landing phase rather than by altering the timing of muscle forces. Further studies are necessary to quantify whether prophylactic knee bracing can reduce the load placed on the ACL during intense dynamic movements. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Single-fiber electromyography of facial and limb muscles in diabetic patients with or without neuropathy.

    Science.gov (United States)

    Al-Hashel, Jasem Y; Rousseff, Rossen T; Khuraibet, Adnan J; Tzvetanov, Plamen

    2014-10-01

    In diabetic patients, single-fiber electromyography (SFEMG) is often abnormal in the limb muscles and is considered unreliable in diagnosis of synaptic disorders. We aimed to compare SFEMG abnormalities of frontalis muscle (FM) and extensor digitorum communis muscle in diabetic patients with neuropathy and without neuropathy. Stimulation SFEMG of FM and extensor digitorum communis muscle was performed in matched groups of 30 diabetic patients with neuropathy and 20 diabetic patients without neuropathy. Single-fiber electromyography in the FM was abnormal in four diabetic patients with neuropathy and in one diabetic patient without neuropathy. Changes were rather mild. Extensor digitorum communis abnormalities were significantly more frequent-in 20 diabetic patients with neuropathy and in 7 diabetic patients without neuropathy (P diabetes, FM exhibits rare and quite mild SFEMG changes. This muscle may be suitable for SFEMG in diabetic patients with clinical suspicion for synaptic disorder.

  11. An Official American Thoracic Society/European Respiratory Society Statement: Update on Limb Muscle Dysfunction in Chronic Obstructive Pulmonary Disease

    Science.gov (United States)

    Maltais, François; Decramer, Marc; Casaburi, Richard; Barreiro, Esther; Burelle, Yan; Debigaré, Richard; Dekhuijzen, P. N. Richard; Franssen, Frits; Gayan-Ramirez, Ghislaine; Gea, Joaquim; Gosker, Harry R.; Gosselink, Rik; Hayot, Maurice; Hussain, Sabah N. A.; Janssens, Wim; Polkey, Micheal I.; Roca, Josep; Saey, Didier; Schols, Annemie M. W. J.; Spruit, Martijn A.; Steiner, Michael; Taivassalo, Tanja; Troosters, Thierry; Vogiatzis, Ioannis; Wagner, Peter D.

    2014-01-01

    Background: Limb muscle dysfunction is prevalent in chronic obstructive pulmonary disease (COPD) and it has important clinical implications, such as reduced exercise tolerance, quality of life, and even survival. Since the previous American Thoracic Society/European Respiratory Society (ATS/ERS) statement on limb muscle dysfunction, important progress has been made on the characterization of this problem and on our understanding of its pathophysiology and clinical implications. Purpose: The purpose of this document is to update the 1999 ATS/ERS statement on limb muscle dysfunction in COPD. Methods: An interdisciplinary committee of experts from the ATS and ERS Pulmonary Rehabilitation and Clinical Problems assemblies determined that the scope of this document should be limited to limb muscles. Committee members conducted focused reviews of the literature on several topics. A librarian also performed a literature search. An ATS methodologist provided advice to the committee, ensuring that the methodological approach was consistent with ATS standards. Results: We identified important advances in our understanding of the extent and nature of the structural alterations in limb muscles in patients with COPD. Since the last update, landmark studies were published on the mechanisms of development of limb muscle dysfunction in COPD and on the treatment of this condition. We now have a better understanding of the clinical implications of limb muscle dysfunction. Although exercise training is the most potent intervention to address this condition, other therapies, such as neuromuscular electrical stimulation, are emerging. Assessment of limb muscle function can identify patients who are at increased risk of poor clinical outcomes, such as exercise intolerance and premature mortality. Conclusions: Limb muscle dysfunction is a key systemic consequence of COPD. However, there are still important gaps in our knowledge about the mechanisms of development of this problem

  12. Effects of isometric muscle training on residual limb volume, strength, and gait of below-knee amputees.

    Science.gov (United States)

    Kegel, B; Burgess, E M; Starr, T W; Daly, W K

    1981-10-01

    This study was undertaken to determine if prosthetic suspension capabilities of below-knee amputees could be improved by using biofeedback in a controlled exercise program. Improvements in muscle bulk of four amputees were assessed. Changes in transverse cross-sectional areas and suspension ability of the residual limb were measured. The effect of muscle training on gait and on muscle-use patterns during gait was observed. Marked increases in muscle bulk below the knee and improvement in suspension capabilities were seen in two of the subjects, and somewhat lesser improvements were seen in the remaining two subjects. From these changes, one could modify prosthetic designs to take advantage of the residual limb muscles for suspension. For this reason, training the below-knee amputee to exercise the residual limb musculature should become part of routine physical therapy management. In this study, biofeedback was proven to be a useful tool for the reeducation of the residual limb musculature.

  13. Mitochondrial dysfunction and therapeutic approaches in respiratory and limb muscles of cancer cachectic mice.

    Science.gov (United States)

    Fermoselle, Clara; García-Arumí, Elena; Puig-Vilanova, Ester; Andreu, Antoni L; Urtreger, Alejandro J; de Kier Joffé, Elisa D Bal; Tejedor, Alberto; Puente-Maestu, Luís; Barreiro, Esther

    2013-09-01

    What is the central question of this study? We explored whether experimental cancer-induced cachexia may alter mitochondrial respiratory chain (MRC) complexes and oxygen uptake in respiratory and peripheral muscles,and whether signalling pathways, proteasome and oxidative stress influence that process. What is the main finding and what is its importance? In cancer cachectic mice, MRC complexes and oxygen consumption were decreased in the diaphragm and gastrocnemius. Blockade of nuclear factor-κB and mitogen-activated protein kinase actions partly restored the muscle mass and force and corrected the MRC dysfunction,while concomitantly reducing tumour burden. Antioxidants improved mitochondrial oxygen consumption without eliciting effects on the loss of muscle mass and force or the tumour size,whereas bortezomib reduced tumour burden without influencing muscle mass and strength or MRC function. Abnormalities in mitochondrial content, morphology and function have been reported in several muscle-wasting conditions. We specifically explored whether experimental cancer-induced cachexia may alter mitochondrial respiratory chain (MRC) complexes and oxygen uptake in respiratory and peripheral muscles, and whether signalling pathways, proteasomes and oxidative stress may influence that process. We evaluated complex I, II and IV enzyme activities (specific activity assays) and MRC oxygen consumption (polarographic measurements) in diaphragm and gastrocnemius of cachectic mice bearing the LP07 lung tumour, with and without treatment with N-acetylcysteine, bortezomib and nuclear factor-κB (sulfasalazine) and mitogen-activated protein kinases (MAPK, U0126) inhibitors (n = 10 per group for all groups). Whole-body and muscle weights and limb muscle force were also assessed in all rodents at baseline and after 1 month. Compared with control animals, cancer cachectic mice showed a significant reduction in body weight gain, smaller sizes of the diaphragm and gastrocnemius, lower

  14. Gene expression reveals evidence for EGFR-dependent proximal-distal limb patterning in a myriapod.

    Science.gov (United States)

    Janssen, Ralf

    2017-05-01

    Evolution of segmented limbs is one of the key innovations of Arthropoda, allowing development of functionally specific specialized head and trunk appendages, a major factor behind their unmatched evolutionary success. Proximodistal limb patterning is controlled by two regulatory networks in the vinegar fly Drosophila melanogaster, and other insects. The first is represented by the function of the morphogens Wingless (Wg) and Decapentaplegic (Dpp); the second by the EGFR-signaling cascade. While the role of Wg and Dpp has been studied in a wide range of arthropods representing all main branches, that is, Pancrustacea (= Hexapoda + Crustacea), Myriapoda and Chelicerata, investigation of the potential role of EGFR-signaling is restricted to insects (Hexapoda). Gene expression analysis of Egfr, its potential ligands, and putative downstream factors in the pill millipede Glomeris marginata (Myriapoda: Diplopoda), reveals that-in at least mandibulate arthropods-EGFR-signaling is likely a conserved regulatory mechanism in proximodistal limb patterning. © 2017 The Authors. Evolution and Development Published by Wiley Periodicals, Inc.

  15. Age-related alterations in the activation of trunk and lower limb muscles during walking.

    Science.gov (United States)

    Marques, Nise Ribeiro; Hallal, Camilla Zamfolini; Spinoso, Deborah Hebling; Crozara, Luciano Fernandez; Morcelli, Mary Hellen; Karuka, Aline Harumi; Navega, Marcelo Tavella; Gonçalves, Mauro

    2016-04-27

    Walking is a complex motor task that requires an integrated coordination of the trunk, lower limb, and upper limb movements. Previously, few studies have investigated the activation pattern of trunk muscles during walking. However, the mechanisms by how aging affects the recruitment of trunk muscles during walking remain unclear. The present study aimed to compare the activation of trunk and lower limb muscles during walking in younger and older women. Fifteen younger women between 18 and 30 yr and 19 older women between 60-82 yr walked on the treadmill at a self-selected speed, while 1-min surface electromyography (EMG) signals were recorded from the multifidus, internal oblique, gluteus maximus, rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius lateralis. EMG signals were processed and a linear envelope was calculated at an initial stance (50 ms after heel contact) and final stance (50 ms before toe-off). Compared with younger women, older women had 52.32% lower activation of the internal oblique (p = 0.027) and 39.95% lower activation of the rectus femoris (p = 0.003) at initial stance. Results of this study demonstrated that older women had lower activation of trunk and knee muscles during the initial stance, which may have resulted from weakness and balance impairments caused by aging.

  16. The role of the biarticular hamstrings and gastrocnemius muscles in closed chain lower limb extension.

    Science.gov (United States)

    Cleather, Daniel J; Southgate, Dominic F L; Bull, Anthony M J

    2015-01-21

    The role of the biarticular muscles is a topic that has received considerable attention however their function is not well understood. In this paper, we argue that an analysis that is based upon considering the effect of the biarticular muscles on the segments that they span (rather than their effect on joint rotations) can be illuminating. We demonstrate that this understanding is predicated on a consideration of the relative sizes of the moment arms of a biarticular muscle about the two joints that it crosses. The weight of the previous literature suggests that the moment arms of both the biarticular hamstrings and gastrocnemius are smaller at the knee than at the hip or ankle, (respectively). This in turn leads to the conclusion that both biarticular hamstrings and gastrocnemius are extensors of the lower limb. We show that the existence of these biarticular structures lends a degree of flexibility to the motor control strategies available for lower limb extension. In particular, the role of the gastrocnemius and biarticular hamstrings in permitting a large involvement of the quadriceps musculature in closed chain lower limb extension may be more important than is typically portrayed. Finally, the analysis presented in this paper demonstrates the importance of considering the effects of muscles on the body as a whole, not just on the joints they span. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Relationships between Lower Limb Muscle Strength and Locomotor Capacity in Children and Adolescents with Cerebral Palsy Who Walk Independently

    Science.gov (United States)

    Ferland, Chantale; Lepage, Celine; Moffet, Helene; Maltais, Desiree B.

    2012-01-01

    This study aimed to quantify relationships between lower limb muscle strength and locomotor capacity for children and adolescents with cerebral palsy (CP) to identify key muscle groups for strength training. Fifty 6- to 16-year-olds with CP (Gross Motor Function Classification System level I or II) participated. Isometric muscle strength of hip…

  18. Effect of Changes in Cycle Ergometer Settings on Bioelectrical Activity in Selected Muscles of the Lower Limbs

    Directory of Open Access Journals (Sweden)

    Staszkiewicz Robert

    2017-12-01

    Full Text Available Introduction. The aim of this study was to measure the duration of biopotentials in selected muscles of the lower limbs, evaluate the time of elevated bioelectrical activity in these muscles, and identify similarities and differences in electrical phenomena that occur in the muscles for various external settings of a cycle ergometer.

  19. The Activation Pattern of Trunk and Lower Limb Muscles in an Electromyographic Assessment; Comparison Between Ground and Treadmill Walking.

    Science.gov (United States)

    Mazaheri, Reza; Sanjari, Mohammad Ali; Radmehr, Gelareh; Halabchi, Farzin; Angoorani, Hooman

    2016-09-01

    Due to biomechanical differences, various patterns of muscle contraction are expected to occur while walking over ground versus when walking on a treadmill. This study aimed to compare amplitude and duration of activation of selected trunk and lower extremity muscles during over-ground and treadmill walking. Through a simple sampling method, 19 sedentary healthy men within the age range of 20 - 40 were selected. Surface electromyography of rectus abdominis, external oblique, longissimus and multifidus muscles as the selected trunk muscles and vastus medialis, vastus lateralis and hamstrings as the selected lower limb muscles were recorded. In each gait cycle, there were no statistically significant differences in duration of selected trunk as well as lower limb muscles activity between treadmill and over-ground walking. However the mean amplitude of rectus abdominis (P = 0.005), longissimus (P = 0.018) and multifidus (P = 0.044) as the selected trunk muscles as well as the mean amplitude of vastus lateralis (P = 0.005) and vastus medialis (P lower limb muscles was greater on treadmill compared with over ground. Due to the stabilizing role of trunk and lower limb muscles during walking, these muscles seem to be active throughout the entire gait cycle. The increased muscle amplitude on treadmill can demonstrate that more motor units may be recruited during the contraction, which can be helpful in prescribing the appropriate type of exercise especially for patients with core muscle weakness.

  20. Convergent evidence for construct validity of a 7-point likert scale of lower limb muscle soreness.

    Science.gov (United States)

    Impellizzeri, Franco M; Maffiuletti, Nicola A

    2007-11-01

    The aim of this study was to examine the construct validity of the 7-point Likert scale of muscle soreness, assessing its relationship with Visual Analogue Scale (VAS). An additional aim was to examine its sensitivity as measure of symptom of eccentric-contraction muscle damage. Correlational study. Self-administered questionnaires collected in field setting. Twenty-six soccer players. 4-week preseason training camp, which included high-intensity plyometric training sessions. Players self-reported the perceived muscle soreness of the lower limbs using the VAS (criterion measure) and the 7-point Likert scale of muscle soreness. Significant individual correlations were found between the 2 muscle soreness scales (mean r=0.80+/-0.07; range, 0.65 to 0.94). The correlation using the pooled data was 0.81. No significant muscle soreness scale x time interaction was found for standardized measures of muscle soreness (P=0.98). The main factor for time (24, 48, 72, and 96 hours after the first plyometric training session) was significant (P=0.0001). Effect sizes for the changes in the Likert and VAS absolute scores during the first 96 hours were similar (partial eta=0.13). The results of this study provide further convergent evidence for the construct validity of the 7-point Likert scale of muscle soreness. The 2 scales showed similar sensitivity to muscle soreness caused by eccentric contractions during the first 96 hours after plyometric exercises.

  1. Macroscopic description of the limb muscles of Tupinambis merianae

    Directory of Open Access Journals (Sweden)

    Juliana Barbosa Casals

    2012-03-01

    Full Text Available Tegu lizard (Tupinambis merianae belongs to the Teiidae family. It is distributed throughout the Americas, with many species, including Brazilian ones. They are from the Tupinambis genus, the largest representatives of the Teiidae family. For this study three animals (run over coming from donation were used. The dissected lizards were fixed in 10%, formaldehyde, and the macroscopic analysis was carried out in a detailed and photo documented way, keeping the selected structures “in situ”. This paper had as its main aim contributing to the macroscopic description of the chest myology, as well as the thoracic and pelvic limbs of the lizard T. merianae. The results obtained from this research were compared to authors who have studied animals from the same Reptilia class. Thus, we conclude that our macroscopic results are similar to those already described by the researchers Hildebrand (1995, Moro and Abdala (2004 and Abdala and Diogo (2010. We should highlight that the knowledge on anatomy has importance and applications to various areas within Biology, contributing in a substantial way to the areas of human health and technology.

  2. A comparison of the moment arms of pelvic limb muscles in horses bred for acceleration (Quarter Horse) and endurance (Arab).

    Science.gov (United States)

    Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wilson, A M; Hodson-Tole, E; Payne, R C

    2010-07-01

    Selective breeding for performance has resulted in distinct breeds of horse, such as the Quarter Horse (bred for acceleration) and the Arab (bred for endurance). Rapid acceleration, seen during Quarter Horse racing, requires fast powerful muscular contraction and the generation of large joint torques, particularly by the hind limb muscles. This study compared hind limb moment arm lengths in the Quarter Horse and Arab. We hypothesized that Quarter Horse hind limb extensor muscles would have longer moment arms when compared to the Arab, conferring a greater potential for torque generation at the hip, stifle and tarsus during limb extension. Six Quarter Horse and six Arab hind limbs were dissected to determine muscle moment arm lengths for the following muscles: gluteus medius, biceps femoris, semitendinosus, vastus lateralis, gastrocnemius (medialis and lateralis) and tibialis cranialis. The moment arms of biceps femoris (acting at the hip) and gastrocnemius lateralis (acting at the stifle) were significantly longer in the Quarter Horse, although the length of the remaining muscle moment arms were similar in both breeds of horse. All the Quarter Horse muscles were capable of generating greater muscle moments owing to their greater physiological cross-sectional area (PCSA) and therefore greater isometric force potential, which suggests that PCSA is a better determinant of muscle torque than moment arm length in these two breeds of horse. With the exception of gastrocnemius and tibialis cranialis, the observed muscle fascicle length to moment arm ratio (MFL : MA ratio) was greater for the Arab horse muscles. It appears that the Arab muscles have the potential to operate at slower velocities of contraction and hence generate greater force outputs when compared to the Quarter Horse muscles working over a similar range of joint motion; this would indicate that Arab hind limb muscles are optimized to function at maximum economy rather than maximum power output.

  3. An analysis on muscle tone of lower limb muscles on flexible flat foot.

    Science.gov (United States)

    Um, Gi-Mai; Wang, Joong-San; Park, Si-Eun

    2015-10-01

    [Purpose] The aim of this study was to examine differences in the muscle tone and stiffness of leg muscles according to types of flexible flat foot. [Subjects and Methods] For 30 subjects 10 in a normal foot group (NFG), 10 in group with both flexible flat feet (BFFG), and 10 in a group with flexible flat feet on one side (OFFG), myotonometry was used to measure the muscle tone and stiffness of the tibialis anterior muscle (TA), the rectus femoris muscle (RF), the medial gastrocnemius (MG), and the long head of the biceps femoris muscle (BF) of both lower extremities. [Results] In the measurement results, only the stiffness of TA and MG of the NFG and the BFFG showed significant differences. The muscle tone and stiffness were highest in the BFFG, followed by the OFFG and NFG, although the difference was insignificant. In the case of the OFFG, there was no significant difference in muscle tone and stiffness compared to that in the NGF and the BFFG. Furthermore, in the NFG, the non-dominant leg showed greater muscle tone and stiffness than the dominant leg, although the difference was insignificant. [Conclusion] During the relax condition, the flexible flat foot generally showed a greater muscle tone and stiffness of both lower extremities compared to the normal foot. The stiffness was particularly higher in the TA and MG muscles. Therefore, the muscle tone and stiffness of the lower extremity muscles must be considered in the treatment of flat foot.

  4. Effects of 5 weeks of lower limb suspension on muscle size and strength

    Science.gov (United States)

    Tesch, P. A.; Ploutz, L. L.; Dudley, G. A.

    1994-01-01

    Lack of weight-bearing, as occurs in space, appears to be associated with reductions in strength and mass of skeletal muscle. Very limited data, however, is at hand describing changes in skeletal muscle size and function following manned space missions. Our current knowledge therefore is mainly based on studies of space flown rats. It is obvious though that this information, only in part can be extrapolated to humans. A few bed rest studies have demonstrated that decreases in strength and muscle size are substantial. At this time, however, the magnitude or time course of such changes either in response to space flight or simulations of microgravity have not been defined. In the last few years we have employed a human model to simulate unloading of lower limb skeletal muscles that occurs in microgravity. This model was essentially adopted from the rat hindlimb suspension technique. The purpose of this study was to assess the magnitude of decreases in muscle strength and size as a result of five weeks of unilateral lower limb suspension.

  5. Effects of fatigue on lower limb, pelvis and trunk kinematics and muscle activation: Gender differences.

    Science.gov (United States)

    Lessi, Giovanna Camparis; Dos Santos, Ana Flávia; Batista, Luis Fylipe; de Oliveira, Gabriela Clemente; Serrão, Fábio Viadanna

    2017-02-01

    Muscle fatigue is associated with biomechanical changes that may lead to anterior cruciate ligament (ACL) injuries. Alterations in trunk and pelvis kinematics may also be involved in ACL injury. Although some studies have compared the effects of muscle fatigue on lower limb kinematics between men and women, little is known about its effects on pelvis and trunk kinematics. The aim of the study was to compare the effects of fatigue on lower limb, pelvis and trunk kinematics and muscle activation between men and women during landing. The participants included forty healthy subjects. We performed kinematic analysis of the trunk, pelvis, hip and knee and muscle activation analysis of the gluteal muscles, vastus lateralis and biceps femoris, during a single-leg landing before and after fatigue. Men had greater trunk flexion than women after fatigue. After fatigue, a decrease in peak knee flexion and an increase in Gmax and BF activation were observed. The increase in the trunk flexion can decrease the anterior tibiofemoral shear force resulted from the lower knee flexion angle, thereby decreasing the stress on the ACL. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The effect of arm weight support on upper limb muscle synergies during reaching movements

    OpenAIRE

    Coscia, Martina; Cheung, Vincent CK; Tropea, Peppino; Koenig, Alexander; Monaco, Vito; Bennis, Caoimhe; Micera, Silvestro; Bonato, Paolo

    2013-01-01

    Background: Compensating for the effect of gravity by providing arm-weight support (WS) is a technique often utilized in the rehabilitation of patients with neurological conditions such as stroke to facilitate the performance of arm movements during therapy. Although it has been shown that, in healthy subjects as well as in stroke survivors, the use of arm WS during the performance of reaching movements leads to a general reduction, as expected, in the level of activation of upper limb muscle...

  7. EMG threshold determination in eight lower limb muscles during cycling exercise: A pilot study

    OpenAIRE

    Hug, François; Laplaud, David; Lucía Mulas, Alejandro; Grelot, Laurent

    2006-01-01

    The first aim of this study was to verify the occurrence of the EMG threshold (EMG (Th)) in each of eight lower limb muscles (vastus lateralis [VL], vatus medialis [VM], rectus femoris [RF], semimembranosus [SM], biceps femoris [BF], gastrocnemius lateralis [GL] and medialis [GM], and tibialis anterior [TA]) during incremental cycling exercise. The second aim was to investigate the test-retest reproducibility of the EMG (Th) occurrence. Six sedentary male subjects (27 +/- 1 years) performed t...

  8. Methods for Dynamic Characterization of the Major Muscles Activating the Lower Limb Joints in Cycling Motion.

    Science.gov (United States)

    Roth, Navit; Wiener, Avi; Mizrahi, Joseph

    2014-09-23

    The functional activation, through electrical stimulation, of the lower limb consisting of several deficient muscles requires well-patterned and coordinated activation of these muscles. This study presents a method for characterizing the parameters of the major muscle groups controlling the ankle and knee joints in cycling motion, the latter having particular significance in the rehabilitation of locomotion. To lower mechanical indeterminacy in the joints the system is reduced by grouping the muscles acting in synergism. The joint torques were calculated by inverse dynamics methods from cycling motion data, including kinematics and foot/pedal reaction loads (forces, moments). The mechanical indeterminacy was resolved by applying optimization criteria and the individual muscle torques were parceled-out from the joint torques. System identification of the individual muscles, part of which being bi-articular, in this non-isometric condition was performed from the relationship between the evaluated force and the measured EMG of each the muscles, using both first and second order linear transfer functions. Feasibility of the presented method was demonstrated through the computation of the coefficients of the muscles involved and validating the results on the experimental data obtained from one subject.

  9. Methods for dynamic characterization of the major muscles activating the lower limb joints in cycling motion

    Directory of Open Access Journals (Sweden)

    Navit Roth

    2014-09-01

    Full Text Available The functional activation, through electrical stimulation, of the lower limb consisting of several deficient muscles requires well-patterned and coordinated activation of these muscles. This study presents a method for characterizing the parameters of the major muscle groups controlling the ankle and knee joints in cycling motion, the latter having particular significance in the rehabilitation of locomotion. To lower mechanical indeterminacy in the joints the system is reduced by grouping the muscles acting in synergism. The joint torques were calculated by inverse dynamics methods from cycling motion data, including kinematics and foot/pedal reaction loads (forces, moments. The mechanical indeterminacy was resolved by applying optimization criteria and the individual muscle torques were parceled-out from the joint torques. System identification of the individual muscles, part of which being bi-articular, in this non-isometric condition was performed from the relationship between the evaluated force and the measured EMG of each the muscles, using both first and second order linear transfer functions. Feasibility of the presented method was demonstrated through the computation of the coefficients of the muscles involved and validating the results on the experimental data obtained from one subject.

  10. Methods for dynamic characterization of the major muscles activating the lower limb joints in cycling motion

    Directory of Open Access Journals (Sweden)

    Navit Roth

    2014-04-01

    Full Text Available The functional activation, through electrical stimulation, of the lower limb consisting of several deficient muscles requires well-patterned and coordinated activation of these muscles. This study presents a method for characterizing the parameters of the major muscle groups controlling the ankle and knee joints in cycling motion, the latter having particular significance in the rehabilitation of locomotion. To lower mechanical indeterminacy in the joints the system is reduced by grouping the muscles acting in synergism. The joint torques were calculated by inverse dynamics methods from cycling motion data, including kinematics and foot/pedal reaction loads (forces, moments. The mechanical indeterminacy was resolved by applying optimization criteria and the individual muscle torques were parceled-out from the joint torques. System identification of the individual muscles, part of which being bi-articular, in this non-isometric condition was performed from the relationship between the evaluated force and the measured EMG of each the muscles, using both first and second order linear transfer functions. Feasibility of the presented method was demonstrated through the computation of the coefficients of the muscles involved and validating the results on the experimental data obtained from one subject.

  11. Associations Between Individual Lower-Limb Muscle Volumes and 100-m Sprint Time in Male Sprinters.

    Science.gov (United States)

    Sugisaki, Norihide; Kobayashi, Kai; Tsuchie, Hiroyasu; Kanehisa, Hiroaki

    2018-02-13

    To elucidate the relationship between the muscularity of individual lower-limb muscles and 100-m-race time (t 100 ) in young-adult male sprinters. Thirty-one young-adult male sprinters took part in this study (age 19.9 ± 1.4 y, height 173.5 ± 4.6 cm, body mass 67.0 ± 4.9 kg, t 100 10.23-11.71 s). Cross-sectional images from the origin to insertion of 12 lower-limb muscles were obtained with via magnetic resonance imaging (MRI). The absolute volume of each muscle, the ratio of total volume of measured muscles to body mass, the ratio of individual muscle volume to body mass, and the ratio between 2 individual muscle volumes were calculated as indices of muscularity using the images. A stepwise multiple-regression analysis was performed to examine the association between the indices and t 100 . A stepwise multiple-regression analysis produced an equation (adjusted R 2  = .234) with the gluteus maximus-to-quadriceps femoris muscle-volume ratio (β = -0.509, P = .003) as the explanatory variable. Individual differences in 100-m-race performance cannot be explained by the muscularity of specific muscles, and 23% of the variability in the performance can be explained by the relative difference between the muscularity of gluteus maximus and quadriceps femoris; faster runners have a greater gluteus maximus relative to quadriceps femoris.

  12. Upper limb cortical maps in amputees with targeted muscle and sensory reinnervation.

    Science.gov (United States)

    Serino, Andrea; Akselrod, Michel; Salomon, Roy; Martuzzi, Roberto; Blefari, Maria Laura; Canzoneri, Elisa; Rognini, Giulio; van der Zwaag, Wietske; Iakova, Maria; Luthi, François; Amoresano, Amedeo; Kuiken, Todd; Blanke, Olaf

    2017-11-01

    Neuroprosthetics research in amputee patients aims at developing new prostheses that move and feel like real limbs. Targeted muscle and sensory reinnervation (TMSR) is such an approach and consists of rerouting motor and sensory nerves from the residual limb towards intact muscles and skin regions. Movement of the myoelectric prosthesis is enabled via decoded electromyography activity from reinnervated muscles and touch sensation on the missing limb is enabled by stimulation of the reinnervated skin areas. Here we ask whether and how motor control and redirected somatosensory stimulation provided via TMSR affected the maps of the upper limb in primary motor (M1) and primary somatosensory (S1) cortex, as well as their functional connections. To this aim, we tested three TMSR patients and investigated the extent, strength, and topographical organization of the missing limb and several control body regions in M1 and S1 at ultra high-field (7 T) functional magnetic resonance imaging. Additionally, we analysed the functional connectivity between M1 and S1 and of both these regions with fronto-parietal regions, known to be important for multisensory upper limb processing. These data were compared with those of control amputee patients (n = 6) and healthy controls (n = 12). We found that M1 maps of the amputated limb in TMSR patients were similar in terms of extent, strength, and topography to healthy controls and different from non-TMSR patients. S1 maps of TMSR patients were also more similar to normal conditions in terms of topographical organization and extent, as compared to non-targeted muscle and sensory reinnervation patients, but weaker in activation strength compared to healthy controls. Functional connectivity in TMSR patients between upper limb maps in M1 and S1 was comparable with healthy controls, while being reduced in non-TMSR patients. However, connectivity was reduced between S1 and fronto-parietal regions, in both the TMSR and non-TMSR patients with

  13. Moment arms and lengths of human upper limb muscles as functions of joint angles.

    Science.gov (United States)

    Pigeon, P; Yahia, L; Feldman, A G

    1996-10-01

    Modeling of musculoskeletal structures requires accurate data on anatomical parameters such as muscle lengths (MLs), moment arms (MAs) and those describing the upper limb position. Using a geometrical model of planar arm movements with three degrees of freedom, we present, in an analytical form, the available information on the relationship between MAs and MLs and joint angles for thirteen human upper limb muscles. The degrees of freedom included are shoulder flexion/extension, elbow flexion/extension, and either wrist flexion/extension (the forearm in supination) or radial/ulnar deviation (the forearm in mid-pronation). Previously published MA/angle curves were approximated by polynomials. ML/angle curves were obtained by combining the constant values of MLs (defined by the distance between the origin and insertion points for a specific upper limb position) with a variable part obtained by multiplying the MA (joint radius) and the joint angle. The MAs of the prime wrist movers in radial/ulnar deviation were linear functions of the joint angle (R2 > or = 0.9954), while quadratic polynomials accurately described their MAs during wrist flexion/extensions. The relationship between MAs and the elbow angle was described by 2nd, 3rd or 5th-order polynomials (R2 > or = 0.9904), with a lesser quality of fit for the anconeus (R2 = 0.9349). In the full range of angular displacements, the length of wrist, elbow and shoulder muscles can change by 8.5, 55 and 200%, respectively.

  14. Effects of an Uphill Marathon on Running Mechanics and Lower-Limb Muscle Fatigue.

    Science.gov (United States)

    Giovanelli, Nicola; Taboga, Paolo; Rejc, Enrico; Simunic, Bostjan; Antonutto, Guglielmo; Lazzer, Stefano

    2016-05-01

    To investigate the effects of an uphill marathon (43 km, 3063-m elevation gain) on running mechanics and neuromuscular fatigue in lower-limb muscles. Maximal mechanical power of lower limbs (MMP), temporal tensiomyographic (TMG) parameters, and muscle-belly displacement (Dm) were determined in the vastus lateralis muscle before and after the competition in 18 runners (age 42.8 ± 9.9 y, body mass 70.1 ± 7.3 kg, maximal oxygen uptake 55.5 ± 7.5 mL · kg-1 · min-1). Contact (tc) and aerial (ta) times, step frequency (f), and running velocity (v) were measured at 3, 14, and 30 km and after the finish line (POST). Peak vertical ground-reaction force (Fmax), vertical displacement of the center of mass (Δz), leg-length change (ΔL), and vertical (kvert) and leg (kleg) stiffness were calculated. MMP was inversely related with race time (r = -.56, P = .016), tc (r = -.61, P = .008), and Δz (r = -.57, P = .012) and directly related with Fmax (r = .59, P = .010), ta (r = .48, P = .040), and kvert (r = .51, P = .027). In the fastest subgroup (n = 9) the following parameters were lower in POST (P running mechanics induced by fatigue. Thus, lower-limb power training could improve running performance in uphill marathons.

  15. Effects of cross-education on the muscle after a period of unilateral limb immobilization using a shoulder sling and swathe

    National Research Council Canada - National Science Library

    Charlene R. A. Magnus; Trevor S. Barss; Joel L. Lanovaz; Jonathan P. Farthing

    2010-01-01

    The purpose of this study was to apply cross-education during 4 wk of unilateral limb immobilization using a shoulder sling and swathe to investigate the effects on muscle strength, muscle size, and muscle activation...

  16. Investigation of the Intra- and Inter-Limb Muscle Coordination of Hands-and-Knees Crawling in Human Adults by Means of Muscle Synergy Analysis

    Directory of Open Access Journals (Sweden)

    Xiang Chen

    2017-05-01

    Full Text Available To investigate the intra- and inter-limb muscle coordination mechanism of human hands-and-knees crawling by means of muscle synergy analysis, surface electromyographic (sEMG signals of 20 human adults were collected bilaterally from 32 limb related muscles during crawling with hands and knees at different speeds. The nonnegative matrix factorization (NMF algorithm was exerted on each limb to extract muscle synergies. The results showed that intra-limb coordination was relatively stable during human hands-and-knees crawling. Two synergies, one relating to the stance phase and the other relating to the swing phase, could be extracted from each limb during a crawling cycle. Synergy structures during different speeds kept good consistency, but the recruitment levels, durations, and phases of muscle synergies were adjusted to adapt the change of crawling speed. Furthermore, the ipsilateral phase lag (IPL value which was used to depict the inter-limb coordination changed with crawling speed for most subjects, and subjects using the no-limb-pairing mode at low speed tended to adopt the trot-like mode or pace-like mode at high speed. The research results could be well explained by the two-level central pattern generator (CPG model consisting of a half-center rhythm generator (RG and a pattern formation (PF circuit. This study sheds light on the underlying control mechanism of human crawling.

  17. Potential of lower-limb muscles to accelerate the body during cerebral palsy gait.

    Science.gov (United States)

    Correa, Tomas A; Schache, Anthony G; Graham, H Kerr; Baker, Richard; Thomason, Pam; Pandy, Marcus G

    2012-06-01

    Two of the most common gait patterns in children with spastic diplegic cerebral palsy (CP) are termed 'crouch gait' and 'jump gait'. While outcomes of surgical interventions designed to improve functional mobility are generally positive, many children displaying these gait patterns show minimal or no improvement post-surgery. A poor response to treatment may be partially attributable to incorrect interpretations of muscle function. Computational techniques that assess muscle function may help address this issue, but before studying specific surgeries, the gait patterns themselves must be better understood. The aim of this study was to identify differences in lower-limb muscle function when comparing crouch, jump and able-bodied gait patterns by quantifying the potential of lower-limb muscles to accelerate the body's center of mass. A muscle's potential acceleration was defined as the acceleration induced by a unit of muscle force. Dynamic simulations of walking using musculoskeletal models were developed for eight children with crouch gait, ten with jump gait, and ten controls. There were significant differences (pmuscle potential accelerations between crouch and able-bodied gait patterns, and between jump and able-bodied gait patterns, for most of the major muscles of the hip, knee, and ankle. One important outcome was the identification of the significantly reduced potential of gluteus medius to extend the hip in both crouch gait and jump gait. Potential acceleration analyses appear to be suitable for evaluating differences between common gait patterns and may also be applied to study the effects of surgical treatments. The results of such studies may lead to improved treatment outcomes for individuals with impaired mobility. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Effect of abdominal bracing training on strength and power of trunk and lower limb muscles.

    Science.gov (United States)

    Tayashiki, Kota; Maeo, Sumiaki; Usui, Seiji; Miyamoto, Naokazu; Kanehisa, Hiroaki

    2016-09-01

    It is unknown whether maximal voluntary co-contraction of abdominal muscles, called abdominal bracing, can be a training maneuver for improving strength and power of trunk and lower limb muscles. The present study aimed to elucidate this. Twenty young adult men (23.3 ± 1.8 years) were allocated to training (TG, n = 11) or control (CG, n = 9) group. TG conducted an 8-week training program (3 days/week) consisting of 2-s maximal abdominal bracing followed by 2-s muscle relaxation (5 × 10 repetitions/day). Maximal voluntary isometric strength during trunk flexion and extension, hip extension, and knee extension, maximal lifting power from sitting position, and the thicknesses of abdominal muscles were measured before and after the intervention. In addition, surface electromyograms from trunk and lower limb muscles and intra-abdominal pressure (IAP) during the maximal abdominal bracing and maximal lifting tasks were also determined. After the intervention, TG showed significant increases in isometric trunk extension (+14.4 %) and hip extension (+34.7 %) strength and maximal lifting power (+15.6 %), while CG did not show any changes in strength and power variables. Furthermore, TG had significant gains in the muscle thickness of the oblique internal (+22.4 %), maximal IAP during abdominal bracing (+36.8 %), and the rate of IAP rise during lifting task (+58.8 %), without corresponding changes in CG. The current study indicates that a training style with maximal voluntary co-contraction of abdominal muscles can be an effective maneuver for increasing strength and power during movements involving trunk and hip extensions, without using external load.

  19. Gait training assist system of a lower limb prosthetic visualizing muscle activation pattern using a color-depth sensor.

    Science.gov (United States)

    Ogata, Kunihiro; Mita, Tomoki; Tsuji, Toshiaki; Matsumoto, Yoshio

    2017-07-01

    Some unilateral lower-limb amputees load the intact limb more than the prosthetic limb. This can cause chronic pains, fatigue, lumbago, and joint diseases, including knee osteoarthritis. To avoid and counteract these symptoms it is necessary to improve their asymmetric gait. Increasing the function of the hip abductor muscle is important to maintaining symmetrical weight distribution. Therefore, the purpose of this study is to develop a training assist system, which estimates and visualizes an abductor muscle by using a color-depth sensor. To estimate the muscle activation, first, the floor reaction force is calculated using a simple dynamic model. Then, the hip torque is calculated using joint angles. The floor reaction force and, the muscle length are calculated based on a human musculoskeletal model. Muscle activity is estimated by these parameters. Evaluation experiments of this proposed method were performed on healthy persons and unilateral trans femoral amputees, and the effectiveness of this proposed algorithm has been confirmed.

  20. Development of nylon-based artificial muscles for the usage in robotic prosthetic limb

    Science.gov (United States)

    Atikah, Nurul Anis; Weng, Leong Yeng; Anuar, Adzly; Fat, Chau Chien; Abidin, Izham Zainal; Sahari, Khairul Salleh Mohamed

    2017-09-01

    This paper describes the development of nylon-based artificial muscles that is intended to be used in prosthetic limb for young amputees. Prosthetic limbs are very expensive and this situation is further compounded for young amputees who are very quickly out-grow their prosthesis. The proposed artificial muscles are made of nylon fishing strings from various size such as 0.45mm, 0.55mm, 0.65mm and 1.00mm. These fishing strings were twisted into coils to create Super Coiled Polymers (SCP) and tested using hot air blower. These artificial muscles react counterintuitively, where when it is exposed to heat, contracts, and when cooled, expands. Peltier devices, when switched-on acts as heat pump, where one side is hot and the other is cold. This phenomenon, when affixed in between 2 SCP's, creates tandem motion similar to triceps and biceps. As initial study, the hot side of the Peltier module was tested using these artificial muscles. The string was measured for both its force production, length contraction, the initial results were promising.

  1. Relationship between tightness of the posterior muscles of the lower limb and plantar fasciitis.

    Science.gov (United States)

    Bolívar, Yolanda Aranda; Munuera, Pedro V; Padillo, Juan Polo

    2013-01-01

    The aim of this study was to determine whether tightness of the posterior muscles of the lower extremity was associated with plantar fasciitis. A total of 100 lower limbs of 100 subjects, 50 with plantar fasciitis and 50 matching controls were recruited. Hamstring and calf muscles were evaluated through the straight leg elevation test, popliteal angle test, and ankle dorsiflexion (knee extended and with the knee flexed). All variables were compared between the 2 groups. In addition, ROC curves, sensitivity, and specificity of the muscle contraction tests were also calculated to determine their potential predictive powers. Differences between the 2 groups for the tests used to assess muscular shortening were significant (P muscles of the lower limb was present in the plantar fasciitis patients, but not in the unaffected participants. The results of this study suggest that therapists who are going to employ a stretching protocol for treatment of plantar fasciitis should look for both hamstring as well as triceps surae tightness. Stretching exercise programs could be recommended for treatment of plantar fasciitis, focusing on stretching the triceps surae and hamstrings, apart from an adequate tissue-specific plantar fascia-stretching protocol. Level III, case control study.

  2. Increased lower limb muscle coactivation reduces gait performance and increases metabolic cost in patients with hereditary spastic paraparesis.

    Science.gov (United States)

    Rinaldi, Martina; Ranavolo, Alberto; Conforto, Silvia; Martino, Giovanni; Draicchio, Francesco; Conte, Carmela; Varrecchia, Tiwana; Bini, Fabiano; Casali, Carlo; Pierelli, Francesco; Serrao, Mariano

    2017-10-01

    The aim of this study was to investigate the lower limb muscle coactivation and its relationship with muscles spasticity, gait performance, and metabolic cost in patients with hereditary spastic paraparesis. Kinematic, kinetic, electromyographic and energetic parameters of 23 patients and 23 controls were evaluated by computerized gait analysis system. We computed ankle and knee antagonist muscle coactivation indexes throughout the gait cycle and during the subphases of gait. Energy consumption and energy recovery were measured as well. In addition to the correlation analysis between coactivation indexes and clinical variables, correlations between coactivation indexes and time-distance, kinematic, kinetic, and energetic parameters were estimated. Increased coactivity indexes of both knee and ankle muscles throughout the gait cycle and during the subphases of gait were observed in patients compared with controls. Energetic parameters were significantly higher in patients than in controls. Both knee and ankle muscle coactivation indexes were positively correlated with knee and ankle spasticity (Ashworth score), respectively. Knee and ankle muscle coactivation indexes were both positively correlated with energy consumption and both negatively correlated with energy recovery. Positive correlations between the Ashworth score and lower limb muscle coactivation suggest that abnormal lower limb muscle coactivation in patients with hereditary spastic paraparesis reflects a primary deficit linked to lower limb spasticity. Furthermore, these abnormalities influence the energetic mechanisms during walking. Identifying excessive muscle coactivation may be helpful in individuating the rehabilitative treatments and designing specific orthosis to restrain spasticity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The Prevalence of Latent Trigger Points in Lower Limb Muscles in Asymptomatic Subjects.

    Science.gov (United States)

    Zuil-Escobar, Juan Carlos; Martínez-Cepa, Carmen Belén; Martín-Urrialde, Jose Antonio; Gómez-Conesa, Antonia

    2016-11-01

    Latent trigger points (LTrPs) are prevalent in persons with musculoskeletal pain. Because they could be present in healthy persons, it is necessary to evaluate the prevalence of LTrPs in asymptomatic subjects. To assess the prevalence of LTrPs in lower limb muscles, to evaluate the relationship between LTrP prevalence, gender, and leg dominance, and to determine intra-rater reliability for the diagnosis of LTrPs. Cross-sectional study. University community. A total of 206 asymptomatic subjects (113 women and 93 men, aged 23.2 ± 5.2 years). Not applicable. The prevalence of the LTrPs located in the gastrocnemius, soleus, peroneus longus, peroneus brevis, tibialis anterior, extensor digitorum longus, flexor digitorum longus, rectus femoris, vastus medialis, and vastus lateralis was studied, using the diagnosis criteria recommended by Simons, Travell, and Simons. The pressure pain threshold was also evaluated. Of the 206 subjects evaluated, 166 (77.7%; 95% confidence interval [CI], 72-83.4) were found to have at least one LTrP in the lower limb muscles. The average number of LTrPs found per individual was 7.5 ± 7.7. The prevalence in each muscle group ranged from 19.9% (95% CI, 14.4-25.4) to 37.4% (95% CI, 30.8-44), with gastrocnemius LTrPs being the most prevalent. Women had more LTrPs (9.6 ± 7.8) than did men (4.9 ± 6.6) (P .05). The most prevalent diagnosis criteria were the presence of a taut band and a tender spot (98%-100%); the local twitch response was the least prevalent diagnosis criteria (0%-3.5%). Intra-rater reliability was excellent for all the diagnosis criteria in all the muscles evaluated (κ = 0.762-1), except for the jump sign and the referred pain in several LTrPs. LTrPs were prevalent in the lower limb muscles of asymptomatic subjects. Women have more LTrPs than do men. No differences in LTrP prevalence were found between sides. The presence of the taut band and the tender spot were the most prevalent and reliable diagnosis criteria. It is

  4. Effects of transcutaneous electrical stimulation of lower limb muscles on experimental fatty liver.

    Science.gov (United States)

    El-Kafoury, Bataa M; Seif, Ansam A; El-Aziz Abd El-Hady, Enas A; El-Sebaiee, Ahmed E

    2016-03-01

    Although the beneficial effects of exercise on fatty liver have been described, a previous study conducted at our department showed that transcutaneous electrical muscle stimulation (TEMS) of lower abdominal muscles aggravated fatty liver. The present study aims to evaluate the ability of TEMS of the lower limb muscles to improve fatty liver infiltration. Thirty male Wistar rats were randomly allocated into three groups: control; fructose-fed (F), fed fructose-enriched diet for 6weeks; and fructose-fed with transcutaneous electrical muscle stimulation (F+TEMS), fed fructose-enriched diet for 6weeks and lower limb muscles subjected to TEMS during the last 3weeks of feeding, five sessions/week. Body weight, length, body mass index (BMI), and abdominal and lower limb circumferences were all recorded. Fasting blood glucose, serum insulin, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein, serum albumin, high density lipoprotein cholesterol (HDL-C), triglyceride (TG), and total cholesterol (TC) levels were measured. LDL cholesterol (LDL-C) and the atherogenic index (AI) were calculated. Absolute and relative hepatic weights as well as histological examination of the liver were assessed. Final body weight, abdominal and lower limb circumferences, absolute liver weight, homoeostasis model assessment (HOMA) score, and TG, LDL-C, AI, serum ALT, and AST levels were all significantly reduced in the (F+TEMS) group compared to the (F) group. There was a significant increase in GPx and HDL-C levels, HDL/LDL ratio, and total protein and serum albumin content in (F+TEMS) rats compared to (F) rats. Histologically, hepatic tissue from (F+TEMS) rats had minimal steatotic changes that were restricted to zone 1 and less marked inflammatory cell infiltration compared to (F) rats. TEMS was able to reverse steatosis, hyperglycaemia, insulin resistance, dyslipidaemia, and fatty liver caused by fructose feeding. The study confirmed that the variation in

  5. Impact of Spinal Manipulation on Cortical Drive to Upper and Lower Limb Muscles.

    Science.gov (United States)

    Haavik, Heidi; Niazi, Imran Khan; Jochumsen, Mads; Sherwin, Diane; Flavel, Stanley; Türker, Kemal S

    2016-12-23

    This study investigates whether spinal manipulation leads to changes in motor control by measuring the recruitment pattern of motor units in both an upper and lower limb muscle and to see whether such changes may at least in part occur at the cortical level by recording movement related cortical potential (MRCP) amplitudes. In experiment one, transcranial magnetic stimulation input-output (TMS I/O) curves for an upper limb muscle (abductor pollicus brevis; APB) were recorded, along with F waves before and after either spinal manipulation or a control intervention for the same subjects on two different days. During two separate days, lower limb TMS I/O curves and MRCPs were recorded from tibialis anterior muscle (TA) pre and post spinal manipulation. Dependent measures were compared with repeated measures analysis of variance, with p set at 0.05. Spinal manipulation resulted in a 54.5% ± 93.1% increase in maximum motor evoked potential (MEPmax) for APB and a 44.6% ± 69.6% increase in MEPmax for TA. For the MRCP data following spinal manipulation there were significant difference for amplitude of early bereitschafts-potential (EBP), late bereitschafts potential (LBP) and also for peak negativity (PN). The results of this study show that spinal manipulation leads to changes in cortical excitability, as measured by significantly larger MEPmax for TMS induced input-output curves for both an upper and lower limb muscle, and with larger amplitudes of MRCP component post manipulation. No changes in spinal measures (i.e., F wave amplitudes or persistence) were observed, and no changes were shown following the control condition. These results are consistent with previous findings that have suggested increases in strength following spinal manipulation were due to descending cortical drive and could not be explained by changes at the level of the spinal cord. Spinal manipulation may therefore be indicated for the patients who have lost tonus of their muscle and/or are

  6. Muscular activity of lower limb muscles associated with working on inclined surfaces.

    Science.gov (United States)

    Lu, Ming-Lun; Kincl, Laurel; Lowe, Brian; Succop, Paul; Bhattacharya, Amit

    2015-01-01

    This study investigated the effects of visual cues, muscular fatigue, task performance and experience of working on inclined surfaces on activity of postural muscles in the lower limbs associated with maintaining balance on three inclined surfaces - 0°, 14° and 26°. Normalised electromyographic (NEMG) data were collected in 44 professional roofers bilaterally from the rectus femoris, biceps femoris, tibialii anterior and gastrocnemii medial muscle groups. The 50th and 95th percentile NEMG amplitudes were used as EMG variables. Results showed that inclination angle and task performance caused a significant increase in the NEMG amplitudes of all postural muscles. Visual cues were significantly associated with a decrease in the 95th percentile EMG amplitude for the right gastrocnemius medial and tibialis anterior. Fatigue was related to a significant decrease in the NEMG amplitude for the rectus femoris. Experience of working on inclined surfaces did not have a significant effect on the NEMG amplitude.

  7. Proximal femoral nail shows better concordance of gait analysis between operated and uninjured limbs compared to hemiarthroplasty in intertrochanteric femoral fractures.

    Science.gov (United States)

    Güven, Melih; Kocadal, Onur; Akman, Budak; Poyanlı, Oğuz S; Kemah, Bahattin; Atay, Evren Fehmi

    2016-06-01

    The purpose of this study was to compare the results of pedobarographic gait analysis between the patients treated by proximal femoral nail or bipolar partial hemiarthroplasty due to intertrochanteric fractures. Thirty-seven patients with a minimum 1-year follow-up who had been operated for intertrochanteric fractures were evaluated clinically, radiologically and with pedobarographic gait analysis. Proximal femoral nail had been performed to 21 patients (group A), whilst 16 patients had been operated by partial bipolar hemiarthroplasty (group B). Pedobarographic analysis was performed by measuring plantar pressure, force and contact area values in both static and dynamic manner. Pedobarographic results of operated limb were compared among groups. Same data's also were compared between operated and uninjured limbs in each group to determine any asymmetry on weight-bearing. Average follow-up period in group A and group B was 36 (12-56) and 30 (12-48) months, respectively. There were no statistically significant differences among groups in terms of age, gender, body mass index, type and side of fracture, follow-up period, leg length discrepancy and postoperative hip scores. When the pedobarographic results of operated limb were compared, group B showed much more plantar force and pressure values than group A, on both static and dynamic evaluations. If the evaluation was taken into consideration to comparison of pedobarographic results between operated and uninjured limbs in each group, we found asymmetry in static load bearing, caused by higher load on uninjured limb in both groups. However, there was no statistically significant asymmetry between operated and uninjured limbs in respect to dynamic pedobarographic parameters for patients in group A. On the contrary, operated limbs in group B exposed much more plantar force and pressure values than uninjured limbs, which indicated asymmetric weight-bearing on dynamic evaluation. Assessment of pedobarographic parameters

  8. Influence of mechanical ventilation and sepsis on redox balance in diaphragm, myocardium, limb muscles, and lungs.

    Science.gov (United States)

    Chacon-Cabrera, Alba; Rojas, Yeny; Martínez-Caro, Leticia; Vila-Ubach, Monica; Nin, Nicolas; Ferruelo, Antonio; Esteban, Andrés; Lorente, José A; Barreiro, Esther

    2014-12-01

    Mechanical ventilation (MV), using high tidal volumes (V(T)), causes lung (ventilator-induced lung injury [VILI]) and distant organ injury. Additionally, sepsis is characterized by increased oxidative stress. We tested whether MV is associated with enhanced oxidative stress in sepsis, the commonest underlying condition in clinical acute lung injury. Protein carbonylation and nitration, antioxidants, and inflammation (immunoblotting) were evaluated in diaphragm, gastrocnemius, soleus, myocardium, and lungs of nonseptic and septic (cecal ligation and puncture 24 hours before MV) rats undergoing MV (n = 7 per group) for 150 minutes using 3 different strategies (low V(T) [V(T) = 9 mL/kg], moderate V(T) [V(T) = 15 mL/kg], and high V(T) [V(T) = 25 mL/kg]) and in nonventilated control animals. Compared with nonventilated control animals, in septic and nonseptic rodents (1) diaphragms, limb muscles, and myocardium of high-V(T) rats exhibited a decrease in protein oxidation and nitration levels, (2) antioxidant levels followed a specific fiber-type distribution in slow- and fast-twitch muscles, (3) tumor necrosis factor α (TNF-α) levels were higher in respiratory and limb muscles, whereas no differences were observed in myocardium, and (4) in lungs, protein oxidation was increased, antioxidants were rather decreased, and TNF-α remained unmodified. In this model of VILI, oxidative stress does not occur in distant organs or skeletal muscles of rodents after several hours of MV with moderate-to-high V(T), whereas protein oxidation levels were increased in the lungs of the animals. Inflammatory events were moderately expressed in skeletal muscles and lungs of the MV rats. Concomitant sepsis did not strongly affect the MV-induced effects on muscles, myocardium, or lungs in the rodents. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Muscle involvement in limb-girdle muscular dystrophy with GMPPB deficiency (LGMD2T).

    Science.gov (United States)

    Oestergaard, S T; Stojkovic, T; Dahlqvist, J R; Bouchet-Seraphin, C; Nectoux, J; Leturcq, F; Cossée, M; Solé, G; Thomsen, C; Krag, T O; Vissing, J

    2016-12-01

    In this study, muscle involvement assessed by MRI and levels of GMPPB and glycosylation of α-dystroglycan expression in muscle were examined in patients with limb-girdle muscular dystrophy (LGMD) type 2T. Six new patients with genetically verified mutations in GMPPB were studied. T1-weighted magnetic resonance images were obtained in 4 participants. Muscle strength and potential involvement of extramuscular organs were examined. Glycosylation of α-dystroglycan in muscle was studied, and GMPPB and α-dystroglycan expression was analyzed by Western blotting. Prevalence of LGMD2T was calculated from the total LGMD population in Denmark. GMPPB was sequenced in all unclassified cases. Two patients carried 3 new mutations in GMPPB. The other 4 patients carried previously described pathogenic mutations in GMPPB. MRI showed that the paraspinal muscles were the most affected, followed by involvement of hamstrings. Our results showed a loss of glycosylation of α-dystroglycan as well as secondary loss of merosin expression on Western blotting. The prevalence of LGMD2T in the Danish cohort of patients with LGMD is 1.5%. The new findings of this study are (1) the consistent finding of a preferential affection of paraspinal and hamstring muscles in LGMD2T, (2) 3 new mutations in GMPPB, (3) variable loss of glycosylation tested with IIH6 and VIA4 antibodies, and (4) a prevalence of LGMD2T of 1.5% in a well-characterized Danish LGMD cohort.

  10. Rat diaphragm mitochondria have lower intrinsic respiratory rates than mitochondria in limb muscles.

    Science.gov (United States)

    Garcia-Cazarin, Mary L; Gamboa, Jorge L; Andrade, Francisco H

    2011-06-01

    The mitochondrial content of skeletal muscles is proportional to activity level, with the assumption that intrinsic mitochondrial function is the same in all muscles. This may not hold true for all muscles. For example, the diaphragm is a constantly active muscle; it is possible that its mitochondria are intrinsically different compared with other muscles. This study tested the hypothesis that mitochondrial respiration rates are greater in the diaphragm compared with triceps surae (TS, a limb muscle). We isolated mitochondria from diaphragm and TS of adult male Sprague Dawley rats. Mitochondrial respiration was measured by polarography. The contents of respiratory complexes, uncoupling proteins 1, 2, and 3 (UCP1, UCP2, and UCP3), and voltage-dependent anion channel 1 (VDAC1) were determined by immunoblotting. Complex IV activity was measured by spectrophotometry. Mitochondrial respiration states 3 (substrate and ADP driven) and 5 (uncoupled) were 27 ± 8% and 24 ± 10%, respectively, lower in diaphragm than in TS (P lower rates, despite a higher content of respiratory complexes. The results invalidate our initial hypothesis and indicate that mitochondrial content is not the only determinant of aerobic capacity in the diaphragm. We propose that UCP1 and VDAC1 play a role in regulating diaphragm aerobic capacity.

  11. Antagonistic Mono- and Bi-Articular Lower-Limb Muscle Activities’ Model Characterization at Different Speeds

    Directory of Open Access Journals (Sweden)

    Dzahir M.A.M

    2017-01-01

    Full Text Available Nowadays, medical rehabilitation system has become a requirement due to increment in national rehabilitation centres and medical hospitals. An assistive rehabilitation orthosis becomes essential and was used for rehabilitation therapy, condition monitoring, and physical strengthening. This study focused on the lower limb assistive rehabilitation orthosis development using pneumatic artificial muscle. To successfully control this orthosis system which consists of antagonistic mono- and biarticular muscle actuators, it is necessary to construct a reliable control algorithm. The suitable control scheme and strategy to manoeuvre this orthosis system similar to human musculoskeletal system have yet to be fully developed and established. Based on the review study, it is said that the co-contraction controls of anterior-posterior pneumatic muscles was able to improve the joint stiffness and stability of the orthosis as well as good manoeuvrability. Therefore, a characterization model of an antagonistic mono- and bi-articular muscles activities of human's lowerlimb during walking motion will be necessary. A healthy young male subject was used as test subject to obtain the sEMG muscle activities for antagonistic mono- and bi-articular muscles (i.e., Vastus Medialis-VM, Vastus Lateralis-VL, Rectus Femoris-RF, and Bicep Femoris-BF. The tests were carried out at different speeds of 2km/h, 3km/h, and 4km/h for one minute walking motion on a treadmill. Then, the patterns of the sEMG muscle activities were modelled and characterised using fifth order polynomial equation. Based on the results, it is shown that the anterior and posterior muscles were exhibited a muscle synergy in-between multiple anterior or posterior muscles and muscle co-contraction between anteriorposterior muscles in order to control the movements at the joints during walking motion. As conclusion, it is proven that the sEMG muscle activities of the antagonistic mono- and bi

  12. Regulation of the properties of rat hind limb muscles following gravitational unloading.

    Science.gov (United States)

    Ohira, Motoko; Hanada, Hagino; Kawano, Fuminori; Ishihara, Akihiko; Nonaka, Ikuya; Ohira, Yoshinobu

    2002-06-01

    The mechanisms responsible for the morphological and metabolic adaptation of skeletal muscles to the removal of antigravity activity were investigated in rats. Significant atrophy relative to the levels before suspension was induced in ankle plantarflexsors, may be due to a reduced tension production caused by decreased muscle length and electromyogram activity. Growth failure was significant in ankle dorsiflexors, although these muscles did not atrophy. Forced muscle contraction through electrical stimulation at 1 or 100 Hz during hind limb suspension generally had detrimental effects. The percent contribution of water loss to the suspension-related change in weight was 85, 88, and 93% in soleus, plantaris, and extensor digitorum longus, respectively. The total levels of both beta-hydroxyacyl CoA dehydrogenase (HAD) and lactate dehydrogenase (LDH) were less in the suspended muscles than in the controls, having high positive correlations with the total protein content. The specific activity of HAD, but not of LDH, of the suspended muscles was lower than in the controls (25-61%). These data suggest that the cause of muscle atrophy and changes in metabolic properties may be a decreased tension development, not necessarily the reduction of electrical or contractile activity. Further, it is clearly suggested that electrical stimulation of a muscle group with different composition of fiber phenotype at a certain pattern or frequency is not suitable for the countermeasure. It is also suggested that the major cause of the decreased muscle weight was loss of water, even though protein content was also lowered after suspension. Moreover, the data suggest that the HAD level was affected more than the total protein content and LDH.

  13. Selective effects of arm proximal and distal muscles fatigue on force coordination in manipulation tasks.

    Science.gov (United States)

    Emge, Nicholas; Uygur, Mehmet; Radivoj, Mandic; Kaminski, Thomas W; Royer, Todd; Jaric, Slobodan

    2014-01-01

    Effects of muscle fatigue on force coordination and task performance of various manipulation tasks are explored. Grip force (GF; normal force component acting at the digits-object contact area) and load force (LF; tangential component that lifts and holds objects) were recorded prior to and after fatiguing the distal (DAM; i.e., GF producing) and proximal arm muscles (PAM; LF producing). Results reveal a deterioration of GF scaling (i.e., averaged GF-LF ratio), GF-LF coupling (their correlation), and task performance (ability to exert a prescribed LF pattern) associated with DAM, but not PAM fatigue. Deteriorated force coordination clearly increases the likelihood of dropping an object; however, the observed selective effects of DAM and PAM fatigue represent a novel finding deserving of further research.

  14. A Lower Limb-Pelvis Finite Element Model with 3D Active Muscles.

    Science.gov (United States)

    Mo, Fuhao; Li, Fan; Behr, Michel; Xiao, Zhi; Zhang, Guanjun; Du, Xianping

    2018-01-01

    A lower limb-pelvis finite element (FE) model with active three-dimensional (3D) muscles was developed in this study for biomechanical analysis of human body. The model geometry was mainly reconstructed from a male volunteer close to the anthropometry of a 50th percentile Chinese male. Tissue materials and structural features were established based on the literature and new implemented experimental tests. In particular, the muscle was modeled with a combination of truss and hexahedral elements to define its passive and active properties as well as to follow the detailed anatomy structure. Both passive and active properties of the model were validated against the experiments of Post-Mortem Human Surrogate (PMHS) and volunteers, respectively. The model was then used to simulate driver's emergency braking during frontal crashes and investigate Knee-Thigh-Hip (KTH) injury mechanisms and tolerances of the human body. A significant force and bending moment variance was noted for the driver's femur due to the effects of active muscle forces during emergency braking. In summary, the present lower limb-pelvis model can be applied in various research fields to support expensive and complex physical tests or corresponding device design.

  15. Myofascial force transmisison between antagonistic rat lower limb muscles: effects of single muscle or muscle group lengthening

    NARCIS (Netherlands)

    Meijer, Hanneke J.M; Rijkelijkhuizen, Josina M.; Huijing, P.A.J.B.M.

    2007-01-01

    Effects of lengthening of the whole group of anterior crural muscles (tibialis anterior and extensor hallucis longus muscles (TA + EHL) and extensor digitorum longus (EDL)) on myofascial interaction between synergistic EDL and TA + EHL muscles, and on myofascial force transmission between anterior

  16. Myofascial force transmission between antagonistic rat lower limb muscles: Effects of single muscle or muscle group lengthening.

    NARCIS (Netherlands)

    Meijer, H.J.M.; Rijkelijkhuizen, J.M.; Huijing, P.A.J.B.M.

    2007-01-01

    Effects of lengthening of the whole group of anterior crural muscles (tibialis anterior and extensor hallucis longus muscles (TA + EHL) and extensor digitorum longus (EDL)) on myofascial interaction between synergistic EDL and TA + EHL muscles, and on myofascial force transmission between anterior

  17. The effect of different skin-ankle brace application pressures on quiet single-limb balance and electromyographic activation onset of lower limb muscles.

    Science.gov (United States)

    Papadopoulos, Emmanuel S; Nikolopoulos, Christos; Badekas, Athanasios; Vagenas, George; Papadakis, Stamatios A; Athanasopoulos, Spyros

    2007-09-12

    Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures on quiet single limb balance and the electromyographic (EMG) activation sequence of four lower limb muscles. Thirty three male physical education students who volunteered to take part in the study were measured under three ankle brace conditions: i) without brace, ii) with brace and 30 kPa application pressure and iii) with brace and 60 kPa application pressure. Single limb balance (anteroposterior and mediolateral parameter) was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris) activation onset. The results showed that overall balance (total stability parameter) was not significantly affected in any of the three ankle brace conditions. However, the anteroposterior centre of pressure excursion and centre of pressure excursion velocity were significantly increased with the application of ankle brace, both with 30 and 60 kPa application pressures. Furthermore, it was found that single limb balance was significantly worse with closed eyes compared to open eyes. EMG measurements showed that the sequence of lower limb activation onset was not affected in any of the three ankle brace application conditions. The results of this study showed that the application of an ankle brace with two different skin-brace interface pressures had no effect on overall single limb balance and the sequence of lower limb muscle activation. These findings suggest that peripheral joint receptors are either not adequately stimulated by the brace application and therefore are not able to

  18. The effect of different skin-ankle brace application pressures on quiet single-limb balance and electromyographic activation onset of lower limb muscles

    Directory of Open Access Journals (Sweden)

    Papadakis Stamatios A

    2007-09-01

    Full Text Available Abstract Background Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures on quiet single limb balance and the electromyographic (EMG activation sequence of four lower limb muscles. Methods Thirty three male physical education students who volunteered to take part in the study were measured under three ankle brace conditions: i without brace, ii with brace and 30 kPa application pressure and iii with brace and 60 kPa application pressure. Single limb balance (anteroposterior and mediolateral parameter was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris activation onset. Results The results showed that overall balance (total stability parameter was not significantly affected in any of the three ankle brace conditions. However, the anteroposterior centre of pressure excursion and centre of pressure excursion velocity were significantly increased with the application of ankle brace, both with 30 and 60 kPa application pressures. Furthermore, it was found that single limb balance was significantly worse with closed eyes compared to open eyes. EMG measurements showed that the sequence of lower limb activation onset was not affected in any of the three ankle brace application conditions. The results of this study showed that the application of an ankle brace with two different skin-brace interface pressures had no effect on overall single limb balance and the sequence of lower limb muscle activation. Conclusion These findings suggest that peripheral joint receptors are either not adequately

  19. Gait characteristics and lower limb muscle strength in women with early and established knee osteoarthritis.

    Science.gov (United States)

    Baert, Isabel A C; Jonkers, Ilse; Staes, Filip; Luyten, Frank P; Truijen, Steven; Verschueren, Sabine M P

    2013-01-01

    Based on novel classification criteria using magnetic resonance imaging, a subpopulation of "early knee osteoarthritis patients" was clearly defined recently. This study assessed whether these early osteoarthritis patients already exhibit gait adaptations (knee joint loading in particular) and changes in muscle strength compared to control subjects and established knee osteoarthritis patients. Fourteen female patients with early knee joint degeneration, defined by magnetic resonance imaging (early osteoarthritis), 12 female patients with established osteoarthritis and 14 female control subjects participated. Specific gait parameters and lower limb muscle strength were analyzed and compared between groups. Within the osteoarthritis groups, association between muscle strength and dynamic knee joint loading was also evaluated. Early osteoarthritis patients presented no altered gait pattern, no significant increase in knee joint loading and no significant decrease in hamstring muscle strength compared to controls, while established osteoarthritis patients did. In contrast, early osteoarthritis patients experienced significant quadriceps weakness, comparable to established osteoarthritis patients. Within the osteoarthritis groups, muscle strength was not correlated with knee joint loading during gait. The results suggest that gait changes reflect mechanical overload and are most likely the consequence of structural degeneration in knee osteoarthritis. Quadriceps weakness might however contribute to the onset and progression of the disease. This study supports the relevance of classification of early osteoarthritis patients and assists in identifying their functional characteristics. This helps to understand the trajectory of disease onset and progression and further develop more targeted strategies for prevention and treatment of knee osteoarthritis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Recent Trends in Lower-Limb Robotic Rehabilitation Orthosis: Control Scheme and Strategy for Pneumatic Muscle Actuated Gait Trainers

    Directory of Open Access Journals (Sweden)

    Mohd Azuwan Mat Dzahir

    2014-04-01

    Full Text Available It is a general assumption that pneumatic muscle-type actuators will play an important role in the development of an assistive rehabilitation robotics system. In the last decade, the development of a pneumatic muscle actuated lower-limb leg orthosis has been rather slow compared to other types of actuated leg orthoses that use AC motors, DC motors, pneumatic cylinders, linear actuators, series elastic actuators (SEA and brushless servomotors. However, recent years have shown that the interest in this field has grown exponentially, mainly due to the demand for a more compliant and interactive human-robotics system. This paper presents a survey of existing lower-limb leg orthoses for rehabilitation, which implement pneumatic muscle-type actuators, such as McKibben artificial muscles, rubbertuators, air muscles, pneumatic artificial muscles (PAM or pneumatic muscle actuators (PMA. It reviews all the currently existing lower-limb rehabilitation orthosis systems in terms of comparison and evaluation of the design, as well as the control scheme and strategy, with the aim of clarifying the current and on-going research in the lower-limb robotic rehabilitation field.

  1. Relation between systemic inflammatory markers, peripheral muscle mass, and strength in limb muscles in stable COPD patients

    Directory of Open Access Journals (Sweden)

    Ferrari R

    2015-08-01

    Full Text Available Renata Ferrari,1 Laura MO Caram,1 Marcia M Faganello,2 Fernanda F Sanchez,3 Suzana E Tanni,1 Irma Godoy1 1Botucatu Medical School, Department of Internal Medicine, Pneumology Area, Botucatu, São Paulo, 2Paulista State University, Department of Physiotherapy and Occupational Therapy, Marilia, São Paulo, 3Federal University of Amazonas, Department of Physiotherapy, Manaus, Amazonas, Brazil Abstract: The aim of this study was to investigate the association between systemic inflammatory mediators and peripheral muscle mass and strength in COPD patients. Fifty-five patients (69% male; age: 64±9 years with mild/very severe COPD (defined as forced expiratory volume in the first second [FEV1] =54%±23% were evaluated. We evaluated serum concentrations of IL-8, CRP, and TNF-α. Peripheral muscle mass was evaluated by computerized tomography (CT; midthigh cross-sectional muscle area (MTCSA and midarm cross-sectional muscle area (MACSA were obtained. Quadriceps, triceps, and biceps strength were assessed through the determination of the one-repetition maximum. The multiple regression results, adjusted for age, sex, and FEV1%, showed positive significant association between MTCSA and leg extension (0.35 [0.16, 0.55]; P=0.001, between MACSA and triceps pulley (0.45 [0.31, 0.58]; P=0.001, and between MACSA and biceps curl (0.34 [0.22, 0.47]; P=0.001. Plasma TNF-α was negatively associated with leg extension (-3.09 [-5.99, -0.18]; P=0.04 and triceps pulley (-1.31 [-2.35, -0.28]; P=0.01, while plasma CRP presented negative association with biceps curl (-0.06 [-0.11, -0.01]; P=0.02. Our results showed negative association between peripheral muscle mass (evaluated by CT and muscle strength and that systemic inflammation has a negative influence in the strength of specific groups of muscles in individuals with stable COPD. This is the first study showing association between systemic inflammatory markers and strength in upper limb muscles. Keywords

  2. Quality of life after mastectomy and its relation with muscle strength of upper limb

    OpenAIRE

    Silva, Suelen Helena da; Koetz,Lydia Christmann Espindola; Sehnem, Eduardo; Grave, Magali Teresinha Quevedo

    2014-01-01

    This research transversal, analytical, exploratory and quantitative approach aimed to identify the quality of life of women who have had a mastectomy surgery, relate the results with the strength of the upper limb muscle affected and draw a sociofunctional profile. A total of 10 women participated, from 30 to 60 years old, who underwent to unilateral modified radical mastectomy in a medium-sized hospital in an inner city of Rio Grande do Sul, for at least one year from the date of data collec...

  3. The dance’s influence on muscle strength of lower limbs on the elderly

    OpenAIRE

    Joseane Rodrigues da Silva; Aline Corrêa Bisognin; Patrícia Ogliari; Eduardo Alexandre Loth; Karen Andrea Comparin

    2011-01-01

    The aim of this study was to evaluate the influence of dance in the lower limb muscle strength on the elderly. This research has a qualitative-quantitative aproach. The sample was composed by ten elderly of both sexes, who practiced ballroom dancing classes during twelve weeks. The evaluation was performed before and after the classes and it was composed by a questionnaire with personal data and medical history, “test stand and sit in 30 seconds” and a semi-structured interview with a guiding...

  4. Limb muscle sound speed estimation by ultrasound computed tomography excluding receivers in bone shadow

    Science.gov (United States)

    Qu, Xiaolei; Azuma, Takashi; Lin, Hongxiang; Takeuchi, Hideki; Itani, Kazunori; Tamano, Satoshi; Takagi, Shu; Sakuma, Ichiro

    2017-03-01

    Sarcopenia is the degenerative loss of skeletal muscle ability associated with aging. One reason is the increasing of adipose ratio of muscle, which can be estimated by the speed of sound (SOS), since SOSs of muscle and adipose are different (about 7%). For SOS imaging, the conventional bent-ray method iteratively finds ray paths and corrects SOS along them by travel-time. However, the iteration is difficult to converge for soft tissue with bone inside, because of large speed variation. In this study, the bent-ray method is modified to produce SOS images for limb muscle with bone inside. The modified method includes three steps. First, travel-time is picked up by a proposed Akaike Information Criterion (AIC) with energy term (AICE) method. The energy term is employed for detecting and abandoning the transmissive wave through bone (low energy wave). It results in failed reconstruction for bone, but makes iteration convergence and gives correct SOS for skeletal muscle. Second, ray paths are traced using Fermat's principle. Finally, simultaneous algebraic reconstruction technique (SART) is employed to correct SOS along ray paths, but excluding paths with low energy wave which may pass through bone. The simulation evaluation was implemented by k-wave toolbox using a model of upper arm. As the result, SOS of muscle was 1572.0+/-7.3 m/s, closing to 1567.0 m/s in the model. For vivo evaluation, a ring transducer prototype was employed to scan the cross sections of lower arm and leg of a healthy volunteer. And the skeletal muscle SOSs were 1564.0+/-14.8 m/s and 1564.1±18.0 m/s, respectively.

  5. A portable device for the clinical assessment of upper limb motion and muscle synergies.

    Science.gov (United States)

    Murgia, Alessio; Kerkhofs, Vincent; Savelberg, Hans; Meijer, Kenneth

    2010-01-01

    We present a device for recording and analyzing upper limb movements and muscle activities in a single unit. The device's outputs are related to aspects of clinical assessment such as joint coordination, fatigue and muscle synergies. A comparison with an optoelectronic motion capture system was also carried out during a hand to mouth and a hand to contralateral shoulder task. High correlation was found for the elbow angles, while analysis of the root mean square errors indicated that the angular outputs of the device were overestimated compared to the angles calculated using the optoelectronic system. Biceps and triceps co-contraction patterns were also observed during the hand to mouth task. Applications to the clinical assessment and monitoring of neurological disorders are discussed.

  6. TMEM5-associated dystroglycanopathy presenting with CMD and mild limb-girdle muscle involvement.

    Science.gov (United States)

    Astrea, Guja; Pezzini, Ilaria; Picillo, Ester; Pasquariello, Rosa; Moro, Francesca; Ergoli, Manuela; D'Ambrosio, Paola; D'Amico, Adele; Politano, Luisa; Santorelli, Filippo Maria

    2016-07-01

    The dystroglycanopathies, which are caused by reduced glycosylation of alpha-dystroglycan, are a heterogeneous group of neurodegenerative disorders characterized by variable brain and skeletal muscle involvement. Recently, mutations in TMEM5 have been described in severe dystroglycanopathies. We present the clinical, molecular and neuroimaging features of an Italian boy who had delayed developmental milestones with mild limb-girdle muscle involvement, bilateral frontotemporal polymicrogyria, moderate intellectual disability, and no cerebellar involvement. He also presented a cochlear dysplasia and harbored a reported mutation (p.A47Rfs*42) in TMEM5, detected using targeted next-generation sequencing. The relatively milder muscular phenotype and associated structural brain abnormalities distinguish this case from previously reported patients with severe dystroglycanopathies and expand the spectrum of TMEM5-associated disorders. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Prediction of muscle strength and postoperative function after knee flexor muscle resection for soft tissue sarcoma of the lower limbs.

    Science.gov (United States)

    Tanaka, A; Yoshimura, Y; Aoki, K; Okamoto, M; Kito, M; Suzuki, S; Takazawa, A; Ishida, T; Kato, H

    2017-11-01

    Oncological margins and prognosis are the most important factors for operative planning of soft tissue sarcomas, but prediction of postoperative function is also necessary. The purpose of this study was to predict the knee flexion strength and postoperative function after knee flexor muscle resection for soft tissue sarcoma of the lower limbs. Seventeen patients underwent knee flexor muscle resection for soft tissue sarcoma of the lower limbs between 1991 and 2015. The type of resected muscles was surveyed, knee flexion strength (ratio of affected to unaffected side) was evaluated using the Biodex System isokinetic dynamometer, and differences between the type of resected muscles were examined. The Musculoskeletal Tumor Society (MSTS) score, Toronto Extremity Salvage Score (TESS), European Quality of Life-5 Dimensions (EQ-5D), and Short Form 8 (SF-8) were used to assess postoperative function and examine correlations with flexion strength. The cutoff value for flexion strength to predict good postoperative results was calculated by a receiver operating characteristic (ROC) curve and Fisher's exact test. Median flexion strength decreased in the resection of sartorius (97.8%), gracilis (95.4%), gastrocnemius (85.2%; interquartile range (IQR): 85.0-86.2), medial hamstrings (semimembranosus and semitendinosus, 76.2%; IQR: 73.3-78.0), lateral hamstrings (long and short head of biceps femoris, 66.1%; IQR: 65.9-70.4), and bilateral hamstrings (27.3%; IQR: 26.6-31.5). A significant difference was observed between lateral and bilateral hamstrings resection (P=0.049). Flexion strength was associated with lower functional scales (MSTS score, P=0.021; TESS, P=0.008; EQ-5D, P=0.034). Satisfactory function was obtained at a flexion strength cutoff value of 65.7%, and strength remained above the cutoff value up to unilateral hamstrings resection. Greater knee flexor muscles resection can result in functional deficits that are associated with decreased flexion strength. If

  8. Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands

    Science.gov (United States)

    Wakeling, James M.

    2015-01-01

    This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120–140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. PMID:26445873

  9. Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands.

    Science.gov (United States)

    Blake, Ollie M; Wakeling, James M

    2015-12-01

    This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120-140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. Copyright © 2015 the American Physiological Society.

  10. Normal Values of Tissue-Muscle Perfusion Indexes of Lower Limbs Obtained with a Scintigraphic Method.

    Science.gov (United States)

    Manevska, Nevena; Stojanoski, Sinisa; Pop Gjorceva, Daniela; Todorovska, Lidija; Miladinova, Daniela; Zafirova, Beti

    2017-09-01

    Introduction Muscle perfusion is a physiologic process that can undergo quantitative assessment and thus define the range of normal values of perfusion indexes and perfusion reserve. The investigation of the microcirculation has a crucial role in determining the muscle perfusion. Materials and method The study included 30 examinees, 24-74 years of age, without a history of confirmed peripheral artery disease and all had normal findings on Doppler ultrasonography and pedo-brachial index of lower extremity (PBI). 99mTc-MIBI tissue muscle perfusion scintigraphy of lower limbs evaluates tissue perfusion in resting condition "rest study" and after workload "stress study", through quantitative parameters: Inter-extremity index (for both studies), left thigh/right thigh (LT/RT) left calf/right calf (LC/RC) and perfusion reserve (PR) for both thighs and calves. Results In our investigated group we assessed the normal values of quantitative parameters of perfusion indexes. Indexes ranged for LT/RT in rest study 0.91-1.05, in stress study 0.92-1.04. LC/RC in rest 0.93-1.07 and in stress study 0.93-1.09. The examinees older than 50 years had insignificantly lower perfusion reserve of these parameters compared with those younger than 50, LC (p=0.98), and RC (p=0.6). Conclusion This non-invasive scintigraphic method allows in individuals without peripheral artery disease to determine the range of normal values of muscle perfusion at rest and stress condition and to clinically implement them in evaluation of patients with peripheral artery disease for differentiating patients with normal from those with impaired lower limbs circulation.

  11. Density of muscle spindle profiles in the intrinsic forelimb muscles of the dog.

    Science.gov (United States)

    Buxton, D F; Peck, D

    1990-03-01

    The concept of parallel muscle combinations, in which spindle density is significantly higher in small muscles compared to their larger counterparts in large-small muscle combinations acting across a joint, is supported by the results of this study regardless of the joint. Analysis of the canine data as well as previously published guinea pig forelimb and human pelvic limb data revealed no significant difference in spindle density between antigravity and non-antigravity muscles. Furthermore, a gradual increase in spindle density from proximal to distal on the limb was not found, although spindle density was significantly higher in the intrinsic manus or pes muscles compared to more proximal limb muscles in all three species. The significant differences in spindle densities in parallel muscle combinations and in manus/pes versus proximal muscles are discussed relative to their possible role in the control of locomotion.

  12. Motor unit firing frequency of lower limb muscles during an incremental slide board skating test.

    Science.gov (United States)

    Piucco, Tatiane; Bini, Rodrigo; Sakaguchi, Masanori; Diefenthaeler, Fernando; Stefanyshyn, Darren

    2017-11-01

    This study investigated how the combination of workload and fatigue affected the frequency components of muscle activation and possible recruitment priority of motor units during skating to exhaustion. Ten male competitive speed skaters performed an incremental maximal test on a slide board. Activation of six muscles from the right leg was recorded throughout the test. A time-frequency analysis was performed to compute overall, high, and low frequency bands from the whole signal at 10, 40, 70, and 90% of total test time. Overall activation increased for all muscles throughout the test (p  0.80). There was an increase in low frequency (90 vs. 10%, p = 0.035, ES = 1.06) and a decrease in high frequency (90 vs. 10%, p = 0.009, ES = 1.38, and 90 vs. 40%, p = 0.025, ES = 1.12) components of gluteus maximus. Strong correlations were found between the maximal cadence and vastus lateralis, gluteus maximus and gluteus medius activation at the end of the test. In conclusion, the incremental skating test lead to an increase in activation of lower limb muscles, but only gluteus maximus was sensitive to changes in frequency components, probably caused by a pronounced fatigue.

  13. Electromyographic patterns of lower limb muscles during apprehensive gait in younger and older female adults.

    Science.gov (United States)

    Hallal, Camilla Zamfolini; Marques, Nise Ribeiro; Spinoso, Deborah Hebling; Vieira, Edgar Ramos; Gonçalves, Mauro

    2013-10-01

    Investigate the influence of apprehensive gait on activation and cocontraction of lower limb muscles of younger and older female adults. Data of 17 younger (21.47±2.06yr) and 18 older women (65.33±3.14yr) were considered for this study. Participants walked on the treadmill at two different conditions: normal gait and apprehensive gait. The surface electromyographic signals (EMG) were recorded during both conditions on: rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), tibialis anterior (TA), gastrocnemius lateralis (GL), and soleus (SO). Apprehensive gait promoted greater activation of thigh muscles than normal gait (F=5.34 and p=0.007, for significant main effect of condition; RF, p=0.002; VM, pmuscles than younger women (F=4.05 and p=0.019, for significant main effect of groups; VM/BF, p=0.010; TA/GL, p=0.007; and TA/SO, p=0.002). Apprehensive gait promoted greater activation of thigh muscles and older adults had greater cocontraction of knee and ankle stabilizer muscles. Thus, apprehensive gait may leads to increased percentage of neuromuscular capacity, which is associated with greater cocontraction and contribute to the onset of fatigue and increased risk of falling in older people. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Calpain 3 is important for muscle regeneration: Evidence from patients with limb girdle muscular dystrophies

    Science.gov (United States)

    2012-01-01

    Background Limb girdle muscular dystrophy (LGMD) type 2A is caused by mutations in the CAPN3 gene and complete lack of functional calpain 3 leads to the most severe muscle wasting. Calpain 3 is suggested to be involved in maturation of contractile elements after muscle degeneration. The aim of this study was to investigate how mutations in the four functional domains of calpain 3 affect muscle regeneration. Methods We studied muscle regeneration in 22 patients with LGMD2A with calpain 3 deficiency, in five patients with LGMD2I, with a secondary reduction in calpain 3, and in five patients with Becker muscular dystrophy (BMD) with normal calpain 3 levels. Regeneration was assessed by using the developmental markers neonatal myosin heavy chain (nMHC), vimentin, MyoD and myogenin and counting internally nucleated fibers. Results We found that the recent regeneration as determined by the number of nMHC/vimentin-positive fibers was greatly diminished in severely affected LGMD2A patients compared to similarly affected patients with LGMD2I and BMD. Whorled fibers, a sign of aberrant regeneration, was highly elevated in patients with a complete lack of calpain 3 compared to patients with residual calpain 3. Regeneration is not affected by location of the mutation in the CAPN3 gene. Conclusions Our findings suggest that calpain 3 is needed for the regenerative process probably during sarcomere remodeling as the complete lack of functional calpain 3 leads to the most severe phenotypes. PMID:22443334

  15. Modeling and Simulation to Muscle Strength Training of Lower Limbs Rehabilitation Robots

    Directory of Open Access Journals (Sweden)

    Ke-Yi Wang

    2015-01-01

    Full Text Available Considering the issues of lower limb rehabilitation robots with single control strategies and poor training types, a training method for improving muscle strength was put forward in this paper. Patients’ muscle strength could be achieved by targeted exercises at the end of rehabilitation. This approach could be realized through programming wires’ force. On the one hand, each wires force was measured by tension sensor and force closed loop control was established to control the value of wires’ force which was acted on trainees. On the other hand, the direction of output force was changed by detecting the trainees’ state of motion and the way of putting load to patient was achieved. Finally, the target of enhancing patients’ muscle strength was realized. Dynamic model was built by means of mechanism and training types of robots. Force closed loop control strategy was established based on training pattern. In view of the characteristics of the redundance and economy of wire control, the process for simple wire's load changes was discussed. In order to confirm the characteristics of robot control system, the controller was simulated in Matlab/Simulink. It was verified that command signal could be traced by control system availably and the load during muscle training would be provided effectively.

  16. Calpain 3 is important for muscle regeneration: Evidence from patients with limb girdle muscular dystrophies

    Directory of Open Access Journals (Sweden)

    Hauerslev Simon

    2012-03-01

    Full Text Available Abstract Background Limb girdle muscular dystrophy (LGMD type 2A is caused by mutations in the CAPN3 gene and complete lack of functional calpain 3 leads to the most severe muscle wasting. Calpain 3 is suggested to be involved in maturation of contractile elements after muscle degeneration. The aim of this study was to investigate how mutations in the four functional domains of calpain 3 affect muscle regeneration. Methods We studied muscle regeneration in 22 patients with LGMD2A with calpain 3 deficiency, in five patients with LGMD2I, with a secondary reduction in calpain 3, and in five patients with Becker muscular dystrophy (BMD with normal calpain 3 levels. Regeneration was assessed by using the developmental markers neonatal myosin heavy chain (nMHC, vimentin, MyoD and myogenin and counting internally nucleated fibers. Results We found that the recent regeneration as determined by the number of nMHC/vimentin-positive fibers was greatly diminished in severely affected LGMD2A patients compared to similarly affected patients with LGMD2I and BMD. Whorled fibers, a sign of aberrant regeneration, was highly elevated in patients with a complete lack of calpain 3 compared to patients with residual calpain 3. Regeneration is not affected by location of the mutation in the CAPN3 gene. Conclusions Our findings suggest that calpain 3 is needed for the regenerative process probably during sarcomere remodeling as the complete lack of functional calpain 3 leads to the most severe phenotypes.

  17. [The effect of neurorehabilitation on the functional state and muscle tone of upper limb in patients after ischaemic stroke].

    Science.gov (United States)

    Klimkiewicz, Paulina; Kubsik, Anna; Jankowska, Agnieszka; Woldańska-Okońska, Marta

    2014-03-01

    Rehabilitation of upper limb in patients after ischemic stroke is a major challenge for modern neurorehabilitation. Function of upper limb of patients after ischemic stroke returns on the end of the rehabilitation comparing with another parts of the body. Below presents two groups of patients after ischemic stroke who were rehabilitated with use of the following methods: kinesiotherapy combined with NDT- Bobath method and kinesiotherapy only. The aim of this study was to assess the impact of kinesiotherapy only and NDT- Bobath method combined with kinesiotherapy on the functional state and muscle tone of upper limb in patients after ischemic stroke. The study involved a group of 40 patients after ischemic stroke with motor control and muscle tone problems of upper limb. Patients were divided into two groups, each of them included 20 people. Upper limb in group I was rehabilitated with the use of kinesiotherapy exercise however group II with the use of kinesiotherapy exercise combined with NDT- Bobath method (Neurodevelopmental Treatment Bobath). To evaluate the patients before and after rehabilitation muscle tone Asworth scale was used and to assess functional status Rivermead Motor Assessment (RMAIII) scale was used. After 5 weeks of rehabilitation in group II in majority patients were observed decrease of muscle tone and improvement in upper limb functional status. In group I the muscle tone were also decreased and functional status were better but in smaller impact than in II group. Classical kinesiotherapy combined with the NDT-Bobath method gives better results in neurorehabilitation of upper limb than the use of kinesiotherapy exercises only in patients after ischemic stroke.

  18. Energy flow analysis of amputee walking shows a proximally-directed transfer of energy in intact limbs, compared to a distally-directed transfer in prosthetic limbs at push-off.

    Science.gov (United States)

    Weinert-Aplin, R A; Howard, D; Twiste, M; Jarvis, H L; Bennett, A N; Baker, R J

    2017-01-01

    Reduced capacity and increased metabolic cost of walking occurs in amputees, despite advances in prosthetic componentry. Joint powers can quantify deficiencies in prosthetic gait, but do not reveal how energy is exchanged between limb segments. This study aimed to quantify these energy exchanges during amputee walking. Optical motion and forceplate data collected during walking at a self-selected speed for cohorts of 10 controls, 10 unilateral trans-tibial, 10 unilateral trans-femoral and 10 bilateral trans-femoral amputees were used to determine the energy exchanges between lower limb segments. At push-off, consistent thigh and shank segment powers were observed between amputee groups (1.12W/kg vs. 1.05W/kg for intact limbs and 0.97W/kg vs. 0.99W/kg for prosthetic limbs), and reduced prosthetic ankle power, particularly in trans-femoral amputees (3.12W/kg vs. 0.87W/kg). Proximally-directed energy exchange was observed in the intact limbs of amputees and controls, while prosthetic limbs displayed distally-directed energy exchanges at the knee and hip. This study used energy flow analysis to show a reversal in the direction in which energy is exchanged between prosthetic limb segments at push-off. This reversal was required to provide sufficient energy to propel the limb segments and is likely a direct result of the lack of push-off power at the prosthetic ankle, particularly in trans-femoral amputees, and leads to their increased metabolic cost of walking. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  19. Elective proximal lower limb amputation in spinal cord injury patients with chronic pressure ulcers: improve quality of life, function, and shorten hospital stay. Case report.

    Science.gov (United States)

    Yusmido, Y A; Hisamud-Din, N; Mazlan, M

    2014-10-01

    Pressure ulcers are common among patients with spinal cord injury and can be very challenging to treat. The treatment involves multidisciplinary approach and ranges from simple pressure relieve and wound dressings to a more radical treatment like proximal lower limb amputations, especially in chronic cases with potential detrimental effects to physical and mental health. To report the outcome of three spinal cord injury patients with a history of chronic pressure ulcers who underwent elective proximal lower limb amputations. We reviewed three patients; patient 1 with bilateral hip disarticulation, patient 2 with left hip disarticulation and right transfemoral amputation and patient 3 with bilateral transfemoral amputation. The clinical impact and functional outcome of the patients were reviewed by comparing the length of hospital stay, the short version of the World Health Organization Quality of Life (WHOQOL- BREF) score and the Spinal Cord Independence Measures (SCIM) score before and after amputation. After amputation, all patients have marked reduction in hospital stay (mean reduction of 208 days), improvement in WHOQOL-BREF scores(mean increment of 14.68 scores) and minimal improvement in SCIM scores (mean increment of 3 scores) compared to before amputation. Proximal amputations of the lower limbs are procedures that can be considered as part of the treatment for complicated pressure ulcers. In properly selected patients, it can reduce the number of hospital stay, improve the quality of life and functional outcome.

  20. Characteristics of the muscle activities of the elderly for various pressures in the pneumatic actuator of lower limb orthosis

    Science.gov (United States)

    Kim, Kyong; Yu, Chang-Ho; Kwon, Tae-Kyu; Hong, Chul-Un; Kim, Nam-Gyun

    2005-12-01

    There developed a lower limb orthosis with a pneumatic rubber actuator, which can assist and improve the muscular activities in the lower limb of the elderly. For this purpose, the characteristics of the lower limbs muscle activities for various pressures in the pneumatic actuator for the lower limb orthosis was investigated. To find out the characteristics of the muscle activities for various pneumatic pressures, it analyzed the flexing and extending movement of the knees, and measured the lower limbs muscular power. The subjects wearing the lower limbs orthosis were instructed to perform flexing and extending movement of the knees. The variation in the air pressure of the pneumatic actuator was varies from one kgf/cm2 to four kgf/cm2. The muscular power was measured by monitoring electromyogram using MP100 (BIOPAC Systems, Inc.) and detailed three-dimensional motions of the lower limbs were collected by APAS 3D Motion Analysis system. Through this study, it expected to find the most suitable air pressure for the improvement of the muscular power of the aged.

  1. Proactive Selective Inhibition Targeted at the Neck Muscles: This Proximal Constraint Facilitates Learning and Regulates Global Control.

    Science.gov (United States)

    Loram, Ian D; Bate, Brian; Harding, Pete; Cunningham, Ryan; Loram, Alison

    2017-04-01

    While individual muscle function is known, the sensory and motor value of muscles within the whole-body sensorimotor network is complicated. Specifically, the relationship between neck muscle action and distal muscle synergies is unknown. This work demonstrates a causal relationship between regulation of the neck muscles and global motor control. Studying violinists performing unskilled and skilled manual tasks, we provided ultrasound feedback of the neck muscles with instruction to minimize neck muscle change during task performance and observed the indirect effect on whole-body movement. Analysis of ultrasound, kinematic, electromyographic and electrodermal recordings showed that proactive inhibition targeted at neck muscles had an indirect global effect reducing the cost of movement, reducing complex involuntary, task-irrelevant movement patterns and improving balance. This effect was distinct from the effect of gaze alignment which increased physiological cost and reduced laboratory-referenced movement. Neck muscle inhibition imposes a proximal constraint on the global motor plan, forcing a change in highly automated sensorimotor control. The proximal location ensures global influence. The criterion, inhibition of unnecessary action, ensures reduced cost while facilitating task-relevant variation. This mechanism regulates global motor function and facilitates reinforcement learning to change engrained, maladapted sensorimotor control associated with chronic pain, injury and performance limitation.

  2. The effect of peripheral neuropathy on lower limb muscle strength in diabetic individuals.

    Science.gov (United States)

    Ferreira, Jean P; Sartor, Cristina D; Leal, Ângela M O; Sacco, Isabel C N; Sato, Tatiana O; Ribeiro, Ivana L; Soares, Alice S; Cunha, Jonathan E; Salvini, Tania F

    2017-03-01

    Skeletal muscle strength is poorly described and understood in diabetic participants with diabetic peripheral neuropathy. This study aimed to investigate the extensor and flexor torque of the knee and ankle during concentric, eccentric, and isometric contractions in men with diabetes mellitus type 2 with and without diabetic peripheral neuropathy. Three groups of adult men (n=92), similar in age, body mass index, and testosterone levels, were analyzed: 33 non-diabetic controls, 31 with type 2 diabetes mellitus, and 28 with diabetic peripheral neuropathy. The peak torques in the concentric, eccentric, and isometric contractions were evaluated using an isokinetic dynamometer during knee and ankle flexion and extension. Individuals with diabetes and diabetic peripheral neuropathy presented similar low concentric and isometric knee and ankle torques that were also lower than the controls. However, the eccentric torque was similar among the groups, the contractions, and the joints. Regardless of the presence of peripheral neuropathy, differences in skeletal muscle function were found. The muscle involvement does not follow the same pattern of sensorial losses, since there are no distal-to-proximal impairments. Both knee and ankle were affected, but the effect sizes of the concentric and isometric torques were found to be greater in the participants' knees than in their ankles. The eccentric function did not reveal differences between the healthy control group and the two diabetic groups, raising questions about the involvement of the passive muscle components. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Relationships between power and strength of the upper and lower limb muscles and throwing velocity in male handball players.

    Science.gov (United States)

    Chelly, Mohamed Souhaiel; Hermassi, Souhail; Shephard, Roy J

    2010-06-01

    This study aimed to investigate relationships between peak power (PP) as measured by upper limb (PPUL) and lower limb (PPLL) force-velocity tests, maximal upper limb force assessed by 1 repetition maximum bench press (1RMBP), and pullover (1RMPO) exercises, estimates of local muscle volume and 3-step running handball throwing velocity (T3-Steps). Fourteen male handball players volunteered for the investigation (age: 19.6+/-0.6 years; body mass: 86.7+/-12.9 kg; and height 1.87+/-0.07 m). Lower and upper limb force-velocity tests were performed on appropriately modified forms of a Monark cycle ergometer, with measurement of PPUL and PPLL, and the corresponding respective maximal forces (F0UL and F0LL) and velocities (V0UL and V0LL). T3-Steps was assessed using a radar Stalker ATS system. Muscle volumes of the upper and lower limbs were estimated with a standard anthropometric kit. T3-Steps was closely related to absolute PPUL and to F0UL (r=0.69, plimb muscle volume, the relationship with T3-Steps disappeared. This suggests the importance of muscle volume to performance in throwing events. Force-velocity data may prove useful in regulating conditioning and rehabilitation programs for handball players. Our results also highlight the contribution of both the lower and the upper limbs to handball throwing velocity, suggesting the need for coaches to include upper and lower limb strength and power programs when improving the throwing velocity of handball players.

  4. Ultrasound assessment of lower limb muscle mass in response to resistance training in COPD

    Directory of Open Access Journals (Sweden)

    Menon Manoj K

    2012-12-01

    Full Text Available Abstract Background Quantifying the improvements in lower limb or quadriceps muscle mass following resistance training (RT, is an important outcome measure in COPD. Ultrasound is a portable, radiation free imaging technique that can measure the size of superficial muscles belonging to the quadriceps group such as the rectus femoris, but has not been previously used in COPD patients following RT. We compared the responsiveness of ultrasound derived measures of quadriceps mass against dual energy x-ray absorptiometry (DEXA, in patients with COPD and healthy controls following a programme of high intensity knee extensor RT. Methods Portable ultrasound was used to assess the size of the dominant quadriceps in 45 COPD patients and 19 healthy controls-before, during, and after 8 weeks of bilateral high intensity isokinetic knee extensor RT. Scanning was performed at the mid-thigh region, and 2 indices of quadriceps mass were measured-rectus femoris cross-sectional area (RFcsa and quadriceps muscle thickness (Qt. Thigh lean mass (Tdexa was determined by DEXA. Results Training resulted in a significant increase in Tdexa, RFcsa and Qt in COPD patients [5.7%, 21.8%, 12.1% respectively] and healthy controls [5.4%, 19.5%, 10.9 respectively]. The effect size for the changes in RFcsa (COPD= 0.77; Healthy=0.83 and Qt (COPD=0.36; Healthy=0.78 were greater than the changes in Tdexa (COPD=0.19; Healthy=0.26 following RT. Conclusions Serial ultrasound measurements of the quadriceps can detect changes in muscle mass in response to RT in COPD. The technique has good reproducibility, and may be more sensitive to changes in muscle mass when compared to DEXA. Trial registration http://www.controlled-trials.com (Identifier: ISRCTN22764439

  5. Foot posture influences the electromyographic activity of selected lower limb muscles during gait

    Directory of Open Access Journals (Sweden)

    Menz Hylton B

    2009-11-01

    Full Text Available Abstract Background Some studies have found that flat-arched foot posture is related to altered lower limb muscle function compared to normal- or high-arched feet. However, the results from these studies were based on highly selected populations such as those with rheumatoid arthritis. Therefore, the objective of this study was to compare lower limb muscle function of normal and flat-arched feet in people without pain or disease. Methods Sixty adults aged 18 to 47 years were recruited to this study. Of these, 30 had normal-arched feet (15 male and 15 female and 30 had flat-arched feet (15 male and 15 female. Foot posture was classified using two clinical measurements (the arch index and navicular height and four skeletal alignment measurements from weightbearing foot x-rays. Intramuscular fine-wire electrodes were inserted into tibialis posterior and peroneus longus under ultrasound guidance, and surface EMG activity was recorded from tibialis anterior and medial gastrocnemius while participants walked barefoot at their self-selected comfortable walking speed. Time of peak amplitude, peak and root mean square (RMS amplitude were assessed from stance phase EMG data. Independent samples t-tests were performed to assess for significant differences between the normal- and flat-arched foot posture groups. Results During contact phase, the flat-arched group exhibited increased activity of tibialis anterior (peak amplitude; 65 versus 46% of maximum voluntary isometric contraction and decreased activity of peroneus longus (peak amplitude; 24 versus 37% of maximum voluntary isometric contraction. During midstance/propulsion, the flat-arched group exhibited increased activity of tibialis posterior (peak amplitude; 86 versus 60% of maximum voluntary isometric contraction and decreased activity of peroneus longus (RMS amplitude; 25 versus 39% of maximum voluntary isometric contraction. Effect sizes for these significant findings ranged from 0.48 to 1

  6. Function and position determine relative proportions of different fiber types in limb muscles of the lizard Tropidurus psammonastes.

    Science.gov (United States)

    Pereira, Anieli G; Abdala, Virginia; Kohlsdorf, Tiana

    2015-02-01

    Skeletal muscles can be classified as flexors or extensors according to their function, and as dorsal or ventral according to their position. The latter classification evokes their embryological origin from muscle masses initially divided during limb development, and muscles sharing a given position do not necessarily perform the same function. Here, we compare the relative proportions of different fiber types among six limb muscles in the lizard Tropidurus psammonastes. Individual fibers were classified as slow oxidative (SO), fast glycolytic (FG) or fast oxidative-glycolytic (FOG) based on mitochondrial content; muscles were classified according to position and function. Mixed linear models considering one or both effects were compared using likelihood ratio tests. Variation in the proportion of FG and FOG fibers is mainly explained by function (flexor muscles have on average lower proportions of FG and higher proportions of FOG fibers), while variation in SO fibers is better explained by position (they are less abundant in ventral muscles than in those developed from a dorsal muscle mass). Our results clarify the roles of position and function in determining the relative proportions of the various muscle fibers and provide evidence that these factors may differentially affect distinct fiber types. Copyright © 2014. Published by Elsevier GmbH.

  7. Skiing across the Greenland icecap: divergent effects on limb muscle adaptations and substrate oxidation

    DEFF Research Database (Denmark)

    Helge, Jørn W; Lundby, Carsten; Christensen, Dirk L

    2003-01-01

    This study investigates the adaptive response of the lower limb muscles and substrate oxidation during submaximal arm or leg exercise after a crossing of the Greenland icecap on cross-country skies. Before and after the 42-day expedition, four male subjects performed cycle ergometer and arm......-cranking exercise on two separate days. On each occasion, the subjects exercised at two submaximal loads (arm exercise, 45 W and 100 W; leg exercise, 100 W and 200 W). In addition, peak oxygen uptake ((VO(2max))) was determined for both leg and arm exercise. Before and after the crossing, a muscle biopsy...... was obtained from the vastus lateralis and the triceps brachii muscles prior to exercise (N=3). After the crossing, body mass decreased by 5.7+/-0.5 kg (in four of four subjects), whereas (VO(2max)) was unchanged in the arm (3.1+/-0.2 l min(-1)) and leg (4.0+/-0.1 l min(-1)). Before the crossing, respiratory...

  8. In vivo phosphorus 31 magnetic resonance spectroscopy of rat hind limb skeletal muscle during sepsis.

    Science.gov (United States)

    Jacobs, D O; Maris, J; Fried, R; Settle, R G; Rolandelli, R R; Koruda, M J; Chance, B; Rombeau, J L

    1988-11-01

    High-energy phosphate metabolism in skeletal muscle is altered during sepsis, although the chronology of events is uncertain. Phosphorus 31 magnetic resonance spectroscopy was used to measure changes in muscle energy stores of the left hind limb musculature of adult male rats during sepsis. Following control scans, cecal ligation and puncture were performed and scanning was repeated 6, 24, and 48 hours after surgery. The ratios of phosphocreatine (PCr) to inorganic phosphate (Pi), a measure of energy stores, and adenosine triphosphate (ATP) to Pi ratio, a measure of the energy available for immediate use, were determined from peak heights. Intracellular pH was calculated using the distance between Pi and PCr peaks. In surviving animals, a 40% decrease in PCr/Pi ratio (+/- SEM) was observed by 24 hours (22.3 +/- 3.0 at time 0 vs 13.3 +/- 2.8 at 24 hours), whereas energy availability (beta-ATP/Pi) was statistically unchanged (18.2 +/- 2.2 at time 0 vs 15.2 +/- 1.2 at 48 hours). Intracellular pH did not change. Both PCr/Pi and ATP/Pi ratios were inversely correlated with time. In this model of documented peritonitis, skeletal muscle energy metabolism is rapidly altered following severe infection, and these changes can be detected using 31P magnetic resonance spectroscopy.

  9. Effects of a leaf spring structured midsole on joint mechanics and lower limb muscle forces in running.

    Science.gov (United States)

    Wunsch, Tobias; Alexander, Nathalie; Kröll, Josef; Stöggl, Thomas; Schwameder, Hermann

    2017-01-01

    To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model. A significant reduction in energy absorption at the hip joint as well as energy generation at the ankle joint was found for LEAF compared to FOAM. The mean lower limb muscle forces of the m. soleus, m. gastrocnemius lateralis and m. gastrocnemius medialis were significantly reduced for LEAF compared to FOAM. Furthermore, m. biceps femoris showed a trend of reduction in running with LEAF. The remaining lower limb muscles analyzed (m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. tibialis anterior) did not reveal significant differences between the shoe conditions. The findings of this study indicate that LEAF positively influenced the energy balance in running by reducing lower limb muscle forces compared to FOAM. In this way, LEAF could contribute to an overall increased running performance in heel-toe running.

  10. Effects of a leaf spring structured midsole on joint mechanics and lower limb muscle forces in running

    Science.gov (United States)

    Wunsch, Tobias; Alexander, Nathalie; Kröll, Josef; Stöggl, Thomas; Schwameder, Hermann

    2017-01-01

    To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model. A significant reduction in energy absorption at the hip joint as well as energy generation at the ankle joint was found for LEAF compared to FOAM. The mean lower limb muscle forces of the m. soleus, m. gastrocnemius lateralis and m. gastrocnemius medialis were significantly reduced for LEAF compared to FOAM. Furthermore, m. biceps femoris showed a trend of reduction in running with LEAF. The remaining lower limb muscles analyzed (m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. tibialis anterior) did not reveal significant differences between the shoe conditions. The findings of this study indicate that LEAF positively influenced the energy balance in running by reducing lower limb muscle forces compared to FOAM. In this way, LEAF could contribute to an overall increased running performance in heel-toe running. PMID:28234946

  11. Remote Effect of Lower Limb Acupuncture on Latent Myofascial Trigger Point of Upper Trapezius Muscle: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Kai-Hua Chen

    2013-01-01

    Full Text Available Objectives. To demonstrate the use of acupuncture in the lower limbs to treat myofascial pain of the upper trapezius muscles via a remote effect. Methods. Five adults with latent myofascial trigger points (MTrPs of bilateral upper trapezius muscles received acupuncture at Weizhong (UB40 and Yanglingquan (GB34 points in the lower limbs. Modified acupuncture was applied at these points on a randomly selected ipsilateral lower limb (experimental side versus sham needling on the contralateral lower limb (control side in each subject. Each subject received two treatments within a one-week interval. To evaluate the remote effect of acupuncture, the range of motion (ROM upon bending the contralateral side of the cervical spine was assessed before and after each treatment. Results. There was significant improvement in cervical ROM after the second treatment (P=0.03 in the experimental group, and the increased ROM on the modified acupuncture side was greater compared to the sham needling side (P=0.036. Conclusions. A remote effect of acupuncture was demonstrated in this pilot study. Using modified acupuncture needling at remote acupuncture points in the ipsilateral lower limb, our treatments released tightness due to latent MTrPs of the upper trapezius muscle.

  12. IS PAIN IN ONE KNEE ASSOCIATED WITH ISOMETRIC MUSCLE STRENGTH IN THE CONTRALATERAL LIMB? - DATA FROM THE OSTEOARTHRITIS INITIATIVE (OAI)

    Science.gov (United States)

    Steidle, E.; Wirth, W.; Glass, N.; Ruhdorfer, A.; Cotofana, S.; Eckstein, F.; Segal, N. A.

    2014-01-01

    Objective Knee pain and muscle weakness confer risk for knee osteoarthritis incidence and progression. The purpose of this study was to determine whether unilateral knee pain influences contralateral thigh muscle strength. Design Of 4796 Osteoarthritis Initiative participants, 224 (mean±SD age 63.9±8.9 years) cases could be matched to a control. Cases were defined as having unilateral knee pain (numerical rating scale (NRS)≥4/10; ≥infrequent pain) and one pain-free knee (NRS 0–1; ≤infrequent pain; WOMAC≤1). Controls were defined as having bilaterally pain-free knees (NRS 0–1; ≤infrequent pain; WOMAC≤1). Maximal isometric muscle strength [N] was compared between limbs in participants with unilateral pain (cases), and between pain-free limbs of cases and controls. Results Knee extensor/flexor strength in pain-free limbs of cases was lower than in bilaterally pain-free controls (−5.5%/–8.4%; p=0.043/p=0.022). Within cases, maximum extensor/flexor strength was significantly lower in the painful than in the pain-free limb (−6.4%/4.1%; ppain-free cases and matched bilateral pain-free controls was similar to that between limbs in persons with unilateral knee pain. Lower strength due to contralateral knee pain might be centrally mediated. PMID:25768069

  13. Efficacy of progressive muscle relaxation, mental imagery, and phantom exercise training on phantom limb: a randomized controlled trial.

    Science.gov (United States)

    Brunelli, Stefano; Morone, Giovanni; Iosa, Marco; Ciotti, Cristina; De Giorgi, Roberto; Foti, Calogero; Traballesi, Marco

    2015-02-01

    To evaluate the reduction in phantom pain and sensation with combined training of progressive muscle relaxation, mental imagery, and phantom exercises. Randomized controlled prospective trial with 2 parallel groups. Amputee unit of a rehabilitation hospital. Subjects with unilateral lower limb amputation (N=51) with phantom limb pain (PLP) and/or phantom limb sensation (PLS). The experimental group performed combined training of progressive muscle relaxation, mental imagery, and phantom exercises 2 times/wk for 4 weeks, whereas the control group had the same amount of physical therapy dedicated to the residual limb. No pharmacological intervention was initiated during the trial period. The Prosthesis Evaluation Questionnaire and the Brief Pain Inventory were used to evaluate changes over time in different aspects (intensity, rate, duration, and bother) of PLS and PLP. Blind evaluations were performed before and after treatment and after 1-month follow-up. The experimental group showed a significant decrease over time in all the Prosthesis Evaluation Questionnaire domains (in terms of both PLS and PLP; Pprogressive muscle relaxation, mental imagery, and modified phantom exercises should be taken into account as a valuable technique to reduce phantom limb pain and sensation. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  14. Chronic hypobaric hypoxia increases isolated rat fast-twitch and slow-twitch limb muscle force and fatigue.

    Science.gov (United States)

    El-Khoury, R; Bradford, A; O'Halloran, K D

    2012-01-01

    Chronic hypoxia alters respiratory muscle force and fatigue, effects that could be attributed to hypoxia and/or increased activation due to hyperventilation. We hypothesized that chronic hypoxia is associated with phenotypic change in non-respiratory muscles and therefore we tested the hypothesis that chronic hypobaric hypoxia increases limb muscle force and fatigue. Adult male Wistar rats were exposed to normoxia or hypobaric hypoxia (PB=450 mm Hg) for 6 weeks. At the end of the treatment period, soleus (SOL) and extensor digitorum longus (EDL) muscles were removed under pentobarbitone anaesthesia and strips were mounted for isometric force determination in Krebs solution in standard water-jacketed organ baths at 25 °C. Isometric twitch and tetanic force, contractile kinetics, force-frequency relationship and fatigue characteristics were determined in response to electrical field stimulation. Chronic hypoxia increased specific force in SOL and EDL compared to age-matched normoxic controls. Furthermore, chronic hypoxia decreased endurance in both limb muscles. We conclude that hypoxia elicits functional plasticity in limb muscles perhaps due to oxidative stress. Our results may have implications for respiratory disorders that are characterized by prolonged hypoxia such as chronic obstructive pulmonary disease (COPD).

  15. Stimulus-response characteristics of motor evoked potentials and silent periods in proximal and distal upper-extremity muscles.

    NARCIS (Netherlands)

    Kuijk, A.A. van; Anker, L.C.; Pasman, J.W.; Hendriks, J.C.M.; Elswijk, G.A.F. van; Geurts, A.C.H.

    2009-01-01

    OBJECTIVE: To compare stimulus-response characteristics of both motor evoked potentials (MEP) and silent periods (SP) induced by transcranial magnetic stimulation (TMS) in proximal and distal upper-extremity muscles. METHODS: Stimulus-response curves of MEPs and SPs were obtained from the biceps

  16. Disfunção muscular periférica em DPOC: membros inferiores versus membros superiores Peripheral muscle dysfunction in COPD: lower limbs versus upper limbs

    Directory of Open Access Journals (Sweden)

    Eduardo Foschini Miranda

    2011-06-01

    unsupported upper limbs and two mechanisms have been proposed to explain this fact: neuromechanical dysfunction of respiratory muscles; and changes in lung volume during such activities. The neuromechanical dysfunction seen in COPD patients during this type of exercise is related to changes in the breathing pattern, as well as to the simultaneity of afferent and efferent muscle stimuli, resulting in respiratory muscle asynchrony. In addition, the increased ventilation during upper limb exercise in patients with COPD leads to dynamic hyperinflation at different workloads. During lower limb exercises, the strength and endurance of the quadriceps muscle is lower in COPD patients than in healthy subjects. This could by explained by abnormal muscle metabolism (decreased aerobic capacity, dependence on glycolytic metabolism, and rapid accumulation of lactate during exercise. In comparison with lower limb exercises, upper limb exercises result in higher metabolic and ventilatory demands, as well as in a more intense sensation of dyspnea and greater fatigue. Because there are differences between the upper and lower limb muscles in terms of the morphological and functional adaptations in COPD patients, specific protocols for strength training and endurance should be developed and tested for the corresponding muscle groups

  17. The role of muscle proprioceptors in human limb position sense: a hypothesis.

    Science.gov (United States)

    Proske, Uwe

    2015-08-01

    In this mini-review I have proposed that there are two kinds of position sense, one a sense of the position of one part of the body relative to another, the other a sense of the location in space of our body and its limbs. A common method used to measure position sense is to ask subjects to match with one arm the position adopted by the other. Here all of the evidence points to muscle spindles as the major proprioceptors, with cutaneous receptors acting as proprioceptors providing a supporting role. Other senses such as vision do not play a major role. The sense of localisation in space measured by pointing to the arm, rather than matching its position, I propose, is not served by proprioceptors but by exteroceptors, vision, touch and hearing. Here the afferent input is relayed to sensory areas of the brain, to address the postural schema, a cortical map of the body and limbs, specifying its size and shape. It is here that spatial location is computed. This novel interpretation of position sense as two separate entities has the advantage of proposing new, future experiments and if it is supported by the findings, it will represent an important step forward in our understanding of the central processing of spatial information. © 2015 Anatomical Society.

  18. Upper-limb muscle responses to epidural, subdural and intraspinal stimulation of the cervical spinal cord

    Science.gov (United States)

    Sharpe, Abigail N.; Jackson, Andrew

    2014-02-01

    Objective. Electrical stimulation of the spinal cord has potential applications following spinal cord injury for reanimating paralysed limbs and promoting neuroplastic changes that may facilitate motor rehabilitation. Here we systematically compare the efficacy, selectivity and frequency-dependence of different stimulation methods in the cervical enlargement of anaesthetized monkeys. Approach. Stimulating electrodes were positioned at multiple epidural and subdural sites on both dorsal and ventral surfaces, as well as at different depths within the spinal cord. Motor responses were recorded from arm, forearm and hand muscles. Main results. Stimulation efficacy increased from dorsal to ventral stimulation sites, with the exception of ventral epidural electrodes which had the highest recruitment thresholds. Compared to epidural and intraspinal methods, responses to subdural stimulation were more selective but also more similar between adjacent sites. Trains of stimuli delivered to ventral sites elicited consistent responses at all frequencies whereas from dorsal sites we observed a mixture of short-latency facilitation and long-latency suppression. Finally, paired stimuli delivered to dorsal surface and intraspinal sites exhibited symmetric facilitatory interactions at interstimulus intervals between 2-5 ms whereas on the ventral side interactions tended to be suppressive for near-simultaneous stimuli. Significance. We interpret these results in the context of differential activation of afferent and efferent roots and intraspinal circuit elements. In particular, we propose that distinct direct and indirect actions of spinal cord stimulation on motoneurons may be advantageous for different applications, and this should be taken into consideration when designing neuroprostheses for upper-limb function.

  19. Robot-assisted mechanical therapy attenuates stroke-induced limb skeletal muscle injury.

    Science.gov (United States)

    Sen, Chandan K; Khanna, Savita; Harris, Hallie; Stewart, Richard; Balch, Maria; Heigel, Mallory; Teplitsky, Seth; Gnyawali, Surya; Rink, Cameron

    2017-03-01

    The efficacy and optimization of poststroke physical therapy paradigms is challenged in part by a lack of objective tools available to researchers for systematic preclinical testing. This work represents a maiden effort to develop a robot-assisted mechanical therapy (RAMT) device to objectively address the significance of mechanical physiotherapy on poststroke outcomes. Wistar rats were subjected to right hemisphere middle-cerebral artery occlusion and reperfusion. After 24 h, rats were split into control (RAMT-) or RAMT+ groups (30 min daily RAMT over the stroke-affected gastrocnemius) and were followed up to poststroke d 14. RAMT+ increased perfusion 1.5-fold in stroke-affected gastrocnemius as compared to RAMT- controls. Furthermore, RAMT+ rats demonstrated improved poststroke track width (11% wider), stride length (21% longer), and travel distance (61% greater), as objectively measured using software-automated testing platforms. Stroke injury acutely increased myostatin (3-fold) and lowered brain-derived neurotrophic factor (BDNF) expression (0.6-fold) in the stroke-affected gastrocnemius, as compared to the contralateral one. RAMT attenuated the stroke-induced increase in myostatin and increased BDNF expression in skeletal muscle. Additional RAMT-sensitive myokine targets in skeletal muscle (IL-1ra and IP-10/CXCL10) were identified from a cytokine array. Taken together, outcomes suggest stroke acutely influences signal transduction in hindlimb skeletal muscle. Regimens based on mechanical therapy have the clear potential to protect hindlimb function from such adverse influence.-Sen, C. K., Khanna, S., Harris, H., Stewart, R., Balch, M., Heigel, M., Teplitsky, S., Gnyawali, S., Rink, C. Robot-assisted mechanical therapy attenuates stroke-induced limb skeletal muscle injury. © FASEB.

  20. The dance’s influence on muscle strength of lower limbs on the elderly

    Directory of Open Access Journals (Sweden)

    Joseane Rodrigues da Silva

    2011-09-01

    Full Text Available The aim of this study was to evaluate the influence of dance in the lower limb muscle strength on the elderly. This research has a qualitative-quantitative aproach. The sample was composed by ten elderly of both sexes, who practiced ballroom dancing classes during twelve weeks. The evaluation was performed before and after the classes and it was composed by a questionnaire with personal data and medical history, “test stand and sit in 30 seconds” and a semi-structured interview with a guiding question regarding the perception of muscular strength of the elderly. The quantitative analysis was performed using the Student’s t-test with a significance level of p<0,05%. The qualitative analysis was made according directions proposed by Minayo (1994. The evaluation of muscle strength measured by the test of sitting and standing up, showed that four participants had a decreased and six had an increase in the number of movements executed, but not existed a significant statistical difference between the values before and after intervention (p=0,1934. However, the speech of the participants showed an improvement on the perception in relation muscle strength, mobility, joviality and self-esteem. It suggests that the effect of the dance, performed in the frequency used in this study, has an effect on the well-being and psychosocial sphere of the elderly. Playful activities in physical therapy performed by groups, bringing benefits, however, it should not be an isolated activity, it should be associated with a specific training to improve muscle strength related to the needs of each elderly.

  1. FES-induced co-activation of antagonist muscles for upper limb control and disturbance rejection.

    Science.gov (United States)

    Bó, Antônio Padilha L; da Fonseca, Lucas O; de Sousa, Ana Carolina C

    2016-11-01

    Control systems for human movement based on Functional Electrical Stimulation (FES) have shown to provide excellent performance in different experimental setups. Nevertheless, there is still a limited number of such applications available today on worldwide markets, indicating poor performance in real settings, particularly for upper limb rehabilitation and assistance. Based on these premises, in this paper we explore the use of an alternative control strategy based on co-activation of antagonist muscles using FES. Although co-contraction may accelerate fatigue when compared to single-muscle activation, knowledge from motor control indicate it may be useful for some applications. We have performed a simulation and experimental study designed to evaluate whether controllers that integrate such features can modulate joint impedance and, by doing so, improving performance with respect to disturbance rejection. The simulation results, obtained using a novel model including proprioceptive feedback and anatomical data, indicate that both stiffness and damping components of joint impedance may be modulated by using FES-induced co-activation of antagonist muscles. Preliminary experimental trials were conducted on four healthy subjects using surface electrodes. While the simulation investigation predicted a maximum 494% increase in joint stiffness for wrist flexion/extension, experiments provided an average elbow stiffness increase of 138% using lower stimulation intensity. Closed-loop experiments in which disturbances were applied have demonstrated that improved behavior may be obtained, but increased joint stiffness and other issues related to simultaneous stimulation of antagonist muscles may indeed produce greater errors. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  2. The own method and program of isotope quantitatively assessment of perfusion in muscles of upper limbs (initial report).

    Science.gov (United States)

    Niewiadomski, Dariusz; Tryniszewski, Wieslaw; Marzec, Wojciech; Brocki, Marian; Mikosiński, Jacek; Raciborska, Iwona; Maziarz, Zbigniew

    2014-01-01

    The issue of blood flow in muscles has been dealt with for many years. However, most often it was assessed qualitatively with standard vascular examinations. The quantitatively perfusion assessment is indispensable in the normal and pathological conditions. Some diseases impair the perfusion mainly in the area of upper limbs. It can be observed in Raynaud's disease, vascular occlusive diseases, neurological disturbances, and thermal injuries. Hyperhidrosis of upper limbs after sympathectomy of thoracic part of sympathetic trunk may bring closer the diagnosis statement. Nuclear medicine has the markers and methods that allow for the assessment of the volume of perfusion in muscles. The aim for creating this method and program was the development of radioisotope method allowing for quantitative assessment of perfusion in muscles of upper limbs. This should lead to calculating the perfusion index and its range of normal values in a greater group of patients and to using this method both in the healthy and pathological conditions. 20 patients, age 30.4 ± 7.1 years, who underwent following examinations: qualification to the group, medical history, subject examinations, USG of upper limb vessels, anthropometric examinations, biochemical and hormonal blood tests, the assessment of upper limbs with USG Doppler and FMD (flow mediated dilatation), radioisotope examinations with gamma camera BrightView XCT by own program RAPUL (Radioisotope Assessment Perfusion of Upper Limb). Acquisitions were started five minutes after intravenous injection of 99mTc-MIBI (metoxyisobutylnitrite). The whole body scintigram and scintigrams of arm and forearm muscles in A-P projections were taken. In the examined patients, the results of anthropometric, biochemical and hormonal test were within the range of normal values. In radioisotope quantitative assessment of perfusion, perfusion indexes of left arm were 20 military services) and pathological conditions.

  3. Reconstructing pectoral appendicular muscle anatomy in fossil fish and tetrapods over the fins-to-limbs transition.

    Science.gov (United States)

    Molnar, Julia L; Diogo, Rui; Hutchinson, John R; Pierce, Stephanie E

    2017-11-10

    The question of how tetrapod limbs evolved from fins is one of the great puzzles of evolutionary biology. While palaeontologists, developmental biologists, and geneticists have made great strides in explaining the origin and early evolution of limb skeletal structures, that of the muscles remains largely unknown. The main reason is the lack of consensus about appendicular muscle homology between the closest living relatives of early tetrapods: lobe-finned fish and crown tetrapods. In the light of a recent study of these homologies, we re-examined osteological correlates of muscle attachment in the pectoral girdle, humerus, radius, and ulna of early tetrapods and their close relatives. Twenty-nine extinct and six extant sarcopterygians were included in a meta-analysis using information from the literature and from original specimens, when possible. We analysed these osteological correlates using parsimony-based character optimization in order to reconstruct muscle anatomy in ancestral lobe-finned fish, tetrapodomorph fish, stem tetrapods, and crown tetrapods. Our synthesis revealed that many tetrapod shoulder muscles probably were already present in tetrapodomorph fish, while most of the more-distal appendicular muscles either arose later from largely undifferentiated dorsal and ventral muscle masses or did not leave clear correlates of attachment in these taxa. Based on this review and meta-analysis, we postulate a stepwise sequence of specific appendicular muscle acquisitions, splits, and fusions that led from the ancestral sarcopterygian pectoral fin to the ancestral tetrapod forelimb. This sequence largely agrees with previous hypotheses based on palaeontological and comparative work, but it is much more comprehensive in terms of both muscles and taxa. Combined with existing information about the skeletal system, our new synthesis helps to illuminate the genetic, developmental, morphological, functional, and ecological changes that were key components of the

  4. Efficacy of lower limb compression and combined treatment of manual massage and lower limb compression on symptoms of exercise-induced muscle damage in women.

    Science.gov (United States)

    Jakeman, John R; Byrne, Chris; Eston, Roger G

    2010-11-01

    Strategies to manage the symptoms of exercise-induced muscle damage (EIMD) are widespread, though are often based on anecdotal evidence. The aim of this study was to determine the efficacy of a combination of manual massage and compressive clothing and compressive clothing individually as recovery strategies after muscle damage. Thirty-two female volunteers completed 100 plyometric drop jumps and were randomly assigned to a passive recovery (n = 17), combined treatment (n = 7), or compression treatment group (n = 8). Indices of muscle damage (perceived soreness, creatine kinase activity, isokinetic muscle strength, squat jump, and countermovement jump performance) were assessed immediately before and after 1, 24, 48, 72, and 96 hours of plyometric exercise. The compression treatment group wore compressive tights for 12 hours after damage and the combined treatment group received a 30-minute massage immediately after damaging exercise and wore compression stockings for the following 11.5 hours. Plyometric exercise had a significant effect on all indices of muscle damage (p performance, and countermovement jump performance and reduced the level of perceived soreness in comparison with the passive recovery group (p sports massage to compression after muscle damage did not improve performance recovery, with recovery trends being similar in both treatment groups. The treatment combination of massage and compression significantly moderated perceived soreness at 48 and 72 hours after plyometric exercise (p massage with lower limb compression are effective recovery strategies following EIMD. Minimal performance differences between treatments were observed, although the combination treatment may be beneficial in controlling perceived soreness.

  5. Prediction of upper limb muscle activity from motor cortical discharge during reaching

    Science.gov (United States)

    Pohlmeyer, Eric A; Solla, Sara A; Perreault, Eric J; Miller, Lee E

    2008-01-01

    Movement representation by the motor cortex (M1) has been a theoretical interest for many years, but in the past several years it has become a more practical question, with the advent of the brain–machine interface. An increasing number of groups have demonstrated the ability to predict a variety of kinematic signals on the basis of M1 recordings and to use these predictions to control the movement of a cursor or robotic limb. We, on the other hand, have undertaken the prediction of myoelectric (EMG) signals recorded from various muscles of the arm and hand during button pressing and prehension movements. We have shown that these signals can be predicted with accuracy that is similar to that of kinematic signals, despite their stochastic nature and greater bandwidth. The predictions were made using a subset of 12 or 16 neural signals selected in the order of each signal’s unique, output-related information content. The accuracy of the resultant predictions remained stable through a typical experimental session. Accuracy remained above 80% of its initial level for most muscles even across periods as long as two weeks. We are exploring the use of these predictions as control signals for neuromuscular electrical stimulation in quadriplegic patients. PMID:18057504

  6. One-leg standing performance and muscle activity: are there limb differences?

    Science.gov (United States)

    Muehlbauer, Thomas; Mettler, Claude; Roth, Ralf; Granacher, Urs

    2014-06-01

    The purpose of this study was to compare static balance performance and muscle activity during one-leg standing on the dominant and nondominant leg under various sensory conditions with increased levels of task difficulty. Thirty healthy young adults (age: 23 ± 2 years) performed one-leg standing tests for 30 s under three sensory conditions (ie, eyes open/firm ground; eyes open/ foam ground [elastic pad on top of the balance plate]; eyes closed/firm ground). Center of pressure displacements and activity of four lower leg muscles (ie, m. tibialis anterior [TA], m. soleus [SOL], m. gastrocnemius medialis [GAS], m. peroneus longus [PER]) were analyzed. An increase in sensory task difficulty resulted in deteriorated balance performance (P leg standing on the dominant as compared with the nondominant limb did not produce statistically significant differences in various balance (P > .05, ES = .06-.22) and electromyographic (P > .05, ES = .03-.13) measures. This indicates that the dominant and the nondominant leg can be used interchangeably during static one-leg balance testing in healthy young adults.

  7. Test-retest reliabilities of hand-held dynamometer for lower-limb muscle strength in intellectual disabilities.

    Science.gov (United States)

    Wuang, Yee-Pay; Chang, Jyh-Jong; Wang, Min-Hung; Lin, Hsiu-Ching

    2013-08-01

    The primary purpose of this study was to investigate the test-retest reliabilities of hand-held dynamometer (HDD) for measuring lower-limb muscle strength in intellectual disabilities (ID). The other purposes were to: (1) compare the lower-limb muscle strength between children with and without ID; (2) probe the relationship between the muscle forces and agility performance in ID; and (3) explore the factors associated with muscle strength in ID. Sixty-one participants (30 boys and 31 girls; mean age=14.1 ± 3.3 year) were assessed by the HDD using a "make" test. The comparative group consisted of 63 typically developing children (33 boys and 30 girls; mean age=14.9 ± 2.1 year). The ID group demonstrated lower muscle groups than in typically developing group. Except for the ankle plantarflexors (ICC=0.69, SEM=0.72), test-retest analysis showed good intrarater reliability with ICC ranging from 0.81 to 0.96, and intrarater SEM values ranged from 0.40 to 0.57. The HDD has the potential to be a reliable tool for strength measurement in ID. Muscle strength was positively related to agility performance. Regression analysis indicated that height, weight, BMI, and activity level were significant predictors of muscle strength in ID. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. The relationship between the piriformis muscle, low back pain, lower limb injuries and motor control training among elite football players.

    Science.gov (United States)

    Leung, Felix T; Mendis, M Dilani; Stanton, Warren R; Hides, Julie A

    2015-07-01

    Australian Football League (AFL) players have a high incidence of back injuries. Motor control training to increase lumbopelvic neuromuscular control has been effective in reducing low back pain (LBP) and lower limb injuries in elite athletes. Control of pelvic and femoral alignment during functional activity involves the piriformis muscle. This study investigated (a) the effect of motor control training on piriformis muscle size in AFL players, with and without LBP, during the playing season, and (b) whether there is a relationship between lower limb injury and piriformis muscle size. Stepped-wedge intervention. 46 AFL players participated in a motor control training programme consisting of two 30min sessions per week over 7-8 weeks, delivered across the season as a randomised 3 group single-blinded stepped-wedge design. Assessment of piriformis muscle cross-sectional area (CSA) involved magnetic resonance imaging (MRI) at 3 time points during the season. Assessment of LBP consisted of player interview and physical examination. Injury data were obtained from club records. An interaction effect for Time, Intervention Group and LBP group (F=3.7, p=0.03) was found. Piriformis muscle CSA showed significant increases between Times 1 and 2 (F=4.24, p=0.046), and Times 2 and 3 (F=8.59, p=0.006). Players with a smaller increase in piriformis muscle CSA across the season had higher odds of sustaining an injury (OR=1.08). Piriformis muscle size increases across the season in elite AFL players and is affected by the presence of LBP and lower limb injury. Motor control training positively affects piriformis muscle size in players with LBP. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  9. Effects of fatigue on lower limb, pelvis and trunk kinematics and lower limb muscle activity during single-leg landing after anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Lessi, Giovanna Camparis; Serrão, Fábio Viadanna

    2017-08-01

    Because there are no studies that have evaluated the effects of fatigue on the kinematics of the trunk and pelvis or on muscle activation in subjects with ACL reconstruction, the aim of this study was to evaluate the effects of fatigue on the lower limb, pelvis and trunk kinematics and lower limb muscle activation in subjects with ACL reconstruction during a single-leg landing compared to a healthy control group. The participants included 20 subjects with ACL reconstruction (ACL reconstruction group-ACLRG) and 20 healthy subjects (control group-CG) who were aged between 18 and 35 years. Kinematic and electromyographic analyses were performed during a single-leg landing before and after fatigue. The fatigue protocol included a series of 10 squats, two vertical jumps, and 20 steps. The effects of fatigue were increased peak trunk flexion and increased activation of the vastus lateralis, biceps femoris (BF) and gluteus maximus (GMax) during the landing phase. After the fatigue protocol, an increase in peak trunk flexion and activation of the GMax and BF were observed, most likely as a strategy to reduce the load on the ACL. ACL injury prevention programs should include strength and endurance exercises for the hip and trunk extensor muscles so that they can efficiently control trunk flexion during landing. Prospective comparative study, Level II.

  10. Effects of hip and trunk muscle strengthening on hip function and lower limb kinematics during step-down task.

    Science.gov (United States)

    Araújo, Vanessa Lara; Souza, Thales Rezende; Carvalhais, Viviane Otoni do Carmo; Cruz, Aline Castro; Fonseca, Sérgio Teixeira

    2017-05-01

    Strengthening of the hip and trunk muscles has the potential to change lower limb kinematic patterns, such as excessive hip medial rotation and adduction during weight-bearing tasks. This study aimed to investigate the effect of hip and trunk muscles strengthening on hip muscle performance, hip passive properties, and lower limb kinematics during step-down task in women. Thirty-four young women who demonstrated dynamic knee valgus during step-down were divided into two groups. The experimental group underwent three weekly sessions of strengthening exercises for eight weeks, and the control group continued their usual activities. The following evaluations were carried out: (a) isokinetic maximum concentric and eccentric work of hip lateral rotators, (b) isokinetic hip passive torque of lateral rotation and resting transverse plane position, and (c) three-dimensional kinematics of the lower limb during step-down. The strengthening program increased concentric (Plower limb adduction during step-down. The changes in hip maximum work and resting position may have contributed to the observed kinematic effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. The Effects of Abdominal Hollowing in Lower-limb PNF Pattern Training on the Activation of Contralateral Muscles.

    Science.gov (United States)

    Yoo, Byungho; Park, Hankyu; Heo, Kwangjin; Lee, Joongsook; Lee, Jaeseok; Oh, Taeyoung; Han, Dongwook

    2013-10-01

    [Purpose] The purpose of this study was to determine the effects of abdominal hollowing during lower-limb proprioceptive neuromuscular facilitation (PNF) training on the activation of contralateral muscles. [Subjects] Twenty male college students without symptoms or signs of muscular or nervous disease participated in this experiment after signing a consent form. [Methods] All the subjects were measured with electromyography (EMG) in a muscle activation test before and after abdominal hollowing. In the PNF program, the lower-limb pattern of PNF training, was maintained for 5 seconds, followed by a 2-minute break. This was repeated three times. The resting time between sets was 30 minutes. Surface EMG (Keypoint, Medtronic Inc., USA) was used for the measurements, and the highest value of three measurements was used in the analysis. [Result] The results revealed a significant change in the muscular activation of the opposite-side lower limbs. The muscular activations of the vastus lateralis, tibialis anterior, semitendinosus and gastrocnemius were increased significantly after the abdominal hollowing. [Conclusion] The findings suggest that abdominal hollowing in PNF pattern training can be effective at promoting muscular activation of the contralateral muscles. To promote muscular activation of the opposite side in lower-limb PNF pattern training, abdominal hollowing should be considered to improve the effect of PNF pattern training.

  12. Foot center of pressure manipulation and gait therapy influence lower limb muscle activation in patients with osteoarthritis of the knee.

    Science.gov (United States)

    Goryachev, Yulia; Debbi, Eytan M; Haim, Amir; Rozen, Nimrod; Wolf, Alon

    2011-10-01

    Foot center of pressure (COP) manipulation has been associated with improved gait patterns. The purpose of this study was to determine lower limb muscle activation changes in knee osteoarthritis patients, both immediately after COP manipulation and when COP manipulation was combined with continuous gait therapy (AposTherapy). Fourteen females with medial compartment knee osteoarthritis underwent EMG analyzes of key muscles of the leg. In the initial stage, trials were carried out at four COP positions. Following this, gait therapy was initiated for 3 months. The barefoot EMG was compared before and after therapy. The average EMG varied significantly with COP in at least one phase of stance in all examined muscles of the less symptomatic leg and in three muscles of the more symptomatic leg. After training, a significant increase in average EMG was observed in most muscles. Most muscles of the less symptomatic leg showed significantly increased peak EMG. Activity duration was shorter for all muscles of the less symptomatic leg (significant in the lateral gastrocnemius) and three muscles of the more symptomatic leg (significant in the biceps femoris). These results were associated with reduced pain, increased function and improved spatiotemporal parameters. COP manipulation influences the muscle activation patterns of the leg in patients with knee osteoarthritis. When combined with a therapy program, muscle activity increases and activity duration decreases. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Decoding Lower Limb Muscle Activity and Kinematics from Cortical Neural Spike Trains during Monkey Performing Stand and Squat Movements

    Science.gov (United States)

    Ma, Xuan; Ma, Chaolin; Huang, Jian; Zhang, Peng; Xu, Jiang; He, Jiping

    2017-01-01

    Extensive literatures have shown approaches for decoding upper limb kinematics or muscle activity using multichannel cortical spike recordings toward brain machine interface (BMI) applications. However, similar topics regarding lower limb remain relatively scarce. We previously reported a system for training monkeys to perform visually guided stand and squat tasks. The current study, as a follow-up extension, investigates whether lower limb kinematics and muscle activity characterized by electromyography (EMG) signals during monkey performing stand/squat movements can be accurately decoded from neural spike trains in primary motor cortex (M1). Two monkeys were used in this study. Subdermal intramuscular EMG electrodes were implanted to 8 right leg/thigh muscles. With ample data collected from neurons from a large brain area, we performed a spike triggered average (SpTA) analysis and got a series of density contours which revealed the spatial distributions of different muscle-innervating neurons corresponding to each given muscle. Based on the guidance of these results, we identified the locations optimal for chronic electrode implantation and subsequently carried on chronic neural data recordings. A recursive Bayesian estimation framework was proposed for decoding EMG signals together with kinematics from M1 spike trains. Two specific algorithms were implemented: a standard Kalman filter and an unscented Kalman filter. For the latter one, an artificial neural network was incorporated to deal with the nonlinearity in neural tuning. High correlation coefficient and signal to noise ratio between the predicted and the actual data were achieved for both EMG signals and kinematics on both monkeys. Higher decoding accuracy and faster convergence rate could be achieved with the unscented Kalman filter. These results demonstrate that lower limb EMG signals and kinematics during monkey stand/squat can be accurately decoded from a group of M1 neurons with the proposed

  14. Lower limb muscle volume estimation from maximum cross-sectional area and muscle length in cerebral palsy and typically developing individuals.

    Science.gov (United States)

    Vanmechelen, Inti M; Shortland, Adam P; Noble, Jonathan J

    2018-01-01

    Deficits in muscle volume may be a significant contributor to physical disability in young people with cerebral palsy. However, 3D measurements of muscle volume using MRI or 3D ultrasound may be difficult to make routinely in the clinic. We wished to establish whether accurate estimates of muscle volume could be made from a combination of anatomical cross-sectional area and length measurements in samples of typically developing young people and young people with bilateral cerebral palsy. Lower limb MRI scans were obtained from the lower limbs of 21 individuals with cerebral palsy (14.7±3years, 17 male) and 23 typically developing individuals (16.8±3.3years, 16 male). The volume, length and anatomical cross-sectional area were estimated from six muscles of the left lower limb. Analysis of Covariance demonstrated that the relationship between the length*cross-sectional area and volume was not significantly different depending on the subject group. Linear regression analysis demonstrated that the product of anatomical cross-sectional area and length bore a strong and significant relationship to the measured muscle volume (R2 values between 0.955 and 0.988) with low standard error of the estimates of 4.8 to 8.9%. This study demonstrates that muscle volume may be estimated accurately in typically developing individuals and individuals with cerebral palsy by a combination of anatomical cross-sectional area and muscle length. 2D ultrasound may be a convenient method of making these measurements routinely in the clinic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Influence of Lateral Muscle Loading in the Proximal Femur after Fracture Stabilization with a Trochanteric Gamma Nail (TGN)

    Science.gov (United States)

    Sitthiseripratip, Kriskrai; Mahaisavariya, Banchong; Suwanprateeb, Jintamai; Bohez, Erik; Vander Sloten, Jos

    The purpose of this study was to investigate the influence of lateral muscle loading on the stress/strain distributions of the trochanteric Gamma nail (TGN) fixation within the healed, trochanteric and subtrochanteric femoral fractures by means of a finite element method. The effect of three muscle groups, the abductors (ABD), the vastus lateralis (VL) and the iliotibial band (ITB), were investigated. The analytical results showed that addition of lateral muscle forces, iliotibial band and vastus lateralis, produced compensation of forces and reduction of bending moments in the bone and in the trochanteric Gamma nail especially in the lateral aspect. The iliotibial band produced a higher impact as compared to the vastus lateralis. Therefore in the finite element analysis of the proximal femur with the trochanteric Gamma nail fracture fixation should include the lateral muscle forces to simulate load condition with maximal physiological relevance to the closed nailing technique.

  16. Glu20Ter Variant in PLEC 1f Isoform Causes Limb-Girdle Muscle Dystrophy with Lung Injury

    Science.gov (United States)

    Deev, Roman V.; Bardakov, Sergei N.; Mavlikeev, Mikhail O.; Yakovlev, Ivan A.; Umakhanova, Zoya R.; Akhmedova, Patimat G.; Magomedova, Raisat M.; Chekmaryeva, Irina A.; Dalgatov, Gimat D.; Isaev, Artur A.

    2017-01-01

    Plectinopathies are orphan diseases caused by PLEC gene mutations. PLEC is encoding the protein plectin, playing a role in linking cytoskeleton components in various tissues. In this study, we describe the clinical case of a 26-year-old patient with an early onset plectinopathy variant “limb-girdle muscle dystrophy type 2Q,” report histopathological and ultrastructural findings in m. vastus lateralis biopsy and a novel homozygous likely pathogenic variant (NM_201378.3:c.58G>T, NP_958780.1:p.Glu20Ter) in isoform 1f of the gene PLEC. The patient had an early childhood onset with retarded physical development, moderate weakness in pelvic girdle muscles, progressive weakening of limb-girdle muscles after the age of 21, pronounced atrophy of axial muscles, and hypertrophy of the gastrocnemius, deltoid, and triceps muscles, intermittent dyspnea, and no skin involvement. Findings included: non-infectious bronchiolitis and atelectasis signs, biopsy revealed myodystrophal pattern without macrophage infiltration, muscle fiber cytoskeleton disorganization resulted from the plectin loss, incomplete reparative rhabdomyogenesis, and moderate endomysial fibrosis. We have determined a novel likely pathogenic variant in PLEC 1f isoform that causes limb-girdle muscle dystrophy type 2Q and described the third case concerning an isolated myodystrophic phenotype of LGMD2Q with the likely pathogenic variant in PLEC 1f isoform. In addition, we have demonstrated the presence of severe lung injury in a patient and his siblings with the same myodystrophic phenotype and discussed the possible role of plectin deficiency in its pathogenesis. PMID:28824526

  17. Glu20Ter Variant in PLEC 1f Isoform Causes Limb-Girdle Muscle Dystrophy with Lung Injury

    Directory of Open Access Journals (Sweden)

    Roman V. Deev

    2017-07-01

    Full Text Available Plectinopathies are orphan diseases caused by PLEC gene mutations. PLEC is encoding the protein plectin, playing a role in linking cytoskeleton components in various tissues. In this study, we describe the clinical case of a 26-year-old patient with an early onset plectinopathy variant “limb-girdle muscle dystrophy type 2Q,” report histopathological and ultrastructural findings in m. vastus lateralis biopsy and a novel homozygous likely pathogenic variant (NM_201378.3:c.58G>T, NP_958780.1:p.Glu20Ter in isoform 1f of the gene PLEC. The patient had an early childhood onset with retarded physical development, moderate weakness in pelvic girdle muscles, progressive weakening of limb-girdle muscles after the age of 21, pronounced atrophy of axial muscles, and hypertrophy of the gastrocnemius, deltoid, and triceps muscles, intermittent dyspnea, and no skin involvement. Findings included: non-infectious bronchiolitis and atelectasis signs, biopsy revealed myodystrophal pattern without macrophage infiltration, muscle fiber cytoskeleton disorganization resulted from the plectin loss, incomplete reparative rhabdomyogenesis, and moderate endomysial fibrosis. We have determined a novel likely pathogenic variant in PLEC 1f isoform that causes limb-girdle muscle dystrophy type 2Q and described the third case concerning an isolated myodystrophic phenotype of LGMD2Q with the likely pathogenic variant in PLEC 1f isoform. In addition, we have demonstrated the presence of severe lung injury in a patient and his siblings with the same myodystrophic phenotype and discussed the possible role of plectin deficiency in its pathogenesis.

  18. Glu20Ter Variant in PLEC 1f Isoform Causes Limb-Girdle Muscle Dystrophy with Lung Injury.

    Science.gov (United States)

    Deev, Roman V; Bardakov, Sergei N; Mavlikeev, Mikhail O; Yakovlev, Ivan A; Umakhanova, Zoya R; Akhmedova, Patimat G; Magomedova, Raisat M; Chekmaryeva, Irina A; Dalgatov, Gimat D; Isaev, Artur A

    2017-01-01

    Plectinopathies are orphan diseases caused by PLEC gene mutations. PLEC is encoding the protein plectin, playing a role in linking cytoskeleton components in various tissues. In this study, we describe the clinical case of a 26-year-old patient with an early onset plectinopathy variant "limb-girdle muscle dystrophy type 2Q," report histopathological and ultrastructural findings in m. vastus lateralis biopsy and a novel homozygous likely pathogenic variant (NM_201378.3:c.58G>T, NP_958780.1:p.Glu20Ter) in isoform 1f of the gene PLEC. The patient had an early childhood onset with retarded physical development, moderate weakness in pelvic girdle muscles, progressive weakening of limb-girdle muscles after the age of 21, pronounced atrophy of axial muscles, and hypertrophy of the gastrocnemius, deltoid, and triceps muscles, intermittent dyspnea, and no skin involvement. Findings included: non-infectious bronchiolitis and atelectasis signs, biopsy revealed myodystrophal pattern without macrophage infiltration, muscle fiber cytoskeleton disorganization resulted from the plectin loss, incomplete reparative rhabdomyogenesis, and moderate endomysial fibrosis. We have determined a novel likely pathogenic variant in PLEC 1f isoform that causes limb-girdle muscle dystrophy type 2Q and described the third case concerning an isolated myodystrophic phenotype of LGMD2Q with the likely pathogenic variant in PLEC 1f isoform. In addition, we have demonstrated the presence of severe lung injury in a patient and his siblings with the same myodystrophic phenotype and discussed the possible role of plectin deficiency in its pathogenesis.

  19. Central and peripheral fatigue of human diaphragm and limb muscles assessed by twitch interpolation.

    Science.gov (United States)

    McKenzie, D K; Bigland-Ritchie, B; Gorman, R B; Gandevia, S C

    1992-08-01

    1. This study used a sensitive modification of the twitch interpolation technique to compare the extent of voluntary neural drive to the diaphragm and the elbow flexors during fatigue. For the diaphragm both inspiratory and expulsive efforts were tested, and fatigue was induced by expulsive efforts which were either maximal voluntary contractions (MVCs, 10 s duration, 50% duty cycle) or submaximal contractions (50% MVC, 3 s duration, 60% duty cycle). 2. Over the series of thirty MVCs peak elbow torque declined to 57.9 +/- 3.0% (mean +/- S.E.M.) of the initial value while maximal inspiratory pressure declined to 78.7 +/- 7.3% (P develop a marked inability to contract the diaphragm voluntarily, but when the diaphragm performed inspiratory manoeuvres at the same level of contractile fatigue, the index of voluntary drive was greater than 94%. 7. In conclusion, when tested with inspiratory efforts the diaphragm developed less central fatigue than the limb muscle over the same exercise period.(ABSTRACT TRUNCATED AT 400 WORDS)

  20. Cloxacillin concentrations in serum, subcutaneous fat, and muscle in patients with chronic critical limb ischemia.

    Science.gov (United States)

    Jonsson, T B; Nilsson, T K; Breimer, L H; Schneede, J; Arfvidsson, B; Norgren, L

    2014-08-01

    Patients suffering from critical limb ischemia (CLI) have poor wound healing in the ankle and foot areas. Secondary wound infections are frequent and often treated with prolonged courses of antibiotics. This study set out to investigate to what extent the unbound fraction of 4 g of cloxacillin i.v. reaches its target organ in poorly vascularized tissues, i.e., the calf and foot of patients suffering from CLI. Cloxacillin concentrations were measured by HPLC in serum and in microdialysis samples from skin and muscle of the lower part of the calf and as reference subcutaneously at the pectoral level in eight patients suffering from CLI (four males, four females, mean age 78 years, range 66-85 years) and in three healthy controls (two females, one male, mean age 67, range 66-68 years). In patients suffering from CLI, the tissue penetration of cloxacillin after a single 4 g dose was comparable to that of healthy controls, despite impaired blood circulation. The reduced blood flow in the peripheral vessels of the CLI patients presented here apparently is not the rate-limiting factor for delivery or tissue penetration of cloxacillin.

  1. Older Age Is Associated with Lower Optimal Vibration Frequency in Lower-Limb Muscles During Whole-Body Vibration.

    Science.gov (United States)

    Carlucci, Flaminia; Orlando, Giorgio; Haxhi, Jonida; Laudani, Luca; Giombini, Arrigo; Macaluso, Andrea; Pigozzi, Fabio; Sacchetti, Massimo

    2015-07-01

    The aim of this study was to compare the optimal vibration frequency (OVF), which corresponds to maximal electromyographic muscle response during whole-body vibration, between young, middle-aged, and older women in four muscles of the lower-limbs. OVF was measured as the frequency corresponding to maximal root mean square of the surface electromyogram (RMSmax) during a continuous incremental protocol, with a succession of vibration frequencies from 20 to 55 Hz (A = 2 mm), on the vastus lateralis, vastus medialis, rectus femoris, and gastrocnemius lateralis muscles of the dominant lower-limb. Seventy-eight women were divided into three age groups, that is, young, 21.6 ± 2.4 yrs; middle aged, 43.0 ± 5.2 yrs; and older, 74.2 ± 6.0 yrs. OVF in the vastus medialis was lower in the older women than in the middle-aged and young women, whereas OVF in the vastus lateralis was lower in the older than in the young women. There were no differences in OVF between muscles within each group. RMSmax was higher in the older than in the young women in all muscles. Age range should be taken into consideration when determining OVF because it decreases with age. Properly individualizing the vibration protocol might greatly influence neuromuscular effects of vibration training.

  2. Assessment of the strength of the trunk and upper limb muscles in stroke subjects with portable dynamometry: a literature review

    OpenAIRE

    Martins, Júlia Caetano; Teixeira-Salmela, Luci Fuscaldi; Aguiar, Larissa Tavares; Souza, Lucas Araújo Castro e; Lara, Eliza Maria; Faria, Christina Danielli Coelho de Morais

    2015-01-01

    Introduction Clinical measurements of strength in stroke subjects are usually performed and portable dynamometers are one of the most employed instruments. Objective To verify the standardization procedures of the methods used to assess the strength of the trunk and upper limb muscles with portable dynamometers in stroke subjects, as well as to assess the psychometric properties which were already investigated. Materials and methods An extensive search was performed on the MEDLINE, SciELO, LI...

  3. Lower limb muscle coactivation levels in healthy younger and older adults during functional dual-task gait

    OpenAIRE

    Hallal, Camilla Zamfolini; Marques, Nise Ribeiro; Vieira, Edgar Ramos; Brunt, Denis; Spinoso, Deborah Hebling; Castro, Alex; Cardozo, Adalgiso Coscrato; Gonçalves, Mauro

    2013-01-01

    The purpose of this study was to investigate the influence of daily cognitive task on stiffness of old and young female adults during the gait. The study included 17 physically active younger and 18 older women, with low risk of falls. The volunteers were asked to walk on the treadmill at two different gait conditions: normal gait and functional dual-task gait. The electromyographic signals were collected of the lower limb muscles. The percentage of coactivation for the tibialis anterior/gast...

  4. Muscular Activity and Fatigue in Lower-Limb and Trunk Muscles during Different Sit-To-Stand Tests.

    Directory of Open Access Journals (Sweden)

    Cristina Roldán-Jiménez

    Full Text Available Sit-to-stand (STS tests measure the ability to get up from a chair, reproducing an important component of daily living activity. As this functional task is essential for human independence, STS performance has been studied in the past decades using several methods, including electromyography. The aim of this study was to measure muscular activity and fatigue during different repetitions and speeds of STS tasks using surface electromyography in lower-limb and trunk muscles. This cross-sectional study recruited 30 healthy young adults. Average muscle activation, percentage of maximum voluntary contraction, muscle involvement in motion and fatigue were measured using surface electrodes placed on the medial gastrocnemius (MG, biceps femoris (BF, vastus medialis of the quadriceps (QM, the abdominal rectus (AR, erector spinae (ES, rectus femoris (RF, soleus (SO and the tibialis anterior (TA. Five-repetition STS, 10-repetition STS and 30-second STS variants were performed. MG, BF, QM, ES and RF muscles showed differences in muscle activation, while QM, AR and ES muscles showed significant differences in MVC percentage. Also, significant differences in fatigue were found in QM muscle between different STS tests. There was no statistically significant fatigue in the BF, MG and SO muscles of the leg although there appeared to be a trend of increasing fatigue. These results could be useful in describing the functional movements of the STS test used in rehabilitation programs, notwithstanding that they were measured in healthy young subjects.

  5. Changes in postural and trunk muscles responses in patients with chronic nonspecific low back pain during sudden upper limb loading.

    Science.gov (United States)

    Akbari, Mahmood; Sarrafzadeh, Javad; Maroufi, Nader; Haghani, Hamid

    2015-01-01

    Alterations in the neuromuscular control of the spine were found in patients with chronic low back pain (CLBP). Sudden loading of the spine is assumed to be the cause of approximately 12% of lower back injuries. However, some aspects of this problem, such as alterations in the sensory-motor control of the spine, remain questionable. This study investigated postural and neuro- motor changes in trunk muscles during sudden upper limb loading in patients with CLBP. Electromyography of the erector spinae (ES) and transverses abdominis/internal oblique (TrA/IO) and external oblique (EOA) muscles were recorded in 20 patients with CLBP and 20 asymptomatic individuals with eyes open (EO) and eyes closed (EC) conditions. Moreover, measurements of the center of pressure (COP) and vertical ground reaction force (GRF) or Fz were recorded using a force plate. Data were analyzed using paired t-test and independent t-test at the significance level of 0.05. In patients with CLBP, decreased electrical activity of the ES muscle was observed under both the EO and EC conditions and that of the TrA/IO muscle was observed under the EO condition (pmuscle in the EO condition and a greater increase in the peak latency of the ES muscle following the EC condition (pmuscle activity may indicate less stiffening or preparatory muscle activity in the trunk muscle of patients with CLBP. Altered latency of the muscle may lead to microtrauma of lumbar structures and CLBP.

  6. Muscular Activity and Fatigue in Lower-Limb and Trunk Muscles during Different Sit-To-Stand Tests.

    Science.gov (United States)

    Roldán-Jiménez, Cristina; Bennett, Paul; Cuesta-Vargas, Antonio I

    2015-01-01

    Sit-to-stand (STS) tests measure the ability to get up from a chair, reproducing an important component of daily living activity. As this functional task is essential for human independence, STS performance has been studied in the past decades using several methods, including electromyography. The aim of this study was to measure muscular activity and fatigue during different repetitions and speeds of STS tasks using surface electromyography in lower-limb and trunk muscles. This cross-sectional study recruited 30 healthy young adults. Average muscle activation, percentage of maximum voluntary contraction, muscle involvement in motion and fatigue were measured using surface electrodes placed on the medial gastrocnemius (MG), biceps femoris (BF), vastus medialis of the quadriceps (QM), the abdominal rectus (AR), erector spinae (ES), rectus femoris (RF), soleus (SO) and the tibialis anterior (TA). Five-repetition STS, 10-repetition STS and 30-second STS variants were performed. MG, BF, QM, ES and RF muscles showed differences in muscle activation, while QM, AR and ES muscles showed significant differences in MVC percentage. Also, significant differences in fatigue were found in QM muscle between different STS tests. There was no statistically significant fatigue in the BF, MG and SO muscles of the leg although there appeared to be a trend of increasing fatigue. These results could be useful in describing the functional movements of the STS test used in rehabilitation programs, notwithstanding that they were measured in healthy young subjects.

  7. Formoterol attenuates increased oxidative stress and myosin protein loss in respiratory and limb muscles of cancer cachectic rats

    Directory of Open Access Journals (Sweden)

    Anna Salazar-Degracia

    2017-12-01

    Full Text Available Muscle mass loss and wasting are characteristic features of patients with chronic conditions including cancer. Therapeutic options are still scarce. We hypothesized that cachexia-induced muscle oxidative stress may be attenuated in response to treatment with beta2-adrenoceptor-selective agonist formoterol in rats. In diaphragm and gastrocnemius of tumor-bearing rats (108 AH-130 Yoshida ascites hepatoma cells inoculated intraperitoneally with and without treatment with formoterol (0.3 mg/kg body weight/day for seven days, daily subcutaneous injection, redox balance (protein oxidation and nitration and antioxidants and muscle proteins (1-dimensional immunoblots, carbonylated proteins (2-dimensional immunoblots, inflammatory cells (immunohistochemistry, and mitochondrial respiratory chain (MRC complex activities were explored. In the gastrocnemius, but not the diaphragm, of cancer cachectic rats compared to the controls, protein oxidation and nitration levels were increased, several functional and structural proteins were carbonylated, and in both study muscles, myosin content was reduced, inflammatory cell counts were greater, while no significant differences were seen in MRC complex activities (I, II, and IV. Treatment of cachectic rats with formoterol attenuated all the events in both respiratory and limb muscles. In this in vivo model of cancer-cachectic rats, the diaphragm is more resistant to oxidative stress. Formoterol treatment attenuated the rise in oxidative stress in the limb muscles, inflammatory cell infiltration, and the loss of myosin content seen in both study muscles, whereas no effects were observed in the MRC complex activities. These findings have therapeutic implications as they demonstrate beneficial effects of the beta2 agonist through decreased protein oxidation and inflammation in cachectic muscles, especially the gastrocnemius.

  8. Infrared thermography applied to lower limb muscles in elite soccer players with functional ankle equinus and non-equinus condition.

    Science.gov (United States)

    Rodríguez-Sanz, David; Losa-Iglesias, Marta Elena; López-López, Daniel; Calvo-Lobo, César; Palomo-López, Patricia; Becerro-de-Bengoa-Vallejo, Ricardo

    2017-01-01

    Gastrocnemius-soleus equinus (GSE) is a foot-ankle complaint in which the extensibility of the gastrocnemius (G) and soleus muscles (triceps surae) and ankle are limited to a dorsiflexion beyond a neutral ankle position. The asymmetric forces of leg muscles and the associated asymmetric loading forces might promote major activation of the triceps surae, tibialis anterior, transverses abdominal and multifidus muscles. Here, we made infrared recordings of 21 sportsmen (elite professional soccer players) before activity and after 30 min of running. These recordings were used to assess temperature modifications on the gastrocnemius, tibialis anterior, and Achilles tendon in GSE and non-GSE participants. We identified significant temperature modifications among GSE and non-GSE participants for the tibialis anterior muscle (mean, minimum, and maximum temperature values). The cutaneous temperature increased as a direct consequence of muscle activity in GSE participants. IR imaging capture was reliable to muscle pattern activation for lower limb. Based on our findings, we propose that non-invasive IR evaluation is suitable for clinical evaluation of the status of these muscles.

  9. Infrared thermography applied to lower limb muscles in elite soccer players with functional ankle equinus and non-equinus condition

    Directory of Open Access Journals (Sweden)

    David Rodríguez-Sanz

    2017-05-01

    Full Text Available Gastrocnemius-soleus equinus (GSE is a foot-ankle complaint in which the extensibility of the gastrocnemius (G and soleus muscles (triceps surae and ankle are limited to a dorsiflexion beyond a neutral ankle position. The asymmetric forces of leg muscles and the associated asymmetric loading forces might promote major activation of the triceps surae, tibialis anterior, transverses abdominal and multifidus muscles. Here, we made infrared recordings of 21 sportsmen (elite professional soccer players before activity and after 30 min of running. These recordings were used to assess temperature modifications on the gastrocnemius, tibialis anterior, and Achilles tendon in GSE and non-GSE participants. We identified significant temperature modifications among GSE and non-GSE participants for the tibialis anterior muscle (mean, minimum, and maximum temperature values. The cutaneous temperature increased as a direct consequence of muscle activity in GSE participants. IR imaging capture was reliable to muscle pattern activation for lower limb. Based on our findings, we propose that non-invasive IR evaluation is suitable for clinical evaluation of the status of these muscles.

  10. Metabolic and structural changes in lower-limb skeletal muscle following neuromuscular electrical stimulation: a systematic review.

    Directory of Open Access Journals (Sweden)

    Maurice J H Sillen

    Full Text Available BACKGROUND: Transcutaneous neuromuscular electrical stimulation (NMES can be applied as a complementary intervention to regular exercise training programs. A distinction can be made between high-frequency (HF NMES and low-frequency (LF NMES. In order to increase understanding of the mechanisms of functional improvements following NMES, the purpose of this study was to systematically review changes in enzyme activity, muscle fiber type composition and muscle fiber size in human lower-limb skeletal muscles following only NMES. METHODS: Trials were collected up to march 2012 and were identified by searching the Medline/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL and The Physical Therapy Evidence Database (PEDro databases and reference lists. 18 trials were reviewed in detail: 8 trials studied changes in enzyme activities, 7 trials studied changes in muscle fiber type composition and 14 trials studied changes in muscle fiber size following NMES. RESULTS: The methodological quality generally was poor, and the heterogeneity in study design, study population, NMES features and outcome parameters prohibited the use of meta-analysis. Most of the LF-NMES studies reported significant increases in oxidative enzyme activity, while the results concerning changes in muscle fiber composition and muscle size were conflicting. HF-NMES significantly increased muscle size in 50% of the studies. CONCLUSION: NMES seems to be a training modality resulting in changes in oxidative enzyme activity, skeletal muscle fiber type and skeletal muscle fiber size. However, considering the small sample sizes, the variance in study populations, the non-randomized controlled study designs, the variance in primary outcomes, and the large heterogeneity in NMES protocols, it is difficult to draw definitive conclusions about the effects of stimulation frequencies on muscular changes.

  11. Failure to up-regulate transcription of genes necessary for muscle adaptation underlies limb girdle muscular dystrophy 2A (calpainopathy).

    Science.gov (United States)

    Kramerova, Irina; Ermolova, Natalia; Eskin, Ascia; Hevener, Andrea; Quehenberger, Oswald; Armando, Aaron M; Haller, Ronald; Romain, Nadine; Nelson, Stanley F; Spencer, Melissa J

    2016-06-01

    Limb girdle muscular dystrophy 2A is due to loss-of-function mutations in the Calpain 3 (CAPN3) gene. Our previous data suggest that CAPN3 helps to maintain the integrity of the triad complex in skeletal muscle. In Capn3 knock-out mice (C3KO), Ca2+ release and Ca2+/calmodulin kinase II (CaMKII) signaling are attenuated. We hypothesized that calpainopathy may result from a failure to transmit loading-induced Ca2+-mediated signals, necessary to up-regulate expression of muscle adaptation genes. To test this hypothesis, we compared transcriptomes of muscles from wild type (WT) and C3KO mice subjected to endurance exercise. In WT mice, exercise induces a gene signature that includes myofibrillar, mitochondrial and oxidative lipid metabolism genes, necessary for muscle adaptation. C3KO muscles fail to activate the same gene signature. Furthermore, in agreement with the aberrant transcriptional profile, we observe a commensurate functional defect in lipid metabolism whereby C3KO muscles fail to release fatty acids from stored triacylglycerol. In conjunction with the defects in oxidative metabolism, C3KO mice demonstrate reduced exercise endurance. Failure to up-regulate genes in C3KO muscles is due, in part, to decreased levels of PGC1α, a transcriptional co-regulator that orchestrates the muscle adaptation response. Destabilization of PGC1α is attributable to decreased p38 MAPK activation via diminished CaMKII signaling. Thus, we elucidate a pathway downstream of Ca2+-mediated CaMKII activation that is dysfunctional in C3KO mice, leading to reduced transcription of genes involved in muscle adaptation. These studies identify a novel mechanism of muscular dystrophy: a blunted transcriptional response to muscle loading resulting in chronic failure to adapt and remodel. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Efficacy of lower-limb muscle training modalities in severely dyspnoeic individuals with COPD and quadriceps muscle weakness: results from the DICES trial.

    Science.gov (United States)

    Sillen, Maurice J H; Franssen, Frits M E; Delbressine, Jeannet M L; Vaes, Anouk W; Wouters, Emiel F M; Spruit, Martijn A

    2014-06-01

    Strength training and neuromuscular electrical stimulation (NMES) improve lower-limb muscle function in dyspnoeic individuals with chronic obstructive pulmonary disease (COPD). However, high-frequency NMES (HF-NMES) and strength training have never been compared head-to-head; and effects of low-frequency NMES (LF-NMES) have never been studied in COPD. Therefore, the optimal training modality to improve lower-limb muscle function, exercise performance and other patient-related outcomes in individuals with severe COPD remains unknown. To study prospectively the efficacy of HF-NMES (75 Hz), LF-NMES (15 Hz) or strength training in severely dyspnoeic individuals with COPD with quadriceps muscle weakness at baseline. 120 individuals with COPD (FEV1: 33±1% predicted, men: 52%, age: 64.8±0.8 years) were randomised to HF-NMES, LF-NMES or strength training as part of a comprehensive inpatient pulmonary rehabilitation programme. No treadmill walking or stationary cycling was provided. Groups were comparable at baseline. Quadriceps muscle strength increased after HF-NMES (+10.8 Newton-metre (Nm)) or strength training (+6.1 Nm; both pmuscle endurance, exercise performance, lower-limb fat-free mass, exercise-induced symptoms of dyspnoea and fatigue improved significantly compared with baseline after HF-NMES, LF-NMES or strength training. The increase in quadriceps muscle strength and muscle endurance was greater after HF-NMES than after LF-NMES. HF-NMES is equally effective as strength training in severely dyspnoeic individuals with COPD and muscle weakness in strengthening the quadriceps muscles and thus may be a good alternative in this particular group of patients. HF-NMES, LF-NMES and strength training were effective in improving exercise performance in severely dyspnoeic individuals with COPD and quadriceps weakness. NTR2322. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  13. The pattern of excitation of human lower limb motoneurones by probable group II muscle afferents.

    Science.gov (United States)

    Simonetta-Moreau, M; Marque, P; Marchand-Pauvert, V; Pierrot-Deseilligny, E

    1999-05-15

    1. Heteronymous group II effects were investigated in the human lower limb. Changes in firing probability of single motor units in quadriceps (Q), biceps (Bi), semitendinosus (ST), gastrocnemius medialis (GM) and tibialis anterior (TA) were studied after electrical stimuli between 1 and 3 times motor threshold (MT) applied to common peroneal (CP), superficial (SP) and deep (DP) peroneal, Bi and GM nerves in those nerve-muscle combinations without recurrent inhibition. 2. Stimulation of the CP and Bi nerves evoked in almost all of the explored Q motor units a biphasic excitation with a low-threshold early peak, attributable to non-monosynaptic group I excitation, and a higher threshold late peak. When the CP nerve was cooled (or the stimulation applied to a distal branch, DP), the increase in latency was greater for the late than for the early peak, indicating that the late excitation is due to stimulation of afferents with a slower conduction velocity than group I fibres, presumably in the group II range. In ST motor units the group II excitation elicited by stimulation of the GM and SP nerves was particularly large and frequent, and the non-monosynaptic group I excitation was often replaced by an inhibition. 3. A late group II-induced excitation from CP to Q motoneurones and from GM and SP to ST motoneurones was also observed when using the H reflex as a test. 4. The electrical threshold and conduction velocity of the largest diameter fibres evoking the group II excitation were estimated to be 2.1 and 0.65 times those of the fastest Ia afferents, respectively. In the combinations tested in the present investigation the group II input seemed to be primarily of muscle origin. 5. The potent heteronymous group II excitation of motoneurones of both flexors and extensors of the knee contrasted with the absence of a group II effect from DP to GM and from GM to TA. In none of the combinations explored was there any evidence for group II inhibition of motoneurones. The

  14. Modifications in activation of lower limb muscles as a function of initial foot position in cycling.

    Science.gov (United States)

    Padulo, Johnny; Powell, Douglas W; Ardigò, Luca P; Viggiano, Davide

    2015-08-01

    Cyclic movements, such as walking/cycling, require the activity of spinal-circuits, the central-pattern-generators (CPG). To our knowledge little work has been done to investigate the activation of these circuits, e.g., the muscular and kinematic activity during cycling initiation. This study aims to detail the muscle output properties as a function of the initial lower limb-position using a simple cycling paradigm. Therefore, subjects were required to pedal on a cycle-ergometer in seated position starting at different-crank-angles (0-150°). Surface-electromyography was recorded from the gluteus major (GL), vastus lateralis (VL), and gastrocnemius medialis (GM), while crank position was recorded using a linear-encoder. Gluteus major peak-activity (PA) occurred at 65.0±12.4° when starting with 0° initial crank position (ICP), while occurred maximally at 110.5±2.9 when starting with 70° ICP. Vastus lateralis PA occurred at 40.7±8.8° with 0° ICP, whereas with 70° ICP PA occurred at 103.4±4.0°. Similarly, GM PA occurred at 112.0±10.7° with 0° ICP, whereas with 70° ICP PA occurred at 142.5±4.2° PA. Gluteus major and gastrocnemius medialis showed similar PA phase shifts, which may suggest they are controlled by same local circuitry, in agreement with their common spinal origin, i.e., motoneurons pool in S1-S2. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Preliminary investigation of residual limb plantarflexion and dorsiflexion muscle activity during treadmill walking for trans-tibial amputees.

    Science.gov (United States)

    Silver-Thorn, Barbara; Current, Thomas; Kuhse, Benjamin

    2012-12-01

    Novel powered prosthetic ankles currently incorporate finite state control, using kinematic and kinetic sensors to differentiate stance and swing phases/sub-phases and control joint impedance and position or torque. For more intuitive control, myoelectric control of the ankle using the remnant residual limb dorsiflexors and plantarflexors, perhaps in concert with kinetic and kinematic sensors, may be possible. The specific research objective was to assess the feasibility of using myoelectric control of future active or powered prosthetic ankle joints for trans-tibial amputees. The project involved human subject trials to determine whether current techniques of myoelectric control of upper extremity prostheses might be readily adapted for lower extremity prosthetic control. Gait analysis was conducted for three unilateral trans-tibial amputee subjects during ambulation on an instrumented split belt treadmill. Data included ankle plantarflexor and dorsiflexor activity for the residual limb, as well as lower limb kinematics and ground reaction forces and moments of both the sound and prosthetic limbs. These data indicate that: 1) trans-tibial amputees retain some independent ankle plantarflexor and dorsiflexor muscle activity of their residual limb; 2) it is possible to position surface electromyographic electrodes within a trans-tibial socket that maintain contact during ambulation; 3) both the plantarflexors and dorsiflexors of the residual limb are active during gait; 4) plantarflexor and dorsiflexor activity is consistent during multiple gait cycles; and 5) with minimal training, trans-tibial amputees may be able to activate their plantarflexors during push-off. These observations demonstrate the potential for future myoelectric control of active prosthetic ankles. Clinical relevance This study demonstrated the feasibility of applying upper extremity prosthetic myoelectric signal acquisition, processing and control techniques to future myoelectric control of

  16. [Diabetic foot syndrome: importance of calf muscles MR spectroscopy in the assessment of limb ischemia and effect of revascularization].

    Science.gov (United States)

    Němcová, Andrea; Dubský, Michal; Jirkovská, Alexandra; Šedivý, Petr; Drobný, Miloslav; Hájek, Milan; Dezortová, Monika; Bém, Robert; Fejfarová, Vladimíra; Pyšná, Anna

    The standard method for assessment of effect of revascularization in patients with diabetic foot (DF) and critical limb ischemia (CLI) is transcutaneous oxygen pressure (TcPO2). Phosphorus magnetic resonance spectroscopy (31P MRS) enables to evaluate oxidative muscle metabolism that could be impaired in patients with diabetes and its complications. The aim of our study was to compare MRS of calf muscle between patients with DF and CLI and healthy controls and to evaluate the contribution of MRS in the assessment of the effect of revascularization. Thirty-four diabetic patients with DF and CLI treated either by autologous cell therapy (ACT; 15 patients) or percutaneous transluminal angioplasty (PTA; 12 patients) in our foot clinic during 2013-2016 and 19 healthy controls were included into the study. TcPO2 measurement was used as a standard method of non-invasive evaluation of limb ischemia. MRS examinations were performed using the whole-body 3T MR system 1 day before and 3 months after the procedure. Subjects were examined in a supine position with the coil fixed under the m. gastrocnemius. MRS parameters were obtained at rest and during the exercise period. Rest MRS parameters of oxidative muscle metabolism such as phosphocreatine (PCr), inorganic phosphate (Pi), phosphodiesters (PDE), adenosine triphosphate (ATP), dynamic MRS parameters such as recovery constant PCr (τPCr) and mitochondrial capacity (Qmax), and pH were compared between patients and healthy controls, and also before and 3 months after revascularization. Patients with CLI had significantly lower PCr/Pi (p lower Qmax and prolonged τPCr (both p muscles in patients with CLI in comparison with healthy controls. We observed an improvement in dynamic MRS parameters in individual cases; this finding should be verified in a large number of patients during longer follow-up.Key words: autologous cell therapy - critical limb ischemia - diabetic foot - MR spectroscopy.

  17. Medium-latency stretch reflexes of foot and leg muscles analysed by cooling the lower limb in standing humans.

    Science.gov (United States)

    Schieppati, M; Nardone, A

    1997-09-15

    1. In standing subjects, an ankle-dorsiflexing perturbation of the supporting surface evokes a short-latency response (SLR) and a medium-latency response (MLR) to stretch in both soleus (Sol) and flexor digitorum brevis (FDB) muscles. The SLR is the counterpart of the monosynaptic reflex, whilst the MLR might be either mediated by Ia fibres, the delay being due to a long-loop central circuit, or by fibres of slower conduction velocity. Since small afferents are slowed more than large ones by low temperature, a greater latency increment for the MLR than the SLR induced by cooling of the limb would point to a peripheral origin of the MLR. 2. In nine subjects, one limb was cooled by circulating water in a tube wrapped around it for about 120 min. Perturbations were delivered to the same limb prior to and during cooling, and after rewarming. EMG was recorded by surface electrodes from the Sol and FDB muscles. 3. The mean increase in latency of MLRs was significantly greater than that of SLRs in both muscles. On average, the Sol SLR increased from 42.4 to 47.0 ms and the Sol MLR from 72.0 to 82.3 ms. The FDB SLR increased from 58.1 to 66.5 ms and the FDB MLR from 94.9 to 110.5 ms. The mean difference (MLR minus SLR) increased from 29.6 to 35.2 ms for Sol, and from 36.8 to 43.9 ms for FDB at the end of cooling. After 30 min of rewarming, the responses of both muscles recovered towards control values. 4. The greater latency increment of the MLRs than of the SLRs favours the hypothesis of a slower conduction velocity of the responsible afferent fibres. The most likely candidate fibres are the spindle group II afferents.

  18. Pattern of myosin heavy chain isoforms in different fibre types of canine trunk and limb skeletal muscles.

    Science.gov (United States)

    Strbenc, M; Smerdu, V; Zupanc, M; Tozon, N; Fazarinc, G

    2004-01-01

    The aim of this study was to determine the pattern of myosin heavy chain (MHC) isoform expressions within the muscle fibres of functionally diverse trunk and limb dog muscles using monoclonal antibodies that are specific to MHC isoforms. We found that three MHC isoforms are expressed in dog skeletal muscles. The pattern of their expressions determined the existence of 'pure' fibres, i.e. I and IIa, both expressing only one MHC isoform, and 'hybrid' fibres, i.e. I/IIa and IIa/x, that co-expressed two MHC isoforms. While the MHCI, MHCIIa and MHCI/IIa fibres corresponded to the myofibrillar ATPase type fibres I, IIA and IIC, respectively, the hybrid MHCIIa/x fibres mostly behaved like the IIDog fibre type in myofibrillar ATPase reaction as described by Latorre et al. No pure MHCIIx fibres were found. Though MHCIIa/x fibres were quite numerous, their presence varied not only within different muscles but within the same muscle of different animals as well. We suggest that the discrepancies in the classification of fibre types according to their myofibrillar ATPase activity between different studies of dog skeletal muscles are probably a consequence of the variable content of the MHCIIa and MHCIIx isoforms in the MHCIIa/x hybrid fibres. Estimating the histochemical metabolic profile of fibres we found that in all fast fibres oxidative-glycolytic metabolism prevailed, whereas in slow fibres oxidative metabolism was more pronounced. Copyright 2004 S. Karger AG, Basel

  19. Replacing a Swiss ball for an exercise bench causes variable changes in trunk muscle activity during upper limb strength exercises.

    Science.gov (United States)

    Lehman, Gregory J; Gordon, Trish; Langley, Jo; Pemrose, Patricia; Tregaskis, Sara

    2005-06-03

    The addition of Swiss balls to conventional exercise programs has recently been adopted. Swiss balls are an unstable surface which may result in an increased need for force output from trunk muscles to provide adequate spinal stability or balance. The aim of the study was to determine whether the addition of a Swiss ball to upper body strength exercises results in consistent increases in trunk muscle activation levels. The myoelectric activity of four trunk muscles was quantified during the performance of upper body resistance exercises while seated on both a stable (exercise bench) and labile (swiss ball) surface. Participants performed the supine chest press, shoulder press, lateral raise, biceps curl and overhead triceps extension. A repeated measures ANOVA with post-hoc Tukey test was used to determine the influence of seated surface type on muscle activity for each muscle. There was no statistically significant (p swiss balls instead of an exercise bench into upper body strength training regimes may not be justified based only on the belief that an increase spinal stabilizing musculature activity is inherent. Biomechanically justified ground based exercises have been researched and should form the basis for spinal stability training as preventative and therapeutic exercise training regimes. Selected trunk muscle activity during certain upper limb strength training exercises is not consistently influenced by the replacement of an exercise bench with a swiss ball.

  20. In vivo and in vitro evidence that in oldest-old humans intrinsic upper- and lower-limb skeletal muscle function is unaffected by ageing and disuse

    Science.gov (United States)

    Venturelli, M.; Saggin, P.; Muti, E.; Naro, F.; Cancellara, L.; Toniolo, L.; Tarperi, C.; Calabria, E.; Richardson, R.S.; Reggiani, C.; Schena, F.

    2015-01-01

    Aim To parse out the impact of advanced ageing and disuse on skeletal muscle function, we utilized both in vivo and in vitro techniques to comprehensively assess upper- and lower-limb muscle contractile properties in 8 young (YG; 25±6yrs) and 8 oldest-old mobile (OM; 87±5yrs) and 8 immobile (OI; 88±4yrs) women. Methods In vivo, maximal voluntary contraction (MVC), electrically evoked resting twitch force (RT), and physiological cross sectional area (PCSA) of the quadriceps and elbow flexors was assessed. Muscle biopsies of the vastus lateralis and biceps brachii facilitated the in vitro assessment of single fibre specific tension (Po). Results In vivo, compared to the young, both the OM and OI exhibited a more pronounced loss of MVC in the lower-limb (OM (−60%) and OI (−75%)) than the upper-limb (OM=−51%; OI=−47%). Taking into account the reduction in muscle PCSA (OM=−10%; OI=−18%), only evident in the lower-limb, by calculating voluntary muscle specific force, the lower-limb of the OI (−40%) was more compromised than the OM (−13%). However, in vivo, RT in both upper- and lower-limbs (~9.8 N·m·cm−2) and Po (~123 mN·mm−2), assessed in vitro, implies preserved intrinsic contractile function in all muscles of the oldest-old and were well correlated (r=0.81). Conclusion These findings suggest that in the oldest-old neither advanced ageing nor disuse, per se, impact intrinsic skeletal muscle function, as assessed in vitro. However, in vivo, muscle function is attenuated by age and exacerbated by disuse, implicating factors other than skeletal muscle, such as neuromuscular control, in this diminution of function. PMID:25965867

  1. In vivo and in vitro evidence that intrinsic upper- and lower-limb skeletal muscle function is unaffected by ageing and disuse in oldest-old humans.

    Science.gov (United States)

    Venturelli, M; Saggin, P; Muti, E; Naro, F; Cancellara, L; Toniolo, L; Tarperi, C; Calabria, E; Richardson, R S; Reggiani, C; Schena, F

    2015-09-01

    To parse out the impact of advanced ageing and disuse on skeletal muscle function, we utilized both in vivo and in vitro techniques to comprehensively assess upper- and lower-limb muscle contractile properties in 8 young (YG; 25 ± 6 years) and 8 oldest-old mobile (OM; 87 ± 5 years) and 8 immobile (OI; 88 ± 4 years) women. In vivo, maximal voluntary contraction (MVC), electrically evoked resting twitch force (RT), and physiological cross-sectional area (PCSA) of the quadriceps and elbow flexors were assessed. Muscle biopsies of the vastus lateralis and biceps brachii facilitated the in vitro assessment of single fibre-specific tension (Po). In vivo, compared to the young, both the OM and OI exhibited a more pronounced loss of MVC in the lower limb [OM (-60%) and OI (-75%)] than the upper limb (OM = -51%; OI = -47%). Taking into account the reduction in muscle PCSA (OM = -10%; OI = -18%), only evident in the lower limb, by calculating voluntary muscle-specific force, the lower limb of the OI (-40%) was more compromised than the OM (-13%). However, in vivo, RT in both upper and lower limbs (approx. 9.8 N m cm(-2) ) and Po (approx. 123 mN mm(-2) ), assessed in vitro, implies preserved intrinsic contractile function in all muscles of the oldest-old and were well correlated (r = 0.81). These findings suggest that in the oldest-old, neither advanced ageing nor disuse, per se, impacts intrinsic skeletal muscle function, as assessed in vitro. However, in vivo, muscle function is attenuated by age and exacerbated by disuse, implicating factors other than skeletal muscle, such as neuromuscular control, in this diminution of function. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  2. Concurrent assessments of lower limb loading patterns, mechanical muscle strength and functional performance in ACL-patients - A cross-sectional study

    DEFF Research Database (Denmark)

    Holsgaard-Larsen, Anders; Jensen, C; Mortensen, N H M

    2014-01-01

    Full recovery in muscle strength and functional performance may not be achieved after ACL-injury. Aim: The aim of this study is to investigate loading patterns during jumping, muscle function and functional performance in ACL-reconstructed patients and to investigate the origin of between-limb...

  3. Colgajo de So en reconstrucción de miembro inferior So muscle flap in lower limb reconstruction

    Directory of Open Access Journals (Sweden)

    Márquez Zevallos

    2008-12-01

    Full Text Available El tratamiento de la extremidad inferior siempre ha sido una dura prueba para el cirujano plástico. La situación anatómica de la tibia, desprovista de protección muscular en su aspecto anterior, la hace altamente vulnerable ante cualquier traumatismo de la extremidad. Toda lesión a este nivel exige un tratamiento óseo y cutáneo adecuados, que deben realizarse primariamente y en forma conjunta. En el presente trabajo describimos 3 casos de pacientes con traumatismos de extremidad inferior, fracturas acompañadas de pérdida de sustancia, en los cuales se practicaron colgajos musculares para reconstruir las partes afectadas. Estos colgajos, en primera instancia se tomaron del músculo sóleo, pero encontramos el inconveniente del grosor exagerado que presentaba la cobertura a pesar de su atrofia posterior y del defecto estético desagradable que quedaba en la zona donante. Por todo ello realizamos una variante: en lugar de tomar la mitad del músculo como indica la técnica convencional, tomamos solo un cuadrante que sobrevivió a expensas de un solo pedículo vascular dominante. El cuadrante restante sirvió para hacer menos notorio el defecto de la zona donante. Los 3 casos tuvieron éxito y los pacientes están muy satisfechos con los resultados estéticos. Presentamos una alternativa quirúrgica innovadora de Colgajo de Sóleo que se puede aplicar satisfactoriamente para la cobertura de defectos de miembro inferior, al cual hemos llamado colgajo de So.Lower limb treatment has always been a headache to the plastic surgeon. Tibial anatomy, doesn´t has frontal muscle protection and it´s vulnerable in any trauma. Every lesion in the lower limb must be treated by traumatologyst and plastic surgeon. In this study we present 3 patients with lower limb trauma, fractures and soft tissue lost, treated with muscle flap to cover affected parts. First, we took the flaps from soleous muscle, but we had problems with flap thickness and with the

  4. Reliability of electromyographic amplitude values of the upper limb muscles during closed kinetic chain exercises with stable and unstable surfaces.

    Science.gov (United States)

    de Araújo, Rodrigo Cappato; Tucci, Helga Tatiana; de Andrade, Rodrigo; Martins, Jaqueline; Bevilaqua-Grossi, Débora; de Oliveira, Anamaria Siriani

    2009-08-01

    The purpose of the present study was to evaluate the intra and interday reliability of surface electromyographic amplitude values of the scapular girdle muscles and upper limbs during 3 isometric closed kinetic chain exercises, involving upper limbs with the fixed distal segment extremity on stable base of support and on a Swiss ball (relatively unstable). Twenty healthy adults performed the exercises push-up, bench-press and wall-press with different effort levels (80% and 100% maximal load). Subjects performed three maximal voluntary contractions (MVC) in muscular testing position of each muscle to obtain a reference value for root mean square (RMS) normalization. Individuals were instructed to randomly perform three isometric contraction series, in which each exercise lasted 6 s with a 2-min resting-period between series and exercises. Intra and interday reliabilities were calculated through the intraclass correlation coefficient (ICC 2.1), standard error of the measurement (SEM). Results indicated an excellent intraday reliability of electromyographic amplitude values (ICC > or = 0.75). The interday reliability of normalized RMS values ranged between good and excellent (ICC 0.52-0.98). Finally, it is suggested that the reliability of normalized electromyographic amplitude values of the analyzed muscles present better values during exercises on a stable surface. However, load levels used during the exercises do not seem to have any influence on variability levels, possibly because the loads were quite similar.

  5. The effect of added degrees of freedom and handle type on upper limb muscle activity during simulated hand tool use.

    Science.gov (United States)

    Fischer, Steven L; Wells, Richard P; Dickerson, Clark R

    2009-01-01

    The human upper limb serves a number of functions ranging from coarse movements such as supporting a load when lifting overhead to the fine motor control required when painting a portrait. However, there are limited data available that address upper extremity function and performance when using hand tools in situations where the tool endpoint is not fixed but can move translationally or rotationally. The goal of this study was to examine variation in arm muscle activity when added degrees of freedom (DOF) were introduced through the use of a force application apparatus with two different handle designs (D-handle or screwdriver). Electromyography of seven forearm muscles and five muscles crossing the shoulder joint were measured to determine relative activity from a reference (0 DOF), most stable condition, to combinations of DOF ranging from 1 to 4. Substantial and statistically significant increases in muscle activity resulted from adding DOF. The screwdriver handle increased forearm muscle activity compared to the D-handle, except in the highest DOF condition. These findings have significance in the planning of work and design of tools because of the potential for increased fatigue that accompanies increased DOF at the tool endpoint. Handle type also influenced the magnitude of the muscular activity.

  6. Satellite cells senescence in limb muscle of severe patients with COPD.

    Directory of Open Access Journals (Sweden)

    Marie-Eve Thériault

    Full Text Available RATIONALE: The maintenance of peripheral muscle mass may be compromised in chronic obstructive pulmonary disease (COPD due to premature cellular senescence and exhaustion of the regenerative potential of the muscles. METHODS: Vastus lateralis biopsies were obtained from patients with COPD (n = 16 and healthy subjects (n = 7. Satellite cell number and the proportion of central nuclei, as a marker of muscle regenerative events, were assessed on cryosections. Telomere lengths, used as a marker of cellular senescence, were determined using Southern blot analyses. RESULTS: Central nuclei proportion was significantly higher in patients with COPD with a preserved muscle mass compared to controls and patients with COPD with muscle atrophy (p<0.001. In COPD, maximal telomere length was significantly decreased compared to controls (p<0.05. Similarly, minimal telomere length was significantly reduced in GOLD III-IV patients with muscle atrophy compared to controls (p<0.005. Minimal, mean and maximum telomere lengths correlated with mid-thigh muscle cross-sectional area (MTCSA (R = 0.523, p = 0.005; R = 0.435, p = 0.019 and R = 0.491, p = 0.009, respectively. CONCLUSIONS: Evidence of increased regenerative events was seen in GOLD III-IV patients with preserved muscle mass. Shortening of telomeres in GOLD III-IV patients with muscle atrophy is consistent with an increased number of senescent satellite cells and an exhausted muscle regenerative capacity, compromising the maintenance of muscle mass in these individuals.

  7. Resistance to rocuronium of rat diaphragm as compared with limb muscles.

    Science.gov (United States)

    Huang, Lina; Yang, Meirong; Chen, Lianhua; Li, Shitong

    2014-12-01

    Skeletal muscles are composed of different muscle fiber types. We investigated the different potency to rocuronium among diaphragm (DIA), extensor digitorum longus (EDL), and soleus (SOL) in vitro as well as to investigate the differences of acetylcholine receptors (AChRs) among these three typical kinds of muscles. The isolated left hemidiaphragm nerve-muscle preparations, the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations were established to evaluate the potency to rocuronium. Concentration-response curves were constructed and the values of IC50 were obtained. The density of AChRs at the end plate and the number of AChRs per unit fiber cross fiber area (CSA), AChR affinity for muscle relaxants were evaluated. The concentration-twitch tension curves of rocuronium were significantly different. The curves demonstrated a shift to the right of the DIA compared with the EDL and SOL (P  0.05). IC50 was significantly largest in DIA, second largest in SOL, and smallest in EDL (P lower affinity of the AChRs. These findings may be the mechanisms of different potency to rocuronium in DIA, EDL, and SOL. The results of the study could help to explain the relationship between different composition of muscle fibers and the potency to muscle relaxants. Extra caution should be taken in clinical practice when monitoring muscle relaxation in anesthetic management using different muscles. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Effects of 2 weeks lower limb immobilization and two separate rehabilitation regimens on gastrocnemius muscle protein turnover signaling and normalization genes

    DEFF Research Database (Denmark)

    Nedergaard, Anders; Jespersen, Jakob G; Pingel, Jessica

    2012-01-01

    in the rehabilitation of immobilization-induced muscle atrophy is only sparsely studied. To investigate the phosphorylation and expression of candidate key molecular muscle mass regulators after immobilization and subsequent rehabilitation we performed two separate studies. METHODS: We immobilized the lower limb for 2......ABSTRACT: BACKGROUND: Limb immobilization causes a rapid loss of muscle mass and strength that requires appropriate rehabilitation to ensure restoration of normal function. Whereas the knowledge of muscle mass signaling with immobilization has increased in recent years, the molecular regulation...... of resistance training and continued protein/carbohydrate supplementation (Study 2). We obtained muscle biopsies from the medial gastrocnemius prior to immobilization (PRE), post-immobilization (IMMO) and post-rehabilitation (REHAB) and measured protein expression and phosphorylation of Akt, mTOR, S6k, 4E-BP1...

  9. Effects of cross-education on the muscle after a period of unilateral limb immobilization using a shoulder sling and swathe.

    Science.gov (United States)

    Magnus, Charlene R A; Barss, Trevor S; Lanovaz, Joel L; Farthing, Jonathan P

    2010-12-01

    The purpose of this study was to apply cross-education during 4 wk of unilateral limb immobilization using a shoulder sling and swathe to investigate the effects on muscle strength, muscle size, and muscle activation. Twenty-five right-handed participants were assigned to one of three groups as follows: the Immob + Train group wore a sling and swathe and strength trained (n = 8), the Immob group wore a sling and swathe and did not strength train (n = 8), and the Control group received no treatment (n = 9). Immobilization was applied to the nondominant (left) arm. Strength training consisted of maximal isometric elbow flexion and extension of the dominant (right) arm 3 days/wk. Torque (dynamometer), muscle thickness (ultrasound), maximal voluntary activation (interpolated twitch), and electromyography (EMG) were measured. The change in right biceps and triceps brachii muscle thickness [7.0 ± 1.9 and 7.1 ± 2.2% (SE), respectively] was greater for Immob + Train than Immob (0.4 ± 1.2 and -1.9 ± 1.7%) and Control (0.8 ± 0.5 and 0.0 ± 1.1%, P effect on maximal voluntary activation or EMG. The cross-education effect on the immobilized limb was greater after elbow extension training. This study suggests that strength training the nonimmobilized limb benefits the immobilized limb for muscle size and strength.

  10. Muscle precursor cells in the developing limbs of two isopods (Crustacea, Peracarida): an immunohistochemical study using a novel monoclonal antibody against myosin heavy chain

    Science.gov (United States)

    Kreissl, S.; Uber, A.

    2008-01-01

    In the hot debate on arthropod relationships, Crustaceans and the morphology of their appendages play a pivotal role. To gain new insights into how arthropod appendages evolved, developmental biologists recently have begun to examine the expression and function of Drosophila appendage genes in Crustaceans. However, cellular aspects of Crustacean limb development such as myogenesis are poorly understood in Crustaceans so that the interpretative context in which to analyse gene functions is still fragmentary. The goal of the present project was to analyse muscle development in Crustacean appendages, and to that end, monoclonal antibodies against arthropod muscle proteins were generated. One of these antibodies recognises certain isoforms of myosin heavy chain and strongly binds to muscle precursor cells in malacostracan Crustacea. We used this antibody to study myogenesis in two isopods, Porcellio scaber and Idotea balthica (Crustacea, Malacostraca, Peracarida), by immunohistochemistry. In these animals, muscles in the limbs originate from single muscle precursor cells, which subsequently grow to form multinucleated muscle precursors. The pattern of primordial muscles in the thoracic limbs was mapped, and results compared to muscle development in other Crustaceans and in insects. Electronic supplementary material The online version of this article (doi:10.1007/s00427-008-0216-1) contains supplementary material, which is available to authorized users. PMID:18443823

  11. Proposal of Method for Control of Muscle Activation Level for Limbs during Motion and Application of this Method in Strength Training

    Science.gov (United States)

    Komada, Satoshi; Murakami, Yosuke; Hirai, Junji

    With an increase in the number of elderly people in our society, the need for equipments that ensure activities of daily living and that can be used in strength training for reducing the need for nursing care is increasing. In this paper, we propose a method for controlling the level of muscle activation for a particular muscle group without EMG sensors; the force exerted by the tips of the limbs during motion is used to control the level of muscle activation. The method is based on a musculoskeletal model for limbs called functionally different effective muscles of three antagonistic pairs of six muscles in 2D space. Hill's equation is incorporated in the method to consider force-velocity characteristics of muscles. EMG measurement results for two muscles under isokinetic contraction in the lower limbs of a subject show that difference between the achieved activation level and the desired activation level is less than the error of the output force distribution. Moreover, the control method is applied to strength training. A manipulator that can facilitate the isokinetic contraction with more than the desired activation level for a specific muscle group is developed.

  12. Pretreatment with Fish Oil-Based Lipid Emulsion Modulates Muscle Leukocyte Chemotaxis in Murine Model of Sublethal Lower Limb Ischemia

    Directory of Open Access Journals (Sweden)

    Yao-Ming Shih

    2017-01-01

    Full Text Available This study investigated the effects of a fish oil- (FO- based lipid emulsion on muscle leukocyte chemotaxis and inflammatory responses in a murine model of limb ischemia-reperfusion (IR injury. Mice were assigned randomly to 1 sham (sham group, 2 ischemic groups, and 2 IR groups. The sham group did not undergo the ischemic procedure. The mice assigned to the ischemic or IR groups were pretreated intraperitoneally with either saline or FO-based lipid emulsion for 3 consecutive days. The IR procedure was induced by applying a 4.5 oz orthodontic rubber band to the left thigh above the greater trochanter for 120 min and then cutting the band to allow reperfusion. The ischemic groups were sacrificed immediately while the IR groups were sacrificed 24 h after reperfusion. Blood, IR-injured gastrocnemius, and lung tissues were collected for analysis. The results showed that FO pretreatment suppressed the local and systemic expression of several IR-induced proinflammatory mediators. Also, the FO-pretreated group had lower blood Ly6ChiCCR2hi monocyte percentage and muscle M1/M2 ratio than the saline group at 24 h after reperfusion. These findings suggest that FO pretreatment may have a protective role in limb IR injury by modulating the expression of proinflammatory mediators and regulating the polarization of macrophage.

  13. BAG3 (Bcl-2-Associated Athanogene-3) Coding Variant in Mice Determines Susceptibility to Ischemic Limb Muscle Myopathy by Directing Autophagy.

    Science.gov (United States)

    McClung, Joseph M; McCord, Timothy J; Ryan, Terence E; Schmidt, Cameron A; Green, Tom D; Southerland, Kevin W; Reinardy, Jessica L; Mueller, Sarah B; Venkatraman, Talaignair N; Lascola, Christopher D; Keum, Sehoon; Marchuk, Douglas A; Spangenburg, Espen E; Dokun, Ayotunde; Annex, Brian H; Kontos, Christopher D

    2017-07-18

    Critical limb ischemia is a manifestation of peripheral artery disease that carries significant mortality and morbidity risk in humans, although its genetic determinants remain largely unknown. We previously discovered 2 overlapping quantitative trait loci in mice, Lsq-1 and Civq-1, that affected limb muscle survival and stroke volume after femoral artery or middle cerebral artery ligation, respectively. Here, we report that a Bag3 variant (Ile81Met) segregates with tissue protection from hind-limb ischemia. We treated mice with either adeno-associated viruses encoding a control (green fluorescent protein) or 2 BAG3 (Bcl-2-associated athanogene-3) variants, namely Met81 or Ile81, and subjected the mice to hind-limb ischemia. We found that the BAG3 Ile81Met variant in the C57BL/6 (BL6) mouse background segregates with protection from tissue necrosis in a shorter congenic fragment of Lsq-1 (C.B6-Lsq1-3). BALB/c mice treated with adeno-associated virus encoding the BL6 BAG3 variant (Ile81; n=25) displayed reduced limb-tissue necrosis and increased limb tissue perfusion compared with Met81- (n=25) or green fluorescent protein- (n=29) expressing animals. BAG3Ile81, but not BAG3Met81, improved ischemic muscle myopathy and muscle precursor cell differentiation and improved muscle regeneration in a separate, toxin-induced model of injury. Systemic injection of adeno-associated virus-BAG3Ile81 (n=9), but not BAG3Met81 (n=10) or green fluorescent protein (n=5), improved ischemic limb blood flow and limb muscle histology and restored muscle function (force production). Compared with BAG3Met81, BAG3Ile81 displayed improved binding to the small heat shock protein (HspB8) in ischemic skeletal muscle cells and enhanced ischemic muscle autophagic flux. Taken together, our data demonstrate that genetic variation in BAG3 plays an important role in the prevention of ischemic tissue necrosis. These results highlight a pathway that preserves tissue survival and muscle function in the

  14. Motor unit loss is accompanied by decreased peak muscle power in the lower limb of older adults.

    Science.gov (United States)

    McKinnon, Neal B; Montero-Odasso, Manuel; Doherty, Timothy J

    2015-10-01

    This study investigated the relationship between motor unit (MU) properties and the isometric strength and power of two lower limb muscles in healthy young and older adults. Twelve older adults (6 men, mean age, 77 ± 5 years) and twelve young adults (6 men, mean age, 24 ± 3 years) were studied. MU properties of the tibialis anterior (TA) and vastus medialis (VM) muscles were determined electrophysiologically using decomposition-enhanced spike-triggered averaging (DE-STA). Motor unit number estimates (MUNEs) of the TA were significantly reduced (pmuscle power were observed between young (TA: 33 W, KE: 35 7 W) and old adults (TA: 26 W, KE: 224 W). The greatest deficit between young and old subjects in peak power output occurred at 20% MVC for the TA and 40% MVC for the knee extensors. Results from this study indicate that there are changes in MU properties with age, and that this effect may be greater in the more distal TA muscle. Further, this study demonstrates that muscle power may be a sensitive marker of changes in neuromuscular function with aging. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Optimization of muscle activity for task-level goals predicts complex changes in limb forces across biomechanical contexts.

    Directory of Open Access Journals (Sweden)

    J Lucas McKay

    Full Text Available Optimality principles have been proposed as a general framework for understanding motor control in animals and humans largely based on their ability to predict general features movement in idealized motor tasks. However, generalizing these concepts past proof-of-principle to understand the neuromechanical transformation from task-level control to detailed execution-level muscle activity and forces during behaviorally-relevant motor tasks has proved difficult. In an unrestrained balance task in cats, we demonstrate that achieving task-level constraints center of mass forces and moments while minimizing control effort predicts detailed patterns of muscle activity and ground reaction forces in an anatomically-realistic musculoskeletal model. Whereas optimization is typically used to resolve redundancy at a single level of the motor hierarchy, we simultaneously resolved redundancy across both muscles and limbs and directly compared predictions to experimental measures across multiple perturbation directions that elicit different intra- and interlimb coordination patterns. Further, although some candidate task-level variables and cost functions generated indistinguishable predictions in a single biomechanical context, we identified a common optimization framework that could predict up to 48 experimental conditions per animal (n = 3 across both perturbation directions and different biomechanical contexts created by altering animals' postural configuration. Predictions were further improved by imposing experimentally-derived muscle synergy constraints, suggesting additional task variables or costs that may be relevant to the neural control of balance. These results suggested that reduced-dimension neural control mechanisms such as muscle synergies can achieve similar kinetics to the optimal solution, but with increased control effort (≈2× compared to individual muscle control. Our results are consistent with the idea that hierarchical, task

  16. Limb edema and anasarca associated with severe dermatomyositis: report of four cases.

    Science.gov (United States)

    Chai, Yaohui; Bertorini, Tulio E; Li, Yingjun D; Mitchell, Christopher; Guan, Hongzhi

    2011-06-01

    Dermatomyositis is an autoimmune disorder that causes proximal muscle weakness and skin changes which include generalized erythema, heliotrope rash and/or Gottron's papules. Generalized or limb edema is an uncommon manifestation of dermatomyositis. Here, we report four cases who presented with generalized or limb edema, proximal muscle weakness, erythematous skin rash and/or dysphagia. Muscle biopsy revealed perifascicular fiber atrophy, a characteristic finding of dermatomyositis. The absence of other causes indicated that the generalized or limb edema was caused by dermatomyositis. None of our patients showed significant improvement with steroids alone, and more aggressive immunotherapy eventually resolved the edema. We concluded that generalized or limb edema may be a hallmark of a severe form of dermatomyositis and requires prompt and aggressive therapies. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Enhanced maximal exercise capacity, vasodilation to electrical muscle contraction, and hind limb vascular density in ASIC1a null mice.

    Science.gov (United States)

    Drummond, Heather A; Xiang, Lusha; Chade, Alejandro R; Hester, Robert

    2017-08-01

    Acid-sensing ion channel (ASIC) proteins form extracellular proton-gated, cation-selective channels in neurons and vascular smooth muscle cells and are proposed to act as extracellular proton sensors. However, their importance to vascular responses under conditions associated with extracellular acidosis, such as strenuous exercise, is unclear. Therefore, the purpose of this study was to determine if one ASIC protein, ASIC1a, contributes to extracellular proton-gated vascular responses and exercise tolerance. To determine if ASIC1a contributes to exercise tolerance, we determined peak oxygen (O2) uptake in conscious ASIC1a-/- mice during exhaustive treadmill running. Loss of ASIC1a was associated with a greater peak running speed (60 ± 2 vs. 53 ± 3 m·min-1, P = 0.049) and peak oxygen (O2) uptake during exhaustive treadmill running (9563 ± 120 vs. 8836 ± 276 mL·kg-1·h-1, n = 6-7, P = 0.0082). There were no differences in absolute or relative lean body mass, as determined by EchoMRI. To determine if ASIC1a contributes to vascular responses during muscle contraction, we measured femoral vascular conductance (FVC) during a stepwise electrical stimulation (0.5-5.0 Hz at 3 V for 60 sec) of the left major hind limb muscles. FVC increased to a greater extent in ASIC1a-/- versus ASIC1a+/+ mice (0.44 ± 0.03 vs. 0.30 ± 0.04 mL·min-1·100 g hind limb mass-1 · mmHg-1, n = 5 each, P = 0.0009). Vasodilation following local application of external protons in the spinotrapezius muscle increased the duration, but not the magnitude, of the vasodilatory response in ASIC1a-/- mice. Finally, we examined hind limb vascular density using micro-CT and found increased density of 0-80 μm vessels (P < 0.05). Our findings suggest an increased vascular density and an enhanced vasodilatory response to local protons, to a lesser degree, may contribute to the enhanced vascular conductance and increased peak exercise capacity in ASIC1a-/- mice. © 2017 The

  18. Effect of Passive, Active and Combined Warm up on Lower Limb Muscle Performance and Dynamic Stability in Recreational Sports Players.

    Science.gov (United States)

    Gogte, Kedar; Srivastav, Prateek; Miyaru, Ganesh Balthillaya

    2017-03-01

    Warm up is an activity that is done before a sports activity. The warm up can be done actively and passively. The preferred mode is active warm up in athletes. There are inconclusive effects of passive warm up compared with an active warm up on short term muscle performance. The cumulative effect of passive and active warm up on muscle performance and dynamic stability is not known. To find out the effects of passive, active and combined warm up on lower limb muscle performance and dynamic stability in recreational sports players. A randomized crossover study was done on 19 recreational lower limb dominant sports players. Three different warm ups were included in the study passive, active and combined. Active warm up included series of activities like cycling, leg press, jump squats, squat jumps while passive warm up included application of moist heat for a period of 20 minutes on lower limb muscles. Combined warm up included both passive and active warm up. Six different sequences were made from these three warm ups. Subjects were screened and allotted into different groups based on the six warm up sequences after sequence randomization with 48 hours wash out period. After every warm up session Vertical Jump Test (VJT) and Star Excursion Balance Test (SEBT) was performed and results were recorded. Study duration was one year and six months. There was no difference noticed in both the outcome measures. Mean and SD values for passive, active and combined warm up are 47.62±9.64, 48.50±10.16 and 48.87±10.70 respectively in Vertical Jump Test (VJT) and 85.43±8.61, 85.17±8.60 and 85.17±8.38 respectively for SEBT. The p-value for mean difference between passive-active, active-combined, combined-passive are 0.67, 1.00, 0.51 respectively, for VJT and 1.00, 1.00, 1.00 respectively for SEBT. All warm ups are equally effective in short term sports performance.

  19. Ubiquitination and proteolysis in limb and respiratory muscles of patients with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Debigaré, Richard; Côté, Claude H; Maltais, François

    2010-02-01

    Peripheral muscle dysfunction associated with chronic diseases is undeniably a growing problem as one of its main causes, chronic obstructive pulmonary disease (COPD), progresses. Among others, muscle atrophy is one component building the concept of muscle dysfunction. Muscle atrophy has a significant impact on patient clinical status, independent of the impairment in lung function. A lot of effort has been devoted lately to increasing our understanding of the relationship between COPD and the initiation and the development of muscle atrophy. A growing body of evidence is showing that the ubiquitin-proteasome system, an ATP-dependent proteolytic pathway, is playing a crucial role in the cascade leading to degradation of contractile proteins, thus promoting the development of muscle atrophy. Interestingly, this system is also involved in essential cellular processes such as response to hypoxemia and muscle tissue regeneration. In this review, existing evidence linking the activity of the ubiquitin-proteasome system and the cellular events taking place in respiratory and peripheral muscles of patients with COPD are reported. Based on this information, the reader should be able to understand the essential role of this pathway in the context of muscle homeostasis and to picture the coming research in this area.

  20. Development of a hybrid strength training technique for paretic lower-limb muscles

    NARCIS (Netherlands)

    Bennett, T. L.; Glaser, R. M.; Janssen, T. W J; Couch, W. P.; Herr, C. J.; Almeyda, J. W.; Petrofsky, S. H.; Akuthota, P.

    1996-01-01

    A hybrid resistance exercise technique for strength training of patients with lower-limb paresis was developed. It consists of electrical stimulation-induced contractions (ESIC) superimposed on voluntary contractions to increase recruitment of motor units and the functional load capability of

  1. Limb Girdle Muscular Dystrophy (LGMD): Case Report.

    Science.gov (United States)

    Kanitkar, Shubhangi A; Kalyan, Meenakshi; Gaikwad, Anu N; Makadia, Ankit; Shah, Harshad

    2015-01-01

    We report a young male of autosomal recessive limb girdle muscular dystrophy (LGMD) with positive family history presented with gradual onset proximal muscle weakness in all four limbs since eight years and thinning of shoulders, arms and thighs. Neurological examination revealed atrophy of both shoulders with wasting of both deltoids thinning of thighs and pseudo hypertrophy of both calves, hypotonia in all four limbs. Gower's sign was positive. Winging of scapula was present. Power was 3/5 at both shoulders, 4/5 at both elbows, 5/5 at both wrists, 3/5 at both hip joints, 3/5 at both knees, 5/5 at both ankles. All deep tendon reflexes and superficial reflexes were present with plantars bilateral flexors. Electromyography (EMG) showed myopathic pattern. He had elevated creatinine phosphokinase levels and muscle biopsy findings consistent with muscular dystrophy.

  2. Transcriptional and functional differences in stem cell populations isolated from Extraocular and Limb muscles

    DEFF Research Database (Denmark)

    Pacheco-Pinedo, Eugenia Cristina; Budak, Murat T; Zeiger, Ulrike

    2008-01-01

    The extraocular muscles (EOMs) are a distinct muscle group that displays an array of unique contractile, structural and regenerative properties. They also have differential sensitivity to certain diseases and are enigmatically spared in Duchenne muscular dystrophy (DMD). The EOMs are so distinct...

  3. Improvement of diaphragm and limb muscle isotonic contractile performance by K+ channel blockade

    Directory of Open Access Journals (Sweden)

    Pollarine Jennifer

    2010-01-01

    Full Text Available Abstract The K+ channel blocking aminopyridines greatly improve skeletal muscle isometric contractile performance during low to intermediate stimulation frequencies, making them potentially useful as inotropic agents for functional neuromuscular stimulation applications. Most restorative applications involve muscle shortening; however, previous studies on the effects of aminopyridines have involved muscle being held at constant length. Isotonic contractions differ substantially from isometric contractions at a cellular level with regards to factors such as cross-bridge formation and energetic requirements. The present study tested effects of 3,4-diaminopyridine (DAP on isotonic contractile performance of diaphragm, extensor digitorum longus (EDL and soleus muscles from rats. During contractions elicited during 20 Hz stimulation, DAP improved work over a range of loads for all three muscles. In contrast, peak power was augmented for the diaphragm and EDL but not the soleus. Maintenance of increased work and peak power was tested during repetitive fatigue-inducing stimulation using a single load of 40% and a stimulation frequency of 20 Hz. Work and peak power of both diaphragm and EDL were augmented by DAP for considerable periods of time, whereas that of soleus muscle was not affected significantly. These results demonstrate that DAP greatly improves both work and peak power of the diaphragm and EDL muscle during isotonic contractions, which combined with previous data on isometric contractions indicates that this agent is suitable for enhancing muscle performance during a range of contractile modalities.

  4. Biofeedback effectiveness to reduce upper limb muscle activity during computer work is muscle specific and time pressure dependent

    DEFF Research Database (Denmark)

    Vedsted, Pernille; Søgaard, Karen; Blangsted, Anne Katrine

    2011-01-01

    Continuous electromyographic (EMG) activity level is considered a risk factor in developing muscle disorders. EMG biofeedback is known to be useful in reducing EMG activity in working muscles during computer work. The purpose was to test the following hypotheses: (1) unilateral biofeedback from...... computer work during two different working conditions (time constraint/no time constraint) while receiving biofeedback. Biofeedback was given from right TRA or EDC through two modes (visual/auditory) by the use of EMG or mechanomyography as biofeedback source. During control sessions (no biofeedback), EMG...

  5. Anatomical and biomechanical traits of broiler chickens across ontogeny. Part II. Body segment inertial properties and muscle architecture of the pelvic limb

    Science.gov (United States)

    Tickle, Peter G.; Rankin, Jeffery W.; Codd, Jonathan R.; Hutchinson, John R.

    2014-01-01

    In broiler chickens, genetic success for desired production traits is often shadowed by welfare concerns related to musculoskeletal health. Whilst these concerns are clear, a viable solution is still elusive. Part of the solution lies in knowing how anatomical changes in afflicted body systems that occur across ontogeny influence standing and moving. Here, to demonstrate these changes we quantify the segment inertial properties of the whole body, trunk (legs removed) and the right pelvic limb segments of five broilers at three different age groups across development. We also consider how muscle architecture (mass, fascicle length and other properties related to mechanics) changes for selected muscles of the pelvic limb. All broilers used had no observed lameness, but we document the limb pathologies identified post mortem, since these two factors do not always correlate, as shown here. The most common leg disorders, including bacterial chondronecrosis with osteomyelitis and rotational and angular deformities of the lower limb, were observed in chickens at all developmental stages. Whole limb morphology is not uniform relative to body size, with broilers obtaining large thighs and feet between four and six weeks of age. This implies that the energetic cost of swinging the limbs is markedly increased across this growth period, perhaps contributing to reduced activity levels. Hindlimb bone length does not change during this period, which may be advantageous for increased stability despite the increased energetic costs. Increased pectoral muscle growth appears to move the centre of mass cranio-dorsally in the last two weeks of growth. This has direct consequences for locomotion (potentially greater limb muscle stresses during standing and moving). Our study is the first to measure these changes in the musculoskeletal system across growth in chickens, and reveals how artificially selected changes of the morphology of the pectoral apparatus may cause deficits in

  6. The comparison of ground reaction forces and lower limb muscles correlation and activation time delay between forward and backward walking.

    Science.gov (United States)

    Mahaki, Mohammadreza; De Sá E Souza, Gustavo Souto; Mimar, Raghad; Vieira, Marcus Fraga

    2017-10-01

    This study aimed to compare the ground reaction forces (GRF) and lower limb muscles correlation and activation time delay between Forward (FW) and Backward (BW) walking. Twenty-four male students participated in this research. Electromyogram activities of gluteus medius, biceps femoris, medial gastrocnemius, soleus and anterior tibialis muscles along with GRFs were measured. Each participant performed two FW and two BW trials bare foot. Statistical parametric mapping (SPM) analysis was performed over anterior-posterior and vertical GRFs time series. The paired t-test was used in SPM analysis. Cross-correlation analysis compared similarity in shape and time delay of EMG pattern. SPM analysis of GRFs showed that these two walking modes have asymmetrical kinetic behavior during most parts of stance phase. Based on cross-correlation analysis, the shape of EMG activation profiles differed, where a phase shift in the muscle activation pattern of approximately 60% occurred. This shift may indicate different control mechanisms, at the spinal level, underpin FW and BW walking modalities. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Serum Proteases Potentiate BMP-Induced Cell Cycle Re-entry of Dedifferentiating Muscle Cells during Newt Limb Regeneration.

    Science.gov (United States)

    Wagner, Ines; Wang, Heng; Weissert, Philipp M; Straube, Werner L; Shevchenko, Anna; Gentzel, Marc; Brito, Goncalo; Tazaki, Akira; Oliveira, Catarina; Sugiura, Takuji; Shevchenko, Andrej; Simon, András; Drechsel, David N; Tanaka, Elly M

    2017-03-27

    Limb amputation in the newt induces myofibers to dedifferentiate and re-enter the cell cycle to generate proliferative myogenic precursors in the regeneration blastema. Here we show that bone morphogenetic proteins (BMPs) and mature BMPs that have been further cleaved by serum proteases induce cell cycle entry by dedifferentiating newt muscle cells. Protease-activated BMP4/7 heterodimers that are present in serum strongly induced myotube cell cycle re-entry with protease cleavage yielding a 30-fold potency increase of BMP4/7 compared with canonical BMP4/7. Inhibition of BMP signaling via muscle-specific dominant-negative receptor expression reduced cell cycle entry in vitro and in vivo. In vivo inhibition of serine protease activity depressed cell cycle re-entry, which in turn was rescued by cleaved-mimic BMP. This work identifies a mechanism of BMP activation that generates blastema cells from differentiated muscle. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The effect of different skin-ankle brace application pressures with and without shoes on single-limb balance, electromyographic activation onset and peroneal reaction time of lower limb muscles.

    Science.gov (United States)

    Papadopoulos, E S; Nikolopoulos, C S; Athanasopoulos, S

    2008-12-01

    Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures, with and without shoes, on quiet single-limb balance and the electromyographic (EMG) activation sequence of four lower limb muscles. Twelve male physical education students who volunteered to take part in the study were measured with and without shoes under three ankle brace conditions: (i) without brace, (ii) with brace and 30 kilopascals (kPa) application pressure and (iii) with brace and 60 kPa application pressure. Single-limb balance (anteroposterior and mediolateral parameter) was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris) activation onset. Peroneus longus reaction time was also measured by provoking a sudden subtalar inversion stress test using a trap-door. The results showed that the application of athletic footwear resulted in a significant difference between the condition with shoes and without shoes, with a significantly increased anteroposterior sway and sway velocity, in all three ankle brace application conditions with shoes (F=50.9, d.f.=1, plower limb muscles. Lastly, ankle brace application with 30 and 60 kPa application pressures, with and without athletic footwear, led to a significant delay in the peroneus longus reaction time (F=9.71, d.f.=2, plimb balance, and peroneal reaction time. The application of athletic footwear, further adversely affects these parameters significantly. Further research is needed in this area with more dynamic and functional measurements, before the safe use of ankle bracing can be widely recommended.

  9. Fiber size and myosin phenotypes of selected rhesus lower limb muscles after a 14-day spaceflight

    Science.gov (United States)

    Roy, R. R.; Zhong, H.; Bodine, S. C.; Pierotti, D. J.; Talmadge, R. J.; Barkhoudarian, G.; Kim, J.; Fanton, J. W.; Kozlovskaya, I. B.; Edgerton, V. R.

    2000-01-01

    Muscle biopsies were taken from the rhesus (Macaca mulatta) soleus (Sol, a slow ankle extensor), medial gastrocnemius (MG, a fast ankle extensor), tibialis anterior (TA, a fast ankle flexor), and vastus lateralis (VL, a fast knee extensor) muscles in vivarium controls (n=5) before and after either a 14-day spaceflight (Bion 11, n=2) or a 14-day ground-based flight simulation (n=3). Myosin heavy chain (MHC) composition (gel electrophoresis), fiber type distribution (immunohistochemistry), and fiber size were determined. Although there were no significant changes, each muscle showed trends towards adaptation.

  10. Coexistence and Impact of Limb Muscle and Diaphragm Weakness at Time of Liberation from Mechanical Ventilation in Medical Intensive Care Unit Patients.

    Science.gov (United States)

    Dres, Martin; Dubé, Bruno-Pierre; Mayaux, Julien; Delemazure, Julie; Reuter, Danielle; Brochard, Laurent; Similowski, Thomas; Demoule, Alexandre

    2017-01-01

    Intensive care unit (ICU)- and mechanical ventilation (MV)-acquired limb muscle and diaphragm dysfunction may both be associated with longer length of stay and worse outcome. Whether they are two aspects of the same entity or have a different prevalence and prognostic impact remains unclear. To quantify the prevalence and coexistence of these two forms of ICU-acquired weakness and their impact on outcome. In patients undergoing a first spontaneous breathing trial after at least 24 hours of MV, diaphragm dysfunction was evaluated using twitch tracheal pressure in response to bilateral anterior magnetic phrenic nerve stimulation (a pressure <11 cm H2O defined dysfunction) and ultrasonography (thickening fraction [TFdi] and excursion). Limb muscle weakness was defined as a Medical Research Council (MRC) score less than 48. Seventy-six patients were assessed at their first spontaneous breathing trial: 63% had diaphragm dysfunction, 34% had limb muscle weakness, and 21% had both. There was a significant but weak correlation between MRC score and twitch pressure (ρ = 0.26; P = 0.03) and TFdi (ρ = 0.28; P = 0.01), respectively. Low twitch pressure (odds ratio, 0.60; 95% confidence interval, 0.45-0.79; P < 0.001) and TFdi (odds ratio, 0.84; 95% confidence interval, 0.76-0.92; P < 0.001) were independently associated with weaning failure, but the MRC score was not. Diaphragm dysfunction was associated with higher ICU and hospital mortality, and limb muscle weakness was associated with longer duration of MV and hospital stay. Diaphragm dysfunction is twice as frequent as limb muscle weakness and has a direct negative impact on weaning outcome. The two types of muscle weakness have only limited overlap.

  11. Patterns of Lower Limb Muscle Activity in Young Boys During a One Foot Static Balance Task.

    Science.gov (United States)

    Layne, Charles S.; Abraham, Lawrence D.

    1987-01-01

    This study of 10 seven- to nine-year-old boys was undertaken to determine the electromyographic activity of four muscles in the supporting leg during one foot static balancing. Results are presented and analyzed. (Author/MT)

  12. Functional assessment of muscle response in lower limbs of tumbling gymnasts through tensiomyography

    Directory of Open Access Journals (Sweden)

    Nicolás Rojas-Barrionuevo

    2016-07-01

    Conclusions: Tensiomyography allows estimating the states of activation-enhancing of the musculature responsible of jumping in tumblers, as well as planning the training based on the state of muscle fatigue.

  13. Comparison of upper limb muscles behaviour for skilled and recreational archers using compound bow

    Science.gov (United States)

    Ariffin, Muhammad Shahimi; Rambely, Azmin Sham

    2017-04-01

    The purpose of this study was to investigate muscles activity during archery by carrying out an electromyography (EMG) experiment towards 12 muscles and six joints involving two types of subject (skilled and recreational). EMG is used to detect muscle signals during any particular activity. There were two types of data recorded which were maximum voluntary contraction (MVC) and archery activity. The skilled archer was found to produce 280 N of biceps brachii, 213.9 N of the deltoid, 123.4 N of trapezius forces compare to that of the recreational archer with 371.1 N, 164.9 N and 163.8 N, respectively for the draw arm during drawing phase. It is concluded that the recreational archer tends to a muscle fatigue phenomenon thus may contribute to possible serious injuries.

  14. The pectoral fin muscles of the coelacanth Latimeria chalumnae: Functional and evolutionary implications for the fin-to-limb transition and subsequent evolution of tetrapods.

    Science.gov (United States)

    Miyake, Tsutomu; Kumamoto, Minayori; Iwata, Masamitsu; Sato, Ryuichi; Okabe, Masataka; Koie, Hiroshi; Kumai, Nori; Fujii, Kenichi; Matsuzaki, Koji; Nakamura, Chiho; Yamauchi, Shinya; Yoshida, Kosuke; Yoshimura, Kohtaroh; Komoda, Akira; Uyeno, Teruya; Abe, Yoshitaka

    2016-09-01

    To investigate the morphology and evolutionary origin of muscles in vertebrate limbs, we conducted anatomical dissections, computed tomography and kinematic analyses on the pectoral fin of the African coelacanth, Latimeria chalumnae. We discovered nine antagonistic pairs of pronators and supinators that are anatomically and functionally distinct from the abductor and adductor superficiales and profundi. In particular, the first pronator and supinator pair represents mono- and biarticular muscles; a portion of the muscle fibers is attached to ridges on the humerus and is separated into two monoarticular muscles, whereas, as a biarticular muscle, the main body is inserted into the radius by crossing two joints from the shoulder girdle. This pair, consisting of a pronator and supinator, constitutes a muscle arrangement equivalent to two human antagonistic pairs of monoarticular muscles and one antagonistic pair of biarticular muscles in the stylopod between the shoulder and elbow joints. Our recent kinesiological and biomechanical engineering studies on human limbs have demonstrated that two antagonistic pairs of monoarticular muscles and one antagonistic pair of biarticular muscles in the stylopod (1) coordinately control output force and force direction at the wrist and ankle and (2) achieve a contact task to carry out weight-bearing motion and maintain stable posture. Therefore, along with dissections of the pectoral fins in two lungfish species, Neoceratodus forsteri and Protopterus aethiopicus, we discuss the functional and evolutionary implications for the fin-to-limb transition and subsequent evolution of tetrapods. Anat Rec, 299:1203-1223, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Changes in input-output relations in the corticospinal pathway to the lower limb muscles during robot-assisted passive stepping.

    Science.gov (United States)

    Kamibayashi, Kiyotaka; Nakajima, Tsuyoshi; Takahashi, Makoto; Nakazawa, Kimitaka

    2011-01-01

    We investigated input (stimulus)-output (response) relations of the corticospinal pathway in the lower limb muscles during passive stepping using a robotic driven gait orthosis. Nine healthy adult subjects passively stepped with 40% body weight unloading (ground stepping) and 100% body weight unloading in the air (air stepping). During passive stepping, the motor evoked potentials (MEPs) of the lower limb muscles elicited by transcranial magnetic stimulation (TMS) were recorded at late-stance, early-, and late-swing phases of 2 stepping conditions. The input-output relation at each phase of the stepping conditions was obtained by increasing stimulus intensity in 5% increments from 40% to 70% of maximal stimulator output. The slopes of input-output relations were steeper at the early-swing phase in the rectus femoris muscle and at the late-stance and late-swing phases in the biceps femoris muscle in both stepping conditions. There were no significant differences in the MEP responses of the rectus femoris and biceps femoris muscles at each phase between the 2 conditions. Low muscle activity was seen at the late-stance phase of ground stepping in the soleus muscle and the MEP amplitude at this phase became larger. The slopes in the tibialis anterior muscle were steep at the early- and late-swing phases of ground stepping. There was a significant difference in the MEPs of the tibialis anterior muscle between the late-swing phases in ground and air stepping. The present study indicates that corticospinal excitability to the lower limb muscles is modulated by sensory inputs elicited by passive stepping.

  16. Tensiomyography of selected lower-limb muscles in professional soccer players.

    Science.gov (United States)

    Rey, Ezequiel; Lago-Peñas, Carlos; Lago-Ballesteros, Joaquín

    2012-12-01

    Tensiomyography is a non-invasive method of neuromuscular assessment used to measure muscle action characteristics, muscle tone, and muscle fiber type, and provides information on acute and chronic responses of muscle to different training loads. The aims of the present study were: to analyse differences in muscle response and mechanical characteristics of two major muscles of the lower extremity in a large group of Spanish soccer players according to playing position, and to provide group norms against which clinical findings may be compared. Data were collected from 78 professional soccer players (age 26.6 ± 4.4 years; height: 179.2 ± 5.3 cm; body mass: 75.8 ± 5.3 kg). Tensiomyography was recorded from the rectus femoris (RF) and biceps femoris (BF) muscles after 2 days without take part in any strenuous exercise or training. Five tensiomyographic parameters were analyzed: maximal displacement (D(m)), contraction time (T(c)), sustain time (T(s)), delay time (T(d)), and half-relaxation time (T(r)). A good to excellent intra-session reliability was found for all contractile parameters (ICC ranged from 0.78 to 0.95). No significant differences between players of any position were observed in absolute values of BF. However, significant differences were observed for T(c), T(r) and T(s) between the different playing positions on RF (P muscles with ability to rapidly generate force during contractions. The neuromuscular profile provided could help in identifying the normative data that are important for the different positions in order to optimize the training and recovery process of each individual player. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Lower limb muscle coactivation levels in healthy younger and older adults during functional dual-task gait

    Directory of Open Access Journals (Sweden)

    Camilla Zamfolini Hallal

    2013-09-01

    Full Text Available The purpose of this study was to investigate the influence of daily cognitive task on stiffness of old and young female adults during the gait. The study included 17 physically active younger and 18 older women, with low risk of falls. The volunteers were asked to walk on the treadmill at two different gait conditions: normal gait and functional dual-task gait. The electromyographic signals were collected of the lower limb muscles. The percentage of coactivation for the tibialis anterior/gastrocnemius lateralis and tibialis anterior/soleus were significantly higher in elderly than in younger in the normal gait and dual-task gait. Our results suggest that the elderly have a greater stiffness in the ankle joint during gait normal and daily dual task gait. Thus, we conclude that challenging cognitively situations during the gait may increase the risk of falls in this population.

  18. Muscle activation patterns of knee flexors and extensors during passive and active movement of the spastic lower limb in chronic stroke patients

    NARCIS (Netherlands)

    Fleuren, J.F.M.; Fleuren, J.F.M.; Snoek, G.J.; Voerman, Gerlienke; Hermens, Hermanus J.

    2009-01-01

    The aim of this study was to describe the characteristics of spasticity, quantified as muscle activity during stretch, during passive and active movement. For this cross sectional study 19 stroke patients with spasticity in the lower limb were recruited. Reflex activity was studied with surface

  19. Activity of Lower Limb Muscles During Squat With and Without Abdominal Drawing-in and Pilates Breathing.

    Science.gov (United States)

    Barbosa, Alexandre C; Martins, Fábio M; Silva, Angélica F; Coelho, Ana C; Intelangelo, Leonardo; Vieira, Edgar R

    2017-11-01

    Barbosa, AC, Martins, FM, Silva, AF, Coelho, AC, Intelangelo, L, and Vieira, ER. Activity of lower limb muscles during squat with and without abdominal drawing-in and Pilates breathing. J Strength Cond Res 31(11): 3018-3023, 2017-The purpose of this study was to assess the effects of abdominal drawing-in and Pilates breathing on the activity of lower limb muscles during squats. Adults (n = 13, 22 ± 3 years old) with some Pilates experience performed three 60° squats under each of the following conditions in a random order: (I) normal breathing, (II) drawing-in maneuver with normal breathing, and (III) drawing-in maneuver with Pilates breathing. Peak-normalized surface electromyography of the rectus femoris, biceps femoris, gastrocnemius medialis, and tibialis anterior during the knee flexion and extension phases of squat exercises was analyzed. There were significant differences among the conditions during the knee flexion phase for the rectus femoris (p = 0.001), biceps femoris (p = 0.038), and tibialis anterior (p = 0.001), with increasing activation from conditions I to III. For the gastrocnemius medialis, there were significant differences among the conditions during the knee extension phase (p = 0.023), with increased activity under condition I. The rectus and biceps femoris activity was higher during the extension vs. flexion phase under conditions I and II. The tibialis anterior activity was higher during the flexion compared with the extension phase under all conditions, and the medial gastrocnemius activity was higher during the extension phase under condition I. Doing squats with abdominal drawing-in and Pilates breathing resulted in increased rectus, biceps femoris, and tibialis anterior activity during the flexion phase, increasing movement stability during squat exercises.

  20. B4GALNT2 (GALGT2) Gene Therapy Reduces Skeletal Muscle Pathology in the FKRP P448L Mouse Model of Limb Girdle Muscular Dystrophy 2I.

    Science.gov (United States)

    Thomas, Paul J; Xu, Rui; Martin, Paul T

    2016-09-01

    Overexpression of B4GALNT2 (previously GALGT2) inhibits the development of muscle pathology in mouse models of Duchenne muscular dystrophy, congenital muscular dystrophy 1A, and limb girdle muscular dystrophy 2D. In these models, muscle GALGT2 overexpression induces the glycosylation of α dystroglycan with the cytotoxic T cell glycan and increases the overexpression of dystrophin and laminin α2 surrogates known to inhibit disease. Here, we show that GALGT2 gene therapy significantly reduces muscle pathology in FKRP P448Lneo(-) mice, a model for limb girdle muscular dystrophy 2I. rAAVrh74.MCK.GALGT2-treated FKRP P448Lneo(-) muscles showed reduced levels of centrally nucleated myofibers, reduced variance, increased size of myofiber diameters, reduced myofiber immunoglobulin G uptake, and reduced muscle wasting at 3 and 6 months after treatment. GALGT2 overexpression in FKRP P448Lneo(-) muscles did not cause substantial glycosylation of α dystroglycan with the cytotoxic T cell glycan or increased expression of dystrophin and laminin α2 surrogates in mature skeletal myofibers, but it increased the number of embryonic myosin-positive regenerating myofibers. These data demonstrate that GALGT2 overexpression can reduce the extent of muscle pathology in FKRP mutant muscles, but that it may do so via a mechanism that differs from its ability to induce surrogate gene expression. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  1. Dose-Effect Relationships for Femoral Fractures After Multimodality Limb-Sparing Therapy of Soft-Tissue Sarcomas of the Proximal Lower Extremity

    Energy Technology Data Exchange (ETDEWEB)

    Pak, Daniel; Vineberg, Karen A. [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Griffith, Kent A. [Biostatistics Unit, Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI (United States); Sabolch, Aaron [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Chugh, Rashmi [Department of Internal Medicine, Division of Hematology/Oncology, University of Michigan, Ann Arbor, MI (United States); Ben-Josef, Edgar [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Biermann, Janet Sybil [Department of Orthopedic Surgery, University of Michigan, Ann Arbor, MI (United States); Feng, Mary, E-mail: maryfeng@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States)

    2012-07-15

    Purpose: We investigated the clinical and dosimetric predictors for radiation-associated femoral fractures in patients with proximal lower extremity soft tissue sarcomas (STS). Methods and Materials: We examined 131 patients with proximal lower extremity STS who received limb-sparing surgery and external-beam radiation therapy between 1985 and 2006. Five (4%) patients sustained pathologic femoral fractures. Dosimetric analysis was limited to 4 fracture patients with full three-dimensional dose information, who were compared with 59 nonfracture patients. The mean doses and volumes of bone (V{sub d}) receiving specified doses ({>=}30 Gy, 45 Gy, 60 Gy) at the femoral body, femoral neck, intertrochanteric region, and subtrochanteric region were compared. Clinical predictive factors were also evaluated. Results: Of 4 fracture patients in our dosimetric series, there were three femoral neck fractures with a mean dose of 57.6 {+-} 8.9 Gy, V30 of 14.5 {+-} 2.3 cc, V45 of 11.8 {+-} 1.1 cc, and V60 of 7.2 {+-} 2.2 cc at the femoral neck compared with 22.9 {+-} 20.8 Gy, 4.8 {+-} 5.6 cc, 2.5 {+-} 3.9 cc, and 0.8 {+-} 2.7 cc, respectively, for nonfracture patients (p < 0.03 for all). The femoral neck fracture rate was higher than at the subtrochanteric region despite lower mean doses at these subregions. All fracture sites received mean doses greater than 40 Gy. Also, with our policy of prophylactic femoral intramedullary nailing for high-risk patients, there was no significant difference in fracture rates between patients with and without periosteal excision. There were no significant differences in age, sex, tumor size, timing of radiation therapy, and use of chemotherapy between fracture and nonfracture patients. Conclusions: These dose-volume toxicity relationships provide RT optimization goals to guide future efforts for reducing pathologic fracture rates. Prophylactic femoral intramedullary nailing may also reduce fracture risk for susceptible patients.

  2. Postexercise cold water immersion modulates skeletal muscle PGC-1α mRNA expression in immersed and nonimmersed limbs: evidence of systemic regulation.

    Science.gov (United States)

    Allan, Robert; Sharples, Adam P; Close, Graeme L; Drust, Barry; Shepherd, Sam O; Dutton, John; Morton, James P; Gregson, Warren

    2017-08-01

    Mechanisms mediating postexercise cold-induced increases in PGC-1α gene expression in human skeletal muscle are yet to be fully elucidated but may involve local cooling effects on AMPK and p38 MAPK-related signaling and/or increased systemic β-adrenergic stimulation. Therefore, we aimed to examine whether postexercise cold water immersion enhancement of PGC-1α mRNA is mediated through local or systemic mechanisms. Ten subjects completed acute cycling (8 × 5 min at ~80% peak power output) followed by seated-rest (CON) or single-leg cold water immersion (CWI; 10 min, 8°C). Muscle biopsies were obtained preexercise, postexercise, and 3 h postexercise from a single limb in the CON condition but from both limbs in CWI [thereby providing tissue from a CWI and nonimmersed limb (NOT)]. Muscle temperature decreased up to 2 h postexercise following CWI (-5°C) in the immersed limb, with lesser changes observed in CON and NOT (-3°C, P cold induction of PGC-1α mRNA.NEW & NOTEWORTHY We report for the first time that postexercise cold water immersion of one limb also enhances PGC-1α expression in a contralateral, nonimmersed limb. We suggest that increased systemic β-adrenergic stimulation, and not localized cooling per se, exerts regulatory effects on local signaling cascades, thereby modulating PGC-1α expression. Therefore, these data have important implications for research designs that adopt contralateral, nonimmersed limbs as a control condition while also increasing our understanding of the potential mechanisms underpinning cold-mediated PGC-1α responses. Copyright © 2017 the American Physiological Society.

  3. Lower limb muscle pre-motor time measures during a choice reaction task associate with knee abduction loads during dynamic single leg landings.

    Science.gov (United States)

    McLean, Scott G; Borotikar, Bhushan; Lucey, Sarah M

    2010-07-01

    Female neuromuscular control during dynamic landings is considered central to their increased ACL injury risk relative to males. There is limited insight, however, into the neuromuscular parameters governing this risk, which may hinder prevention success. This study targeted a new screenable and potentially trainable neuromuscular risk factor. Specifically, we examined whether lower limb muscle pre-motor times, being the time between stimulus presentation and initiation of the muscle EMG burst, elicited during a simple choice reaction task correlated with knee abduction loads during separate single leg landings. Twenty female NCAA athletes had muscle (n=8) pre-motor time and knee biomechanics data recorded bilaterally during a choice reaction task. Knee biomechanics were also quantified during anticipated and unanticipated single (dominant and non-dominant) leg landings. Mean peak knee abduction loads during landings were submitted to a two-way ANOVA to test for limb and decision effects. Individual regression coefficients were initially computed between-limb-based muscle pre-motor times and peak abduction moments elicited during both the choice reaction and landing tasks. Limb-based linear stepwise regression coefficients were also computed between muscle PMT's demonstrating significant (Pmuscle pre-motor times during a specific choice reaction task are associated with peak knee abduction loads during separate single leg landings. These muscles appear critical in stabilizing the knee against the extreme dynamic load states associated with such tasks. Targeted screening and training of supraspinal processes governing these muscle pre-motor times may ultimately enable external knee loads associated with landings to be more effectively countered by the overarching neuromuscular strategy. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. Evaluation of fatigue of respiratory and lower limb muscles during prolonged aerobic exercise.

    Science.gov (United States)

    Nadiv, Yaara; Vachbroit, Ricki; Gefen, Amit; Elad, David; Zaretsky, Uri; Moran, Dani; Halpern, Pinchas; Ratnovsky, Anat

    2012-05-01

    The respiratory muscles may fatigue during prolonged exercises and thereby become a factor that limits extreme physical activity. The aim of the current study was to determine whether respiratory muscle fatigue imposes a limitation on extreme physical activity of well-trained young men. Electromyography (EMG) signals of respiratory (external intercostal and sternomastoid) and calf muscles (gastrocnemius) were measured (N = 8) during 1 hr of treadmill marching at a speed of 8 km/hr with and without a 15 kg backpack. The root mean square (RMS) and the mean power frequency of the EMG signals were evaluated for calculating fatigue indices. The EMG RMS revealed that the respiratory and calf muscles did not fatigue during the marching without a backpack load. The study did show, however, a significant rise in the EMG values when a backpack was carried with respect to the no-load condition (p muscles should be trained in military recruits who are required to carry loaded backpacks while marching.

  5. An evolutionary algorithm for the segmentation of muscles and bones of the lower limb.

    Science.gov (United States)

    Lpez, Marco A.; Braidot, A.; Sattler, Anbal; Schira, Claudia; Uriburu, E.

    2016-04-01

    In the field of medical image segmentation, muscles segmentation is a problem that has not been fully resolved yet. This is due to the fact that the basic assumption of image segmentation, which asserts that a visual distinction should ex- ist between the different structures to be identified, is infringed. As the tissue composition of two different muscles is the same, it becomes extremely difficult to distinguish one another if they are near. We have developed an evolutionary algorithm which selects the set and the sequence of morphological operators that better segments muscles and bones from an MRI image. The achieved results shows that the developed algorithm presents average sensitivity values close to 75% in the segmentation of the different processed muscles and bones. It also presents average specificity values close to 93% for the same structures. Furthermore, the algorithm can identify muscles that are closely located through the path from their origin point to their insertions, with very low error values (below 7%) .

  6. Built for rowing: frog muscle is tuned to limb morphology to power swimming.

    Science.gov (United States)

    Richards, Christopher T; Clemente, Christofer J

    2013-07-06

    Rowing is demanding, in part, because drag on the oars increases as the square of their speed. Hence, as muscles shorten faster, their force capacity falls, whereas drag rises. How do frogs resolve this dilemma to swim rapidly? We predicted that shortening velocity cannot exceed a terminal velocity where muscle and fluid torques balance. This terminal velocity, which is below Vmax, depends on gear ratio (GR = outlever/inlever) and webbed foot area. Perhaps such properties of swimmers are 'tuned', enabling shortening speeds of approximately 0.3Vmax for maximal power. Predictions were tested using a 'musculo-robotic' Xenopus laevis foot driven either by a living in vitro or computational in silico plantaris longus muscle. Experiments verified predictions. Our principle finding is that GR ranges from 11.5 to 20 near the predicted optimum for rowing (GR ≈ 11). However, gearing influences muscle power more strongly than foot area. No single morphology is optimal for producing muscle power. Rather, the 'optimal' GR decreases with foot size, implying that rowing ability need not compromise jumping (and vice versa). Thus, despite our neglect of additional forces (e.g. added mass), our model predicts pairings of physiological and morphological properties to confer effective rowing. Beyond frogs, the model may apply across a range of size and complexity from aquatic insects to human-powered rowing.

  7. Effects of teeth clenching on the soleus H reflex during lower limb muscle fatigue.

    Science.gov (United States)

    Mitsuyama, Akihiro; Takahashi, Toshiyuki; Ueno, Toshiaki

    2017-04-01

    We assessed whether the soleus H reflex was depressed or facilitated in association with voluntary teeth clenching during muscle fatigue. A total of 13 and 9 healthy adult subjects were instructed to perform right-side tiptoe standing for 5 (TS1) and 10min (TS2) to induce the soleus muscle fatigue. Electromyograms (EMGs) were recorded from the bilateral masseter as well as the right-side soleus muscles. H reflex was evoked using a surface electrode. The isometric muscle strength during plantar flexion was measured. We tested two dental occlusal conditions (1) with maximal voluntary teeth clenching (MVTC) and (2) at mandibular rest position (RP). H reflex was evoked before and after TS1 and TS2. The isometric muscle strength during plantar flexion was measured before and after TS1 and TS2. Mean amplitudes of H reflex with MVTC before and after TS1 were significantly larger than that with RP before and after TS1. The mean peak torque (PT) during isometric plantar flexion was observed significant differences in all subjects. The mean amplitude of H reflex with MVTC before TS2 was significantly larger than that with RP before TS2. No significant difference between RP after TS2 and MVTC after TS2. The mean PT with MVTC before TS2 was significantly larger than that with RP before TS2. There was no significant difference between RP and MVTC after TS2. The present study demonstrated that teeth clenching could facilitate H reflex regardless of the degree of muscle fatigue. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  8. [18F]FDG uptake in proximal muscles assessed by PET/CT reflects both global and local muscular inflammation and provides useful information in the management of patients with polymyositis/dermatomyositis.

    Science.gov (United States)

    Tanaka, Shigeru; Ikeda, Kei; Uchiyama, Katsuhiro; Iwamoto, Taro; Sanayama, Yoshie; Okubo, Ayako; Nakagomi, Daiki; Takahashi, Kentaro; Yokota, Masaya; Suto, Akira; Suzuki, Kotaro; Nakajima, Hiroshi

    2013-07-01

    This study aimed to determine whether [(18)F]fluorodeoxyglucose-PET/CT ([(18)F]FDG-PET/CT) discriminates PM/DM from non-muscular diseases and also whether FDG uptake in proximal muscles reflects the activity and severity of muscular inflammation in PM/DM. Twenty treatment-naïve PM/DM patients who underwent [(18)F]FDG-PET/CT were retrospectively identified by reviewing medical records. The same number of age- and sex-matched control patients with non-muscular diseases were also identified. Standardized uptake value (SUV) was calculated for each of the seven proximal muscles. For patient-based assessment, mean proximal muscle SUV was calculated by averaging the SUVs for these proximal muscles bilaterally. Mean proximal muscle SUVs were significantly greater in PM/DM patients than in control patients (median 1.05 vs 0.69, P muscle SUVs significantly correlated with mean proximal manual muscle test scores (ρ = 0.49, P = 0.028) and serum levels of creatine kinase (ρ = 0.54, P = 0.015) and aldolase (ρ = 0.64, P = 0.002). Furthermore, SUVs in proximal muscles from which biopsy specimens were obtained significantly correlated with histological grade for inflammatory cell infiltration (ρ = 0.66, P = 0.002). Our results suggest that [(18)F]FDG-PET/CT is useful in the diagnosis of PM/DM when inflammation in proximal muscles is globally assessed with quantitative measurements. Our results also indicate that local FDG uptake in a proximal muscle reflects the activity of inflammation in the same muscle and provides useful information in determining the region for muscle biopsy.

  9. Are Muscle Strength and Function of the Uninjured Lower Limb Weakened After Anterior Cruciate Ligament Injury? Two-Year Follow-up After Reconstruction.

    Science.gov (United States)

    Chung, Kyu Sung; Ha, Jeong Ku; Yeom, Cheol Hyun; Ra, Ho Jong; Lim, Jin Woo; Kwon, Min Soo; Kim, Jin Goo

    2015-12-01

    After an anterior cruciate ligament (ACL) injury, the uninjured contralateral lower limb may become weakened because of neuromuscular changes, proprioceptive deficits, and disuse of the limb; this weakness predisposes the limb to ACL injury. However, no results have been reported regarding weakness in the contralateral limb after ACL injury. Muscle strength and functional status of the contralateral lower limb are reduced after unilateral ACL injury. Cohort study; Level of evidence, 3. The ACL group consisted of 75 patients who underwent primary unilateral ACL reconstruction and were followed at 3, 6, 12, and 24 months postoperatively. A group of 75 healthy individuals (controls) were matched one-to-one with the ACL group for age, sex, body mass index, and initial Tegner activity level. The side that was evaluated in each control subject corresponded to the injured limb in the matched ACL subject. Isokinetic muscle strength, including extension peak torque per body weight (EPT) and flexion peak torque per body weight (FPT), was evaluated at angular velocities of 60 and 180 deg/s. Patients were also evaluated by single-legged hop test. Compared with the EPT at 60 deg/s in the control group (290.9 ± 40.1 N · m/kg), the value in the ACL group 24-month follow-up (276.6 ± 42.8 N · m/kg) as well as other follow-up times was significantly lower (P follow-up but were restored to normal levels at final follow-up. Results from the single-legged hop test demonstrated that the ACL group performed at a significantly lower level than the control group at 24-month follow-up (158.4 ± 25.3 vs 176.3 ± 24.7 cm; P follow-up times. However, both measurements improved significantly as the follow-up time progressed. After ACL injury, isokinetic extensor muscle strength and functional status of the contralateral limb were reduced, even at 24 months after ACL reconstruction. However, both measurements improved significantly as the follow-up time progressed. In contrast, flexion

  10. Effects of load on the acute response of muscles proximal and distal to blood flow restriction.

    Science.gov (United States)

    Jessee, Matthew B; Mouser, J Grant; Buckner, Samuel L; Dankel, Scott J; Mattocks, Kevin T; Abe, Takashi; Loenneke, Jeremy P

    2018-01-18

    To determine the effects of load and blood flow restriction (BFR) on muscular responses, we asked 12 participants to perform chest presses under four different conditions [30/0, 30/40, 50/0, and 50/40, presented as percentage one-repetition maximum (1RM)/percentage arterial occlusion pressure (AOP)]. Muscle thickness increased pre- to post-exercise [chest: mean 0.29, 95% confidence interval (CI) 0.21, 0.37 cm; triceps: mean 0.44, 95% CI 0.34, 0.54 cm], remaining elevated for 15 min post-exercise. Electromyography amplitude was greater with 50% 1RM and increased over time for the first three repetitions of each set of chest presses. The last three repetitions differed across time only. AOP increased from pre- to post-exercise, augmented by BFR [30/0: mean 31, 95% CI 18, 44 mmHg; 30/40: mean 39, 95% CI 28, 50 mmHg; 50/0: mean 32, 95% CI 23, 41 mmHg; 50/40: mean 46, 95% CI 32, 59 mmHg). Tranquility decreased and physical exhaustion increased from the pre- to post-condition, with both parameters returning to the baseline 15 min post-exercise level. In conclusion, load and BFR do not elicit meaningful differences in the acute response of chest press exercise taken to failure.

  11. Blood flow response to electrically induced twitch and tetanic lower-limb muscle contractions.

    NARCIS (Netherlands)

    Janssen, T.W.; Hopman, M.T.E.

    2003-01-01

    OBJECTIVES: To compare the effect of electric stimulation (ES)-induced twitch with tetanic leg muscle contractions on blood flow responses and to assess blood flow responses in the contralateral inactive leg. DESIGN: Intervention with within-subject comparisons. SETTING: University research

  12. Control of support limb muscles in recovery after tripping in young and older subjects

    NARCIS (Netherlands)

    Pijnappels, M.A.G.M.; Bobbert, M.F.; van Dieen, J.H.

    2005-01-01

    Older people fall more often after tripping than young people due to a slower development of mechanical responses. This might be due to age-related changes in muscle properties, but also to changes in motor control. The purpose of the present study was to determine whether (a) timing and sequencing

  13. Blood flow response to electrically induced twitch and tetanic lower-limb muscle contractions

    NARCIS (Netherlands)

    Janssen, T.W.J.; Hopman, M.T.E.

    2003-01-01

    Objectives: To compare the effect of electric stimulation (ES)-induced twitch with tetanic leg muscle contractions on blood flow responses and to assess blood flow responses in the contralateral inactive leg. Design: Intervention with within-subject comparisons. Setting: University research

  14. Prototype Multifunctional Device for Contraction Exercises of Joints and Muscles of the Lower Limb

    Directory of Open Access Journals (Sweden)

    Pawel JURECZKO

    2013-12-01

    Full Text Available In the article Authors are showing the endurance test of the prototype multifunctional device for contraction exercises of joints and strengthening muscles. The endurance test was conducted with finite element method in the Ansys Workbench program and permitted the durability of material checking, whether the structural figure of the device is safe from the side for patients.

  15. Strength of the respiratory and lower limb muscles and functional capacity in chronic stroke survivors with different physical activity levels.

    Science.gov (United States)

    Polese, Janaine C; Pinheiro, Marina B; Faria, Christina D C M; Britto, Raquel R; Parreira, Verônica F; Teixeira-Salmela, Luci F

    2013-01-01

    The assessment of strength and its relationships with functional capacity could contribute to more specific and effective disability management of stroke survivors. To compare and investigate associations between measures of strength and functional capacity of 98 chronic stroke survivors, stratified into three groups, according to their physical activity levels. The physical activity levels were classified as impaired, moderately active, and active, based on their Human Activity Profile (HAP) scores. Strength was assessed by the maximal inspiratory (MIP) and expiratory (MEP) pressures and by the residual deficits (RDs) of work of the lower limb and trunk muscles, whereas functional capacity was evaluated by the distance covered during the six-minute walking test (6MWT). One-way analyses of variance revealed significant differences between the groups, except between the active and moderately active groups regarding the RDS of the hip and knee flexors/extensors and ankle dorsiflexors (2.91muscles and the 6MWT (0.30Lower strength deficits and higher functional capacity were associated with higher physical activity levels. However, the moderately active and active groups demonstrated similar strength deficits.

  16. Control of non-linear actuator of artificial muscles for the use in low-cost robotics prosthetics limbs

    Science.gov (United States)

    Anis Atikah, Nurul; Yeng Weng, Leong; Anuar, Adzly; Chien Fat, Chau; Sahari, Khairul Salleh Mohamed; Zainal Abidin, Izham

    2017-10-01

    Currently, the methods of actuating robotic-based prosthetic limbs are moving away from bulky actuators to more fluid materials such as artificial muscles. The main disadvantages of these artificial muscles are their high cost of manufacturing, low-force generation, cumbersome and complex controls. A recent discovery into using super coiled polymer (SCP) proved to have low manufacturing costs, high force generation, compact and simple controls. Nevertheless, the non-linear controls still exists due to the nature of heat-based actuation, which is hysteresis. This makes position control difficult. Using electrically conductive devices allows for very quick heating, but not quick cooling. This research tries to solve the problem by using peltier devices, which can effectively heat and cool the SCP, hence giving way to a more precise control. The peltier device does not actively introduce more energy to a volume of space, which the coiled heating does; instead, it acts as a heat pump. Experiments were conducted to test the feasibility of using peltier as an actuating method on different diameters of nylon fishing strings. Based on these experiments, the performance characteristics of the strings were plotted, which could be used to control the actuation of the string efficiently in the future.

  17. Development of Activity-Related Muscle Fatigue during Robot-Mediated Upper Limb Rehabilitation Training in Persons with Multiple Sclerosis: A Pilot Trial

    Directory of Open Access Journals (Sweden)

    Johanna Renny Octavia

    2015-01-01

    Full Text Available Robot-assisted rehabilitation facilitates high-intensity training of the impaired upper limb in neurological rehabilitation. It has been clinically observed that persons with Multiple Sclerosis (MS have difficulties in sustaining the training intensity during a session due to the development of activity-related muscle fatigue. An experimental observational pilot study was conducted to examine whether or not the muscle fatigue develops in MS patients during one session of robot-assisted training within a virtual learning environment. Six MS patients with upper limb impairment (motricity index ranging from 50 to 91/100 and six healthy persons completed five training bouts of three minutes each performing lifting tasks, while EMG signals of anterior deltoid and lower trapezius muscles were measured and their subjective perceptions on muscle fatigue were registered. Decreased performance and higher subjective fatigue perception were present in the MS group. Increased mean EMG amplitudes and subjective perception levels on muscle fatigue were observed in both groups. Muscle fatigue development during 15′ training has been demonstrated in the arm of MS patients, which influences the sustainability of training intensity in MS patients. To optimize the training performance, adaptivity based on the detection of MS patient’s muscle fatigue could be provided by means of training program adjustment.

  18. THE ANALYSIS OF MORPHOFUNCTIONAL CONDITION OF THE UPPER LIMB MUSCLES IN TREATMENT OF PATIENTS WITH POSTTRAUMATIC ELBOW FLEXION-AND-EXTENSION CONTRACTURES

    Directory of Open Access Journals (Sweden)

    L. A. Grebenyuk

    2012-01-01

    Full Text Available The aim of the work was to study the echography visualization-based structural features of muscles and the wrist radial flexors for surgical treatment of 56 patients with the elbow flexion-and-extension contractures. The result of surgical treatment in the main group of patients consisted in the increase of the elbow extension angle. Muscle pattern was similar to a typical, normal ultrasound image. The most characteristic feature was a significant decrease in the muscle belly thickness. The thickness of fore-arm flexor muscular layer was 29,2% decreased for the brachium injured amounting to 16.5 ± 4.7 mm (P ≤ 0.05, and that for the intact segment - to 23.3 ± 2.6 mm. In the immediate periods after treatment the signs of atrophy remained. It manifested by the significant decrease of the anterior muscle group thickness with regard to the intact segment values. The index of the echo intensity of m. biceps brachii in operated limb increased by 53.7% compared to preoperative values, reaching 22.8 ± 2.1 conv. u (P m. brachialis - 30 conv. u (P> 0.05. Before the treatment in patients aged 8-13 years the relative strength of the forearm muscles was reduced by 12% compared with those on the contralateral limb (P <0.05 according to t-test, and in the older age group - 20.9% (P <0.01. With increasing of movement range in the late periods after treatment were observed satisfactory contractile response of the upper limb muscles. At different stages of reconstructive and restorative treatment of patients with posttraumatic elbow contractures it is advisable to use a combination of ultrasonic imaging of muscles and hand dynamometry with the definition of the relative strength of the muscles.

  19. Upper Limb Evaluation in Duchenne Muscular Dystrophy: Fat-Water Quantification by MRI, Muscle Force and Function Define Endpoints for Clinical Trials.

    Science.gov (United States)

    Ricotti, Valeria; Evans, Matthew R B; Sinclair, Christopher D J; Butler, Jordan W; Ridout, Deborah A; Hogrel, Jean-Yves; Emira, Ahmed; Morrow, Jasper M; Reilly, Mary M; Hanna, Michael G; Janiczek, Robert L; Matthews, Paul M; Yousry, Tarek A; Muntoni, Francesco; Thornton, John S

    2016-01-01

    A number of promising experimental therapies for Duchenne muscular dystrophy (DMD) are emerging. Clinical trials currently rely on invasive biopsies or motivation-dependent functional tests to assess outcome. Quantitative muscle magnetic resonance imaging (MRI) could offer a valuable alternative and permit inclusion of non-ambulant DMD subjects. The aims of our study were to explore the responsiveness of upper-limb MRI muscle-fat measurement as a non-invasive objective endpoint for clinical trials in non-ambulant DMD, and to investigate the relationship of these MRI measures to those of muscle force and function. 15 non-ambulant DMD boys (mean age 13.3 y) and 10 age-gender matched healthy controls (mean age 14.6 y) were recruited. 3-Tesla MRI fat-water quantification was used to measure forearm muscle fat transformation in non-ambulant DMD boys compared with healthy controls. DMD boys were assessed at 4 time-points over 12 months, using 3-point Dixon MRI to measure muscle fat-fraction (f.f.). Images from ten forearm muscles were segmented and mean f.f. and cross-sectional area recorded. DMD subjects also underwent comprehensive upper limb function and force evaluation. Overall mean baseline forearm f.f. was higher in DMD than in healthy controls (pmuscle f.f. as a biomarker to monitor disease progression in the upper limb in non-ambulant DMD, with sensitivity adequate to detect group-level change over time intervals practical for use in clinical trials. Clinical validity is supported by the association of the progressive fat transformation of muscle with loss of muscle force and function.

  20. Unexpected dependence of RyR1 splice variant expression in human lower limb muscles on fiber-type composition.

    Science.gov (United States)

    Willemse, Hermia; Theodoratos, Angelo; Smith, Paul N; Dulhunty, Angela F

    2016-02-01

    The skeletal muscle ryanodine receptor Ca(2+) release channel (RyR1), essential for excitation-contraction (EC) coupling, demonstrates a known developmentally regulated alternative splicing in the ASI region. We now find unexpectedly that the expression of the splice variants is closely related to fiber type in adult human lower limb muscles. We examined the distribution of myosin heavy chain isoforms and ASI splice variants in gluteus minimus, gluteus medius and vastus medialis from patients aged 45 to 85 years. There was a strong positive correlation between ASI(+)RyR1 and the percentage of type 2 fibers in the muscles (r = 0.725), and a correspondingly strong negative correlation between the percentages of ASI(+)RyR1 and percentage of type 1 fibers. When the type 2 fiber data were separated into type 2X and type 2A, the correlation with ASI(+)RyR1 was stronger in type 2X fibers (r = 0.781) than in type 2A fibers (r = 0.461). There was no significant correlation between age and either fiber-type composition or ASI(+)RyR1/ASI(-)RyR1 ratio. The results suggest that the reduced expression of ASI(-)RyR1 during development may reflect a reduction in type 1 fibers during development. Preferential expression of ASI(-) RyR1, having a higher gain of in Ca(2+) release during EC coupling than ASI(+)RyR1, may compensate for the reduced terminal cisternae volume, fewer junctional contacts and reduced charge movement in type 1 fibers.

  1. Low back and lower-limb muscle performance in male and female recreational runners with chronic low back pain.

    Science.gov (United States)

    Cai, Congcong; Kong, Pui W

    2015-06-01

    Controlled laboratory study, cross-sectional. To compare lumbar extensor muscle fatigability, lumbar stabilizing muscle activation, and lower-limb strength between male and female runners with chronic low back pain (LBP) and healthy runners. Little is known about muscle performance in runners with chronic LBP. Eighteen recreational runners with chronic LBP (9 men, 9 women; mean age, 27.8 years) and 18 healthy recreational runners (9 men, 9 women; mean age, 24.6 years) were recruited. The median frequency slopes for bilateral iliocostalis and longissimus were calculated from electromyographic signals captured during a 2-minute Sorensen test. The thickness changes of the transversus abdominis and lumbar multifidus between resting and contraction were measured using an ultrasound scanner. Peak concentric torques of the bilateral hip extensors, hip abductors, and knee extensors were measured using an isokinetic dynamometer at 60°/s. The average values for both sides were used for statistical analysis. When averaged across sexes, peak knee extensor torque was 12.2% lower in the LBP group compared to the healthy group (mean difference, 0.29 Nm/kg; 95% confidence interval: 0.06, 0.53; P = .016). Male runners with chronic LBP exhibited smaller lumbar multifidus thickness changes compared to healthy male runners (mean difference, 0.13 cm; 95% confidence interval: 0.01, 0.25; P = .033). No other group differences were observed. Runners with chronic LBP exhibited diminished knee extensor strength compared to healthy runners. Male runners with chronic LBP demonstrated additional deficits in lumbar multifidus activation.

  2. Effect of muscular fatigue on fractal upper limb coordination dynamics and muscle synergies.

    Science.gov (United States)

    Bueno, Diana R; Lizano, J M; Montano, L

    2015-01-01

    Rehabilitation exercises cause fatigue because tasks are repetitive. Therefore, inevitable human motion performance changes occur during the therapy. Although traditionally fatigue is considered an event that occurs in the musculoskeletal level, this paper studies whether fatigue can be regarded as context that influences lower-dimensional motor control organization and coordination at neural level. Non Negative Factorization Matrix (NNFM) and Detrended Fluctuations Analysis (DFA) are the tools used to analyze the changes in the coordination of motor function when someone is affected by fatigue. The study establishes that synergies remain fairly stable with the onset of fatigue, but the fatigue affects the dynamical coordination understood as a cognitive process. These results have been validated with 9 healthy subjects for three representative exercises for upper limb: biceps, triceps and deltoid.

  3. EMGD-FE: an open source graphical user interface for estimating isometric muscle forces in the lower limb using an EMG-driven model

    Science.gov (United States)

    2014-01-01

    Background This paper describes the “EMG Driven Force Estimator (EMGD-FE)”, a Matlab® graphical user interface (GUI) application that estimates skeletal muscle forces from electromyography (EMG) signals. Muscle forces are obtained by numerically integrating a system of ordinary differential equations (ODEs) that simulates Hill-type muscle dynamics and that utilises EMG signals as input. In the current version, the GUI can estimate the forces of lower limb muscles executing isometric contractions. Muscles from other parts of the body can be tested as well, although no default values for model parameters are provided. To achieve accurate evaluations, EMG collection is performed simultaneously with torque measurement from a dynamometer. The computer application guides the user, step-by-step, to pre-process the raw EMG signals, create inputs for the muscle model, numerically integrate the ODEs and analyse the results. Results An example of the application’s functions is presented using the quadriceps femoris muscle. Individual muscle force estimations for the four components as well the knee isometric torque are shown. Conclusions The proposed GUI can estimate individual muscle forces from EMG signals of skeletal muscles. The estimation accuracy depends on several factors, including signal collection and modelling hypothesis issues. PMID:24708668

  4. EMGD-FE: an open source graphical user interface for estimating isometric muscle forces in the lower limb using an EMG-driven model.

    Science.gov (United States)

    Menegaldo, Luciano Luporini; de Oliveira, Liliam Fernandes; Minato, Kin K

    2014-04-04

    This paper describes the "EMG Driven Force Estimator (EMGD-FE)", a Matlab® graphical user interface (GUI) application that estimates skeletal muscle forces from electromyography (EMG) signals. Muscle forces are obtained by numerically integrating a system of ordinary differential equations (ODEs) that simulates Hill-type muscle dynamics and that utilises EMG signals as input. In the current version, the GUI can estimate the forces of lower limb muscles executing isometric contractions. Muscles from other parts of the body can be tested as well, although no default values for model parameters are provided. To achieve accurate evaluations, EMG collection is performed simultaneously with torque measurement from a dynamometer. The computer application guides the user, step-by-step, to pre-process the raw EMG signals, create inputs for the muscle model, numerically integrate the ODEs and analyse the results. An example of the application's functions is presented using the quadriceps femoris muscle. Individual muscle force estimations for the four components as well the knee isometric torque are shown. The proposed GUI can estimate individual muscle forces from EMG signals of skeletal muscles. The estimation accuracy depends on several factors, including signal collection and modelling hypothesis issues.

  5. Substrate exchange in human limb muscle during exercise at reduced blood flow.

    Science.gov (United States)

    Lundgren, F; Bennegård, K; Elander, A; Lundholm, K; Scherstén, T; Bylund-Fellenius, A C

    1988-11-01

    The substrate exchange of the calf muscles during leg exercise was compared in patients with chronically reduced blood flow and in matched controls. The arteriovenous differences of glucose, lactate, pyruvate, free fatty acids, glycerol, acetoacetate, beta-OH-butyrate, oxygen, and carbon dioxide were analyzed at rest, at the end of two exercise periods at various work loads, and after 10 min of recovery. Calf blood flow was measured with an electrocardiogram-triggered, computerized, strain gauge, venous occlusion plethysmograph. The results indicate that there was increased extraction of oxygen and ketone bodies in patients with reduced blood flow during exercise, whereas the glucose extraction tended to be lower than in controls. The leg respiratory quotient was lower in the patients even at the point of claudicating pain, suggesting oxidation of endogenous fat. The simultaneously elevated lactate release can be explained by local hypoxia in some muscle fiber populations. The findings are discussed in relation to the enzymatic adaptations known to occur in the calf muscle tissue of these patients.

  6. Comparison of algorithms to quantify muscle fatigue in upper limb muscles based on sEMG signals.

    Science.gov (United States)

    Kahl, Lorenz; Hofmann, Ulrich G

    2016-11-01

    This work compared the performance of six different fatigue detection algorithms quantifying muscle fatigue based on electromyographic signals. Surface electromyography (sEMG) was obtained by an experiment from upper arm contractions at three different load levels from twelve volunteers. Fatigue detection algorithms mean frequency (MNF), spectral moments ratio (SMR), the wavelet method WIRM1551, sample entropy (SampEn), fuzzy approximate entropy (fApEn) and recurrence quantification analysis (RQA%DET) were calculated. The resulting fatigue signals were compared considering the disturbances incorporated in fatiguing situations as well as according to the possibility to differentiate the load levels based on the fatigue signals. Furthermore we investigated the influence of the electrode locations on the fatigue detection quality and whether an optimized channel set is reasonable. The results of the MNF, SMR, WIRM1551 and fApEn algorithms fell close together. Due to the small amount of subjects in this study significant differences could not be found. In terms of disturbances the SMR algorithm showed a slight tendency to out-perform the others. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  7. Bethlem myopathy is not allelic to limb-girdle muscular dystrophy type 1A

    Energy Technology Data Exchange (ETDEWEB)

    Speer, M.C.; Yamaoka, L.H.; Stajich, J.; Lewis, K. [and others

    1995-08-28

    The Bethlem myopathy, an autosomal-dominant myopathy, shows a distribution of proximal muscle weakness similar to that observed in dominant limb-girdle muscular dystrophy (LGMD). Yet the Bethlem myopathy differs from most limb-girdle dystrophies in two important regards. First, the Bethlem myopathy presents with joint contractures most commonly observed at the elbows, ankles, and neck. Secondly, disease onset in the Bethlem myopathy is in early childhood, while most dominant LGMDs present with adult onset. 6 refs., 1 fig.

  8. Associations between lower-limb muscle activation and knee flexion in post-stroke individuals: A study on the stance-to-swing phases of gait.

    Science.gov (United States)

    Wang, Wei; Li, Ke; Yue, Shouwei; Yin, Cuiping; Wei, Na

    2017-01-01

    Reduced knee flexion is a leading feature of post-stroke gait, but the causes have not been well understood. The purpose of this study was to investigate the relationship between the knee flexion and the lower-limb muscle activation within the stance-to-swing phases of gait cycle in the post-stroke hemiplegic patients. Ten stroke patients and 10 age- and gender-matched healthy subjects participated in the experiment. The lower-limb kinematic signals and the surface electromyography (sEMG) signals of the left and right rectus femoris (RF), biceps femoris (BF) and lateral gastrocnemius (GS) were recorded during walking. The angle range (AR) of knee flexion, the root mean square (RMS) and the mean frequency (MNF) of sEMG signals were calculated from the terminal stance (TSt) to the initial swing (ISw) phases of gait cycle. Stroke patients showed lower bilateral AR of knee flexion and lower RMS of GS on the paretic side, but higher MNF of RF on the non-paretic side compared with the controls. Within the stroke patients, significant differences were found between their paretic and non-paretic limbs in the AR of knee flexion, as well as in the RMS and MNF of GS (p gait was associated with altered magnitude and frequency of muscle contractions and with simplified muscle synergy in the post-stroke hemiplegic patients. Identifying the muscles that are responsible for knee stiffness may facilitate improvement of rehabilitation strategy for post-stroke gait.

  9. Localization of the motor endplate zone in human skeletal muscles of the lower limb: anatomical guidelines for injection with botulinum toxin.

    Science.gov (United States)

    Van Campenhout, Anja; Molenaers, Guy

    2011-02-01

    Botulinum toxin gives a local tone reduction by blocking neurotransmission at the motor endplate (MEP). The importance of using MEP-targeted injections is demonstrated in animal models and in a clinical human study. The goal of this review is to present the available data on the localization of the MEP zone of frequently injected muscles of the lower limb and to compare this with current practice. Current knowledge on the localization of the MEP zone is based on some older histological studies, and for some of the more frequently injected muscles also on more recent anatomical dissection. We find that for some muscles the MEP zone can be more precisely demarcated, and for many other muscles that its location is somewhat different than the currently injected areas in clinical practice. Optimal injection sites are presented for gastrocnemius, soleus, tibialis posterior, semitendinosus, semimembranosus, gracilis, biceps femoris, rectus femoris, adductor longus, brevis and magnus, and psoas muscles. We propose optimal injection sites in relation to external anatomical landmarks for the frequently injected muscles of the human lower limb to facilitate the efficiency of botulinum toxin injections. © The Authors. Journal compilation © Mac Keith Press 2010.

  10. Motor fatigability in persons with multiple sclerosis: Relation between different upper limb muscles, and with fatigue and the perceived use of the arm in daily life.

    Science.gov (United States)

    Severijns, Deborah; Van Geel, Fanny; Feys, Peter

    2018-01-01

    Motor fatigability is increasingly acknowledged in persons with MS (pwMS). It is unknown whether fatigability is generalized across upper limb muscles and relates to fatigue and perceived difficulties in upper limb use. This observational case-controlled study included twenty PwMS (median EDSS = 3, range 1.5-6.5) and twenty healthy controls who performed 30″ sustained maximal muscle contractions for index finger abduction, hand grip, elbow flexion and shoulder abduction. A static fatigue index (SFI) was calculated to assess motor fatigability for each muscle group. PwMS completed the Fatigue Severity Scale (FSS) and Modified Fatigue Index Scale (MFIS), to quantify severity and perceived impact of fatigue and the Manual Ability Measure (MAM-36) reflecting perceived difficulty in using the upper limbs. Comparisons between groups and muscles was made by t-tests. Associations between outcomes were calculated with correlation coefficients. Fatigue was highest in pwMS. PwMS showed preserved muscle strength and a greater motor fatigability in elbow flexors compared to healthy controls. SFI of elbow flexors and shoulder abductors were associated, and contributed to FSS and MFIS. SFI of elbow flexors and finger abductors predicted half of the variation in MAM-36. Increased motor fatigability was only present in elbow flexors of PwMS, indicating that expression of motor fatigability is not generalized. Fatigability was associated with perceived fatigue (impact) and daily life upper limb use. Results are preliminary given the small sample size with predominantly persons with mild MS. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Role of Muscle Synergies in Real-Time Classification of Upper Limb Motions using Extreme Learning Machines.

    Science.gov (United States)

    Antuvan, Chris Wilson; Bisio, Federica; Marini, Francesca; Yen, Shih-Cheng; Cambria, Erik; Masia, Lorenzo

    2016-08-15

    Myoelectric signals offer significant insights in interpreting the motion intention and extent of effort involved in performing a movement, with application in prostheses, orthosis and exoskeletons. Feature extraction plays a vital role, and follows two approaches: EMG and synergy features. More recently, muscle synergy based features are being increasingly explored, since it simplifies dimensionality of control, and are considered to be more robust to signal variations. Another important aspect in a myoelectrically controlled devices is the learning capability and speed of performance for online decoding. Extreme learning machine (ELM) is a relatively new neural-network based learning algorithm: its performance hasn't been explored in the context of online control, which is a more reliable measure compared to offline analysis. To this purpose we aim at focusing our investigation on a myoelectric-based interface which is able to identify and online classify, upper limb motions involving shoulder and elbow. The main objective is to compare the performance of the decoder trained using ELM, for two different features: EMG and synergy features. The experiments are broadly divided in two phases training/calibration and testing respectively. ELM is used to train the decoder using data acquired during the calibration phase. The performance of the decoder is then tested in online motion control by using a simulated graphical user interface replicating the human limb: subjects are requested to control a virtual arm by using their muscular activity. The decoder performance is quantified using ad-hoc metrics based on the following indicators: motion selection time, motion completion time, and classification accuracy. Performance has been evaluated for both offline and online contexts. The offline classification results indicated better performance in the case of EMG features, whereas a better classification accuracy for synergy feature was observed for online decoding. Also

  12. Stabilometric response during single-leg stance after lower limb muscle fatigue

    Directory of Open Access Journals (Sweden)

    Carlos A. V. Bruniera

    2013-10-01

    Full Text Available OBJECTIVE: This study sought to analyze the effect of muscle fatigue induced by active isotonic resistance training at a moderate intensity by measuring the knee extension motion during the stabilometric response in a single-leg stance among healthy university students who perform resistance training on a regular basis. METHOD: Eleven healthy university students were subjected to a one-repetition maximum (1RM test. In addition, stabilometric assessment was performed before and after the intervention and consisted of a muscle fatiguing protocol, in which knee extension was selected as the fatiguing task. The Shapiro-Wilk test was used to investigate the normality of the data, and the Wilcoxon test was used to compare the stabilometric parameters before and after induction of muscle fatigue, at a significance level of p≤0.05. Descriptive statistics were used in the analysis of the volunteers' age, height, body mass, and body mass index (BMI. RESULTS: The sample population was 23.1±2.7 years of age, averaged 1.79.2±0.07 m in height and 75.6±8.0 Kg in weight, and had a BMI of 23.27±3.71 Kg.m-2. The volunteers performed exercises 3.36±1.12 days/week and achieved a load of 124.54±22.07 Kg on 1RM and 74.72±13.24 Kg on 60% 1RM. The center of pressure (CoP oscillation on the mediolateral plane before and after fatigue induction was 2.89±0.89 mm and 4.09±0.59 mm, respectively, while the corresponding values on the anteroposterior plane were 2.5±2.2 mm and 4.09±2.26 mm, respectively. The CoP oscillation amplitude on the anteroposterior and mediolateral planes exhibited a significant difference before and after fatigue induction (p=0.04 and p=0.05, respectively. CONCLUSIONS: The present study showed that muscle fatigue affects postural control, particularly with the mediolateral and anteroposterior CoP excursion.

  13. Limb myokymia

    Energy Technology Data Exchange (ETDEWEB)

    Albers, J.W.; Allen, A.A.; Bastron, J.A.; Daube, J.R.

    Thirty-eight patients with myokymic discharges localized to limb muscles on needle electromyography had various neurologic lesions, both acute and chronic. Of the 38 patients, 27 had had previous radiation therapy and the clinical diagnosis of radiation-induced plexopathy, myelopathy, or both. For the remaining 11 patients, the diagnoses included multiple sclerosis, inflammatory polyradiculoneuropathy, ischemic neuropathy, inflammatory myopathy, and chronic disorders of the spinal cord and peripheral nerves. The clinical presentations and results of local ischemia, peripheral nerve block, and percutaneous stimulation suggest that most limb myokymic discharges arise focally at the site of a chronic peripheral nerve lesion.

  14. Upper Limb Evaluation in Duchenne Muscular Dystrophy: Fat-Water Quantification by MRI, Muscle Force and Function Define Endpoints for Clinical Trials.

    Directory of Open Access Journals (Sweden)

    Valeria Ricotti

    Full Text Available A number of promising experimental therapies for Duchenne muscular dystrophy (DMD are emerging. Clinical trials currently rely on invasive biopsies or motivation-dependent functional tests to assess outcome. Quantitative muscle magnetic resonance imaging (MRI could offer a valuable alternative and permit inclusion of non-ambulant DMD subjects. The aims of our study were to explore the responsiveness of upper-limb MRI muscle-fat measurement as a non-invasive objective endpoint for clinical trials in non-ambulant DMD, and to investigate the relationship of these MRI measures to those of muscle force and function.15 non-ambulant DMD boys (mean age 13.3 y and 10 age-gender matched healthy controls (mean age 14.6 y were recruited. 3-Tesla MRI fat-water quantification was used to measure forearm muscle fat transformation in non-ambulant DMD boys compared with healthy controls. DMD boys were assessed at 4 time-points over 12 months, using 3-point Dixon MRI to measure muscle fat-fraction (f.f.. Images from ten forearm muscles were segmented and mean f.f. and cross-sectional area recorded. DMD subjects also underwent comprehensive upper limb function and force evaluation.Overall mean baseline forearm f.f. was higher in DMD than in healthy controls (p<0.001. A progressive f.f. increase was observed in DMD over 12 months, reaching significance from 6 months (p<0.001, n = 7, accompanied by a significant loss in pinch strength at 6 months (p<0.001, n = 9 and a loss of upper limb function and grip force observed over 12 months (p<0.001, n = 8.These results support the use of MRI muscle f.f. as a biomarker to monitor disease progression in the upper limb in non-ambulant DMD, with sensitivity adequate to detect group-level change over time intervals practical for use in clinical trials. Clinical validity is supported by the association of the progressive fat transformation of muscle with loss of muscle force and function.

  15. Reliability of hand-held dynamometry for measurement of lower limb muscle strength in children with Duchenne and Becker muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Wei SHI

    2015-05-01

    Full Text Available Objective To determine the reliability of hand-held dynamometry (HHD for lower limb isometric muscle strength measurement in children with Duchenne and Becker muscular dystrophy (DMD/BMD.  Methods A total of 21 children [20 males and one female; mean age was (7.88 ± 2.87 years, ranging between 3.96-14.09 years; mean age at diagnosis was (5.88 ± 2.88 years, ranging between 1.35-12.89 years; mean height was (120.64 ± 16.30 cm, ranging between 97-153 cm; mean body weight was (24.62 ± 9.05 kg, ranging between 14-50 kg] with DMD (19/21 and BMD (2/21 were involved from Rehabilitation Center of Children's Hospital of Fudan University. The muscle strength of hip, knee and ankle was measured by HHD under standardized test methods. The test-retest results were compared to determine the inter-test reliability, and the results among testers were compared to determine the inter-tester reliability.  Results HHD showed fine inter-tester reliability (ICC = 0.762-0.978 and inter-test reliability (ICC = 0.690-0.938 in measuring lower limb muscle strength of children with DMD/BMD. Results also showed relatively poor reliability in distal muscle groups (foot plantar flexion and dorsiflexion.  Conclusions HHD, showing fine inter-tester and inter-test reliability in measuring the lower limb muscle strength of children with DMD/BMD, can be used in monitoring muscle strength changing and assessing effects of clinical interventions. DOI: 10.3969/j.issn.1672-6731.2015.05.009

  16. Exercise-induced muscle fatigue in the unaffected knee joint and its influence on postural control and lower limb kinematics in stroke patients.

    Science.gov (United States)

    Park, Sun Wook; Son, Sung Min; Lee, Na Kyung

    2017-05-01

    This study aimed to investigate the effects of exercise-induced muscle fatigue in the unaffected knee joint on postural control and kinematic changes in stroke patients. Forty participants (20 stroke patients, 20 age-matched healthy participants) were recruited. To induce fatigue, maximum voluntary isometric contractions were performed in the unaffected knee joint in a Leg Extension Rehab exercise machine using the pneumatic resistance. We measured static and dynamic balance and lower-limb kinematics during gait. Changes in postural control parameters anteroposterior sway speed and total center of pressure distance differed significantly between the stroke and control groups. In addition, changes in gait kinematic parameters knee and ankle angles of initial contact differed significantly between stroke (paretic and non-paretic) and control groups. Muscle fatigue in the unaffected knee and ankle impaired postural control and debilitates kinematic movement of ipsilateral and contralateral lower limbs, and may place the fatigued stroke patients at greater risk for falls.

  17. Exercise-induced muscle fatigue in the unaffected knee joint and its influence on postural control and lower limb kinematics in stroke patients

    Directory of Open Access Journals (Sweden)

    Sun Wook Park

    2017-01-01

    Full Text Available This study aimed to investigate the effects of exercise-induced muscle fatigue in the unaffected knee joint on postural control and kinematic changes in stroke patients. Forty participants (20 stroke patients, 20 age-matched healthy participants were recruited. To induce fatigue, maximum voluntary isometric contractions were performed in the unaffected knee joint in a Leg Extension Rehab exercise machine using the pneumatic resistance. We measured static and dynamic balance and lower-limb kinematics during gait. Changes in postural control parameters anteroposterior sway speed and total center of pressure distance differed significantly between the stroke and control groups. In addition, changes in gait kinematic parameters knee and ankle angles of initial contact differed significantly between stroke (paretic and non-paretic and control groups. Muscle fatigue in the unaffected knee and ankle impaired postural control and debilitates kinematic movement of ipsilateral and contralateral lower limbs, and may place the fatigued stroke patients at greater risk for falls.

  18. Repeated prolonged whole-body low-intensity exercise: effects on insulin sensitivity and limb muscle adaptations

    DEFF Research Database (Denmark)

    Helge, Jørn Mikael; Overgaard, Kristian; Damsgaard, Rasmus

    2006-01-01

    was performed to establish maximal oxygen uptake. During the crossing, subjects skied for 342 ± 41 min/d. Peak oxygen uptake (4.6 ± 0.2 L/min) was decreased (P body mass decreased (P body mass......This study investigates the effect of prolonged whole-body low-intensity exercise on insulin sensitivity and the limb muscle adaptive response. Seven male subjects (weight, 90.2 ± 3.2 kg; age, 35 ± 3 years) completed a 32-day unsupported crossing of the Greenland icecap on cross-country skies....... Glycosylated hemoglobin (5.6% ± 0.01%) was not affected by the crossing. The IVGTT data revealed that insulin sensitivity (7.3 ± 0.6 mU · L-1 · min-1) and glucose effectiveness (0.024 ± 0.002 min-1) were not changed after the crossing. Similarly, the IVGTT data, when expressed per kilogram of lean body mass...

  19. The influence of different non-articular proximal forearm orthoses (brace) widths in the wrist extensors muscle activity, range of motion and grip strength in healthy volunteers.

    Science.gov (United States)

    Marcolino, Alexandre Márcio; Fonseca, Marisa de Cássia Registro; Leonardi, Naiara Tais; Barbosa, Rafael Inácio; Neves, Lais Mara Siqueira das; de Jesus Guirro, Rinaldo Roberto

    2016-06-30

    The purpose this study was perform a biomechanical evaluation to compare the influence of commercial models of different non-articular proximal forearm orthoses widths (2.5 cm, 5.5 cm, 7.5 cm and 12.0 cm) in the extensor muscle activation, range of motion and grip strength in healthy subjects. Was analyzed data from extensor carpi radialis, extensor carpi ulnares and extensor digitorum comunis using surface electromyography, simultaneous with a wrist electrogoniometer MiotecTM and a hydraulic dynamometer JamarTM. The sequence of tests with all the commercial orthoses models was randomized. Statistics analyses were performed by linear model with mixed effects. According to our findings the non-articular proximal forearm orthoses (2.5 cm - narrowest) positioned close to lateral epicondyle provided lesser muscle activation on extensor carpi radialis brevis/longus and extensor digitorum comunis, decreased wrist extension and grip strength during submaximal grip task (p< 0.01). A narrow non-articular proximal forearm orthosis positioned close to the lateral epicondyle might decrease the extensor muscle activation and therefore could reduce mechanical stress on its insertion, based on this sample. Clinical studies must be conducted to confirm these findings.

  20. Upper limb neurorehabilitation in patients with stroke using haptic device system: reciprocal bi-articular muscle activities reflect as a result of improved circle-drawing smoothness.

    Science.gov (United States)

    Miyoshi, Tasuku; Takahashi, Yoshiyuki; Lee, Hokyoo; Suzuki, Tadashi; Komeda, Takashi

    2010-01-01

    Muscular co-contraction resulted in corrected elbow and shoulder joint stiffness; however, this correction neither ameliorated endpoint oscillation nor assisted in the execution of smooth two-joint arm movements. We hypothesised that the reacquisition of smooth arm movements became synonymous with the restoration of time-domain reciprocal electromyographic (EMG) activities in biarticular arm muscles. The purpose of this study was to investigate whether or not the restored reciprocal EMG activities in biarticular arm muscles reflected improved smooth motor performance in patients with stroke after 10 days of two-joint arm-movement training. Three male patients with sub-acute stroke with left-arm paralysis performed circle-drawing tasks using a haptic device system for upper limb neuromuscular rehabilitation. After the training, the movement velocities and achievement periods increased with the enhancement of the reciprocal EMG activities in biarticular arm muscles, and there was less jerkness in movement after training for the same duration. Patients with stroke could achieve smooth motor performance with the restoration of the reciprocal EMG activities in biarticular arm muscles. Therefore, the reciprocal EMG activities in biarticular arm muscles in response to circle drawing would be an index for the progressive improvements of smooth motor functions in the upper limbs.

  1. Pace bowlers in cricket with history of lumbar stress fracture have increased risk of lower limb muscle strains, particularly calf strains

    OpenAIRE

    Orchard, John

    2010-01-01

    John Orchard1, Patrick Farhart2, Alex Kountouris3, Trefor James3, Marc Portus31School of Public Health, University of Sydney, Australia; 2Punjab Kings XI team, Indian Premier League, India; 3Cricket Australia, Melbourne, AustraliaObjective: To assess whether a history of lumbar stress fracture in pace bowlers in cricket is a risk factor for lower limb muscle strains.Methods: This was a prospective cohort risk factor study, conducted using injury data from contracted first class pace bowlers i...

  2. A heterozygous 21-bp deletion in CAPN3 causes dominantly inherited limb girdle muscular dystrophy

    DEFF Research Database (Denmark)

    Vissing, John; Barresi, Rita; Witting, Nanna

    2016-01-01

    Limb girdle muscular dystrophy type 2A is the most common limb girdle muscular dystrophy form worldwide. Although strict recessive inheritance is assumed, patients carrying a single mutation in the calpain 3 gene (CAPN3) are reported. Such findings are commonly attributed to incomplete mutation...... creatine kinase or myoglobin. Muscle weakness was generally milder than observed in limb girdle muscular dystrophy type 2A, but affected the same muscle groups (proximal leg, lumbar paraspinal and medial gastrocnemius muscles). In some cases, the weakness was severely disabling. The 21-bp deletion did...... affecting the calpain 3 homodimer. This renders patients deficient in calpain 3 as in limb girdle muscular dystrophy type 2A, albeit in a milder form in most cases. Based on findings in 10 families, our study indicates that a dominantly inherited pattern of calpainopathy exists, and should be considered...

  3. Effects of training programs based on ipsilateral voluntary and stimulated contractions on muscle strength and monopedal postural control of the contralateral limb.

    Science.gov (United States)

    Kadri, Mohamed Abdelhafid; Noé, Frederic; Nouar, Merbouha Boulahbel; Paillard, Thierry

    2017-07-03

    To compare the effects of unilateral strength training by stimulated and voluntary contractions on muscle strength and monopedal postural control of the contralateral limb. 36 non-active healthy male subjects were recruited and split randomly into three groups. Two groups of 12 subjects took part in a strength-training program (3 sessions a week over 8 weeks) comprising 43 contractions of the quadriceps femoris of the ipsilateral limb (at 20% of the MVC). One group carried out voluntary contractions exclusively (VOL group), while the other group benefited exclusively from electro-induced contractions (NMES group). The other 12 subjects formed the control (CON) group. Assessments of MVC and monopedal postural control in static and dynamic postural tasks were performed with the ipsilateral (ISPI) and contralateral (CONTRA) limbs before (PRE) and after (POST) completion of the training program. After the training program, the MVC of the IPSI and CONTRA limbs increased similarly for both experimental groups (VOL and NMES). There were no significant improvements of monopedal postural control for the IPSI or CONTRA limbs in either the VOL or NMES experimental group. No change was observed for the CON group over the protocol period. The purposed training program with NMES vs VOL contractions induced strength gains but did not permit any improvement of contralateral monopedal postural control in healthy young subjects. This has potential for therapeutic application and allows clinicians to focus their training programs on dynamic and poly-articular exercises to improve the postural control in young subjects.

  4. Morphology of peroneus tertius muscle.

    Science.gov (United States)

    Joshi, S D; Joshi, S S; Athavale, S A

    2006-10-01

    Peroneus tertius (PT) muscle is peculiar to man, and man is the only member among the primates in whom this muscle occurs. The muscle is variable in its development and attachment. Because of functional demands of bipedal gait and plantigrade foot, part of extensor digitorum brevis (EDB) has migrated upwards into the leg from the dorsum of foot. PT is a muscle that evolution is rendering more important. In a total of 110 cadavers, extensor compartment of leg and dorsum of foot were dissected in both the lower limbs and extensor digitorum longus (EDL), and PT muscles were dissected and displayed. PT was found to be absent in 10.5% limbs, the incidence being greater on the right side. The remaining limbs in which the PT muscle was present had a very extensive origin from lower 3/4th of extensor surface of fibula (20% on right and in 17% on left), and the EDL was very much reduced in size. In approximately 12%, the tendon of PT was thick or even thicker than the tendon of EDL. In 4%, the tendon extended beyond fifth metatarsal up to metatarsophalangeal joint of fifth toe, and in 1.5%, it extended up to the proximal phalanx of little toe. In two cases (both on the right side), where PT was absent, it was replaced by a slip from lateral margin of EDL. We conclude that PT, which is preeminently human, is extending its purchase both proximally and distally. Copyright 2006 Wiley-Liss, Inc.

  5. Soft-tissue anatomy of the primates: phylogenetic analyses based on the muscles of the head, neck, pectoral region and upper limb, with notes on the evolution of these muscles

    Science.gov (United States)

    Diogo, R; Wood, B

    2011-01-01

    Apart from molecular data, nearly all the evidence used to study primate relationships comes from hard tissues. Here, we provide details of the first parsimony and Bayesian cladistic analyses of the order Primates based exclusively on muscle data. The most parsimonious tree obtained from the cladistic analysis of 166 characters taken from the head, neck, pectoral and upper limb musculature is fully congruent with the most recent evolutionary molecular tree of Primates. That is, this tree recovers not only the relationships among the major groups of primates, i.e. Strepsirrhini {Tarsiiformes [Platyrrhini (Cercopithecidae, Hominoidea)]}, but it also recovers the relationships within each of these inclusive groups. Of the 301 character state changes occurring in this tree, ca. 30% are non-homoplasic evolutionary transitions; within the 220 changes that are unambiguously optimized in the tree, ca. 15% are reversions. The trees obtained by using characters derived from the muscles of the head and neck are more similar to the most recent evolutionary molecular tree than are the trees obtained by using characters derived from the pectoral and upper limb muscles. It was recently argued that since the Pan/Homo split, chimpanzees accumulated more phenotypic adaptations than humans, but our results indicate that modern humans accumulated more muscle character state changes than chimpanzees, and that both these taxa accumulated more changes than gorillas. This overview of the evolution of the primate head, neck, pectoral and upper limb musculature suggests that the only muscle groups for which modern humans have more muscles than most other extant primates are the muscles of the face, larynx and forearm. PMID:21689100

  6. Remote dose-dependent effects of dry needling at distant myofascial trigger spots of rabbit skeletal muscles on reduction of substance P levels of proximal muscle and spinal cords.

    Science.gov (United States)

    Hsieh, Yueh-Ling; Yang, Chen-Chia; Liu, Szu-Yu; Chou, Li-Wei; Hong, Chang-Zern

    2014-01-01

    Dry needling at distant myofascial trigger points is an effective pain management in patients with myofascial pain. However, the biochemical effects of remote dry needling are not well understood. This study evaluates the remote effects of dry needling with different dosages on the expressions of substance P (SP) in the proximal muscle, spinal dorsal horns of rabbits. Male New Zealand rabbits (2.5-3.0 kg) received dry needling at myofascial trigger spots of a gastrocnemius (distant muscle) in one (1D) or five sessions (5D). Bilateral biceps femoris (proximal muscles) and superficial laminaes of L5-S2, T2-T5, and C2-C5 were sampled immediately and 5 days after dry needling to determine the levels of SP using immunohistochemistry and western blot. Immediately after dry needling for 1D and 5D, the expressions of SP were significantly decreased in ipsilateral biceps femoris and bilateral spinal superficial laminaes (P dry needling, these reduced immunoactivities of SP were found only in animals receiving 5D dry needling (P dry needling involves the reduction of SP levels in proximal muscle and spinal superficial laminaes, which may be closely associated with the control of myofascial pain.

  7. Remote Dose-Dependent Effects of Dry Needling at Distant Myofascial Trigger Spots of Rabbit Skeletal Muscles on Reduction of Substance P Levels of Proximal Muscle and Spinal Cords

    Directory of Open Access Journals (Sweden)

    Yueh-Ling Hsieh

    2014-01-01

    Full Text Available Background. Dry needling at distant myofascial trigger points is an effective pain management in patients with myofascial pain. However, the biochemical effects of remote dry needling are not well understood. This study evaluates the remote effects of dry needling with different dosages on the expressions of substance P (SP in the proximal muscle, spinal dorsal horns of rabbits. Methods. Male New Zealand rabbits (2.5–3.0 kg received dry needling at myofascial trigger spots of a gastrocnemius (distant muscle in one (1D or five sessions (5D. Bilateral biceps femoris (proximal muscles and superficial laminaes of L5-S2, T2-T5, and C2-C5 were sampled immediately and 5 days after dry needling to determine the levels of SP using immunohistochemistry and western blot. Results. Immediately after dry needling for 1D and 5D, the expressions of SP were significantly decreased in ipsilateral biceps femoris and bilateral spinal superficial laminaes (P<.05. Five days after dry needling, these reduced immunoactivities of SP were found only in animals receiving 5D dry needling (P<.05. Conclusions. This remote effect of dry needling involves the reduction of SP levels in proximal muscle and spinal superficial laminaes, which may be closely associated with the control of myofascial pain.

  8. Relationship between lower limb position and pelvic floor muscle surface electromyography activity in menopausal women: a prospective observational study

    Science.gov (United States)

    Halski, Tomasz; Ptaszkowski, Kuba; Słupska, Lucyna; Dymarek, Robert; Paprocka-Borowicz, Małgorzata

    2017-01-01

    Objectives In physiotherapeutic practice, special attention is being given to the reciprocal anatomical, physiological, and biomechanical relationship of the pelvis and the structures connected to it. However, the scientific literature shows mainly the theoretical information about their mutual connections. The lack of information about these relations from a practical aspect coupled with the paucity of scientific papers on the impact of posture changes on the pelvic floor led the authors to conduct this study. The primary aim of this study was to compare the resting and functional bioelectrical activities of pelvic floor muscles (PFMs) depending on three different positions of the lower limbs (positions A, B, and C) in the supine position. Materials and methods This was a prospective observational study evaluating resting and functional activities of the PFM depending on the position of the lower limbs. The study was carried out at the Department and Clinic of Urology, University Hospital in Wroclaw, Poland and the target group were women in the menopausal period. Bioelectrical activity of PFM was recorded using a surface electromyographic instrument in the supine position. Results of the values obtained in A, B, and C positions were compared using a one-way analysis of variance. Results In position A, the average resting surface electromyography (sEMG) activity of PFM was 6.9±2.6 µV; in position B, the result was 6.9±2.5 µV and in position C, the resting sEMG activity was 5.7±1.8 µV (P=0.0102). The results of the functional bioelectrical activity of PFM were as follows: position A – 20.3±11.8 µV, position B – 19.9±10.6 µV, and position C – 25.3±10.9 µV (P=0.0104). Conclusion The results showed that in the supine position, the PFM achieved the lowest resting activity and the highest functional activity. Therefore, the supine position can be recommended for the diagnosis and therapy of weakened PFM. PMID:28115836

  9. A murine model of a novel surgical architecture for proprioceptive muscle feedback and its potential application to control of advanced limb prostheses

    Science.gov (United States)

    Clites, Tyler R.; Carty, Matthew J.; Srinivasan, Shriya; Zorzos, Anthony N.; Herr, Hugh M.

    2017-06-01

    Objective. Proprioceptive mechanisms play a critical role in both reflexive and volitional lower extremity control. Significant strides have been made in the development of bionic limbs that are capable of bi-directional communication with the peripheral nervous system, but none of these systems have been capable of providing physiologically-relevant muscle-based proprioceptive feedback through natural neural pathways. In this study, we present the agonist-antagonist myoneural interface (AMI), a surgical approach with the capacity to provide graded kinesthetic feedback from a prosthesis through mechanical activation of native mechanoreceptors within residual agonist-antagonist muscle pairs. Approach. (1) Sonomicrometery and electroneurography measurement systems were validated using a servo-based muscle tensioning system. (2) A heuristic controller was implemented to modulate functional electrical stimulation of an agonist muscle, using sonomicrometric measurements of stretch from a mechanically-coupled antagonist muscle as feedback. (3) One AMI was surgically constructed in the hindlimb of each rat. (4) The gastrocnemius-soleus complex of the rat was cycled through a series of ramp-and-hold stretches in two different muscle architectures: native (physiologically-intact) and AMI (modified). Integrated electroneurography from the tibial nerve was compared across the two architectures. Main results. Correlation between stretch and afferent signal demonstrated that the AMI is capable of provoking graded afferent signals in response to ramp-and-hold stretches, in a manner similar to the native muscle architecture. The response magnitude in the AMI was reduced when compared to the native architecture, likely due to lower stretch amplitudes. The closed-loop control system showed robustness at high stretch magnitudes, with some oscillation at low stretch magnitudes. Significance. These results indicate that the AMI has the potential to communicate meaningful kinesthetic

  10. The effects of speed on the in vivo activity and length of a limb muscle during the locomotion of the iguanian lizard Dipsosaurus dorsalis.

    Science.gov (United States)

    Nelson, F E; Jayne, B C

    2001-10-01

    The caudofemoralis muscle is the largest muscle that inserts onto the hindlimb of most ectothermic tetrapods, and previous studies hypothesize that it causes several movements that characterize the locomotion of vertebrates with a sprawling limb posture. Predicting caudofemoralis function is complicated because the muscle spans multiple joints with movements that vary with speed. Furthermore, depending on when any muscle is active relative to its change in length, its function can change from actively generating mechanical work to absorbing externally applied forces. We used synchronized electromyography, sonomicrometry and three-dimensional kinematics to determine in vivo caudofemoralis function in the desert iguana Dipsosaurus dorsalis for a wide range of speeds of locomotion from a walk to nearly maximal sprinting (50-350 cm s(-1)). Strain of the caudofemoralis increased with increasing tail elevation and long-axis rotation and protraction of the femur. However, knee extension only increased caudofemoralis strain when the femur was protracted. The maximum and minimum length of the caudofemoralis muscle and its average shortening velocity increased from the slowest speed up to the walk-run transition, but changed little with further increases in speed. The times of muscle shortening and lengthening were often not equal at higher locomotor speeds. Some (20-25 ms) activity occurred during lengthening of the caudofemoralis muscle before footfall. However, most caudofemoralis activity was consistent with performing positive mechanical work to flex the knee shortly after foot contact and to retract and rotate the femur throughout the propulsive phase.

  11. Association between insulin resistance, lean mass and muscle torque/force in proximal versus distal body parts in healthy young men.

    Science.gov (United States)

    Gysel, T; Calders, P; Cambier, D; Roman de Mettelinge, T; Kaufman, J-M; Taes, Y; Zmierczak, H-G; Goemaere, S

    2014-03-01

    The purpose of this study was to investigate whether there is already an association of insulin resistance (IR) with muscle mass and -force/torque in an adult population and whether this relationship is the same in distal and proximal body parts. 358 Healthy young men were divided into a more insulin sensitive (MIS) (n=89) and a less insulin sensitive (LIS) group (n=89), respectively using lower and upper quartiles of HOMA-IR index (Homeostasis Model Assessment of IR). Muscle force/torque and lean mass, were compared between the two groups. LIS subjects had higher absolute thigh lean mass, but not higher thigh muscle torque, resulting in a lower torque per kg muscle. In upper arm, lean mass was higher in LIS subjects, but also absolute muscle torque resulted higher. For handgrip force, the LIS and MIS group had similar results, despite a trend towards higher forearm lean mass in LIS subjects. Lean mass % of total lean mass is lower in LIS subjects in more distal body parts. Already in a young healthy population, IR seems to be associated with lower force/torque per muscle mass and lower lean mass % of total lean mass predominantly in more distal body parts.

  12. Remote Dose-Dependent Effects of Dry Needling at Distant Myofascial Trigger Spots of Rabbit Skeletal Muscles on Reduction of Substance P Levels of Proximal Muscle and Spinal Cords

    OpenAIRE

    Yueh-Ling Hsieh; Chen-Chia Yang; Szu-Yu Liu; Li-Wei Chou; Chang-Zern Hong

    2014-01-01

    Background. Dry needling at distant myofascial trigger points is an effective pain management in patients with myofascial pain. However, the biochemical effects of remote dry needling are not well understood. This study evaluates the remote effects of dry needling with different dosages on the expressions of substance P (SP) in the proximal muscle, spinal dorsal horns of rabbits. Methods. Male New Zealand rabbits (2.5–3.0 kg) received dry needling at myofascial trigger spots of a gastrocnemiu...

  13. The postural response of the pelvic floor muscles during limb movements: a methodological electromyography study in parous women without lumbopelvic pain.

    Science.gov (United States)

    Sjödahl, Jenny; Kvist, Joanna; Gutke, Annelie; Oberg, Birgitta

    2009-02-01

    Pregnancy-related lumbopelvic pain is common. More than 30% of women have persistent pain 3 months after giving birth. There is no consensus regarding the pathology. However, coordination of muscle activity by appropriate timing and amplitude is necessary for maintaining adequate stability in the lumbopelvic area. The aim was to develop a method using surface electromyography to detect a feed-forward response in the pelvic floor muscles during limb movements performed at a comfortable speed applicable in future studies for women with lumbopelvic pain. Ten parous women with no lumbopelvic pain in the past 12 months were included. Surface electromyographic activity was recorded from the pelvic floor muscles and unilaterally from transversus abdominis/internal oblique, rectus abdominis, erector spinae, hip adductors, rectus femoris and deltoid. The subjects performed leg lift in supine and arm lift from standing. The electromyographic onset was related to the initiation of the movement. In the majority of the women the electromyographic onsets of the pelvic floor muscles occurred before the movement was initiated, regardless of whether it was a leg or an arm lift. In addition, electromyographic onsets for the other muscles, except the rectus abdominis during the arm lift, also occurred prior to the movements. The findings suggest a feed-forward response in the pelvic floor muscles during leg and arm lifts in women who had previously given birth and were without lumbopelvic pain. Movements performed at a comfortable speed seem to be useful in order to detect such a response.

  14. A continuum-mechanical skeletal muscle model including actin-titin interaction predicts stable contractions on the descending limb of the force-length relation

    Science.gov (United States)

    Rode, Christian

    2017-01-01

    Contractions on the descending limb of the total (active + passive) muscle force—length relationship (i. e. when muscle stiffness is negative) are expected to lead to vast half-sarcomere—length inhomogeneities. This is however not observed in experiments—vast half-sarcomere—length inhomogeneities can be absent in myofibrils contracting in this range, and initial inhomogeneities can even decrease. Here we show that the absence of half-sarcomere—length inhomogeneities can be predicted when considering interactions of the semi-active protein titin with the actin filaments. Including a model of actin—titin interactions within a multi-scale continuum-mechanical model, we demonstrate that stability, accurate forces and nearly homogeneous half-sarcomere lengths can be obtained on the descending limb of the static total force—length relation. This could be a key to durable functioning of the muscle because large local stretches, that might harm, for example, the transverse-tubule system, are avoided. PMID:28968385

  15. Energy flow analysis of amputee walking shows a proximally-directed transfer of energy in intact limbs, compared to a distally-directed transfer in prosthetic limbs at push-off

    OpenAIRE

    Weinert-Aplin, RA; Howard, D; Twiste, M; Jarvis, HL; Bennett, A.N.; Baker, RJ

    2016-01-01

    Reduced capacity and increased metabolic cost of walking occurs in amputees, despite advances in prosthetic componentry. Joint powers can quantify deficiencies in prosthetic gait, but do not reveal how energy is exchanged between limb segments. This study aimed to quantify these energy exchanges during amputee walking. Optical motion and forceplate data collected during walking at a self-selected speed for cohorts of 10 controls, 10 unilateral trans-tibial, 10 unilateral trans-femoral and 10 ...

  16. Correlation between mild hypoxaemia and limb skeletal muscle function in chronic obstructive pulmonary disease – Pilot study

    Directory of Open Access Journals (Sweden)

    Sérgio Leite Rodrigues

    2008-11-01

    Full Text Available Rationale: Exercise capacity in COPD patients depends on the degree of airflow obstruction, the severity of the hypoxaemia and skeletal muscle function. Muscle atrophy and weakness are considered systemic consequences of COPD and are associated with reduced exercise capacity. Aims: To investigate the correlation between mild hypoxaemia and muscular strength, muscular fatigue and functional capacity in COPD patients. Methods: Ten patients enrolled on a PRP at the Hospital Universitário de Brasília – HUB were included in this study. Lung function was evaluated by spirometry and arterial blood gas analysis. Functional evaluation was made using the 6MWT and using isometric contraction of deltoid and quadriceps muscles. Results: There were positive correlations between PaO2, quadriceps strength (r2 = 0.61 and p = 0.007 and PaO2 and the 6MWT (r2 = 0.96, p = 0.001. There were negative correlations between PaO2 and median frequency of quadriceps (r2 = -0.42 and p = 0.04. We observed significant correlation between quadriceps strength and the 6MWT (r2 = 0.67 and p = 0.001. There was negative correlation between median frequency of quadriceps and the 6MWT (r2 = -0.42 and p = 0.04. We did not observe any correlation between PaO2 and strength or median frequency of deltoid muscle. Conclusions: PaO2 has important correlations with muscular function variables. The main negative impact of mild hypoxaemia and precocious limb muscular disability on COPD patients is decreased functional capacity. Resumo: Introdução: A capacidade de exercício em portadores de DPOC depende da gravidade da limitação ao fluxo aéreo, do grau de hipoxemia e da função muscular esquelética. Nesses doentes, a atrofia e a fraqueza da musculatura periférica são consideradas consequências sistémicas da DPOC e estão associadas à redução da capacidade de exercício. Objectivos

  17. The Use of Functional Electrical Stimulation on the Upper Limb and Interscapular Muscles of Patients with Stroke for the Improvement of Reaching Movements: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Alicia Cuesta-Gómez

    2017-05-01

    Full Text Available IntroductionReaching movements in stroke patients are characterized by decreased amplitudes at the shoulder and elbow joints and greater displacements of the trunk, compared to healthy subjects. The importance of an appropriate and specific contraction of the interscapular and upper limb (UL muscles is crucial to achieving proper reaching movements. Functional electrical stimulation (FES is used to activate the paretic muscles using short-duration electrical pulses.ObjectiveTo evaluate whether the application of FES in the UL and interscapular muscles of stroke patients with motor impairments of the UL modifies patients’ reaching patterns, measured using instrumental movement analysis systems.DesignA cross-sectional study was carried out.SettingThe VICON Motion System® was used to conduct motion analysis.ParticipantsTwenty-one patients with chronic stroke.InterventionThe Compex® electric stimulator was used to provide muscle stimulation during two conditions: a placebo condition and a FES condition.Main outcome measuresWe analyzed the joint kinematics (trunk, shoulder, and elbow from the starting position until the affected hand reached the glass.ResultsParticipants receiving FES carried out the movement with less trunk flexion, while shoulder flexion elbow extension was increased, compared to placebo conditions.ConclusionThe application of FES to the UL and interscapular muscles of stroke patients with motor impairment of the UL has improved reaching movements.

  18. Myofascial force transmission also occurs between antagonistic muscles located within opposite compartments of the rat lower hind limb

    NARCIS (Netherlands)

    Rijkelijkhuizen, J.M.; Meijer, H.J.M.; Baan, G.C.; Huijing, P.A.J.B.M.

    2007-01-01

    Force transmission via pathways other than myotendinous ones, is referred to as myofascial force transmission. The present study shows that myofascial force transmission occurs not only between adjacent synergistic muscles or antagonistic muscles in adjacent compartments, but also between most

  19. Comparison of Protein Supplementation and Resistance Training Exercise on Lower Limbs Muscles Strength and Range of Motion of Elderly

    OpenAIRE

    Aparna Sarkar; Suman Dahiya; Harshita Sharma; Pratiba Gupta

    2016-01-01

    Background and introduction: Advancing age is associated with reduced muscle protein synthesis, altered expression of and chemical modifications to muscle proteins, reduced muscle strength, and muscle power. These age-related impairments in the quantity and quality of contractile proteins contribute to physical disability and frailty, loss of independent function, the risk of falling and fractures and escalating health care costs. The aim of the study was to find out whether the combined effe...

  20. Relationships between calf muscle density and muscle strength, mobility and bone status in the stroke survivors with subacute and chronic lower limb hemiparesis.

    Science.gov (United States)

    MacIntyre, N J; Rombough, R; Brouwer, B

    2010-12-01

    To determine the relationship between muscle density and neuromusculoskeletal status in stroke survivors with subacute and chronic hemiparesis. Community-dwelling adults were recruited into one of 3 groups (11 per group): subacute stroke group (SSG, 1 year post-stroke), or age- and gender-matched control group (CG). Muscle density, muscle mass and tibial bone status (cortical density, mass and polar stress-strain index (pSSI)) were measured bilaterally at the tibial 66% site using peripheral quantitative computed tomography. Muscle strength of ankle plantarflexors and knee extensors was assessed using isokinetic dynamometry. Mobility was assessed using the Berg Balance Scale. Univariate regression analyses by group tested whether side-to-side differences in muscle density and measures of neuromusculoskeletal status were related. In the SSG and CG, relationships were observed for muscle density and ankle plantarflexor strength (R²= 0.365 and 0.503). Muscle density related to muscle mass in the CG only (R²= 0.889). Muscle density related to cortical bone density in the SSG (R²= 0.602) and pSSI in the CSG (R²= 0.434). Muscle density may provide insight into the side-to-side changes in muscle and bone strength following hemiparetic stroke.

  1. Remote Dose-Dependent Effects of Dry Needling at Distant Myofascial Trigger Spots of Rabbit Skeletal Muscles on Reduction of Substance P Levels of Proximal Muscle and Spinal Cords

    Science.gov (United States)

    Hsieh, Yueh-Ling; Liu, Szu-Yu; Hong, Chang-Zern

    2014-01-01

    Background. Dry needling at distant myofascial trigger points is an effective pain management in patients with myofascial pain. However, the biochemical effects of remote dry needling are not well understood. This study evaluates the remote effects of dry needling with different dosages on the expressions of substance P (SP) in the proximal muscle, spinal dorsal horns of rabbits. Methods. Male New Zealand rabbits (2.5–3.0 kg) received dry needling at myofascial trigger spots of a gastrocnemius (distant muscle) in one (1D) or five sessions (5D). Bilateral biceps femoris (proximal muscles) and superficial laminaes of L5-S2, T2-T5, and C2-C5 were sampled immediately and 5 days after dry needling to determine the levels of SP using immunohistochemistry and western blot. Results. Immediately after dry needling for 1D and 5D, the expressions of SP were significantly decreased in ipsilateral biceps femoris and bilateral spinal superficial laminaes (P myofascial pain. PMID:25276839

  2. Effects of Replacement of Fishmeal with other Alternative Plant Sources in the Feed on Proximate Composition of Muscle, Liver and Ovary in Tilapia (Oreochromis nioloticus

    Directory of Open Access Journals (Sweden)

    Khalid Al-Ghanim

    2017-08-01

    Full Text Available ABSTRACT The major objective of this experiment was to assess the effect of alternate plant protein sources as a replacement for fish meal in feed on the proximate composition of muscle, liver and tissue in Oreochromis niloticus. O. niloticus of average size (average Weight 45.00±1.25 g, total length 13.28±1.42 cm were stocked in 100 L glass aquarium. Fish were fed with three experimental feeds (A, B and C and reference commercial feed (D for 16 weeks. Feed A, B and C was prepared from four different plant sources and fish meal (40 % crude protein. Fish were fed at the rate 3 % of body weight daily. It has been observed that tilapia fed with feed B in which 20 % fish meal was replaced compared to feed C with other plant sources of protein, had shown significantly higher total protein in their muscle compared to diet other experimental and commercial feeds. In O. niloticus minimum lipid content was recorded in fish fed with diet B compared to A, C and commercial feed. It has been concluded that 20-40% level of fish meal can be replaced in the diet of fish without having any impact on growth and chemical composition of muscle.

  3. p53 and ATF4 mediate distinct and additive pathways to skeletal muscle atrophy during limb immobilization.

    Science.gov (United States)

    Fox, Daniel K; Ebert, Scott M; Bongers, Kale S; Dyle, Michael C; Bullard, Steven A; Dierdorff, Jason M; Kunkel, Steven D; Adams, Christopher M

    2014-08-01

    Immobilization causes skeletal muscle atrophy via complex signaling pathways that are not well understood. To better understand these pathways, we investigated the roles of p53 and ATF4, two transcription factors that mediate adaptations to a variety of cellular stresses. Using mouse models, we demonstrate that 3 days of muscle immobilization induces muscle atrophy and increases expression of p53 and ATF4. Furthermore, muscle fibers lacking p53 or ATF4 are partially resistant to immobilization-induced muscle atrophy, and forced expression of p53 or ATF4 induces muscle fiber atrophy in the absence of immobilization. Importantly, however, p53 and ATF4 do not require each other to promote atrophy, and coexpression of p53 and ATF4 induces more atrophy than either transcription factor alone. Moreover, muscle fibers lacking both p53 and ATF4 are more resistant to immobilization-induced atrophy than fibers lacking only p53 or ATF4. Interestingly, the independent and additive nature of the p53 and ATF4 pathways allows for combinatorial control of at least one downstream effector, p21. Using genome-wide mRNA expression arrays, we identified p21 mRNA as a skeletal muscle transcript that is highly induced in immobilized muscle via the combined actions of p53 and ATF4. Additionally, in mouse muscle, p21 induces atrophy in a manner that does not require immobilization, p53 or ATF4, and p21 is required for atrophy induced by immobilization, p53, and ATF4. Collectively, these results identify p53 and ATF4 as essential and complementary mediators of immobilization-induced muscle atrophy and discover p21 as a critical downstream effector of the p53 and ATF4 pathways. Copyright © 2014 the American Physiological Society.

  4. Pace bowlers in cricket with history of lumbar stress fracture have increased risk of lower limb muscle strains, particularly calf strains.

    Science.gov (United States)

    Orchard, John; Farhart, Patrick; Kountouris, Alex; James, Trefor; Portus, Marc

    2010-01-01

    To assess whether a history of lumbar stress fracture in pace bowlers in cricket is a risk factor for lower limb muscle strains. This was a prospective cohort risk factor study, conducted using injury data from contracted first class pace bowlers in Australia during seasons 1998-1999 to 2008-2009 inclusive. There were 205 pace bowlers, 33 of whom suffered a lumbar stress fracture when playing first class cricket. Risk ratios ([RR] with 95% confidence intervals[CI]) were calculated to compare the seasonal incidence of various injuries between bowlers with a prior history of lumbar stress fracture and those with no history of lumbar stress fracture. Risk of calf strain was strongly associated with prior lumbar stress fracture injury history (RR = 4.1; 95% CI: 2.4-7.1). Risks of both hamstring strain (RR = 1.5; 95% CI: 1.03-2.1) and quadriceps strain (RR = 2.0; 95% CI: 1.1-3.5) were somewhat associated with history of lumbar stress fracture. Risk of groin strain was not associated with history of lumbar stress fracture (RR = 0.7; 95% CI: 0.4-1.1). Other injuries showed little association with prior lumbar stress fracture, although knee cartilage injuries were more likely in the non-stress fracture group. Bony hypertrophy associated with lumbar stress fracture healing may lead to subsequent lumbar nerve root impingement, making lower limb muscle strains more likely to occur. Confounders may be responsible for some of the findings. In particular, bowling speed is likely to be independently correlated with risk of lumbar stress fracture and risk of muscle strain. However, as the relationship between lumbar stress fracture history and calf strain was very strong, and that there is a strong theoretical basis for the connection, it is likely that this is a true association.

  5. Serum Proteases Potentiate BMP-Induced Cell Cycle Re-entry of Dedifferentiating Muscle Cells during Newt Limb Regeneration

    NARCIS (Netherlands)

    Wagner, Ines; Wang, Heng; Weissert, Philipp M.; Straube, Werner L.; Shevchenko, Anna; Gentzel, Marc; Brito, Goncalo; Tazaki, Akira; Oliveira, Catarina; Sugiura, Takuji; Shevchenko, Andrej; Simon, Andras; Drechsel, David N.; Tanaka, Elly M.

    2017-01-01

    Limb amputation in the newt induces myofibers to dedifferentiate and re-enter the cell cycle to generate proliferative myogenic precursors in the regeneration blastema. Here we show that bone morphogenetic proteins (BMPs) and mature BMPs that have been further cleaved by serum proteases induce cell

  6. Application of neuromuscular electrical stimulation of the lower limb skeletal muscles in the rehabilitation of patients with chronic heart failure and chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Ewa Barbara Kucio

    2017-03-01

    Full Text Available Increasing physical activity is a widely-known method of rehabilitation of patients with chronic heart failure (CHF and chronic obstructive pulmonary disease (COPD. However, what kind of procedure is to be applied if a patient suffers from advanced heart or respiratory failure, cannot undertake physical exercise due to locomotor system disorders or is currently undergoing respiratorotherapy? Recent research shows that neuromuscular electrical stimulation of the lower limb skeletal muscles (NMES may comprise an alternative to physical training in patients with CHF and COPD. The aim of this study is to summarize the current state of knowledge on the use of NMES in cardiac rehabilitation of patients with CHF and pulmonary rehabilitation of patients with COPD. As demonstrated in recent research on the topic, NMES – due to forcing the muscles to activate – increases exercise tolerance, muscle mass and endurance in patients with CHF and COPD. The beneficial effect of NMES on blood circulation in the muscles, aerobic enzymes activity, functioning of the vascular endothelium, reduction of pro-inflammatory cytokines concentration and increased quality of life has also been presented. It is to be accentuated that NMES treatment, due to lesser physical exertion and, in turn, a decreased feeling of dyspnea are more comfortable for the patient than traditional physical training. Moreover, NMES treatment, after foregoing training, can be applied at home. Potential side effects include transient muscle pain and minor skin damage due to improper positioning of the electrodes. To summarize, NMES treatment is well received by CHF and COPD patients and brings about increased exercise tolerance, as well as better quality of life. Devices used for NMES therapy, due to progressive miniaturization, are easily accessible and relatively inexpensive.

  7. Diffusion and ideal MRI techniques to characterize limb-girdle muscular dystrophy

    Science.gov (United States)

    Hernández-Salazar, G.; Hidalgo-Tobon, S.; Vargas-Cañas, S.; Marrufo-Melendez, O.; Solis-Najera, S.; Taboada-Barajas, J.; Rodríguez, A. O.; Delgado-Hernández, R.

    2012-10-01

    Limb-girdle muscular dystrophies (LGMD) are a group of autosomal dominantly or recessively inherited muscular dystrophies that also present with primary proximal (limb-girdle) muscle weakness. In the thigh, muscles at the back are affected, with a tendency to preserve the tibialis anterior and gastrocnemius. The aim of this study was to compare quantitative MRI measurements from IDEAL-based imaging and DW imaging in the thigh muscles of adults with LGMDs and healthy volunteers(HC). Six women (three patients and three healthy volunteers) were examined. Imaging experiments were conducted on a 1.5T GE scanner (General Electric Medical Systems. Milwaukee). T1 IDEAL 2D images and diffusion images were acquired. Results demonstrated that the use of noninvasive MRI techniques may provide the means to characterize the muscle through quantitative methods to determine the percentage of fat and ADC values.

  8. An investigation of fatigue phenomenon in the upper limb muscle due to short duration pulses in an FES system

    Science.gov (United States)

    Naeem, Jannatul; Wong Azman, Amelia; Khan, Sheroz; Mohd Mustafah, Yasir

    2013-12-01

    Functional Electrical Stimulation (FES) is a method of artificially stimulating muscles or nerves in order to result in contraction or relaxation of muscles. Many studies have shown that FES system has helped patients to live a better lives especially those who are suffering from physical mobility. Unfortunately, one of the main limitations of an FES system besides of its high cost is largely due to muscle fatigue. Muscle fatigue will affect the training duration which could delay patients' recovery rate. In this paper, we analyzed the occurrence of this fatigue phenomenon in terms of stimulator parameters such as amplitude, frequency, pulse width and pulse shape. The objective of this investigation is to identify other key features of the FES system parameters in order to prolong the training duration among patients. The experiment has been done on a healthy person for the duration of one minute and later the muscles response will be observed. Resultant muscle response is recorded as force using force resistive sensor. The experimental results show muscles will get fatigue at a different rate as the frequency increases. The experiment also shows that the duty cycle is reciprocal to the resultant force.

  9. Responsiveness of the double limb lowering test and lower abdominal muscle progression to core stabilization exercise programs in healthy adults: a pilot study.

    Science.gov (United States)

    Haladay, Douglas E; Miller, Sayers J; Challis, John H; Denegar, Craig R

    2014-07-01

    Low back pain (LBP) is one of the most prevalent and expensive health care problems in the United States. Studies suggest that stabilization exercise may be effective in the management of people with LBP. To accurately assess the effect of stabilization programs on muscle performance, clinicians need an objective measure that is both valid and reliable. The purpose of this study was to determine whether the double limb lowering test (DLLT) and lower abdominal muscle progression (LAMP) can detect a change in abdominal muscle performance after stabilization exercises. Eleven healthy participants (4 men and 7 women) were randomly assigned to either a specific stabilization exercise (SSE) or general stabilization exercise (GSE) group and were evaluated by the DLLT and LAMP before, during, and at the end of 8 weeks of training. Subjects attended exercise sessions twice per week over 8 weeks. No significant difference in pretest performance existed between the 2 groups. No significant difference was detected with the DLLT for either the SSE or GSE over time or when groups were combined. The LAMP detected a significant difference for the combined groups and GSE but not SSE over time. These data indicate that the LAMP is sensitive to change after a spinal stabilization program, whereas the DLLT does not detect a change after these programs. Furthermore, the GSE was more effective in producing these changes. Additional testing of these assessments is necessary to further validate these tests and to identify specific populations for which these tests may be most appropriate.

  10. Infantile lipofibromatosis of the upper limb

    Energy Technology Data Exchange (ETDEWEB)

    Teo, Harvey E.L.; Peh, Wilfred C.G. [KK Women' s and Children' s Hospital, Department of Diagnostic Imaging, Singapore (Singapore); Chan, Mei-Yoke [KK Women' s and Children' s Hospital, Department of Paediatric Medicine, Singapore (Singapore); Walford, Norman [Tan Tock Seng Hospital, Department of Pathology, Singapore (Singapore)

    2005-12-01

    The imaging features of extensive lipofibromatosis presenting in a 1-day-old female infant are reported. This lesion involved her entire right upper limb, extending from the axilla to the palm of the hand. Radiographs showed marked deformity and thinning of all the right upper-limb bones due to pressure effect of soft-tissue enlargement, especially affecting the distal humerus and proximal forearm bones. Magnetic resonance imaging showed a huge soft-tissue mass infiltrating most of the muscles of the entire upper limb, with bony erosion. The mass was largely T1-isointense, moderately T2-hyperintense and showed marked enhancement. There were intra-lesional signal changes consistent with fatty elements. A lesion debulking procedure was performed and the histology was that of lipofibromatosis. The limb was found to be non-viable after the procedure and a subsequent above-elbow amputation was performed. Although the resection margins were not clear, she had no further recurrence over a subsequent 3-year follow-up period. (orig.)

  11. A comprehensive characterisation of the fibre composition and properties of a limb (Flexor digitorum superficialis, membri thoraci and a trunk (Psoas major muscle in cattle

    Directory of Open Access Journals (Sweden)

    Rueda Julia

    2008-12-01

    Full Text Available Abstract Background The fibre type attributes and the relationships among their properties play an important role in the differences in muscle capabilities and features. Comprehensive characterisation of the skeletal muscles should study the degree of association between them and their involvement in muscle functionality. The purposes of the present study were to characterise the fibre type composition of a trunk (Psoas major, PM and a limb (Flexor digitorum, membri thoraci, FD muscle in the bovine species and to study the degree of coordination among contractile, metabolic and histological properties of fibre types. Immunohistochemical, histochemical and histological techniques were used. Results The fibre type composition was delineated immunohistochemically in calf muscle samples, identifying three pure (I, IIA, and IIX and two hybrid type fibres (I+IIA, and IIAX. Most of the fibres in FD were types I and IIA, while pure IIX were absent. All fibre types were found in PM, the IIX type being the most frequent. Compared to other species, small populations of hybrid fibres were detected. The five fibre types, previously identified, were ascribed to three different acid and alkaline mATPase activity patterns. Type I fibres had the highest oxidative capacity and the lowest glycolytic capacity. The reverse was true for the IIX fibres, whereas the type IIA fibres showed intermediate properties. Regarding the histological properties, type I fibres tended to be more capillarised than the II types. Correlations among contractile, metabolic and histological features on individual fibres were significantly different from zero (r values varied between -0.31 and 0.78. Hybrid fibre values were positioned between their corresponding pure types, and their positions were different regarding their metabolic and contractile properties. Conclusion Coordination among the contractile, metabolic and histological properties of fibres has been observed. However, the

  12. Co-injection of mesenchymal stem cells with endothelial progenitor cells accelerates muscle recovery in hind limb ischemia through an endoglin-dependent mechanism.

    Science.gov (United States)

    Rossi, Elisa; Smadja, David; Goyard, Celine; Cras, Audrey; Dizier, Blandine; Bacha, Nour; Lokajczyk, Anna; Guerin, Coralie L; Gendron, Nicolas; Planquette, Benjamin; Mignon, Virginie; Bernabéu, Carmelo; Sanchez, Olivier; Smadja, David M

    2017-10-05

    Endothelial colony-forming cells (ECFCs) are progenitor cells committed to endothelial lineages and have robust vasculogenic properties. Mesenchymal stem cells (MSCs) have been described to support ECFC-mediated angiogenic processes in various matrices. However, MSC-ECFC interactions in hind limb ischemia (HLI) are largely unknown. Here we examined whether co-administration of ECFCs and MSCs bolsters vasculogenic activity in nude mice with HLI. In addition, as we have previously shown that endoglin is a key adhesion molecule, we evaluated its involvement in ECFC/MSC interaction. Foot perfusion increased on day 7 after ECFC injection and was even better at 14 days. Co-administration of MSCs significantly increased vessel density and foot perfusion on day 7 but the differences were no longer significant at day 14. Analysis of mouse and human CD31, and in situ hybridization of the human ALU sequence, showed enhanced capillary density in ECFC+MSC mice. When ECFCs were silenced for endoglin, coinjection with MSCs led to lower vessel density and foot perfusion at both 7 and 14 days (p<0.001). Endoglin silencing in ECFCs did not affect MSC differentiation into perivascular cells or other mesenchymal lineages. Endoglin silencing markedly inhibited ECFC adhesion to MSCs. Thus, MSCs, when combined with ECFCs, accelerate muscle recovery in a mouse model of hind limb ischemia, through an endoglin-dependent mechanism.

  13. Influence of complementing a robotic upper limb rehabilitation system with video games on the engagement of the participants: a study focusing on muscle activities.

    Science.gov (United States)

    Li, Chong; Rusák, Zoltán; Horváth, Imre; Ji, Linhong

    2014-12-01

    Efficacious stroke rehabilitation depends not only on patients' medical treatment but also on their motivation and engagement during rehabilitation exercises. Although traditional rehabilitation exercises are often mundane, technology-assisted upper-limb robotic training can provide engaging and task-oriented training in a natural environment. The factors that influence engagement, however, are not fully understood. This paper therefore studies the relationship between engagement and muscle activities as well as the influencing factors of engagement. To this end, an experiment was conducted using a robotic upper limb rehabilitation system with healthy individuals in three training exercises: (a) a traditional exercise, which is typically used for training the grasping function, (b) a tracking exercise, currently used in robot-assisted stroke patient rehabilitation for fine motor movement, and (c) a video game exercise, which is a proliferating approach of robot-assisted rehabilitation enabling high-level active engagement of stroke patients. These exercises differ not only in the characteristics of the motion that they use but also in their method of triggering engagement. To measure the level of engagement, we used facial expressions, motion analysis of the arm movements, and electromyography. The results show that (a) the video game exercise could engage the participants for a longer period than the other two exercises, (b) the engagement level decreased when the participants became too familiar with the exercises, and (c) analysis of normalized root mean square in electromyographic data indicated that muscle activities were more intense when the participants are engaged. This study shows that several sub-factors on engagement, such as versatility of feedback, cognitive tasks, and competitiveness, may influence engagement more than the others. To maintain a high level of engagement, the rehabilitation system needs to be adaptive, providing different exercises to

  14. Concurrent assessments of lower limb loading patterns, mechanical muscle strength and functional performance in ACL-patients--a cross-sectional study.

    Science.gov (United States)

    Holsgaard-Larsen, A; Jensen, C; Mortensen, N H M; Aagaard, P

    2014-01-01

    Full recovery in muscle strength and functional performance may not be achieved after ACL-injury. The aim of this study is to investigate loading patterns during jumping, muscle function and functional performance in ACL-reconstructed patients and to investigate the origin of between-limb asymmetry by means of a 3-dimensional movement analysis. Design is cross-sectional. 23 ACL-reconstructed men (27.2±7.5 years, BMI: 25.4±3.2) 27±7 month post-surgery and 25 matched controls (27.2±5.4 years, BMI: 24.1±1.8) were included. Participants performed (i) bilateral and (ii) unilateral counter movement jumps (CMJ). A 3-D movement analysis was performed by a six-camera Vicon MX-system. Subsequently, jump height (JH), knee joint range of motion (ROM), peak and mean sagittal knee moments were analyzed (iii) one-leg maximal jump for distance was performed, and (iv) maximal unilateral isometric knee extensor and flexor strength (MVC) were measured using stabilized dynamometry. No in-between group differences in age or BMI were observed. CMJ: Between-limb asymmetry ratios for ROM differed (p<0.01) between patients and controls in both types of CMJ (96.1% vs. 102.6% and 87.0% vs. 99.9% in bilateral and single-leg CMJs, respectively). Jump for distance: Patients demonstrated greater (p<0.01) asymmetry for jump length (92.9% vs. 98.6%). MVC: Asymmetry in hamstring MVC was greater (p<0.001) for patients than controls (77.4% vs. 101.3%). ACL-patients showed reduced function of the operated leg~2 years post ACL-reconstruction, especially for hamstring MVC. Hamstrings are important protagonists to the ACL, thus representing a potential risk factor for secondary ACL-rupture and/or osteoarthritis. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Is two better than one? Muscle vibration plus robotic rehabilitation to improve upper limb spasticity and function: A pilot randomized controlled trial

    Science.gov (United States)

    Russo, Margherita; Milardi, Demetrio; Leo, Antonino; Filoni, Serena; Trinchera, Antonia; Bramanti, Placido

    2017-01-01

    Even though robotic rehabilitation is very useful to improve motor function, there is no conclusive evidence on its role in reducing post-stroke spasticity. Focal muscle vibration (MV) is instead very useful to reduce segmental spasticity, with a consequent positive effect on motor function. Therefore, it could be possible to strengthen the effects of robotic rehabilitation by coupling MV. To this end, we designed a pilot randomized controlled trial (Clinical Trial NCT03110718) that included twenty patients suffering from unilateral post-stroke upper limb spasticity. Patients underwent 40 daily sessions of Armeo-Power training (1 hour/session, 5 sessions/week, for 8 weeks) with or without spastic antagonist MV. They were randomized into two groups of 10 individuals, which received (group-A) or not (group-B) MV. The intensity of MV, represented by the peak acceleration (a-peak), was calculated by the formula (2πf)2A, where f is the frequency of MV and A is the amplitude. Modified Ashworth Scale (MAS), short intracortical inhibition (SICI), and Hmax/Mmax ratio (HMR) were the primary outcomes measured before and after (immediately and 4 weeks later) the end of the treatment. In all patients of group-A, we observed a greater reduction of MAS (p = 0.007, d = 0.6) and HMR (pspastic muscles (p = 0.004). Our data show that this combined rehabilitative approach could be a promising option in improving upper limb spasticity and motor function. We could hypothesize that the greater rehabilitative outcome improvement may depend on a reshape of corticospinal plasticity induced by a sort of associative plasticity between Armeo-Power and MV. PMID:28973024

  16. Effect of acute inspiratory muscle exercise on blood flow of resting and exercising limbs and glucose levels in type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Ana Paula dos Santos Corrêa

    Full Text Available To evaluate the effects of inspiratory loading on blood flow of resting and exercising limbs in patients with diabetic autonomic neuropathy. Ten diabetic patients without cardiovascular autonomic neuropathy (DM, 10 patients with cardiovascular autonomic neuropathy (DM-CAN and 10 healthy controls (C were randomly assigned to inspiratory muscle load of 60% or 2% of maximal inspiratory pressure (PImax for approximately 5 min, while resting calf blood flow (CBF and exercising forearm blood flow (FBF were measured. Reactive hyperemia was also evaluated. From the 20 diabetic patients initially allocated, 6 wore a continuous glucose monitoring system to evaluate the glucose levels during these two sessions (2%, placebo or 60%, inspiratory muscle metaboreflex. Mean age was 58 ± 8 years, and mean HbA1c, 7.8% (62 mmol/mol (DM and DM-CAN. A PImax of 60% caused reduction of CBF in DM-CAN and DM (P<0.001, but not in C, whereas calf vascular resistance (CVR increased in DM-CAN and DM (P<0.001, but not in C. The increase in FBF during forearm exercise was blunted during 60% of PImax in DM-CAN and DM, and augmented in C (P<0.001. Glucose levels decreased by 40 ± 18.8% (P<0.001 at 60%, but not at 2%, of PImax. A negative correlation was observed between reactive hyperemia and changes in CVR (Beta coefficient = -0.44, P = 0.034. Inspiratory muscle loading caused an exacerbation of the inspiratory muscle metaboreflex in patients with diabetes, regardless of the presence of neuropathy, but influenced by endothelial dysfunction. High-intensity exercise that recruits the diaphragm can abruptly reduce glucose levels.

  17. Morphology and morphometry of the ulnar head of the pronator teres muscle in relation to median nerve compression at the proximal forearm.

    Science.gov (United States)

    Gurses, I A; Altinel, L; Gayretli, O; Akgul, T; Uzun, I; Dikici, F

    2016-12-01

    The pronator syndrome is a rare compression neuropathy of the median nerve. Ulnar head of the pronator teres muscle may cause compression at proximal forearm. Detailed morphologic and morphometric studies on the anatomy of the ulnar head of pronator teres is scarce. We dissected 112 forearms of fresh cadavers. We evaluated the morphology and morphometry of the ulnar head of pronator teres muscle. The average ulnar head width was 16.3±8.2mm. The median nerve passed anterior to the ulnar head at a distance of 50.4±10.7mm from the interepicondylar line. We classified the morphology of the ulnar head into 5 types. In type 1, the ulnar head was fibromuscular in 60 forearms (53.6%). In type 2, it was muscular in 23 forearms (20.5%). In type 3, it was just a fibrotic band in 18 forearms (16.1%). In type 4, it was absent in 9 forearms (8%). In type 5, the ulnar head had two arches in 2 forearms (1.8%). In 80 forearms (71.5%: types 1, 3, and 5), the ulnar head was either fibromuscular or a fibrotic band. Although the pronator syndrome is a rare compression syndrome, the ulnar head of pronator teres is reported as the major cause of entrapment in the majority of the cases. The location of the compression of the median nerve in relation to the ulnar head of pronator teres muscle and the morphology of the ulnar head is important for open or minimally-invasive surgical treatment. Sectional study. Basic science study. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Effects of hyperbaric oxygen therapy on biochemical and histological parameters of muscle groups in proximity to the distracted rat tibia.

    Science.gov (United States)

    Kaynar, A; Civelek, S; Kasymova, Z; Keklikoglu, N; Toklu, S; Uzun, H

    2014-12-01

    We investigated the effect of hyperbaric oxygen therapy (HBOT) on rat muscles during tibial distraction osteogenesis (DO) at normal and hyperdistraction rates. Animals in groups 1 and 2 were distracted by 0.5 mm/day and those in groups 3 and 4 by 1 mm/day. Groups 2 and 4 received HBOT during distraction. Group 5 served as control. Superoxide dismutase (SOD; U/g protein), malondialdehyde (nmol/g protein), glutathione (mmol/g protein), and protein levels (g/dl) were determined. SOD was significantly higher in group 2 (4.59 ± 0.97) than in controls (2.19 ± 0.7) (P = 0.0001), and lower in group 4 (3.74 ± 1.70) than in group 2 (P=0.011). Malondialdehyde was significantly higher in group 2 (0.72 ± 0.23) than in controls (0.38 ± 0.10) (P=0.005). Total protein levels were better preserved with HBOT in distracted muscles: group 2 (3.24 ± 0.37) vs. group 1 (1.88 ± 0.60), and group 4 (3.45 ± 0.70) vs. group 3 (2.03 ± 0.75) (both P=0.0001). Numbers of fibres were lower in group 1 (4.88 ± 0.59) than in group 2 (6.07 ± 0.86), and in group 3 (5.13 ± 0.36) than in group 4 (6.14 ± 0.74) (both P=0.001). Numbers of nuclei were higher in group 1 (11.29 ± 2.47) than in group 2 (9.03 ± 1.53) (P=0.04), and in group 3 (12.43 ± 3.32) than in group 4 (9.08 ± 1.58) (P=0.001). Fibres and nuclei with HBOT were similar to those of controls. HBOT decreased the inflammatory cell infiltrate for group 1 (19.8 ± 8.54) vs. group 2 (4.2 ± 2.53) and group 3 (36.54 ± 11.29) vs. group 4 (21.5 ± 9.23) (both P=0.001). HBOT improves the adaptation of distracted muscle by increasing fibres and antioxidants while decreasing inflammation. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  19. Home-Based Virtual Reality-Augmented Training Improves Lower Limb Muscle Strength, Balance, and Functional Mobility following Chronic Incomplete Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Michael Villiger

    2017-11-01

    Full Text Available Key factors positively influencing rehabilitation and functional recovery after spinal cord injury (SCI include training variety, intensive movement repetition, and motivating training tasks. Systems supporting these aspects may provide profound gains in rehabilitation, independent of the subject’s treatment location. In the present study, we test the hypotheses that virtual reality (VR-augmented training at home (i.e., unsupervised is feasible with subjects with an incomplete SCI (iSCI and that it improves motor functions such as lower limb muscle strength, balance, and functional mobility. In the study, 12 chronic iSCI subjects used a home-based, mobile version of a lower limb VR training system. The system included motivating training scenarios and combined action observation and execution. Virtual representations of the legs and feet were controlled via movement sensors. The subjects performed home-based training over 4 weeks, with 16–20 sessions of 30–45 min each. The outcome measures assessed were the Lower Extremity Motor Score (LEMS, Berg Balance Scale (BBS, Timed Up and Go (TUG, Spinal Cord Independence Measure mobility, Walking Index for Spinal Cord Injury II, and 10 m and 6 min walking tests. Two pre-treatment assessment time points were chosen for outcome stability: 4 weeks before treatment and immediately before treatment. At post-assessment (i.e., immediately after treatment, high motivation and positive changes were reported by the subjects (adapted Patients’ Global Impression of Change. Significant improvements were shown in lower limb muscle strength (LEMS, P = 0.008, balance (BBS, P = 0.008, and functional mobility (TUG, P = 0.007. At follow-up assessment (i.e., 2–3 months after treatment, functional mobility (TUG remained significantly improved (P = 0.005 in contrast to the other outcome measures. In summary, unsupervised exercises at home with the VR training system led to beneficial

  20. Home-Based Virtual Reality-Augmented Training Improves Lower Limb Muscle Strength, Balance, and Functional Mobility following Chronic Incomplete Spinal Cord Injury.

    Science.gov (United States)

    Villiger, Michael; Liviero, Jasmin; Awai, Lea; Stoop, Rahel; Pyk, Pawel; Clijsen, Ron; Curt, Armin; Eng, Kynan; Bolliger, Marc

    2017-01-01

    Key factors positively influencing rehabilitation and functional recovery after spinal cord injury (SCI) include training variety, intensive movement repetition, and motivating training tasks. Systems supporting these aspects may provide profound gains in rehabilitation, independent of the subject's treatment location. In the present study, we test the hypotheses that virtual reality (VR)-augmented training at home (i.e., unsupervised) is feasible with subjects with an incomplete SCI (iSCI) and that it improves motor functions such as lower limb muscle strength, balance, and functional mobility. In the study, 12 chronic iSCI subjects used a home-based, mobile version of a lower limb VR training system. The system included motivating training scenarios and combined action observation and execution. Virtual representations of the legs and feet were controlled via movement sensors. The subjects performed home-based training over 4 weeks, with 16-20 sessions of 30-45 min each. The outcome measures assessed were the Lower Extremity Motor Score (LEMS), Berg Balance Scale (BBS), Timed Up and Go (TUG), Spinal Cord Independence Measure mobility, Walking Index for Spinal Cord Injury II, and 10 m and 6 min walking tests. Two pre-treatment assessment time points were chosen for outcome stability: 4 weeks before treatment and immediately before treatment. At post-assessment (i.e., immediately after treatment), high motivation and positive changes were reported by the subjects (adapted Patients' Global Impression of Change). Significant improvements were shown in lower limb muscle strength (LEMS, P  = 0.008), balance (BBS, P  = 0.008), and functional mobility (TUG, P  = 0.007). At follow-up assessment (i.e., 2-3 months after treatment), functional mobility (TUG) remained significantly improved ( P  = 0.005) in contrast to the other outcome measures. In summary, unsupervised exercises at home with the VR training system led to beneficial functional

  1. Is two better than one? Muscle vibration plus robotic rehabilitation to improve upper limb spasticity and function: A pilot randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Rocco Salvatore Calabrò

    Full Text Available Even though robotic rehabilitation is very useful to improve motor function, there is no conclusive evidence on its role in reducing post-stroke spasticity. Focal muscle vibration (MV is instead very useful to reduce segmental spasticity, with a consequent positive effect on motor function. Therefore, it could be possible to strengthen the effects of robotic rehabilitation by coupling MV. To this end, we designed a pilot randomized controlled trial (Clinical Trial NCT03110718 that included twenty patients suffering from unilateral post-stroke upper limb spasticity. Patients underwent 40 daily sessions of Armeo-Power training (1 hour/session, 5 sessions/week, for 8 weeks with or without spastic antagonist MV. They were randomized into two groups of 10 individuals, which received (group-A or not (group-B MV. The intensity of MV, represented by the peak acceleration (a-peak, was calculated by the formula (2πf2A, where f is the frequency of MV and A is the amplitude. Modified Ashworth Scale (MAS, short intracortical inhibition (SICI, and Hmax/Mmax ratio (HMR were the primary outcomes measured before and after (immediately and 4 weeks later the end of the treatment. In all patients of group-A, we observed a greater reduction of MAS (p = 0.007, d = 0.6 and HMR (p<0.001, d = 0.7, and a more evident increase of SICI (p<0.001, d = 0.7 up to 4 weeks after the end of the treatment, as compared to group-B. Likewise, group-A showed a greater function outcome of upper limb (Functional Independence Measure p = 0.1, d = 0.7; Fugl-Meyer Assessment of the Upper Extremity p = 0.007, d = 0.4 up to 4 weeks after the end of the treatment. A significant correlation was found between the degree of MAS reduction and SICI increase in the agonist spastic muscles (p = 0.004. Our data show that this combined rehabilitative approach could be a promising option in improving upper limb spasticity and motor function. We could hypothesize that the greater rehabilitative outcome

  2. Lower-limb venous thrombosis

    African Journals Online (AJOL)

    307. Lower-limb venous thrombosis. July 2009 Vol.27 No.7 CME. Most DVTs arise in calf muscle veins, particularly within the gastrocnemius and soleus muscles (calf vein DVT). Many of these remain localised to the muscle and will not cause any clinical problem. If, however, the circumstances that initially caused the.

  3. Nanospan, an alternatively spliced isoform of sarcospan, localizes to the sarcoplasmic reticulum in skeletal muscle and is absent in limb girdle muscular dystrophy 2F.

    Science.gov (United States)

    Peter, Angela K; Miller, Gaynor; Capote, Joana; DiFranco, Marino; Solares-Pérez, Alhondra; Wang, Emily L; Heighway, Jim; Coral-Vázquez, Ramón M; Vergara, Julio; Crosbie-Watson, Rachelle H

    2017-06-06

    Sarcospan (SSPN) is a transmembrane protein that interacts with the sarcoglycans (SGs) to form a tight subcomplex within the dystrophin-glycoprotein complex that spans the sarcolemma and interacts with laminin in the extracellular matrix. Overexpression of SSPN ameliorates Duchenne muscular dystrophy in murine models. Standard cloning approaches were used to identify nanospan, and nanospan-specific polyclonal antibodies were generated and validated. Biochemical isolation of skeletal muscle membranes and two-photon laser scanning microscopy were used to analyze nanospan localization in muscle from multiple murine models. Duchenne muscular dystrophy biopsies were analyzed by immunoblot analysis of protein lysates as well as indirect immunofluorescence analysis of muscle cryosections. Nanospan is an alternatively spliced isoform of sarcospan. While SSPN has four transmembrane domains and is a core component of the sarcolemmal dystrophin-glycoprotein complex, nanospan is a type II transmembrane protein that does not associate with the dystrophin-glycoprotein complex. We demonstrate that nanospan is enriched in the sarcoplasmic reticulum (SR) fractions and is not present in the T-tubules. SR fractions contain membranes from three distinct structural regions: a region flanking the T-tubules (triadic SR), a SR region across the Z-line (ZSR), and a longitudinal SR region across the M-line (LSR). Analysis of isolated murine muscles reveals that nanospan is mostly associated with the ZSR and triadic SR, and only minimally with the LSR. Furthermore, nanospan is absent from the SR of δ-SG-null (Sgcd-/-) skeletal muscle, a murine model for limb girdle muscular dystrophy 2F. Analysis of skeletal muscle biopsies from Duchenne muscular dystrophy patients reveals that nanospan is preferentially expressed in type I (slow) fibers in both control and Duchenne samples. Furthermore, nanospan is significantly reduced in Duchenne biopsies. Alternative splicing of proteins from the SG

  4. Nanospan, an alternatively spliced isoform of sarcospan, localizes to the sarcoplasmic reticulum in skeletal muscle and is absent in limb girdle muscular dystrophy 2F.

    Science.gov (United States)

    Peter, Angela K; Miller, Gaynor; Capote, Joana; DiFranco, Marino; Solares-Pérez, Alhondra; Wang, Emily L; Heighway, Jim; Coral-Vázquez, Ramón M; Vergara, Julio; Crosbie-Watson, Rachelle H

    2017-01-01

    Sarcospan (SSPN) is a transmembrane protein that interacts with the sarcoglycans (SGs) to form a tight subcomplex within the dystrophin-glycoprotein complex that spans the sarcolemma and interacts with laminin in the extracellular matrix. Overexpression of SSPN ameliorates Duchenne muscular dystrophy in murine models. Standard cloning approaches were used to identify nanospan, and nanospan-specific polyclonal antibodies were generated and validated. Biochemical isolation of skeletal muscle membranes and two-photon laser scanning microscopy were used to analyze nanospan localization in muscle from multiple murine models. Duchenne muscular dystrophy biopsies were analyzed by immunoblot analysis of protein lysates as well as indirect immunofluorescence analysis of muscle cryosections. Nanospan is an alternatively spliced isoform of sarcospan. While SSPN has four transmembrane domains and is a core component of the sarcolemmal dystrophin-glycoprotein complex, nanospan is a type II transmembrane protein that does not associate with the dystrophin-glycoprotein complex. We demonstrate that nanospan is enriched in the sarcoplasmic reticulum (SR) fractions and is not present in the T-tubules. SR fractions contain membranes from three distinct structural regions: a region flanking the T-tubules (triadic SR), a SR region across the Z-line (ZSR), and a longitudinal SR region across the M-line (LSR). Analysis of isolated murine muscles reveals that nanospan is mostly associated with the ZSR and triadic SR, and only minimally with the LSR. Furthermore, nanospan is absent from the SR of δ-SG-null (Sgcd-/-) skeletal muscle, a murine model for limb girdle muscular dystrophy 2F. Analysis of skeletal muscle biopsies from Duchenne muscular dystrophy patients reveals that nanospan is preferentially expressed in type I (slow) fibers in both control and Duchenne samples. Furthermore, nanospan is significantly reduced in Duchenne biopsies. Alternative splicing of proteins from the SG

  5. Inter-Tester Reliability and Precision of Manual Muscle Testing and Hand-Held Dynamometry in Lower Limb Muscles of Children with Spina Bifida

    Science.gov (United States)

    Mahony, Kate; Hunt, Adrienne; Daley, Deborah; Sims, Susan; Adams, Roger

    2009-01-01

    Reliability and measurement precision of manual muscle testing (MMT) and hand-held dynamometry (HHD) were compared for children with spina bifida. Strength measures were obtained of the hip flexors, hip abductors, and knee extensors of 20 children (10 males, 10 females; mean age 9 years 10 months; range: 5 to 15 years) by two experienced physical…

  6. Lower limb muscle strengthening does not change frontal plane moments in women with knee osteoarthritis: A randomized controlled trial.

    Science.gov (United States)

    Foroughi, Nasim; Smith, Richard M; Lange, Angela K; Baker, Michael K; Fiatarone Singh, Maria A; Vanwanseele, Benedicte

    2011-02-01

    Osteoarthritis is a common musculo-skeletal problem accompanied with muscle weakness. Muscle weakness may be readily improved by resistance training. Greater muscle strength has been associated with a lower knee joint loading rate. We conducted a single-blind randomized controlled trial of 54 female patients with osteoarthritis in at least one knee, according to the American College of Rheumatology clinical criteria. Patients were randomized into a 6-month high intensity progressive resistance training or a sham-exercise program. The primary outcomes were first peak knee and hip adduction moment measured using three-dimensional gait analysis at self-selected habitual and maximal speeds. Secondary outcomes were sagittal plane knee and hip moments, peak muscle strength, gait speed, and self-reported knee osteoarthritis symptoms measured by the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Six months of high intensity resistance training did not change the first peak knee or hip adduction moment at either habitual or maximum walking speeds (P>0.413) compared to the sham-exercise. However, the second peak hip adduction moment (P=0.025) and WOMAC pain score (PMuscle strength training in women with osteoarthritis, while effective for reducing osteoarthritis symptoms, appeared to operate through mechanisms other than improved knee or hip joint loading, as paradoxically, improved symptoms were related to decreases of hip adduction moment in late stance. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  7. EMG Activity in the Abdominal Muscles and the Kinematics of the Lumbar Spine during Unilateral Upper-limb Resistance Exercises under Stable and Unstable Conditions.

    Science.gov (United States)

    Kang, Min-Hyeok; Kim, Man-Sig

    2014-06-01

    [Purpose] We investigated the effects of unstable conditions on the electromyographic (EMG) activity of the rectus abdominis (RA) and the transverse abdominis-internal oblique (TrA-IO) muscles, and lumbar kinematics during unilateral upper-limb resistance exercises using elastic tubing bands. [Subjects] Twelve healthy males were recruited. [Methods] The subjects performed isometric left shoulder abduction using an elastic tubing band in a sitting position on a chair, and on a Swiss ball. During this exercise, EMG activities of the RA and TrA-IO were recorded using a wireless EMG system, and a three-dimensional motion analysis system monitored lumbar kinematics. Differences in EMG activities of the RA and TrA-IO, the ratio of TrA-IO to RA activity, and lumbar kinematics were compared between the stable and unstable conditions using the paired t-test. [Results] Under the unstable condition, the EMG activities of both muscles were significantly greater than that under the stable condition; however the ratio of TrA-IO to RA activity did not significantly differ between the conditions. The lumbar angle significantly differed only in the coronal plane. [Conclusions] These findings indicate that trunk posture should be considered when performing exercises under unstable conditions.

  8. Pace bowlers in cricket with history of lumbar stress fracture have increased risk of lower limb muscle strains, particularly calf strains

    Directory of Open Access Journals (Sweden)

    John Orchard

    2010-09-01

    Full Text Available John Orchard1, Patrick Farhart2, Alex Kountouris3, Trefor James3, Marc Portus31School of Public Health, University of Sydney, Australia; 2Punjab Kings XI team, Indian Premier League, India; 3Cricket Australia, Melbourne, AustraliaObjective: To assess whether a history of lumbar stress fracture in pace bowlers in cricket is a risk factor for lower limb muscle strains.Methods: This was a prospective cohort risk factor study, conducted using injury data from contracted first class pace bowlers in Australia during seasons 1998–1999 to 2008–2009 inclusive. There were 205 pace bowlers, 33 of whom suffered a lumbar stress fracture when playing first class cricket. Risk ratios ([RR] with 95% confidence intervals[CI] were calculated to compare the seasonal incidence of various injuries between bowlers with a prior history of lumbar stress fracture and those with no history of lumbar stress fracture.Results: Risk of calf strain was strongly associated with prior lumbar stress fracture injury history (RR = 4.1; 95% CI: 2.4–7.1. Risks of both hamstring strain (RR = 1.5; 95% CI: 1.03–2.1 and quadriceps strain (RR = 2.0; 95% CI: 1.1–3.5 were somewhat associated with history of lumbar stress fracture. Risk of groin strain was not associated with history of lumbar stress fracture (RR = 0.7; 95% CI: 0.4–1.1. Other injuries showed little association with prior lumbar stress fracture, although knee cartilage injuries were more likely in the non-stress fracture group.Conclusion: Bony hypertrophy associated with lumbar stress fracture healing may lead to subsequent lumbar nerve root impingement, making lower limb muscle strains more likely to occur. Confounders may be responsible for some of the findings. In particular, bowling speed is likely to be independently correlated with risk of lumbar stress fracture and risk of muscle strain. However, as the relationship between lumbar stress fracture history and calf strain was very strong, and that there is a

  9. Development of an inverse approach for the characterization of in vivo mechanical properties of the lower limb muscles.

    Science.gov (United States)

    Affagard, Jean-Sébastien; Bensamoun, Sabine F; Feissel, Pierre

    2014-11-01

    The purpose of this study was to develop an inverse method, coupling imaging techniques with numerical methods, to identify the muscle mechanical behavior. A finite element model updating (FEMU) was developed in three main interdependent steps. First, a 2D FE modeling, parameterized by a Neo-Hookean behavior (C10 and D), was developed from a segmented thigh muscle 1.5T MRI (magnetic resonance imaging). Thus, a displacement field was simulated for different static loadings (contention, compression, and indentation). Subsequently, the optimal mechanical test was determined from a sensitivity analysis. Second, ultrasound parameters (gain, dynamic, and frequency) were optimized on the thigh muscles in order to apply the digital image correlation (DIC), allowing the measurement of an experimental displacement field. Third, an inverse method was developed to identify the Neo-Hookean parameters (C10 and D) by performing a minimization of the distance between the simulated and measured displacement fields. To replace the experimental data and to quantify the identification error, a numerical example was developed. The result of the sensitivity analysis showed that the compression test was more adapted to identify the Neo-Hookean parameters. Ultrasound images were recorded with a frequency, gain, and dynamic of 9 MHz, 34 dB, 42 dB, respectively. In addition, the experimental noise on displacement field measurement was estimated to be 0.2 mm. The identification performed on the numerical example revealed a low error for the C10 (muscle behavior will help to follow treatment and to ensure accurate medical procedures during the use of robotic devices.

  10. Lower limb asymmetry in mechanical muscle function: A comparison between ski racers with and without ACL reconstruction.

    Science.gov (United States)

    Jordan, M J; Aagaard, P; Herzog, W

    2015-06-01

    Due to a high incidence of anterior cruciate ligament (ACL) re-injury in alpine ski racers, this study aims to assess functional asymmetry in the countermovement jump (CMJ), squat jump (SJ), and leg muscle mass in elite ski racers with and without anterior cruciate ligament reconstruction (ACL-R). Elite alpine skiers with ACL-R (n = 9; 26.2 ± 11.8 months post-op) and uninjured skiers (n = 9) participated in neuromuscular screening. Vertical ground reaction force during the CMJ and SJ was assessed using dual force plate methodology to obtain phase-specific bilateral asymmetry indices (AIs) for kinetic impulse (CMJ and SJ phase-specific kinetic impulse AI). Dual x-ray absorptiometry scanning was used to assess asymmetry in lower body muscle mass. Compared with controls, ACL-R skiers had increased AI in muscle mass (P ski racers. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Hemiparetic gait and changes in functional performance due to OnabotulinumtoxinA injection to lower limb muscles.

    Science.gov (United States)

    Esquenazi, Alberto; Moon, Daniel; Wikoff, Amanda; Sale, Patricio

    2015-12-01

    To review gait alterations and evaluate the effects of OnabotulinumtoxinA on spatiotemporal walking parameters of patients with hemiparetic gait. Retrospective pre- and post-intervention analysis. Gait analysis laboratory in a tertiary level rehabilitation hospital. 42 patients with hemiparesis. 19 males and 23 females, age 18-78 years were included. Spatiotemporal parameters collected before and within 4-10 weeks after OnabotA injection to the ankle muscles. Data was recorded at self-selected velocity on a 12 m instrumented walkway. The most common muscles injected were medial and lateral gastrocnemius, soleus and tibialis posterior. Average total OnabotulinumtoxinA dose was 320 ± 107 units. Spatiotemporal parameters of walking assessed before (T0) and within 4-10 weeks post injection (T1). Paired t-test was used to compare pre- and post-intervention data. A sequential Holm-Bonferroni procedure was used to adjust for multiple comparisons and minimize the risk of type I error. Statistical significance was set at p muscles selected with the aid of dynamic electromyography can significantly increase gait velocity and enhance functional ambulation in adults with hemiparesis due to upper motor neuron syndrome. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Dose-response effects of customised foot orthoses on lower limb muscle activity and plantar pressures in pronated foot type.

    Science.gov (United States)

    Telfer, Scott; Abbott, Mandy; Steultjens, Martijn; Rafferty, Daniel; Woodburn, James

    2013-07-01

    Customised foot orthoses (FOs) featuring extrinsic rearfoot posting are commonly prescribed for individuals with a symptomatic pronated foot type. By altering the angle of the posting it is purported that a controlled dose-response effect during the stance phase of gait can be achieved, however these biomechanical changes have yet to be characterised. Customised FOs were administered to participant groups with symptomatic pronated foot types and asymptomatic normal foot types. The electromyographic (EMG) and plantar pressure effects of varying the dose were measured. Dose was varied by changing the angle of posting from 6° lateral to 10° medial in 2° steps on customised devices produced using computer aided orthoses design software. No effects due to posting level were found for EMG variables. Significant group effects were seen with customised FOs reducing above knee muscle activity in pronated foot types compared to normal foot types (biceps femoris p=0.022; vastus lateralis pcustomised FOs can provide a dose response effect for selected plantar pressure variables, but no such effect could be identified for muscle activity. Foot type may play an important role in the effect of customised orthoses on activity of muscles above the knee. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Is two better than one? Muscle vibration plus robotic rehabilitation to improve upper limb spasticity and function: A pilot randomized controlled trial.

    Science.gov (United States)

    Calabrò, Rocco Salvatore; Naro, Antonino; Russo, Margherita; Milardi, Demetrio; Leo, Antonino; Filoni, Serena; Trinchera, Antonia; Bramanti, Placido

    2017-01-01

    Even though robotic rehabilitation is very useful to improve motor function, there is no conclusive evidence on its role in reducing post-stroke spasticity. Focal muscle vibration (MV) is instead very useful to reduce segmental spasticity, with a consequent positive effect on motor function. Therefore, it could be possible to strengthen the effects of robotic rehabilitation by coupling MV. To this end, we designed a pilot randomized controlled trial (Clinical Trial NCT03110718) that included twenty patients suffering from unilateral post-stroke upper limb spasticity. Patients underwent 40 daily sessions of Armeo-Power training (1 hour/session, 5 sessions/week, for 8 weeks) with or without spastic antagonist MV. They were randomized into two groups of 10 individuals, which received (group-A) or not (group-B) MV. The intensity of MV, represented by the peak acceleration (a-peak), was calculated by the formula (2πf)2A, where f is the frequency of MV and A is the amplitude. Modified Ashworth Scale (MAS), short intracortical inhibition (SICI), and Hmax/Mmax ratio (HMR) were the primary outcomes measured before and after (immediately and 4 weeks later) the end of the treatment. In all patients of group-A, we observed a greater reduction of MAS (p = 0.007, d = 0.6) and HMR (prehabilitative approach could be a promising option in improving upper limb spasticity and motor function. We could hypothesize that the greater rehabilitative outcome improvement may depend on a reshape of corticospinal plasticity induced by a sort of associative plasticity between Armeo-Power and MV.

  14. Gastrocnemius Myoelectric Control of a Robotic Hip Exoskeleton Can Reduce the User's Lower-Limb Muscle Activities at Push Off

    Directory of Open Access Journals (Sweden)

    Lorenzo Grazi

    2018-02-01

    Full Text Available We present a novel assistive control strategy for a robotic hip exoskeleton for assisting hip flexion/extension, based on a proportional Electromyography (EMG strategy. The novelty of the proposed controller relies on the use of the Gastrocnemius Medialis (GM EMG signal instead of a hip flexor muscle, to control the hip flexion torque. This strategy has two main advantages: first, avoiding the placement of the EMG electrodes at the human–robot interface can reduce discomfort issues for the user and motion artifacts of the recorded signals; second, using a powerful signal for control, such as the GM, could improve the reliability of the control system. The control strategy has been tested on eight healthy subjects, walking with the robotic hip exoskeleton on the treadmill. We evaluated the controller performance and the effect of the assistance on muscle activities. The tuning of the assistance timing in the controller was subject dependent and varied across subjects. Two muscles could benefit more from the assistive strategy, namely the Rectus Femoris (directly assisted and the Tibialis Anterior (indirectly assisted. A significant correlation was found between the timing of the delivered assistance (i.e., synchronism with the biological hip torque, and reduction of the hip flexors muscular activity during walking; instead, no significant correlations were found for peak torque and peak power. Results suggest that the timing of the assistance is the most significant parameter influencing the effectiveness of the control strategy. The findings of this work could be important for future studies aimed at developing assistive strategies for walking assistance exoskeletons.

  15. Limb regeneration.

    Science.gov (United States)

    Simon, András; Tanaka, Elly M

    2013-01-01

    Limb regeneration is observed in certain members of the animal phyla. Some animals keep this ability during their entire life while others lose it at some time during development. How do animals regenerate limbs? Is it possible to find unifying, conserved mechanisms of limb regeneration or have different species evolved distinct means of replacing a lost limb? How is limb regeneration similar or different to limb development? Studies on many organisms, including echinoderms, arthropods, and chordates have provided significant knowledge about limb regeneration. In this focus article, we concentrate on tetrapod limb regeneration as studied in three model amphibians: newts, axolotls, and frogs. We review recent progress on tissue interactions during limb regeneration, and place those findings into an evolutionary context. Copyright © 2012 Wiley Periodicals, Inc.

  16. Unilateral lower limb suspension does not mimic bed rest or spaceflight effects on human muscle fiber function

    Science.gov (United States)

    Widrick, J. J.; Trappe, S. W.; Romatowski, J. G.; Riley, D. A.; Costill, D. L.; Fitts, R. H.

    2002-01-01

    We used Ca2+-activated skinned muscle fibers to test the hypothesis that unilateral lower leg suspension (ULLS) alters cross-bridge mechanisms of muscle contraction. Soleus and gastrocnemius biopsies were obtained from eight subjects before ULLS, immediately after 12 days of ULLS (post-0 h), and after 6 h of reambulation (post-6 h). Post-0 h soleus fibers expressing type I myosin heavy chain (MHC) showed significant reductions in diameter, absolute and specific peak Ca2+-activated force, unloaded shortening velocity, and absolute and normalized peak power. Fibers obtained from the gastrocnemius were less affected by ULLS, particularly fibers expressing fast MHC isoforms. Post-6 h soleus fibers produced less absolute and specific peak force than did post-0 h fibers, suggesting that reambulation after ULLS induced cell damage. Like bed rest and spaceflight, ULLS primarily affects soleus over gastrocnemius fibers. However, in contrast to these other models, slow soleus fibers obtained after ULLS showed a decrease in unloaded shortening velocity and a greater reduction in specific force.

  17. Adaptive Hierarchical Control for the Muscle Strength Training of Stroke Survivors in Robot-Aided Upper-Limb Rehabilitation

    Directory of Open Access Journals (Sweden)

    Guozheng Xu

    2012-10-01

    Full Text Available Muscle strength training for stroke patients is of vital importance for helping survivors to progressively restore muscle strength and improve the performance of their activities in daily living (ADL. An adaptive hierarchical therapy control framework which integrates the patient's real biomechanical state estimation with task-performance quantitative evaluation is proposed. Firstly, a high-level progressive resistive supervisory controller is designed to determine the resistive force base for each training session based on the patient's online task-performance evaluation. Then, a low-level adaptive resistive force triggered controller is presented to further regulate the interactive resistive force corresponding to the patient's real-time biomechanical state – characterized by the patient's bio-damping and bio-stiffness in the course of one training session, so that the patient is challenged in a moderate but engaging and motivating way. Finally, a therapeutic robot system using a Barrett WAM™ compliant manipulator is set up. We recruited eighteen inpatient and outpatient stroke participants who were randomly allocated in experimental (robot-aided and control (conventional physical therapy groups and enrolled for sixteen weeks of progressive resistance training. The preliminary results show that the proposed therapy control strategies can enhance the recovery of strength and motor control ability.

  18. Electromyographic analysis of upper limb muscles during standardized isotonic and isokinetic robotic exercise of spastic elbow in patients with stroke.

    Science.gov (United States)

    Sin, Minki; Kim, Won-Seok; Park, Daegeun; Min, Yu-Sun; Kim, Woo Jin; Cho, Kyujin; Paik, Nam-Jong

    2014-02-01

    Although it has been reported that strengthening exercise in stroke patients is beneficial for their motor recovery, there is little evidence about which exercise method is the better option. The purpose of this study was to compare isotonic and isokinetic exercise by surface electromyography (EMG) analysis using standardized methods. Nine stroke patients performed three sets of isotonic elbow extensions at 30% of their maximal voluntary isometric torque followed by three sets of maximal isokinetic elbow extensions with standardization of mean angular velocity and the total amount of work for each matched set in two strengthening modes. All exercises were done by using 1-DoF planner robot to regulate exact resistive torque and speed. Surface electromyographic activity of eight muscles in the hemiplegic shoulder and elbow was recorded. Normalized root mean square (RMS) values and co-contraction index (CCI) were used for the analysis. The isokinetic mode was shown to activate the agonists of elbow extension more efficiently than the isotonic mode (normalized RMS for pooled triceps: 96.0±17.0 (2nd), 87.8±14.4 (3rd) in isokinetic, 80.9±11.0 (2nd), 81.6±12.4 (3rd) in isotonic contraction, F[1,8]=11.168; P=0.010) without increasing the co-contraction of muscle pairs, implicating spasticity or synergy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Artificial Limbs

    Science.gov (United States)

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as ...

  20. Both Baseline and Change in Lower Limb Muscle Strength in Younger Women Are Independent Predictors of Balance in Middle Age: A 12-Year Population-Based Prospective Study.

    Science.gov (United States)

    Wu, Feitong; Callisaya, Michele; Wills, Karen; Laslett, Laura L; Jones, Graeme; Winzenberg, Tania

    2017-06-01

    Poor balance is a risk factor for falls and fracture in older adults, but little is known about modifiable factors affecting balance in younger women. This study aimed to examine whether lower limb muscle strength (LMS) in young women and changes in LMS are independent predictors of balance in middle age. This was an observational 10-year follow-up of 470 women aged 25 to 44 years at baseline who had previously participated in a 2-year population-based randomized controlled trial of osteoporosis education interventions. Linear regression was used to examine the association between baseline LMS (by dynamometer) and change in LMS over 12 years with balance at 12 years (timed up and go test [TUG], step test [ST], functional reach test [FRT], and lateral reach test [LRT]). LMS declined by a mean of 17.3 kg over 12 years. After adjustment for potential confounders, baseline and change in LMS were independently beneficially associated with TUG (β = -0.008 sec/kg, 95% confidence interval [CI] -0.01 to -0.006, and β = -0.006 sec/kg, 95% CI -0.009 to -0.003 for baseline and change, respectively), FRT (β = 0.057 cm/kg, 95% CI 0.030 to 0.084, and β = 0.071 cm/kg, 95% CI 0.042 to 0.101, respectively), and LRT (β = 0.030 cm/kg, 95% CI 0.012 to 0.049, and β = 0.022 cm/kg, 95% CI 0.002 to 0.043, respectively) 12 years later. There was an association between baseline LMS and ST (β = 0.044 steps/kg, 95% CI 0.022 to 0.067) but not between change in LMS and ST. Among young women, greater LMS at baseline and slower decline over time are both associated with better balance in midlife. Analogous to the contributions of peak bone mass and bone loss to fracture risk in older adults, this suggests that both improvement of muscle strength in younger age and prevention of age-related loss of muscle strength could be potentially useful strategies to improve balance and reduce falls in later life. © 2017 American Society for Bone and Mineral

  1. MR imaging in congenital lower limb deformities

    Energy Technology Data Exchange (ETDEWEB)

    Laor, T. [Dept. of Radiology, Children`s Hospital and Harvard Medical School, Boston, MA (United States); Jaramillo, D. [Dept. of Radiology, Children`s Hospital and Harvard Medical School, Boston, MA (United States); Hoffer, F.A. [Dept. of Radiology, Children`s Hospital and Harvard Medical School, Boston, MA (United States); Kasser, J.R. [Dept. of Orthopedics, Children`s Hospital and Harvard Medical School, Boston, MA (United States)

    1996-06-01

    Treatment for children with cogenital deformities of the lower extremities may vary, depending on the state of the unossified skeletal structures and surrounding soft tissues. The purpose of our study was to demonstrate the spectrum of the osteochondral and extrasosseous abnormalities as depicted with MR imaging. We retrospectively reviewed MR examinations of 13 limbs of ten children (aged 1 month-9 years, mean 2.1 years) with longitudinal and transverse deformities of the lower extremities. The lesions imaged were fibular hemimelia (n=5), tibial hemimelia (n=5), and congenital constriction bands (n=3). Each examination was assessed for abnormalities in the osteocartilaginous and extraosseous (articular or periarticular components such as ligaments, tendons, and menisci; the muscles and the arteries) structures. Abnormalities were seen in all patients. Osteocartilaginous abnormalities in the patients with longitudinal deformities included abnormal distal femoral epiphyses, abnormal proximal tribial physes, hypertrophied and dislocated proximal fibular epiphyses, unsuspected fibular and tibial remnants, and absence or coalition of the tarsal bones. No osteocartilaginous abnormalities were seen in the patients with congential constriction bands. Articular abormalities in patients with either form of hemimelia included absent cruciate ligaments and menisci, dislocated or absent cartilaginous patellae, absent patellar tendons, and abnormal collateral ligaments. All but one limb imaged had absent or attenuated muscle groups. Of the nine MR arteriograms performed at the level of the knee, eight were abnormal. The normal popliteal trifurcation was absent or in an abnormal location. We conclude that MR imaging of children with congenital lower extremity deformities shows many osteochondral and extraosseous abnormalities that are not depicted by conventional radiogrpahy. This information can help to plan early surgical intervention and prosthetic rehabilitation. (orig.)

  2. The organization and control of intra-limb anticipatory postural adjustments and their role in movement performance

    Directory of Open Access Journals (Sweden)

    Paolo Cavallari

    2016-10-01

    Full Text Available Anticipatory Postural Adjustments (APAs are commonly described as unconscious muscular activities aimed to counterbalance the perturbation caused by the primary movement, so as to ensure the whole-body balance, as well as contributing to initiate the displacement of the body centre of mass when starting gait or whole-body reaching movements. These activities usually create one or more fixation chains which spread over several muscles of different limbs, and may be thus called inter-limb APAs. However, it has been reported that APAs also precede voluntary movements involving tiny masses, like a flexion/extension of the wrist or even a brisk flexion of the index-finger. In particular, such movements are preceded by an intra-limb APA chain, that involves muscles acting on the proximal joints. Considering the small mass of the moving segments, it is unlikely that the ensuing perturbation could threaten the whole body balance, so that it is interesting to enquire the physiological role of intra-limb APAs and their organization and control compared to inter-limb APAs.This review is focused on intra-limb APAs and highlights a strict correspondence in their behaviour and temporal/spatial organization with respect to inter-limb APAs. Hence it is suggested that both are manifestations of the same phenomenon. Particular emphasis is given to intra-limb APAs preceding index finger flexion, because their relatively simple biomechanics and the fact that muscular actions were limited to a single arm allowed peculiar investigations, leading to important conclusions. Indeed, such paradigm provided evidence that by granting a proper fixation of those body segments proximal to the moving one APAs are involved in refining movement precision, and also that APAs and prime mover activation are driven by a shared motor command.

  3. Muscle biopsies off-set normal cellular signaling in surrounding musculature

    DEFF Research Database (Denmark)

    Krag, Thomas O; Hauerslev, Simon; Dahlqvist, Julia R

    2013-01-01

    muscle tissue for at least 3 weeks after the biopsy was performed and magnetic resonance imaging suggests that an effect of a biopsy may persist for at least 5 months. Cellular signaling after a biopsy resembles what is seen in severe limb-girdle muscular dystrophy type 2I with respect to protein......Studies of muscle physiology and muscular disorders often require muscle biopsies to answer questions about muscle biology. In this context, we have often wondered if muscle biopsies, especially if performed repeatedly, would affect interpretation of muscle morphology and cellular signaling. We...... hypothesized that muscle morphology and cellular signaling involved in myogenesis/regeneration and protein turnover can be changed by a previous muscle biopsy in close proximity to the area under investigation. Here we report a case where a past biopsy or biopsies affect cellular signaling of the surrounding...

  4. The anatomy and ontogeny of the head, neck, pectoral, and upper limb muscles of Lemur catta and Propithecus coquereli (primates): discussion on the parallelism between ontogeny and phylogeny and implications for evolutionary and developmental biology.

    Science.gov (United States)

    Diogo, Rui; Molnar, Julia L; Smith, Timothy D

    2014-08-01

    Most anatomical studies of primates focus on skeletal tissues, but muscular anatomy can provide valuable information about phylogeny, functional specializations, and evolution. Herein, we present the first detailed description of the head, neck, pectoral, and upper limb muscles of the fetal lemuriforms Lemur catta (Lemuridae) and Propithecus coquereli (Indriidae). These two species belong to the suborder Strepsirrhini, which is often presumed to possess some plesiomorphic anatomical features within primates. We compare the muscular anatomy of the fetuses with that of infants and adults and discuss the evolutionary and developmental implications. The fetal anatomy reflects a phylogenetically more plesiomorphic condition in nine of the muscles we studied and a more derived condition in only two, supporting a parallel between ontogeny and phylogeny. The derived exceptions concern muscles with additional insertions in the fetus which are lost in adults of the same species, that is, flexor carpi radialis inserts on metacarpal III and levator claviculae inserts on the clavicle. Interestingly, these two muscles are involved in movements of the pectoral girdle and upper limb, which are mainly important for activities in later stages of life, such as locomotion and prey capture, rather than activities in fetal life. Accordingly, our findings suggest that some exceptions to the "ontogeny parallels phylogeny" rule are probably driven more by ontogenetic constraints than by adaptive plasticity. © 2014 Wiley Periodicals, Inc.

  5. [Gait analysis after rotationplasty hip surgery for malignant tumor of the proximal femur].

    Science.gov (United States)

    Donati, D; Benedetti, M G; Catani, F; Berti, L; Capanna, R

    2004-10-01

    Rotationplasty of the hip joint is a special surgical technique used for the treatment of malignant tumors of the proximal part of the femur. We report a clinical case and gait analysis results before and after rehabilitation training. Evaluation of joint motion, kinetic moments, and the electromyographic findings enabled us to document progressive adaptation of muscle and joint function to their new role in the motor pattern, demonstrating the exceptional strength of rotationplasty. Active control of two fulcrums in the lower limb, the pseudo hip proximally and the pseudo knee intermedially, makes this type of operation extremely advantageous compared to the alternative of hip disarticulation or hemipelvectomy. Total absence of pain together with the preservation of articular and cutaneous proprioception are important advantages. Rotationplasty is an attractive alternative for treatment of malignant tumors of the proximal part of the femur.

  6. LEGS AND TRUNK MUSCLE HYPERTROPHY FOLLOWING WALK TRAINING WITH RESTRICTED LEG MUSCLE BLOOD FLOW

    Directory of Open Access Journals (Sweden)

    Mikako Sakamaki

    2011-06-01

    Full Text Available We examined the effect of walk training combined with blood flow restriction (BFR on the size of blood flow-restricted distal muscles, as well as, on the size of non-restricted muscles in the proximal limb and trunk. Nine men performed walk training with BFR and 8 men performed walk training alone. Training was conducted two times a day, 6 days/wk, for 3 wk using five sets of 2-min bouts (treadmill speed at 50 m/min, with a 1-min rest between bouts. After walk training with BFR, MRI-measured upper (3.8%, P < 0.05 and lower leg (3.2%, P < 0. 05 muscle volume increased significantly, whereas the muscle volume of the gluteus maximus (-0.6% and iliopsoas (1.8% and the muscle CSA of the lumber L4-L5 (-1.0 did not change. There was no significant change in muscle volume in the walk training alone. Our results suggest that the combination of leg muscle blood flow restriction with slow walk training elicits hypertrophy only in the distal blood flow restricted leg muscles. Exercise intensity may be too low during BFR walk training to increase muscle mass in the non- blood flow restricted muscles (gluteus maximus and other trunk muscles.

  7. Proximal Hypospadias

    Science.gov (United States)

    Kraft, Kate H.; Shukla, Aseem R.; Canning, Douglas A.

    2011-01-01

    Hypospadias results from abnormal development of the penis that leaves the urethral meatus proximal to its normal glanular position. Meatal position may be located anywhere along the penile shaft, but more severe forms of hypospadias may have a urethral meatus located at the scrotum or perineum. The spectrum of abnormalities may also include ventral curvature of the penis, a dorsally redundant prepuce, and atrophic corpus spongiosum. Due to the severity of these abnormalities, proximal hypospadias often requires more extensive reconstruction in order to achieve an anatomically and functionally successful result. We review the spectrum of proximal hypospadias etiology, presentation, correction, and possible associated complications. PMID:21516286

  8. Limb-girdle muscular dystrophy type 2D: clinical and genetic analysis of a family

    Directory of Open Access Journals (Sweden)

    Li-yu OU

    2017-09-01

    Full Text Available Objective To study the characteristics and diagnosis of limb-girdle muscular dystrophy type 2D (LGMD2D. Methods The clinical characteristics, EMG, muscle MRI and muscle pathological studies of 2 female patients in a family with LGMD2D were analyzed. Genetic analysis was used in the diagnosis of this disease. The cases were reported along with related literatures review. Results The onset of the proband and her younger sister occurred at 3 years old with progressive proximal muscle weakness of four limbs as the main clinical manifestation. The serum creatine kinase (CK was significantly high (> 50 × 10 3 U/L. EMG showed myogenic damage. Muscle MRI indicated partial muscle atrophy, fatness or fiber edema. Muscle pathological examination of the proband's younger sister revealed skeletal muscle necrosis and focal regeneration, partial striated muscle disappearance, and the muscle fibers in different sizes. Sequencing of all 10 coding exons of the SGCA gene in 2 patients revealed the same mutation: a c.262delT (p.Phe88SerfsX123 frameshift mutation in exon 3 and a c.409G > A (p.Glu137Lys missense mutation in exon 5. Their mother was a carrier of SGCA gene c.409G > A (p.Glu137Lys mutation. c.409G > A (p.Glu137Lys is a mutation already found, and c.262delT (p.Phe88SerfsX123 is a novel mutation. The proband's father did not take the genetic test for some reason. Conclusions In case of a female with Duchenne muscular dystrophy (DMD.like symptom, if she has been excluded from the DMD gene carrier, pedigree analysis and genetic analysis involving limb . girdle muscular dystrophy (LGMD should be conducted to facilitate the diagnosis of the LGMD and its subtypes. DOI: 10.3969/j.issn.1672-6731.2017.08.010

  9. Thoracic limb morphology of the red panda (Ailurus fulgens evidenced by osteology and radiography

    Directory of Open Access Journals (Sweden)

    Modesta Makungu

    2015-02-01

    Full Text Available The red panda (Ailurus fulgens is distributed primarily in the Himalayas and southern China. It is classified as a vulnerable species by the International Union for Conservation of Nature. The aim of this study was to describe the normal osteology and radiographic anatomy of the thoracic limb of the red panda. Radiography of the right thoracic limb was performed in seven captive adult red pandas. Radiographic findings were correlated with bone specimens from three adult animals. The scapula was wide craniocaudally and presented with a large area for the origin of the teres major muscle. The square-shaped major tubercle did not extend proximal to the head of the humerus. The medial epicondyle was prominent. A supracondylar foramen was present. The radial tuberosity and sesamoid bone for the abductor digiti I longus were prominent. The accessory carpal bone was directed palmarolaterally. Metacarpal bones were widely spread. The thoracic limb morphology of the red panda evidenced by osteology and radiography indicated flexibility of the thoracic limb joints and well-developed flexor and supinator muscles, which are important in arboreal quadrupedal locomotion. Knowledge gained during this study may prove useful in identifying skeletal material or remains and diagnosing musculoskeletal diseases and injuries of the thoracic limb.

  10. Thoracic limb morphology of the red panda (Ailurus fulgens) evidenced by osteology and radiography.

    Science.gov (United States)

    Makungu, Modesta; Groenewald, Hermanus B; du Plessis, Wencke M; Barrows, Michelle; Koeppel, Katja N

    2015-07-15

    The red panda (Ailurus fulgens) is distributed primarily in the Himalayas and southern China. It is classified as a vulnerable species by the International Union for Conservation of Nature. The aim of this study was to describe the normal osteology and radiographic anatomy of the thoracic limb of the red panda. Radiography of the right thoracic limb was performed in seven captive adult red pandas. Radiographic findings were correlated with bone specimens from three adult animals. The scapula was wide craniocaudally and presented with a large area for the origin of the teres major muscle. The square-shaped major tubercle did not extend proximal to the head of the humerus. The medial epicondyle was prominent. A supracondylar foramen was present. The radial tuberosity and sesamoid bone for the abductor digiti I longus were prominent. The accessory carpal bone was directed palmarolaterally. Metacarpal bones were widely spread. The thoracic limb morphology of the red panda evidenced by osteology and radiography indicated flexibility of the thoracic limb joints and well-developed flexor and supinator muscles, which are important in arboreal quadrupedal locomotion. Knowledge gained during this study may prove useful in identifying skeletal material or remains and diagnosing musculoskeletal diseases and injuries of the thoracic limb.

  11. The upper-limb volumetric changes in breast cancer survivors with axillary web syndrome.

    Science.gov (United States)

    Huang, H-C; Liu, H-H; Yin, L-Y; Yeh, C-H; Tu, C-W; Yang, C-S

    2017-03-01

    Whether upper-limb swelling is associated with axillary web syndrome (AWS) is unknown. We recruited unilateral breast cancer (BC) patients who were scheduled for surgical intervention and lymph node dissection. The pre-operative assessment and post-operative assessment 3-4 weeks after surgery evaluated the upper-limb circumferential measurements, segmental limb volume, pain scores, grasp, shoulder range of motion (ROM), shoulder muscle power and quality-of-life scores. In the control group, the peri-elbow volume and upper-arm volume were significantly higher post-operatively than pre-operatively. In the AWS group, no significant difference was found. In comparison with the control group, the AWS group had significantly more pain, less active ROM in shoulder abduction and a lower upper-limb volume at 0-10 cm proximal to the lateral epicondyle. The incidence of lymphedema was 9.9% and was not associated with AWS. AWS is a common morbidity of lymph node dissection and causes significant pain and restricted shoulder abduction in the affected limb in BC survivors. This study is the first to investigate post-operative upper-limb volumetric changes in BC survivors with and without AWS. Our findings are of great value for the clinical effect of AWS in BC survivors, for patient education, and for developing diagnostic tools for detecting AWS. © 2017 John Wiley & Sons Ltd.

  12. The effect of a trampoline-based training program on the muscle strength of the inferior limbs and motor proficiency in children with autism spectrum disorders

    National Research Council Canada - National Science Library

    Carla Lourenço; Dulce Esteves; Rui Corredeira; André Seabra

    2015-01-01

    ...). The main goal of this study was to evaluate the effects of a trampoline-based training program, over a period of 32 weeks, on both the muscular strength of inferior limbs and the motor proficiency in children with ASD...

  13. "An Investigation Into The Interrater Reliability Of The Modified Ashworth Scale In The Assessment Of Muscle Spasticity In Hemiplegic Patients "

    Directory of Open Access Journals (Sweden)

    N. Nokhostin-Ansari

    2006-06-01

    Full Text Available Background and Aim: Spasticity is a velocity-dependent increase in tonic stretch reflexes (muscle tone with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex. The measurement of spasticity is necessary to determine the effect of treatments. The Modified Ashworth Scale is the most widely used method for assessing muscle spasticity in clinical practice and research. The purpose of this study was to investigate the interrater reliability of Modified Ashworth Scale in hemiplegic patients. Materials and Methods: Thirty subjects (16 males, 14 females with a mean age of 59.40 (SD =14.013 recruited. Shoulder adductor , elbow flexor , wrist dorsiflexor , hip adductor , knee extensor and ankle plantarflexor on the hemiplegic side were tested by two physiotherapists. Results: In the upper limb, the interrater reliability for shoulder adductor and elbow flexor muscles was fair (0.372 and 0.369, respectively. The reliability for the wrist flexors was good (0.612. The difference in Kappa value for the proximal muscle (shoulder adductor; 0.372 and the distal muscle (wrist flexor; 0.612 was significant (²X=33.87, df=1, p0.05. The mean value for the upper limb (0.505 and the lower limb (0,.516 was not significantly different (²X=0.1407, df=1, p>0.05. Conclusion: The interrater reliability of Modified Ashworth Scale was not good . The limb, upper or lower, had no significant effect on the reliability. In the upper limb, the reliability for the proximal and distal muscle was significantly different. However. The difference in the lower limb was not significant.When using the scale, one should consider it's limitation.

  14. Lower limb muscle magnetic resonance imaging in myotonic dystrophy type 1 correlates with the six-minute walk test and CTG repeats.

    Science.gov (United States)

    Park, Donghwi; Lee, Sang-Hoon; Shin, Jin-Hong; Park, Jin-Sung

    2018-01-01

    The aim of this study was to elucidate correlations among clinical, genetic, and magnetic resonance imaging (MRI) data of muscles in myotonic dystrophy type 1 (DM1). We retrospectively reviewed the medical records and images of nineteen patients with DM1 from different families. We retrieved the genetic data (CTG repeats) and the clinical data, which included disease duration, creatine kinase level, sum score of manual muscle testing, modified Medical Research Council sum score, and the six-minute walk test results (6MWT). The correlation analyses showed a statistically significant correlation between the modified Medical Research Council sum score and CTG repeat numbers. Among the lower extremity muscles, 6MWT correlated most with the sum of the ankle plantar-flexors (the soleus, medial, and lateral gastrocnemius muscles). Compared to the other plantar-flexor muscles, the soleus muscle presented the highest correlation with the 6MWT. Additionally, our results showed that the CTG repeat numbers did not correlate with the 6MWT. However, it correlated with the modified Medical Research Council sum score. The ankle plantar-flexor muscles were the most severely affected muscles revealed in the whole body MRI, and presented statistically significant correlation with the 6MWT. Among the plantar-flexor muscles, the soleus muscle most influenced the 6MWT. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Use of MRI for volume estimation of tibialis posterior and plantar intrinsic foot muscles in healthy and chronic plantar fasciitis limbs.

    Science.gov (United States)

    Chang, Ryan; Kent-Braun, Jane A; Hamill, Joseph

    2012-06-01

    Due to complexity of the plantar intrinsic foot muscles, little is known about their muscle architecture in vivo. Chronic plantar fasciitis may be accompanied by muscle atrophy of plantar intrinsic foot muscles and tibialis posterior compromising the dynamic support of the foot prolonging the injury. Magnetic resonance images of the foot may be digitized to quantify muscle architecture. The first purpose of this study was to estimate in vivo the volume and distribution of healthy plantar intrinsic foot muscles. The second purpose was to determine whether chronic plantar fasciitis is accompanied by atrophy of plantar intrinsic foot muscles and tibialis posterior. Magnetic resonance images were taken bilaterally in eight subjects with unilateral plantar fasciitis. Muscle perimeters were digitally outlined and muscle signal intensity thresholds were determined for each image for volume computation. The mean volume of contractile tissue in healthy plantar intrinsic foot muscles was 113.3 cm(3). Forefoot volumes of plantar fasciitis plantar intrinsic foot muscles were 5.2% smaller than healthy feet (P=0.03, ES=0.26), but rearfoot (P=0.26, ES=0.08) and total foot volumes (P=0.07) were similar. No differences were observed in tibialis posterior size. While the total volume of plantar intrinsic foot muscles was similar in healthy and plantar fasciitis feet, atrophy of the forefoot plantar intrinsic foot muscles may contribute to plantar fasciitis by destabilizing the medial longitudinal arch. These results suggest that magnetic resonance imaging measures may be useful in understanding the etiology and rehabilitation of chronic plantar fasciitis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. The motor cortex and its role in phantom limb phenomena.

    Science.gov (United States)

    Reilly, Karen T; Sirigu, Angela

    2008-04-01

    Limb amputation results in plasticity of connections between the brain and muscles; the cortical motor representation of the missing limb seemingly disappears. The disappearance of the hand's motor representation is, however, difficult to reconcile with evidence that a perceptual representation of the missing limb persists in the form of a phantom limb endowed with sensory and motor qualities. Here, we argue that despite considerable reorganization within the motor cortex of upper-limb amputees, the representation of the amputated hand does not disappear. We hypothesize that two levels of hand-movement representation coexist within the primary motor cortex; at one level, limb movements are specified in terms of arm and hand motor commands, and at another level, limb movements are specified as muscles synergies. We propose that primary motor cortex reorganization after amputation concerns primarily the upper limb's muscular map but not its motor command map and that the integrity of the motor command map underlies the existence of the phantom limb.

  17. Use of extended curettage with osteotomy and fenestration followed by reconstruction with conservation of muscle insertion in the treatment of Enneking stage II locally aggressive bone tumor of the proximal extremities: resection and treatment of bone tumors

    Science.gov (United States)

    2013-01-01

    Background The purpose of this study was to investigate the clinical efficacy of extended resection with osteotomy, fenestration and conservation of muscle (tendon) insertion in the treatment of bone tumors. Methods A total of 15 patients with locally aggressive bone tumors (Enneking stage II) in the adjacent muscle (tendon) insertion of the proximal extremity were enrolled in the present study (mean age of 29 years). Extended curettage of lesions with osteotomy, fenestration and/or conservation of muscle (tendon) insertion and internal fixation with a bone graft or bone cement was performed at stage I. Postsurgical brace protection was used for 4 to 12 weeks and the patients were periodically followed-up by X-ray and functional assessment. Recurrence, postsurgical Enneking score and outcome rating were assessed. Results Treated cases included 15 patients aged 29 ±7.75 years (range, 18 to 42) with a male to female ratio of 8:7. Six had a femoral tumor and nine had a humeral tumor. These tumors comprised three chondroblastomas, five giant-cell tumors and seven aneurysmal bone cysts. Follow-up for 48 ±12.95 months (range, 25 to 72) revealed that 13 of 15 (87%) patients exhibited no recurrence. Local recurrence was observed in a patient with an aneurysmal bone cyst (nine months) and one with a giant-cell tumor (12 months). Mean Enneking scores were 27 ±4.07 (range, 18 to 29). Except for the patient with the recurrent giant-cell tumor, all patients reported good (13%, 2 out of 15) or very good (80%, 12 out of 15) outcomes. Very good outcomes were reported in 92% of patients (12 out of 13) without recurrence. Conclusions The procedures used in this study achieved high clinical efficacy, complete lesion removal, reduced recurrence and good restoration of joint function in patients with primary locally aggressive Enneking stage II bone tumors of the proximal extremities. PMID:23497479

  18. A newly recognized autosomal dominant limb girdle muscular dystrophy with cardiac involvement

    NARCIS (Netherlands)

    van der Kooi, A. J.; Ledderhof, T. M.; de Voogt, W. G.; Res, C. J.; Bouwsma, G.; Troost, D.; Busch, H. F.; Becker, A. E.; de Visser, M.

    1996-01-01

    Sixty-five members of three families with limb girdle muscular dystrophy (LGMD) underwent neurological, cardiological, and ancillary investigations. Thirty-five individuals were diagnosed as having slowly progressive autosomal dominant LGMD. Symmetrical weakness started in the proximal lower limb

  19. Age-related differences in lower-limb muscle cross-sectional area and torque production in boys with Duchenne muscular dystrophy.

    Science.gov (United States)

    Mathur, Sunita; Lott, Donovan J; Senesac, Claudia; Germain, Sean A; Vohra, Ravneet S; Sweeney, H Lee; Walter, Glenn A; Vandenborne, Krista

    2010-07-01

    To examine the relationship between lower-extremity muscle cross-sectional area, muscle strength, specific torque, and age in ambulatory boys with Duchenne muscular dystrophy (DMD) compared with controls. Observational cross-sectional study. University research setting. Volunteer sample of boys with DMD (n=22) and healthy control boys (n=10), ages 5 through 14 years. Not applicable. Maximal muscle cross-sectional area (CSA(max)) assessed by magnetic resonance imaging of quadriceps, plantarflexors (PFs) and dorsiflexors (DFs), peak isometric torque from dynamometry, and timed functional tests. The average CSA(max) of the triceps surae muscle group was approximately 60% higher in boys with DMD compared with controls (39.1+/-13.6 cm(2) vs 24.5+/-9.3 cm(2); P=.002), while the tibialis anterior muscle showed age-appropriate increases in CSA(max). The increase in quadriceps CSA(max) was also distinctly different in boys with DMD compared with controls. Specific torque (ie, peak torque/CSA(max)) was impaired in all 3 muscles groups, with the knee extensor (KE) and PF muscles showing 4-fold, and the DF muscles 2-fold, higher values in controls compared with boys with DMD. Large age-related gains in specific torque were observed in all 3 muscle groups of control subjects, which were absent in ambulatory boys with DMD. Correlations were observed between performance on functional tasks and quadriceps and PF torque production (r=-.45 to -.57, Pmuscle cross-sectional area and specific torque production in lower-extremity muscles showed distinctly different patterns in the KE, PF, and DF muscles of boys with DMD compared with controls. Copyright 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  20. Ground Reaction Force in Sit-to-stand Movement Reflects Lower Limb Muscle Strength and Power in Community-dwelling Older Adults

    Directory of Open Access Journals (Sweden)

    Taishi Tsuji

    2015-06-01

    Conclusion: Ground reaction force parameters in an STS movement can accurately reflect the dynamic strength and power in the lower limbs, which is approximately equal to or better than the strength and power reflected by the five-times STS test.

  1. Muscle strength measurements and functional outcome of an untreated complete distal rectus femoris muscle tear.

    Science.gov (United States)

    Figved, Wender; Grindem, Hege; Aaberg, Morten; Engebretsen, Lars

    2014-11-05

    A 46-year-old man sustained an injury to his right thigh while skiing. He sought medical advice after 6 weeks, presenting a palpable painful mass of his anterior proximal thigh but no functional deficit. An isolated complete distal intrasubstance tear of the rectus femoris muscle was diagnosed on ultrasound and MRI scans, and the patient received no medical treatment. Functional and dynamometer tests after 1 year showed high limb symmetry indexes and only slightly reduced values for peak torque and total work on the injured side. The patient had resumed skiing activities and reported slight pain after intense downhill skiing runs, but no functional limitations. MRI scans after 19 months showed increased retraction of the rectus femoris muscle. The natural history of an untreated complete distal rectus femoris muscle tear with no functional deficit may result in minimal disability. 2014 BMJ Publishing Group Ltd.

  2. Patient-specific analyses of deep tissue loads post transtibial amputation in residual limbs of multiple prosthetic users.

    Science.gov (United States)

    Portnoy, S; Siev-Ner, I; Shabshin, N; Kristal, A; Yizhar, Z; Gefen, A

    2009-12-11

    Active transtibial amputation (TTA) patients are at risk for developing pressure ulcers (PU) and deep tissue injury (DTI) while using their prosthesis. It is therefore important to obtain knowledge of the mechanical state in the internal soft tissues of the residuum, as well as knowledge of the mechanical state upon its surface. Our aim was to apply patient-specific MRI-based non-linear finite element (FE) models to quantify internal strains in TTA prosthetic users (n=5) during load-bearing. By further employing a strain injury threshold for skeletal muscle, we identified patients susceptible to DTI. The geometrical characteristics of the residuum of the TTA participants varied substantially between patients, e.g. the residuum lengths were 7.6, 8.1, 9.2, 11.5 and 13.3cm. We generally found that internal strains were higher in the bone proximity than in the muscle flap periphery. The highest strains, which in some patients exceeded 50% (engineering strain) for compressive, tensile and shear strains, were found in the shortest residual limbs, i.e. the 7.6 and 8.1cm-long limbs. Correspondingly, the lowest strains were found in the 13.3cm-long residuum, which had the bulkiest muscle flap. Yet, even in the case of a long residuum, about a third of the soft tissue volume at the distal tibial proximity area was occupied by large (>5%) internal compressive, tensile and shear strains. For both patients with shorter residual limbs, the internal principal compressive strains above 5% occupied almost the entire distal tibial proximity area. For a patient whose distal tibial end was flat (non-beveled), internal strains were more uniformly distributed, compared to the strain distributions in the other models, where focal elevated strains accumulated in the bone proximity. We found no muscle strains above the immediate injury threshold, indicating that all patients were not at immediate risk for DTI. Two patients whose residuum fat padding was minimal to none, were the only ones

  3. Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy.

    Science.gov (United States)

    Diogo, Rui; Esteve-Altava, Borja; Smith, Christopher; Boughner, Julia C; Rasskin-Gutman, Diego

    2015-01-01

    How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues

  4. Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy.

    Directory of Open Access Journals (Sweden)

    Rui Diogo

    Full Text Available How do the various anatomical parts (modules of the animal body evolve into very different integrated forms (integration yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA, to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs and diverse or complex tissue composition (e.g. bones, cartilages and muscles, by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are

  5. Proximal focal femoral deficiency in Ibadan a developing country's ...

    African Journals Online (AJOL)

    Prof Ezechukwu

    2011-06-09

    Jun 9, 2011 ... The major problems are limb length inequality and variable inadequacy of the proximal femoral musculature and hip joint. Treatment is indicated and ranges from amputation and prosthetic rehabilitation to limb salvage, lengthening, and hip re- construction. Until the early 1960s, treatment for PFFD at the St.

  6. Unilateral proximal focal femoral deficiency, fibular aplasia, tibial ...

    African Journals Online (AJOL)

    ... dominant mutation with possible gonadal mosaicism and with variable expression in the family, as limb anomaly in one child and cyanotic congenital heart disease in another child. Keywords: Short femur; Limb anomaly; FFU syndrome; Proximal focal femoral deficiency; Fibular aplasia; Tibial campomelia; Oligosyndactyly ...

  7. Local sensation changes and altered hip muscle function following severe ankle sprain.

    Science.gov (United States)

    Bullock-Saxton, J E

    1994-01-01

    Changes in sensory information have been shown to influence muscle function locally. Some clinicians, however, believe that the influence may be more extensive. To investigate this clinical concept, subjects with severe ankle sprain were assessed for local sensation changes and proximal hip/back muscle function. Of a total of 361 potential subjects whose medical histories were assessed, 20 men (age 18-35 years) who had previously sustained a severe unilateral ankle sprain and 11 matched "control" subjects with no previous lower-limb injury participated in the study. Using this experimental model, tests of vibration sensation in the ankle (indicating sensation changes) as well as surface electromyography of muscle recruitment patterns for hip extension (indicating muscle function proximally) of the biceps femoris, gluteus maximus, and lumbar erector spinae muscles were made on both sides of the unilaterally injured and matched control subjects. Significant decreases in vibration perception and significant delays in gluteus maximus muscle recruitment during hip extension were found in the injured group. The author concludes that both local sensory and proximal muscle function changes are associated with unilateral severe ankle sprain.

  8. Poststroke hypertonicity: upper limb assessment and treatment.

    Science.gov (United States)

    Marciniak, Christina

    2011-01-01

    Hypertonicity is common in patients with upper limb dysfunction following hemiplegic stroke and is associated with greater impairment, worse function, and lower health-related quality of life. In addition to increased rest activity, abnormal patterns of muscle activation, such as spastic co-contraction, may contribute to disability. In the upper limb, flexor muscles are more commonly involved distally, and at the shoulder, spasticity of adductors, flexors, and internal rotators is most often observed. Prior to interventions, a history regarding prior interventions, comorbid diagnoses, and limitations imposed by abnormal tone should be elicited. Commonly used scales to assess hypertonicity include the Modified Ashworth, the Modified Tardieu, the Spasm Frequency, the Disability Assessment, the Fugl-Meyer, and the Motor Assessment Scales. Treatment interventions for upper limb hypertonicity include stretching, splinting, strengthening of antagonist muscles, oral medications, and focal injections (phenol or botulinum toxins). Intrathecal baclofen may also impact upper limb tone. For focal injections, correct identification of muscles contributing to problematic tone is evaluated by eliciting resistance to movement at rest and observation of patterns of tightness as the limb is used functionally. The botulinum toxins have been shown to decrease tone in stroke survivors and improve active and passive functioning. Because secondary changes such as contractures and weakness may occur with prolonged hypertonicity, therapy to improve range of motion, strengthen weakened muscles, and incorporate use of the limb should be considered following focal injections, oral medications, or intrathecal pump placement.

  9. The Mouse Limb Anatomy Atlas: An interactive 3D tool for studying embryonic limb patterning

    OpenAIRE

    DeLaurier April; Burton Nicholas; Bennett Michael; Baldock Richard; Davidson Duncan; Mohun Timothy J; Logan Malcolm PO

    2008-01-01

    Abstract Background The developing mouse limb is widely used as a model system for studying tissue patterning. Despite this, few references are available that can be used for the correct identification of developing limb structures, such as muscles and tendons. Existing textual references consist of two-dimensional (2D) illustrations of the adult rat or mouse limb that can be difficult to apply when attempting to describe the complex three-dimensional (3D) relationship between tissues. Result...

  10. Biomechanical behavior of human crural fascia in anterior and posterior regions of the lower limb.

    Science.gov (United States)

    Pavan, Piero G; Pachera, Paola; Stecco, Carla; Natali, Arturo N

    2015-10-01

    The present work focuses on the numerical modeling of the mechanical behavior of the crural fascia, the deep fascia enwrapping the lower limb muscles. This fascia has an important biomechanical role, due to its interaction with muscles during contraction and its association with pathological events, such as compartment syndrome. The mechanical response of the crural fascia is described by assuming a hyperelastic fiber-reinforced constitutive model, with families of fibers disposed according to the spatial disposition of the collagen network, as shown in histological analyses. A two-dimensional finite element model of a lower limb transversal section has been developed to analyze deformational behavior, with particular attention on interaction phenomena between crural fascia and enwrapped muscles. The constitutive model adopted for the crural fascia well fits experimental data taken along the proximal-distal and medial-lateral directions. The finite element analysis allows for interpreting the relation between change in volume and pressure of muscle compartments and the crural fascia deformation.

  11. Proximal Tibia Reconstruction After Bone Tumor Resection: Are Survivorship and Outcomes of Endoprosthetic Replacement and Osteoarticular Allograft Similar?

    National Research Council Canada - National Science Library

    Albergo, Jose I; Gaston, Czar L; Aponte-Tinao, Luis A; Ayerza, Miguel A; Muscolo, D Luis; Farfalli, Germán L; Jeys, Lee M; Carter, Simon R; Tillman, Roger M; Abudu, Adesegun T; Grimer, Robert J

    2017-01-01

    ...) limb salvage reconstruction failures and risk of amputation of the limb; (2) causes of failure; and (3) functional results.Between 1990 and 2012, two oncologic centers treated 385 patients with proximal tibial resections and reconstruction...

  12. The neural response properties and cortical organization of a rapidly adapting muscle sensory group response that overlaps with the frequencies that elicit the kinesthetic illusion.

    Science.gov (United States)

    Marasco, Paul D; Bourbeau, Dennis J; Shell, Courtney E; Granja-Vazquez, Rafael; Ina, Jason G

    2017-01-01

    Kinesthesia is the sense of limb movement. It is fundamental to efficient motor control, yet its neurophysiological components remain poorly understood. The contributions of primary muscle spindles and cutaneous afferents to the kinesthetic sense have been well studied; however, potential contributions from muscle sensory group responses that are different than the muscle spindles have not been ruled out. Electrophysiological recordings in peripheral nerves and brains of male Sprague Dawley rats with a degloved forelimb preparation provide evidence of a rapidly adapting muscle sensory group response that overlaps with vibratory inputs known to generate illusionary perceptions of limb movement in humans (kinesthetic illusion). This group was characteristically distinct from type Ia muscle spindle fibers, the receptor historically attributed to limb movement sensation, suggesting that type Ia muscle spindle fibers may not be the sole carrier of kinesthetic information. The sensory-neural structure of muscles is complex and there are a number of possible sources for this response group; with Golgi tendon organs being the most likely candidate. The rapidly adapting muscle sensory group response projected to proprioceptive brain regions, the rodent homolog of cortical area 3a and the second somatosensory area (S2), with similar adaption and frequency response profiles between the brain and peripheral nerves. Their representational organization was muscle-specific (myocentric) and magnified for proximal and multi-articulate limb joints. Projection to proprioceptive brain areas, myocentric representational magnification of muscles prone to movement error, overlap with illusionary vibrational input, and resonant frequencies of volitional motor unit contraction suggest that this group response may be involved with limb movement processing.

  13. Maternal creatine supplementation during pregnancy prevents acute and long-term deficits in skeletal muscle after birth asphyxia: a study of structure and function of hind limb muscle in the spiny mouse.

    Science.gov (United States)

    LaRosa, Domenic A; Ellery, Stacey J; Snow, Rod J; Walker, David W; Dickinson, Hayley

    2016-12-01

    Maternal antenatal creatine supplementation protects the brain, kidney, and diaphragm against the effects of birth asphyxia in the spiny mouse. In this study, we examined creatine's potential to prevent damage to axial skeletal muscles. Pregnant spiny mice were fed a control or creatine-supplemented diet from mid-pregnancy, and 1 d before term (39 d), fetuses were delivered by c-section with or without 7.5 min of birth asphyxia. At 24 h or 33 ± 2 d after birth, gastrocnemius muscles were obtained for ex-vivo study of twitch-tension, muscle fatigue, and structural and histochemical analysis. Birth asphyxia significantly reduced cross-sectional area of all muscle fiber types (P birth protects the muscle from asphyxia-induced damage at birth.

  14. Clinical findings, treatment, and outcome in 11 dairy heifers with breakdown injury due to interosseous medius muscle rupture.

    Science.gov (United States)

    Nuss, Karl; Boppart, Jasmin; Geyer, Hans

    2017-02-01

    To describe the diagnosis, treatment, and prognosis of fetlock breakdown due to interosseus medius muscle rupture in cattle. Retrospective clinical study. Dairy heifers with unilateral or bilateral interosseus medius muscle rupture (n = 11). Breakdown injury due to rupture of the interosseus medius muscle was documented clinically, radiographically, and ultrasonographically. Breakdown was bilateral in 4 heifers (3 in forelimbs, 1 in hind limbs) and unilateral in 7 (all hind limbs). One heifer with severe bilateral hind limb breakdown was slaughtered and the remaining 10 were treated by transfixation pin cast (1 heifer), box rest (n = 2), and/or a cast and splint (7). Hyperextension of the fetlock and hyperflexion of the proximal interphalangeal joints during weight bearing were characteristic for interosseus muscle breakdown. Ultrasonographically, the origin and body of the interosseus muscle and the branches to the sesamoid bones were primarily affected by the rupture. Conservative treatment was successful (used for their intended purpose) in 8 of 9 heifers with a median lifespan of 32 months after discharge from the clinic (range 6-83). Rupture of the interosseus medius muscle in young cattle may be more common than previously suggested in the literature. Imaging with ultrasound allowed more detailed localization of lesions of the musculo-tendinous structure. Interosseus medius muscle rupture had a favorable prognosis when treated conservatively in these heifers. © 2017 The American College of Veterinary Surgeons.

  15. Muscle Bioenergetic Considerations for Intrinsic Laryngeal Skeletal Muscle Physiology

    Science.gov (United States)

    Sandage, Mary J.; Smith, Audrey G.

    2017-01-01

    Purpose: Intrinsic laryngeal skeletal muscle bioenergetics, the means by which muscles produce fuel for muscle metabolism, is an understudied aspect of laryngeal physiology with direct implications for voice habilitation and rehabilitation. The purpose of this review is to describe bioenergetic pathways identified in limb skeletal muscle and…

  16. Effect of enzyme replacement therapy on isokinetic strength for all major muscle groups in four patients with Pompe disease—a long-term follow-up

    DEFF Research Database (Denmark)

    Andreassen, Christer Swan; Schlütter, Jacob Mørup; Vissing, John

    2014-01-01

    Pompe disease is a rare, inherited metabolic myopathy characterized by progressive weakness of the proximal limb and respiratory muscles. We report the findings from four patients with late-onset Pompe disease treated with α-glucosidase (Myozyme) for 2 (n=2) and 6 (n=2) years, and monitored......, maximal isokinetic muscle strength increased by 11% (0%-50%) [median (range)] and 6MWT improved by 18% (2%-40%). In the two patients treated for 6years, the increase in muscle strength stabilized at 40% and 6MWT stabilized at 32%. The improvements primarily occurred during the first 6months of treatment...

  17. Extracellular Control of Limb Regeneration

    Science.gov (United States)

    Calve, S.; Simon, H.-G.

    Adult newts possess the ability to completely regenerate organs and appendages. Immediately after limb loss, the extracellular matrix (ECM) undergoes dramatic changes that may provide mechanical and biochemical cues to guide the formation of the blastema, which is comprised of uncommitted stem-like cells that proliferate to replace the lost structure. Skeletal muscle is a known reservoir for blastema cells but the mechanism by which it contributes progenitor cells is still unclear. To create physiologically relevant culture conditions for the testing of primary newt muscle cells in vitro, the spatio-temporal distribution of ECM components and the mechanical properties of newt muscle were analyzed. Tenascin-C and hyaluronic acid (HA) were found to be dramatically upregulated in the amputated limb and were co-expressed around regenerating skeletal muscle. The transverse stiffness of muscle measured in situ was used as a guide to generate silicone-based substrates of physiological stiffness. Culturing newt muscle cells under different conditions revealed that the cells are sensitive to both matrix coating and substrate stiffness: Myoblasts on HA-coated soft substrates display a rounded morphology and become more elongated as the stiffness of the substrate increases. Coating of soft substrates with matrigel or fibronectin enhanced cell spreading and eventual cell fusion.

  18. [Control study for muscle force and component of body of female patients with knee osteoarthritis].

    Science.gov (United States)

    Pang, Jian; Cao, Yue-long; Shi, Yin-yu; Zhou, Ji-wei; Wang, Xiang; Shi, Ying

    2008-11-01

    To understand the information of female patients with knee osteoarthritis regarding muscle force, constitution parameter. Thirty-seven cases diagnosed as knee osteoarthritis and 37 controls were examined by MES. T-test was used to analysis two groups differences of muscle force, constitution parameter, et al. Compared between affected limbs and controls limbs in patients revealed that the lower limb muscle distribution index of the affected limbs was higher than the control limbs (Pmuscle force, muscle functional index and muscle force of unit volume of the affected limbs were lower than the control limbs (Pmuscle force of both lower limbs, muscle functional index and muscle force of unit volume were lower than control group (Pmuscle force of lower limbs of female patients with knee osteoarthritis is weaker than healthy female. Muscle function disorder instead of muscle atrophy is the key cause of the weakness.

  19. Moderate exercise of rainbow trout induces only minor differences in fatty acid profile, texture, white muscle fibres and proximate chemical composition of fillets

    DEFF Research Database (Denmark)

    Rasmussen, Richard Skøtt; Heinrich, Maike Timm; Hyldig, Grethe

    2011-01-01

    g after nine weeks of experiment at 15.0 °C. The fatty acid composition in fillets differed only marginally between exercised fish (excF) and control fish (ctrlF) kept in standing water. ExcF fillets had a significantly lower content of fatty acids 16:0 (Pb0.05) and 18:1 (n−7) (Pb0.01) and a higher...... significantly among the two groups (Pb0.01