Anomalous bilateral contribution of extensor pollicis longus and muscle fusion of the first compartment of the wrist

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Rodrigo César Rosa

2016-04-01

Full Text Available Knowledge of the anatomical variations of the muscles of the first dorsal compartments of the wrist is clinically relevant to De Quervain's tenosynovitis and to reconstructive surgeries. In the literature, there are many reports of the presence of multiple insertion tendons in the first dorsal compartment of the wrist, but few reports describe occurrences of fusion and muscle contributions. This case report describes an anomalous bilateral contribution of the extensor pollicis longus. This anomalous contribution was found through a slender auxiliary tendon that crossed laterally under the extensor retinaculum, entered the first dorsal compartment of the wrist and merged with the tendon of the extensor pollicis brevis muscle. In the same cadaver in which this contribution was present, there was atypical muscle fusion of the abductor pollicis longus muscle and extensor pollicis brevis muscle. In conclusion, anomalous bilateral contribution of the extensor pollicis longus muscle and atypical muscle fusion, concomitant with a variant insertion pattern, are the highlight of this case report. Furthermore, it is concluded that additional tendons may be effectively used in reconstructive surgeries, but that there is a need for knowledge of the possible numerical and positional variations of these tendons, with a view to making more effective surgical plans.

Impact of Fat Infiltration in Cervical Extensor Muscles on Cervical Lordosis and Neck Pain: A Cross-Sectional Study.

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Kim, Choong-Young; Lee, Sang-Min; Lim, Seong-An; Choi, Yong-Soo

2018-06-01

Weakness of cervical extensor muscles causes loss of cervical lordosis, which could also cause neck pain. The aim of this study was to investigate the impact of fat infiltration in cervical extensor muscles on cervical lordosis and neck pain. Fifty-six patients who suffered from neck pain were included in this study. Fat infiltration in cervical extensor muscles was measured at each level of C2-3 and C6-7 using axial magnetic resonance imaging. The visual analogue scale (VAS), 12-Item Short Form Health Survey (SF-12), and Neck Disability Index (NDI) were used for clinical assessment. The mean fat infiltration was 206.3 mm 2 (20.3%) at C2-3 and 240.6 mm 2 (19.5%) at C6-7. Fat infiltration in cervical extensor muscles was associated with high VAS scores at both levels ( p = 0.047 at C2-3; p = 0.009 at C6-7). At C2-3, there was a negative correlation between fat infiltration of the cervical extensor muscles and cervical lordosis (r = -0.216; p = 0.020). At C6-7, fat infiltration in the cervical extensor muscles was closely related to NDI ( p = 0.003) and SF-12 ( p > 0.05). However, there was no significant correlation between cervical lordosis and clinical outcomes (VAS, p = 0.112; NDI, p = 0.087; and SF-12, p > 0.05). These results suggest that fat infiltration in the upper cervical extensor muscles has relevance to the loss of cervical lordosis, whereas fat infiltration in the lower cervical extensor muscles is associated with cervical functional disability.

Isokinetic Evaluation of the Hip Flexor and Extensor Muscles: A Systematic Review.

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Zapparoli, Fabricio Yuri; Riberto, Marcelo

2017-11-01

Isokinetic dynamometry testing is a safe and reliable method accepted as the "gold standard" in the evaluation of muscle strength in the open kinetic chain. Isokinetic hip examinations face problems in the standardization of the position of the equipment axis, in the individual being examined, and in the adjustment of the lever arm and in stabilization strategies for the patients during the tests. Identification of the methodologic procedures with best reproducibility is also needed. To review the literature to evaluate the parameters used for the isokinetic evaluation of the hip flexor and extensor muscles and its reproducibility. This is a systematic literature review of the Cochrane, LILACS, PEDro, PubMed, and SciELO databases. The inclusion criteria were articles on the evaluation of hip flexor and/or extensor muscular strength with an isokinetic dynamometer and articles that analyzed the ICC or Pearson's reproducibility. The information extracted was positioning of the patient; positioning of the dynamometer axis; positioning of the lever arm; angular speed; sample size, pathology; type of contraction; and ICC and Pearson's results. 204 articles were found, from which 14 were selected that evaluated hip flexor and extensor muscles, involving 550 individuals who were submitted to an isokinetic hip evaluation. Five articles obtained the best result in reproducibility and had their methodology analyzed. To obtain better reproducibility of the isokinetic evaluation of the hip flexor and extensor muscles, the following recommendations must be followed: the individual must be positioned in the supine position and the dynamometer axis must be aligned with the greater trochanter of the femur. The positioning of the lever arm must be in the most distal region of the thigh possible. The angular speed used to analyze torque peak and muscle work was 60°/s, and to evaluate the muscle power it was 180°/s, with concentric and eccentric contractions being analyzed.

Sex comparisons of non-local muscle fatigue in human elbow flexors and knee extensors

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Ye, Xin; Beck, Travis W.; Wages, Nathan P.; Carr, Joshua C.

2018-01-01

Objectives: To examine non-local muscle fatigue (NLMF) in both contralateral homologous and non-related heterogonous muscles for both sexes. Methods: Ten men and nine women participated in this study. After the familiarization visit, subjects completed four separate randomly sequenced experimental visits, during which the fatiguing interventions (six sets of 30-second maximal isometric contractions) were performed on either their right elbow flexors or knee extensors. Before (Pre-) and after (Post-) the fatiguing interventions, the isometric strength and the corresponding surface electromyographic (EMG) amplitude were measured for the non-exercised left elbow flexors or knee extensors. Results: For the non-exercised elbow flexors, the isometric strength decreased for both sexes (sex combined mean±SE: Pre vs. Post=339.67±18.02 N vs. 314.41±16.37 N; pisometric knee extension strength for men (Pre vs. Post =845.02±66.26 N vs. 817.39±67.64 N; p=0.019), but not for women. Conclusions: The presence of NMLF can be affected by factors such as sex and muscle being tested. Women are less likely to demonstrate NLMF in lower body muscle groups. PMID:29504584

''Dropped-head'' syndrome due to isolated myositis of neck extensor muscles: MRI findings

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Gaeta, Michele; Mazziotti, Silvio; Blandino, Alfredo [University of Messina, Department of Radiological Sciences, Messina (Italy); Toscano, Antonio; Rodolico, Carmelo; Mazzeo, Anna [University of Messina, Department of Neurosciences, Psychiatry and Anaesthesiology, Messina (Italy)

2006-02-15

MRI findings of a patient with dropped-head syndrome due to focal myositis of the neck extensor muscles are presented. MRI showed oedematous changes and marked enhancement of the neck extensor muscles. After therapy MRI demonstrated disappearance of the abnormal findings. (orig.)

Validity and test-retest reliability of a novel simple back extensor muscle strength test.

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Harding, Amy T; Weeks, Benjamin Kurt; Horan, Sean A; Little, Andrew; Watson, Steven L; Beck, Belinda Ruth

2017-01-01

To develop and determine convergent validity and reliability of a simple and inexpensive clinical test to quantify back extensor muscle strength. Two testing sessions were conducted, 7 days apart. Each session involved three trials of standing maximal isometric back extensor muscle strength using both the novel test and isokinetic dynamometry. Lumbar spine bone mineral density was examined by dual-energy X-ray absorptiometry. Validation was examined with Pearson correlations ( r ). Test-retest reliability was examined with intraclass correlation coefficients and limits of agreement. Pearson correlations and intraclass correlation coefficients are presented with corresponding 95% confidence intervals. Linear regression was used to examine the ability of peak back extensor muscle strength to predict indices of lumbar spine bone mineral density and strength. A total of 52 healthy adults (26 men, 26 women) aged 46.4 ± 20.4 years were recruited from the community. A strong positive relationship was observed between peak back extensor strength from hand-held and isokinetic dynamometry ( r  = 0.824, p  strength test, short- and long-term reliability was excellent (intraclass correlation coefficient = 0.983 (95% confidence interval, 0.971-0.990), p  strength measures with the novel back extensor strength protocol were -6.63 to 7.70 kg, with a mean bias of +0.71 kg. Back extensor strength predicted 11% of variance in lumbar spine bone mineral density ( p  strength ( p  strength is quick, relatively inexpensive, and reliable; demonstrates initial convergent validity in a healthy population; and is associated with bone mass at a clinically important site.

Low-level activity of the trunk extensor muscles causes electromyographic manifestations of fatigue in absence of decreased oxygenation

NARCIS (Netherlands)

Dieën, J.H. van; Westebring van der; Putten, E.P.; Kingma, I.; Looze, M.P. de

2009-01-01

This study was designed to determine whether trunk extensor fatigue occurs during low-level activity and whether this is associated with a drop in muscle tissue oxygenation. Electromyography (EMG) feedback was used to impose constant activity in a part of the trunk extensor muscles. We hypothesized

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

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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.

Measurement of maximal isometric torque and muscle quality of the knee extensors and flexors in healthy 50- to 70-year-old women.

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Francis, Peter; Toomey, Clodagh; Mc Cormack, William; Lyons, Mark; Jakeman, Philip

2017-07-01

Muscle quality is defined as strength per unit muscle mass. The aim of this study was to measure the maximal voluntary isometric torque of the knee extensor and flexor muscle groups in healthy older women and to develop an index of muscle quality based on the combined knee extensor and flexor torque per unit lean tissue mass (LTM) of the upper leg. One hundred and thirty-six healthy 50- to 70-year-old women completed an initial measurement of isometric peak torque of the knee extensors and flexors (Con-Trex MJ; CMV AG, Dubendorf, Switzerland) that was repeated 7 days later. Subsequently, 131 women returned for whole- and regional-body composition analysis (iDXA ™ ; GE Healthcare, Chalfont St Giles, Buckinghamshire, UK). Isometric peak torque demonstrated excellent within-assessment reliability for both the knee extensors and flexors (ICC range: 0·991-1·000). Test-retest reliability was lower (ICC range: 0·777-0·828) with an observed mean increase of 5% in peak torque [6·2 (17·2) N m] on the second day of assessment (Ptorque (-12·2%; P = 0·001) was double that of the relative, non-significant, median difference in upper leg LTM (-5·3%; P = 0·102) between those in the 5th and 6th decade. The majority of difference in peak isometric torque came from the knee extensors (15·1 N m, Ptorque normalized for upper leg LTM (muscle quality) was 8% lower between decades (P = 0·029). These findings suggest strength per unit tissue may provide a better indication of age-related differences in muscle quality prior to change in LTM. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

β-alanine supplementation improves isometric endurance of the knee extensor muscles

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Sale Craig

2012-06-01

Full Text Available Abstract Background We examined the effect of four weeks of β-alanine supplementation on isometric endurance of the knee extensors at 45% maximal voluntary isometric contraction (MVIC. Methods Thirteen males (age 23 ± 6 y; height 1.80 ± 0.05 m; body mass 81.0 ± 10.5 kg, matched for pre-supplementation isometric endurance, were allocated to either a placebo (n = 6 or β-alanine (n = 7; 6.4 g·d-1 over 4 weeks supplementation group. Participants completed an isometric knee extension test (IKET to fatigue, at an intensity of 45% MVIC, before and after supplementation. In addition, two habituation tests were completed in the week prior to the pre-supplementation test and a further practice test was completed in the week prior to the post-supplementation test. MVIC force, IKET hold-time, and impulse generated were recorded. Results IKET hold-time increased by 9.7 ± 9.4 s (13.2% and impulse by 3.7 ± 1.3 kN·s-1 (13.9% following β-alanine supplementation. These changes were significantly greater than those in the placebo group (IKET: t(11 = 2.9, p ≤0.05; impulse: t(11 = 3.1, p ≤ 0.05. There were no significant changes in MVIC force in either group. Conclusion Four weeks of β-alanine supplementation at 6.4 g·d-1 improved endurance capacity of the knee extensors at 45% MVIC, which most likely results from improved pH regulation within the muscle cell as a result of elevated muscle carnosine levels.

Muscle protein degradation and amino acid metabolism during prolonged knee-extensor exercise in humans

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Van Hall, Gerrit; Saltin, B; Wagenmakers, A J

1999-01-01

to a substantial increase in net muscle protein degradation, and that a lowering of the starting muscle glycogen content leads to a further increase. The carbon atoms of the branched-chain amino acids (BCAA), glutamate, aspartate and asparagine, liberated by protein degradation, and the BCAA and glutamate......The aim of this study was to investigate whether prolonged one-leg knee-extensor exercise enhances net protein degradation in muscle with a normal or low glycogen content. Net amino acid production, as a measure of net protein degradation, was estimated from leg exchange and from changes...... in the concentrations of amino acids that are not metabolized in skeletal muscle. Experiments were performed at rest and during one-leg knee-extensor exercise in six subjects having one leg with a normal glycogen content and the other with a low glycogen content. Exercise was performed for 90 min at a workload of 60...

Myofascial force transmission causes interaction between adjacent muscles and connective tissue: Effects of blunt dissection and compartmental fasciotomy on length force characteristics of rat extensor digitorum longus muscle

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Huijing, P.A.J.B.M.; Baan, G.C.

2001-01-01

Muscles within the anterior tibial compartment (extensor digitorum longus: EDL. tibialis anterior: TA, and extensor hallucis longus muscles: EHL) and within the peroneal compartment were excited simultaneously and maximally. The ankle joint was fixed kept at 90°. For EDL length force characteristics

Are fatigue-related EMG-parameters correlated to trunk extensor muscles fatigue induced by the Sörensen test?

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Demoulin Christophe; George, Florian; Matheve, Thomas; Jidovtseff, Boris; Vanderthommen, Marc

2016-01-01

The Sorensen test has been extensively studied and is a rapid, simple, and reproducible evaluation of the trunk extensor muscles [1]. It is often considered as a fatigue test because fatigue-related electromyographic (EMG) parameters change throughout the test [2]; however, only recently it has been confirmed that this test induces a decrease of trunk extensor force during a maximal voluntary contraction (MVC) [3], which best characterises muscle fatigue. The main aim of this stud...

Sex differences in muscle morphology of the knee flexors and knee extensors.

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Fearghal P Behan

Full Text Available Females experience higher risk of anterior cruciate ligament (ACL injuries; males experience higher risk of hamstring strain injuries. Differences in injury may be partially due to sex differences in knee flexor (KF to knee extensor (KE muscle size ratio and the proportional size of constituent muscles.To compare the absolute and proportional size, and mass distribution, of individual KE and KF muscles, as well as overall size and balance (size ratio of these muscle groups between the sexes.T1-weighted axial plane MR images (1.5T of healthy untrained young males and females (32 vs 34 were acquired to determine thigh muscle anatomical cross-sectional area (ACSA. Maximal ACSA (ACSAmax of constituent muscles, summated for KF and KE muscle groups, and the KF:KE ratio were calculated.Females had 25.3% smaller KE ACSAmax (70.9±12.1 vs 93.6±10.3 cm2; P<0.001 and 29.6% smaller KF ACSAmax than males (38.8±7.3cm2 vs 55.1±7.3cm2; P<0.001. Consequently, females had lower KF:KE ACSA ratio (P = 0.031. There were sex differences in the proportional size of 2/4 KE and 5/6 KF. In females, vastus lateralis (VL, biceps femoris long-head (BFlh and semimembranosus (SM were a greater proportion and sartorius (SA, gracilis (GR and biceps femoris short-head (BFsh a smaller proportion of their respective muscle groups compared to males (All P<0.05.Sex differences in KF:KE ACSAmax ratio may contribute to increased risk of ACL injury in females. Sex discrepancies in absolute and proportional size of SA, GR, VL and BFlh may contribute further anatomical explanations for sex differences in injury incidence.

Functional and morphological adaptations to aging in knee extensor muscles of physically active men.

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Baroni, Bruno Manfredini; Geremia, Jeam Marcel; Rodrigues, Rodrigo; Borges, Marcelo Krás; Jinha, Azim; Herzog, Walter; Vaz, Marco Aurélio

2013-10-01

It is not known if a physically active lifestyle, without systematic training, is sufficient to combat age-related muscle and strength loss. Therefore, the purpose of this study was to evaluate if the maintenance of a physically active lifestyle prevents muscle impairments due to aging. To address this issue, we evaluated 33 healthy men with similar physical activity levels (IPAQ = 2) across a large range of ages. Functional (torque-angle and torque-velocity relations) and morphological (vastus lateralis muscle architecture) properties of the knee extensor muscles were assessed and compared between three age groups: young adults (30 ± 6 y), middle-aged subjects (50 ± 7 y) and elderly subjects (69 ± 5 y). Isometric peak torques were significantly lower (30% to 36%) in elderly group subjects compared with the young adults. Concentric peak torques were significantly lower in the middle aged (18% to 32%) and elderly group (40% to 53%) compared with the young adults. Vastus lateralis thickness and fascicles lengths were significantly smaller in the elderly group subjects (15.8 ± 3.9 mm; 99.1 ± 25.8 mm) compared with the young adults (19.8 ± 3.6 mm; 152.1 ± 42.0 mm). These findings suggest that a physically active lifestyle, without systematic training, is not sufficient to avoid loss of strength and muscle mass with aging.

Muscle Torque and its Relation to Technique, Tactics, Sports Level and Age Group in Judo Contestants

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Lech, Grzegorz; Chwała, Wiesław; Ambroży, Tadeusz; Sterkowicz, Stanisław

2015-01-01

The aim of this study was to perform a comparative analysis of maximal muscle torques at individual stages of development of athletes and to determine the relationship between muscle torques, fighting methods and the level of sports performance. The activity of 25 judo contestants during judo combats and the effectiveness of actions were evaluated. Maximum muscle torques in flexors/extensors of the body trunk, shoulder, elbow, hip and knee joints were measured. The level of significance was set at p≤0.05; for multiple comparisons the Mann-Whitney U test, p≤0.016, was used. Intergroup differences in relative torques in five muscle groups studied (elbow extensors, shoulder flexors, knee flexors, knee extensors, hip flexors) were not significant. In cadets, relative maximum muscle torques in hip extensors correlated with the activity index (Spearman’s r=0.756). In juniors, maximum relative torques in elbow flexors and knee flexors correlated with the activity index (r=0.73 and r=0.76, respectively). The effectiveness of actions correlated with relative maximum torque in elbow extensors (r=0.67). In seniors, the relative maximum muscle torque in shoulder flexors correlated with the activity index during the second part of the combat (r=0.821). PMID:25964820

Muscle torque and its relation to technique, tactics, sports level and age group in judo contestants.

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Lech, Grzegorz; Chwała, Wiesław; Ambroży, Tadeusz; Sterkowicz, Stanisław

2015-03-29

The aim of this study was to perform a comparative analysis of maximal muscle torques at individual stages of development of athletes and to determine the relationship between muscle torques, fighting methods and the level of sports performance. The activity of 25 judo contestants during judo combats and the effectiveness of actions were evaluated. Maximum muscle torques in flexors/extensors of the body trunk, shoulder, elbow, hip and knee joints were measured. The level of significance was set at p≤0.05; for multiple comparisons the Mann-Whitney U test, p≤0.016, was used. Intergroup differences in relative torques in five muscle groups studied (elbow extensors, shoulder flexors, knee flexors, knee extensors, hip flexors) were not significant. In cadets, relative maximum muscle torques in hip extensors correlated with the activity index (Spearman's r=0.756). In juniors, maximum relative torques in elbow flexors and knee flexors correlated with the activity index (r=0.73 and r=0.76, respectively). The effectiveness of actions correlated with relative maximum torque in elbow extensors (r=0.67). In seniors, the relative maximum muscle torque in shoulder flexors correlated with the activity index during the second part of the combat (r=0.821).

Lumbar extensor muscle force control is associated with disability in people with chronic low back pain.

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Pranata, Adrian; Perraton, Luke; El-Ansary, Doa; Clark, Ross; Fortin, Karine; Dettmann, Tim; Brandham, Robert; Bryant, Adam

2017-07-01

The ability to control lumbar extensor force output is necessary for daily activities. However, it is unknown whether this ability is impaired in chronic low back pain patients. Similarly, it is unknown whether lumbar extensor force control is related to the disability levels of chronic low back pain patients. Thirty-three chronic low back pain and 20 healthy people performed lumbar extension force-matching task where they increased and decreased their force output to match a variable target force within 20%-50% maximal voluntary isometric contraction. Force control was quantified as the root-mean-square-error between participants' force output and target force across the entire, during the increasing and decreasing portions of the force curve. Within- and between-group differences in force-matching error and the relationship between back pain group's force-matching results and their Oswestry Disability Index scores were assessed using ANCOVA and linear regression respectively. Back pain group demonstrated more overall force-matching error (mean difference=1.60 [0.78, 2.43], Pback pain group demonstrated more force-matching error while increasing than decreasing force output (mean difference=1.74, Pback pain group (R 2 =0.19, P=0.006). Lumbar extensor muscle force control is compromised in chronic low back pain patients. Force-matching error predicts disability, confirming the validity of our force control protocol for chronic low back pain patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neck extensor muscle weakness (Dropped head syndrome) following radiotherapy

International Nuclear Information System (INIS)

Bhatia, S.; Miller, R.C.; Lachance, D.L.

2006-01-01

Background. Dropped head syndrome is an unusual condition in which the head cannot be held upright in its normal anatomic position secondary to pronounced, isolated, neck extensor muscle weakness. Case report. A case of dropped head syndrome in a female with a history of radiotherapy for Hodgkin's lymphoma and a clinical history consistent with multiple sclerosis is presented, and potential etiologies are discussed. Conclusions. Muscular atrophy and lower motor neuron injury secondary to isolated anterior horn cell injury from radiotherapy emerge as the most likely etiology. (author)

Proximal forearm extensor muscle strain is reduced when driving nails using a shock-controlled hammer.

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Buchanan, Kimberly A; Maza, Maria; Pérez-Vázquez, Carlos E; Yen, Thomas Y; Kijowski, Richard; Liu, Fang; Radwin, Robert G

2016-10-01

Repetitive hammer use has been associated with strain and musculoskeletal injuries. This study investigated if using a shock-control hammer reduces forearm muscle strain by observing adverse physiological responses (i.e. inflammation and localized edema) after use. Three matched framing hammers were studied, including a wood-handle, steel-handle, and shock-control hammer. Fifty volunteers were randomly assigned to use one of these hammers at a fatiguing pace of one strike every second, to seat 20 nails in a wood beam. Magnetic resonance imaging was used to scan the forearm muscles for inflammation before the task, immediately after hammering, and one to two days after. Electromyogram signals were measured to estimate grip exertions and localized muscle fatigue. High-speed video was used to calculate the energy of nail strikes. While estimated grip force was similar across the three hammers, the shock-control hammer had 40% greater kinetic energy upon impact and markedly less proximal extensor muscle edema than the wood-handle and steel-handle hammers, immediately after use (phandle shock can mitigate strain in proximal forearm extensor muscles. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electromyographic analysis of the vertebral extensor muscles during the Biering-Sorensen Test

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Ligia Moreira de Santana

2014-03-01

Full Text Available The purpose of the study was to analyze the electromyographic signal of the multifidus, longissimus thoracis and the lumbar iliocostalis muscles during the Biering-Sorensen test in subjects without lower back pain. Twenty volunteers performed the test on three separate occasions. An analysis of variance detected a difference between the three test times (p = 0.0026. For the frequency domain, it was observed that there were differences between the multifidus and the lumbar erectors muscles; longissimus and iliocostalis muscles. However, in the time domain analysis, no difference was observed. As the values of the slope coefficients of median frequencies were higher for the multifidus muscle, compared to the longissimus and lumbar iliocostalis muscles, this may indicate a higher tendency toward muscle fatigue. Therefore, considering the applied methodology, the study of electromyographic signals in the frequency domain should be considered as an instrument to assess fatigue of the spinal extensor muscles in clinical situations.

Humeral external rotation handling by using the Bobath concept approach affects trunk extensor muscles electromyography in children with cerebral palsy.

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Grazziotin Dos Santos, C; Pagnussat, Aline S; Simon, A S; Py, Rodrigo; Pinho, Alexandre Severo do; Wagner, Mário B

2014-10-20

This study aimed to investigate the electromyographic activity of cervical and trunk extensors muscles in children with cerebral palsy during two handlings according to the Bobath concept. A crossover trial involving 40 spastic diplegic children was conducted. Electromyography (EMG) was used to measure muscular activity at sitting position (SP), during shoulder internal rotation (IR) and shoulder external rotation (ER) handlings, which were performed using the elbow joint as key point of control. Muscle recordings were performed at the fourth cervical (C4) and at the tenth thoracic (T10) vertebral levels. The Gross Motor Function Classification System (GMFCS) was used to assess whether muscle activity would vary according to different levels of severity. Humeral ER handling induced an increase on EMG signal of trunk extensor muscles at the C4 (P=0.007) and T10 (P<0.001) vertebral levels. No significant effects were observed between SP and humeral IR handling at C4 level; However at T10 region, humeral IR handling induced an increase of EMG signal (P=0.019). Humeral ER resulted in an increase of EMG signal at both levels, suggesting increase of extensor muscle activation. Furthermore, the humeral ER handling caused different responses on EMG signal at T10 vertebra level, according to the GMFCS classification (P=0.017). In summary, an increase of EMG signal was observed during ER handling in both evaluated levels, suggesting an increase of muscle activation. These results indicate that humeral ER handling can be used for diplegic CP children rehabilitation to facilitate cervical and trunk extensor muscles activity in a GMFCS level-dependent manner. Copyright © 2014 Elsevier Ltd. All rights reserved.

Can a fatigue test of the isolated lumbar extensor muscles of untrained young men predict strength progression in a resistance exercise program?

NARCIS (Netherlands)

Helmhout, P.; Staal, B.; Dijk, J. van; Harts, C.; Bertina, F.; Bie, R. de

2010-01-01

AIM: The aim of this exploratory study was to investigate the predictive value of a fatigue test of the lumbar extensor muscles for training progression in a group of 28 healthy but predominantly sedentary male students, in an 8-week resistance exercise program. METHODS: A three-phased fatigue test

Trajectory of self-reported pain and function and knee extensor muscle strength in young patients undergoing arthroscopic surgery for meniscal tears: A systematic review and meta-analysis.

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Thorlund, Jonas Bloch; Østengaard, Lasse; Cardy, Nathan; Wilson, Fiona; Jørgensen, Claus; Juhl, Carsten Bogh

2017-08-01

To investigate the trajectory of patient reported pain and function and knee extensor muscle strength over time in young individuals undergoing arthroscopic meniscal surgery. Systematic review and meta-analysis METHODS: Six databases were searched up to October 13th, 2016. People aged 30 years or younger undergoing surgery for a meniscal tear. and comparator: (1) Self-reported pain and function in patients undergoing meniscal surgery compared to a non-operative control group (2). Knee extensor strength in the leg undergoing surgery compared to a healthy control group or the contra-lateral leg. Methodological quality was assessed using the SIGN 50 guidelines. No studies were found on patient reported pain and function. Six studies, including 137 patients were included in the analysis on knee extensor muscle strength. Knee extensor muscle strength was impaired in the injured leg prior to surgery and was still reduced compared with control data up to 12 months after surgery (SMD: -1.16) (95% CI: -1.83; -0.49). All included studies were assessed to have a high risk of bias. No studies were found comparing the trajectory of self-reported pain and function in patients undergoing arthroscopic surgery compared with non-operative treatments for young patients with meniscal tears. Knee extensor strength seemed to be impaired up to 12 months after surgery in young patients undergoing surgery for meniscal tears. The results of the present study should be interpreted with caution due to a limited number of available studies with high risk of bias including relatively few patients. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Clinical Significance of Presence of Extensor Indicis Brevis Manus – A Case Report

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N Esakkiammal

2017-11-01

Full Text Available Anatomical variations of additional muscles and tendons are commonly encountered in extensor aspect of forearm and hand during surgeries and dissections. There are reports on different kinds of variations like, extra tendons, additional bellies, and abnormal attachments of the muscle. Surgeons should have the knowledge about these variations for muscle or tendon grafting and also to plan surgeries. While dissecting the extensor compartment forearm and dorsum of hand of an elderly female cadaver, an anomalous muscle belly was noticed on dorsum of hand bilaterally alongwith the main tendon of extensor indicis muscle. This additional belly of extensor indicis muscle was called Extensor Indicis Brevis Manus (EIBM. This muscle originated from the dorsal carpal ligament and joined the main tendon of extensor indicis muscle in both the hands. Awareness of existence of this kind of variation is important for clinicians and surgeons for a correct diagnosis and eventual surgery in patients presenting with a cyst on the dorsum of hand, to avoid accidental mishaps.

Activation amplitude and temporal synchrony among back extensor and abdominal muscles during a controlled transfer task: comparison of men and women.

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Hubley-Kozey, Cheryl L; Butler, Heather L; Kozey, John W

2012-08-01

Muscle synergies are important for spinal stability, but few studies examine temporal responses of spinal muscles to dynamic perturbations. This study examined activation amplitudes and temporal synergies among compartments of the back extensor and among abdominal wall muscles in response to dynamic bidirectional moments of force. We further examined whether responses were different between men and women. 19 women and 18 men performed a controlled transfer task. Surface electromyograms from bilateral sites over 6 back extensor compartments and 6 abdominal wall muscle sites were analyzed using principal component analysis. Key features were extracted from the measured electromyographic waveforms capturing amplitude and temporal variations among muscle sites. Three features explained 97% of the variance. Scores for each feature were computed for each measured waveform and analysis of variance found significant (pWomen had more differences among muscle sites than men for the lateral flexion moment feature. For the abdominal wall muscles the oblique muscles responded with synergies related to fiber orientation, with women having higher amplitudes and more responsiveness to the lateral flexion moment than men. Synergies between the abdominal and back extensor sites as the moment demands change are discussed. These findings illustrate differential activation among erector spinae compartments and abdominal wall muscle sites supporting a highly organized pattern of response to bidirectional external moments with asynchronies more apparent in women. Copyright © 2012 Elsevier B.V. All rights reserved.

Electromyographic activity of the trunk extensor muscles: effect of varying hip position and lumbar posture during Roman chair exercise.

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Mayer, John M; Verna, Joe L; Manini, Todd M; Mooney, Vert; Graves, James E

2002-11-01

To evaluate the effect of hip position and lumbar posture on the surface electromyographic activity of the trunk extensors during Roman chair exercise. Descriptive, repeated measures. University-based musculoskeletal research laboratory. Twelve healthy volunteers (7 men, 5 women; age range, 18-35y) without a history of low back pain were recruited from a university setting. Not applicable. Surface electromyographic activity was recorded from the lumbar extensor, gluteal, and hamstring musculature during dynamic Roman chair exercise. For each muscle group, electromyographic activity (mV/rep) was compared among exercises with internal hip rotation and external hip rotation and among exercises by using a typical lumbar posture (nonbiphasic) and a posture that accentuated lumbar lordosis (biphasic). For the lumbar extensors, electromyographic activity during exercise was 18% greater with internal hip rotation than external hip rotation (Phamstrings, there was no difference in electromyographic activity between internal and external hip rotation or between biphasic and nonbiphasic postures (P >.05). The level of recruitment of the lumbar extensors can be modified during Roman chair exercise by altering hip position and lumbar posture. Clinicians can use these data to develop progressive exercise protocols for the lumbar extensors with a variety of resistance levels without the need for complex equipment. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Neck Flexor and Extensor Muscle Endurance in Subclinical Neck Pain: Intrarater Reliability, Standard Error of Measurement, Minimal Detectable Change, and Comparison With Asymptomatic Participants in a University Student Population.

Science.gov (United States)

Lourenço, Ana S; Lameiras, Carina; Silva, Anabela G

2016-01-01

The aims of this study were to assess intrarater reliability and to calculate the standard error of measurement (SEM) and minimal detectable change (MDC) for deep neck flexor and neck extensor muscle endurance tests, and compare the results between individuals with and without subclinical neck pain. Participants were students of the University of Aveiro reporting subclinical neck pain and asymptomatic participants matched for sex and age to the neck pain group. Data on endurance capacity of the deep neck flexors and neck extensors were collected by a blinded assessor using the deep neck flexor endurance test and the extensor endurance test, respectively. Intraclass correlation coefficients (ICCs), SEM, and MDC were calculated for measurements taken within a session by the same assessor. Differences between groups for endurance capacity were investigated using a Mann-Whitney U test. The deep neck flexor endurance test (ICC = 0.71; SEM = 6.91 seconds; MDC = 19.15 seconds) and neck extensor endurance test (ICC = 0.73; SEM = 9.84 minutes; MDC = 2.34 minutes) are reliable. No significant differences were found between participants with and without neck pain for both tests of muscle endurance (P > .05). The endurance capacity of the deep neck flexors and neck extensors can be reliably measured in participants with subclinical neck pain. However, the wide SEM and MDC might limit the sensitivity of these tests. Copyright © 2016. Published by Elsevier Inc.

Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.

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Eric L Voorn

Full Text Available To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS and 18 age-matched healthy individuals.Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD, and early and late relaxation time (RT50 and RT25, using the intraclass correlation coefficient (ICC and standard error of measurement (SEM, expressed as % of the mean.In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90 and small SEM values (PPS: 7.1%, healthy individuals: 7.0%. Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%. We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016.In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

Catalase-positive microperoxisomes in rat soleus and extensor digitorum longus muscle fiber types

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Riley, Danny A.; Bain, James L. W.; Ellis, Stanley

1988-01-01

The size, distribution, and content of catalase-reactive microperoxisomes were investigated cytochemically in three types of muscle fibers from the soleus and the extensor digitorum longus (EDL) of male rats. Muscle fibers were classified on the basis of the mitochondrial content and distribution, the Z-band widths, and the size and shape of myofibrils as the slow-twitch oxidative (SO), the fast-twitch oxidative glycolytic (FOG), and the fast-twitch glycolytic (FG) fibers. It was found that both the EDL and soleus SO fibers possessed the largest microperoxisomes. A comparison of microperoxisome number per muscle fiber area or the microperoxisome area per fiber area revealed following ranking, starting from the largest number and the area-ratio values: soleus SO, EDL SO, EDL FOG, and EDL FG.

Poor correlation between handgrip strength and isokinetic performance of knee flexor and extensor muscles in community-dwelling elderly women.

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Felicio, Diogo Carvalho; Pereira, Daniele Sirineu; Assumpção, Alexandra Miranda; de Jesus-Moraleida, Fabianna Resende; de Queiroz, Barbara Zille; da Silva, Juscelio Pereira; de Brito Rosa, Naysa Maciel; Dias, João Marcos Domingues; Pereira, Leani Souza Máximo

2014-01-01

To investigate the correlation between handgrip strength and performance of knee flexor and extensor muscles determined using an isokinetic dynamometer in community-dwelling elderly women. This was a cross-sectional study. Sample selection for the study was made by convenience, and 221 (71.07 ± 4.93 years) community-dwelling elderly women were included. Knee flexor and extensor muscle performance was measured using an isokinetic dynamometer Biodex System 3 Pro. The isokinetic variables chosen for analysis were peak torque, peak torque/bodyweight, total work/bodyweight, total work, average power, and agonist/antagonist ratio at the angular velocities of 60°/s and 180°/s. Assessment of handgrip strength was carried out using the Jamar dynamometer. Spearman's correlation coefficient was calculated to identify intervariable correlations. Only knee flexor peak torque (60°/s) and average power (60°/s), and knee extensor peak torque (180°/s) and total work (180°/s) were significantly (P women. © 2013 Japan Geriatrics Society.

TRAINING-INDUCED CHANGES IN THE TOPOGRAPHY OF MUSCLE TORQUES AND MAXIMAL MUSCLE TORQUES IN BASKETBALL PLAYERS

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Krzysztof Buśko

2012-01-01

Full Text Available The aim of the study was to detect changes in the maximal muscle torques in male basketball players during a two-year training cycle. We verified the hypothesis that different workloads applied during the preparation and competition periods would result in changes in the maximal muscle torques of the athletes (increase during the former and decrease or no change during the latter period accompanied by no alteration of the percent muscle topography of all the muscle groups tested. The examinations were conducted on nine senior male basketball players from the Polish national team. Estimations of the muscle torques in static conditions were performed at the end of the preparation (measurements I and III and competition (measurements II and IV periods of a two-year training cycle. Eleven muscle groups were studied including flexors and extensors of the trunk and flexors and extensors of the shoulder, the elbow, the hip, the knee, and the ankle. Muscle torques of the shoulder and the elbow insignificantly decreased except for the muscle torque of the flexors of the shoulder. Muscle torques of the flexors and extensors of the trunk as well as of the flexors and extensors of the hip, the knee, and the ankle increased between measurements I and III and between measurements I and IV with the only exception being the muscle torque of the flexors of the knee (which significantly decreased by 7.4% In the case of the flexors and extensors of the trunk and the flexors and extensors of the hip, the changes appeared to be significant. The sum of the muscle torques of the upper limbs markedly decreased between the preparation (measurement I and competition (measurement IV periods. The sum of the muscle torques of the trunk and the lower limbs and the sum of the muscle torques of the eleven muscle groups significantly increased between measurements I and IV. Percent muscle topography significantly decreased for the flexors and extensors of the shoulder and the

Comparison of isokinetic muscle strength and muscle power by types of warm-up.

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Sim, Young-Je; Byun, Yong-Hyun; Yoo, Jaehyun

2015-05-01

[Purpose] The purpose of this study was to clarify the influence of static stretching at warm-up on the isokinetic muscle torque (at 60°/sec) and muscle power (at 180°/sec) of the flexor muscle and extensor muscle of the knee joint. [Subjects and Methods] The subjects of this study were 10 healthy students with no medically specific findings. The warm-up group and warm-up with stretching group performed their respective warm-up prior to the isokinetic muscle torque evaluation of the knee joint. One-way ANOVA was performed by randomized block design for each variable. [Results] The results were as follows: First, the flexor peak torque and extensor peak torque of the knee joint tended to decrease at 60°/sec in the warm-up with stretching group compared with the control group and warm-up group, but without statistical significance. Second, extensor power at 180°/sec was also not statistically significant. However, it was found that flexor power increased significantly in the warm-up with stretching group at 180°/sec compared with the control group and warm-up group in which stretching was not performed. [Conclusion] Therefore, it is considered that in healthy adults, warm-up including two sets of stretching for 20 seconds per muscle group does not decrease muscle strength and muscle power.

Sex differences in neuromuscular function after repeated eccentric contractions of the knee extensor muscles.

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Lee, Andrea; Baxter, Jake; Eischer, Claire; Gage, Matt; Hunter, Sandra; Yoon, Tejin

2017-06-01

This study examined the mechanisms for force and power reduction during and up to 48 h after maximal eccentric contractions of the knee extensor muscles in young men and women. 13 men (22.8 ± 2.6 years) and 13 women (21.6 ± 2.2 years) performed 150 maximal effort eccentric contractions (5 sets of 30) with the knee extensor muscles at 60° s -1 . Maximal voluntary isometric contractions (MVIC) and maximal voluntary concentric contractions (MVCC) were performed before and after the 150 eccentric contractions. The MVCCs involved a set of two isokinetic contractions at 60° s -1 and sets of isotonic contractions performed at seven different resistance loads (1 N m, 10, 20, 30, 40, 50, and 60% MVIC). Electrical stimulation was used during the MVICs and at rest to determine changes in voluntary activation and contractile properties. At baseline, men were stronger than women (MVIC: 276 ± 48 vs. 133 ± 37 N m) and more powerful (MVCC: 649 ± 77 vs. 346 ± 78 W). At termination of the eccentric contractions, voluntary activation, resting twitch amplitude, and peak power during concentric contractions at the seven loads and at 60° s -1 decreased (P  0.05) with no sex differences. Central mechanisms were primarily responsible for the depressed maximal force production up to 48 h after repeated eccentric contractions of the knee extensors and these mechanisms were similar in men and women.

Femoral Neck Strain during Maximal Contraction of Isolated Hip-Spanning Muscle Groups

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Saulo Martelli

2017-01-01

Full Text Available The aim of the study was to investigate femoral neck strain during maximal isometric contraction of the hip-spanning muscles. The musculoskeletal and the femur finite-element models from an elderly white woman were taken from earlier studies. The hip-spanning muscles were grouped by function in six hip-spanning muscle groups. The peak hip and knee moments in the model were matched to corresponding published measurements of the hip and knee moments during maximal isometric exercises about the hip and the knee in elderly participants. The femoral neck strain was calculated using full activation of the agonist muscles at fourteen physiological joint angles. The 5%±0.8% of the femoral neck volume exceeded the 90th percentile of the strain distribution across the 84 studied scenarios. Hip extensors, flexors, and abductors generated the highest tension in the proximal neck (2727 με, tension (986 με and compression (−2818 με in the anterior and posterior neck, and compression (−2069 με in the distal neck, respectively. Hip extensors and flexors generated the highest neck strain per unit of joint moment (63–67 με·m·N−1 at extreme hip angles. Therefore, femoral neck strain is heterogeneous and muscle contraction and posture dependent.

Extensor Tendon Injuries

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... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Extensor Tendon Injuries Email to a friend * required ...

Degree of thoracic kyphosis and peak torque of trunk flexors and extensors among healthy women.

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Granito, Renata Neves; Aveiro, Mariana Chaves; Rennó, Ana Claudia Muniz; Oishi, Jorge; Driusso, Patricia

2014-01-01

The aim of this study was to analyze the effects of aging on the degree of thoracic kyphosis and peak torque of the trunk flexor and extensor muscles among women without a densitometric diagnosis of osteoporosis. Thirty women were selected to make up three groups: young women (n = 10; 24.60 ± 2.27 years of age); adults (n = 10; 43.50 ± 2.88); and elderly women (n = 10; 62.40 ± 2.67). Bone mineral density (BMD), degree of thoracic kyphosis and peak torque of the trunk flexors and extensors were evaluated. Differences between the groups were evaluated using the Kruskal-Wallis ANOVA and Mann-Whitney U tests. Pearson's correlation coefficient was used to assess correlations between the variables. The significance level was taken to be 5% (p ≤ 0.05). The elderly group presented a greater degree of thoracic kyphosis (p = 0.009) and lower peak torque of the trunk flexors and extensors than the young group. The adult group presented lower peak torque of the trunk than the young group. A negative correlation was observed between age and peak torque of the trunk flexors and extensors (p ≤ 0.001), and a positive correlation between age and the degree of thoracic kyphosis (r = 0.58; p ≤ 0.001). The elderly group presented higher values for the eccentric/concentric ratio of the peak torque for flexors (p = 0.03) and extensors (p = 0.02). This study suggests that physiological aging may be associated with a greater degree of thoracic kyphosis and lower muscle strength of the trunk flexors and extensors. Moreover, the elderly women showed a relative capacity for preservation of eccentric strength.

Degree of thoracic kyphosis and peak torque of trunk flexors and extensors among healthy women,

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Renata Neves Granito

2014-06-01

Full Text Available OBJECTIVE: The aim of this study was to analyze the effects of aging on the degree of thoracic kyphosis and peak torque of the trunk flexor and extensor muscles among women without a densitometric diagnosis of osteoporosis.METHODS: Thirty women were selected to make up three groups: young women (n = 10; 24.60 ± 2.27 years of age; adults (n = 10; 43.50 ± 2.88; and elderly women (n= 10; 62.40 ± 2.67. Bone mineral density (BMD, degree of thoracic kyphosis and peak torque of the trunk flexors and extensors were evaluated. Differences between the groups were evaluated using the Kruskal-Wallis ANOVA and Mann-Whitney U tests. Pearson's correlation coefficient was used to assess correlations between the variables. The significance level was taken to be 5% (p < 0.05.RESULTS: The elderly group presented a greater degree of thoracic kyphosis (p = 0.009 and lower peak torque of the trunk flexors and extensors than the young group. The adult group presented lower peak torque of the trunk than the young group. A negative correlation was observed between age and peak torque of the trunk flexors and extensors (p < 0.001, and a positive correlation between age and the degree of thoracic kyphosis (r = 0.58; p < 0.001. The elderly group presented higher values for the eccentric/concentric ratio of the peak torque for flexors (p = 0.03 and extensors (p = 0.02.CONCLUSION: This study suggests that physiological aging may be associated with a greater degree of thoracic kyphosis and lower muscle strength of the trunk flexors and extensors. Moreover, the elderly women showed a relative capacity for preservation of eccentric strength.

Comparing two methods to record maximal voluntary contractions and different electrode positions in recordings of forearm extensor muscle activity: Refining risk assessments for work-related wrist disorders.

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Dahlqvist, Camilla; Nordander, Catarina; Granqvist, Lothy; Forsman, Mikael; Hansson, Gert-Åke

2018-01-01

Wrist disorders are common in force demanding industrial repetitive work. Visual assessment of force demands have a low reliability, instead surface electromyography (EMG) may be used as part of a risk assessment for work-related wrist disorders. For normalization of EMG recordings, a power grip (hand grip) is often used as maximal voluntary contraction (MVC) of the forearm extensor muscles. However, the test-retest reproducibility is poor and EMG amplitudes exceeding 100% have occasionally been recorded during work. An alternative MVC is resisted wrist extension, which may be more reliable. To compare hand grip and resisted wrist extension MVCs, in terms of amplitude and reproducibility, and to examine the effect of electrode positioning. Twelve subjects participated. EMG from right forearm extensors, from four electrode pairs, was recorded during MVCs, on three separate occasions. The group mean EMG amplitudes for resisted wrist extension were 1.2-1.7 times greater than those for hand grip. Resisted wrist extension showed better reproducibility than hand grip. The results indicate that the use of resisted wrist extension is a more accurate measurement of maximal effort of wrist extensor contractions than using hand grip and should increase the precision in EMG recordings from forearm extensor muscles, which in turn will increase the quality of risk assessments that are based on these.

Efeitos da crioterapia e facilitação neuromuscular proprioceptiva sobre a força muscular nas musculaturas flexora e extensora de joelho Effects of cryotherapy and proprioceptive neuromuscular facilitation on muscle strength at the flexor and extensor muscles of the knee

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Daiana Moreira Mortari

2009-12-01

Full Text Available As musculaturas flexora e extensora do joelho são freqüentemente lesionadas devido a um desequilíbrio entre esses grupos. Recursos térmicos, como a crioterapia, e técnicas de alongamento, como a técnica mantém-relaxa da facilitação neuromuscular proprioceptiva (FNP, influenciam a flexibilidade e força muscular, proporcionando maior homogeneidade entre essas musculaturas e diminuindo a incidência de lesões. Este estudo objetivou verificar os efeitos da crioterapia e da FNP sobre a força das musculaturas flexora e extensora de joelho. A amostra foi composta por 18 mulheres com idade entre 18 e 24 anos, não-praticantes de atividade física regular, divididas em dois grupos: um submetido a crioterapia e o outro à técnica mantém-relaxa da FNP. Antes e após uma sessão de aplicação das técnicas foi feita avaliação isocinética. A aplicação da técnica mantém-relaxa provocou aumento da força em ambas as musculaturas em ambos os membros, atingindo nível de significância nos flexores do membro inferior direito (p=0,04. A crioterapia diminuiu a força dos extensores e exerceu efeito contrário sobre os flexores, tendo gerado aumento significativo nos flexores do membro inferior direito (p=0,035. Quando comparadas as técnicas, a técnica mantém-relaxa gerou maiores valores de pico de torque, principalmente nos extensores do membro inferior esquerdo (p=0,042. Conclui-se que a técnica mantém-relaxa da FNP gerou maiores valores no pico de torque em relação à crioterapia.Knee extensor and flexor muscles are often injured due to an imbalance between these groups, which may lead to a deficit in muscle performance. Thermal resources, such as cryotherapy, and stretching techniques, such as the "hold-relax" of proprioceptive neuromuscular facilitation (PNF, influence flexibility and muscle strength and may reduce the chances of muscle tendon injuries. The aim of the study was to verify the effects of cryotherapy and of the PNF

Comparative proteomic profiling of soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscles from the mdx mouse model of Duchenne muscular dystrophy.

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Carberry, Steven; Brinkmeier, Heinrich; Zhang, Yaxin; Winkler, Claudia K; Ohlendieck, Kay

2013-09-01

Duchenne muscular dystrophy is due to genetic abnormalities in the dystrophin gene and represents one of the most frequent genetic childhood diseases. In the X-linked muscular dystrophy (mdx) mouse model of dystrophinopathy, different subtypes of skeletal muscles are affected to a varying degree albeit the same single base substitution within exon 23 of the dystrophin gene. Thus, to determine potential muscle subtype-specific differences in secondary alterations due to a deficiency in dystrophin, in this study, we carried out a comparative histological and proteomic survey of mdx muscles. We intentionally included the skeletal muscles that are often used for studying the pathomechanism of muscular dystrophy. Histological examinations revealed a significantly higher degree of central nucleation in the soleus and extensor digitorum longus muscles compared with the flexor digitorum brevis and interosseus muscles. Muscular hypertrophy of 20-25% was likewise only observed in the soleus and extensor digitorum longus muscles from mdx mice, but not in the flexor digitorum brevis and interosseus muscles. For proteomic analysis, muscle protein extracts were separated by fluorescence two-dimensional (2D) gel electrophoresis. Proteins with a significant change in their expression were identified by mass spectrometry. Proteomic profiling established an altered abundance of 24, 17, 19 and 5 protein species in the dystrophin-deficient soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscle, respectively. The key proteomic findings were verified by immunoblot analysis. The identified proteins are involved in the contraction-relaxation cycle, metabolite transport, muscle metabolism and the cellular stress response. Thus, histological and proteomic profiling of muscle subtypes from mdx mice indicated that distinct skeletal muscles are differentially affected by the loss of the membrane cytoskeletal protein, dystrophin. Varying degrees of perturbed protein

Effects of a low-intensity strength-training program on knee-extensor strength and functional ability of frail older people

NARCIS (Netherlands)

Westhoff, M.H.; Stemmerik, L.; Boshuizen, H.C.

2000-01-01

This study's purpose was to investigate whether a 10-week low-intensity strength-training program could improve strength of the knee extensors and functional ability. Participants 65 years and older with low knee-extensor muscle strength were randomized into an exercise (n = 11) and a control group

Reconstruction of long digital extensor tendon by cranial tibial muscle fascia graft in a dog.

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Sabiza, Soroush; Khajeh, Ahmad; Naddaf, Hadi

2016-01-01

Tendon rupture in dogs is generally the result of a direct trauma. This report described the use of adjacent muscle autogenic fascial graft for reconstruction of distal rupture of long digital extensor tendon in a dog. A two-year-old male mix breed dog, was presented with a non-weight bearing lameness of the right hind limb and a deep rupture of lateral side of right tarsus. History taking revealed that this rupture appeared without any apparent cause, when walking around the farm, three days before. Radiography was done and no fracture was observed. Hyperextension of right tarsal joint compared to left limb was observed. Under general anesthesia, after dissections of the ruptured area, complete rupture of long digital extensor tendon was revealed. Then, we attempted to locate the edge of the tendon, however, the tendon length was shortened approximately 1 cm. Hence, a strip of 1 cm length from fascia of cranial tibial muscle was harvested to fill the defect. The graft was sutured to the two ends of tendon using locking loop pattern. Subcutaneous layers and the skin were sutured routinely. Ehmer sling bandage was applied to prevent weight bearing on the surgical region. Re-examination and phone contact with the owner eight weeks and six months postoperatively revealed a poor lameness and excellent function of the dog, respectively. It could be concluded that the fascia of adjacent muscles can be used as an autogenic graft for reconstruction of some tendon ruptures.

Degree of thoracic kyphosis and peak torque of trunk flexors and extensors among healthy women☆☆☆

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Granito, Renata Neves; Aveiro, Mariana Chaves; Rennó, Ana Claudia Muniz; Oishi, Jorge; Driusso, Patricia

2014-01-01

Objective The aim of this study was to analyze the effects of aging on the degree of thoracic kyphosis and peak torque of the trunk flexor and extensor muscles among women without a densitometric diagnosis of osteoporosis. Methods Thirty women were selected to make up three groups: young women (n = 10; 24.60 ± 2.27 years of age); adults (n = 10; 43.50 ± 2.88); and elderly women (n = 10; 62.40 ± 2.67). Bone mineral density (BMD), degree of thoracic kyphosis and peak torque of the trunk flexors and extensors were evaluated. Differences between the groups were evaluated using the Kruskal–Wallis ANOVA and Mann–Whitney U tests. Pearson's correlation coefficient was used to assess correlations between the variables. The significance level was taken to be 5% (p ≤ 0.05). Results The elderly group presented a greater degree of thoracic kyphosis (p = 0.009) and lower peak torque of the trunk flexors and extensors than the young group. The adult group presented lower peak torque of the trunk than the young group. A negative correlation was observed between age and peak torque of the trunk flexors and extensors (p ≤ 0.001), and a positive correlation between age and the degree of thoracic kyphosis (r = 0.58; p ≤ 0.001). The elderly group presented higher values for the eccentric/concentric ratio of the peak torque for flexors (p = 0.03) and extensors (p = 0.02). Conclusion This study suggests that physiological aging may be associated with a greater degree of thoracic kyphosis and lower muscle strength of the trunk flexors and extensors. Moreover, the elderly women showed a relative capacity for preservation of eccentric strength. PMID:26229814

Muscle imbalance and reduced ankle joint motion in people with hammer toe deformity.

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Kwon, O Y; Tuttle, L J; Johnson, J E; Mueller, M J

2009-10-01

Multiple factors may contribute to hammer toe deformity at the metatarsophalangeal joint. The purposes of this study were to (1) compare the ratio of toe extensor/flexor muscle strength in toes 2-4 among groups with and without hammer toe deformity, (2) to determine correlations between the ratio of toe extensor/flexor muscle strength in toes 2-4, and metatarsophalangeal joint deformity (3) to determine if other clinical measures differ between groups and if these measures are correlated with metatarsophalangeal joint angle. Twenty-seven feet with visible hammer toe deformity and 31 age matched feet without hammer toe deformity were tested. Toe muscle strength was measured using a dynamometer and the ratio of toe extensor muscle strength to flexor muscle strength was calculated. Metatarsophalangeal joint angle was measured from a computerized tomography image. Ankle and subtalar joint range of motion, and tibial torsion were measured using goniometry. Extensor/flexor toe muscle strength ratio was 2.3-3.0 times higher in the hammer toe group compared to the non-hammer toe group, in toes 2-4. The ratios of extensor/flexor toe muscle strength for toes 2-4 and metatarsophalangeal joint angle were highly correlated (r=0.69-0.80). Ankle dorsiflexion and metatarsophalangeal joint angle were negatively correlated for toes 2-4 (r=-0.38 to -0.56) as were eversion and metatarsophalangeal joint angle. These results provide insight into potential risk factors for the development of hammer toe deformity. Additional research is needed to determine the causal relationship between hammer toe deformity and the ratio of toe extensor/flexor muscle strength in toes 2-4.

Relationships between Isometric Muscle Strength, Gait Parameters, and Gross Motor Function Measure in Patients with Cerebral Palsy.

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Shin, Hyung Ik; Sung, Ki Hyuk; Chung, Chin Youb; Lee, Kyoung Min; Lee, Seung Yeol; Lee, In Hyeok; Park, Moon Seok

2016-01-01

This study investigated the correlation between isometric muscle strength, gross motor function, and gait parameters in patients with spastic cerebral palsy and to find which muscle groups play an important role for gait pattern in a flexed knee gait. Twenty-four ambulatory patients (mean age, 10.0 years) with spastic cerebral palsy who were scheduled for single event multilevel surgery, including distal hamstring lengthening, were included. Preoperatively, peak isometric muscle strength was measured for the hip flexor, hip extensor, knee flexor, and knee extensor muscle groups using a handheld dynamometer, and three-dimensional (3D) gait analysis and gross motor function measure (GMFM) scoring were also performed. Correlations between peak isometric strength and GMFM, gait kinematics, and gait kinetics were analyzed. Peak isometric muscle strength of all muscle groups was not related to the GMFM score and the gross motor function classification system level. Peak isometric strength of the hip extensor and knee extensor was significantly correlated with the mean pelvic tilt (r=-0.588, p=0.003 and r=-0.436, p=0.033) and maximum pelvic obliquity (r=-0.450, p=0.031 and r=-0.419, p=0.041). There were significant correlations between peak isometric strength of the knee extensor and peak knee extensor moment in early stance (r=0.467, p=0.021) and in terminal stance (r=0.416, p=0.043). There is no correlation between muscle strength and gross motor function. However, this study showed that muscle strength, especially of the extensor muscle group of the hip and knee joints, might play a critical role in gait by stabilizing pelvic motion and decreasing energy consumption in a flexed knee gait.

Recovery Kinetics of Knee Flexor and Extensor Strength after a Football Match

Science.gov (United States)

Draganidis, Dimitrios; Chatzinikolaou, Athanasios; Avloniti, Alexandra; Barbero-Álvarez, José C.; Mohr, Magni; Malliou, Paraskevi; Gourgoulis, Vassilios; Deli, Chariklia K.; Douroudos, Ioannis I.; Margonis, Konstantinos; Gioftsidou, Asimenia; Fouris, Andreas D.; Jamurtas, Athanasios Z.; Koutedakis, Yiannis; Fatouros, Ioannis G.

2015-01-01

We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12h, 36h and 60h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12h, 36h and 60h after the match. Functional (KFecc/KEcon) and conventional (KFcon/KEcon) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (Pfootball-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players' physical conditioning level. PMID:26043222

Análise eletromiográfica e força do grupo muscular extensor do punho durante isquemia induzida Electromyographic analysis and strength of the wrist extensor muscle group during induced ischemia

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CCA Bandeira

2009-02-01

Full Text Available OBJETIVO: Avaliar o efeito da isquemia induzida sobre os parâmetros do sinal eletromiográfico e a força do grupo muscular extensor do punho (GMEP em mulheres saudáveis. MÉTODOS: Participaram 13 voluntárias, destras, sedentárias, com idade de 23,38±2,32 anos e índice de massa corporal (IMC de 20,68±1,87kg/m². Para determinar a força do GMEP, foram realizadas 3 contrações isométricas voluntárias máximas (CIVM, utilizando-se uma célula de carga por 15 segundos, com intervalos de 2 minutos entre cada contração, sendo todo procedimento repetido por 3 dias não consecutivos. A isquemia foi realizada por 5 minutos, utilizando um esfigmomanômetro posicionado no braço dominante e inflado até a ausência do fluxo sanguíneo, confirmada pelo ultrassom Doppler. Para coleta do sinal eletromiográfico do GMEP, utilizou-se o equipamento EMG1000 (Lynx® com eletrodo de superfície diferencial (Lynx®. Foram coletadas 3 CIVM por 15 segundos, com intervalo de 30 segundos entre elas, nas situações de pré-isquemia; isquemia; pós-isquemia imediata (pós-1 e pós-isquemia tardia (pós-2 - após 10 minutos do início da isquemia. Para análise dos parâmetros do sinal eletromiográfico, root mean square (RMS, e frequência mediana do espectro de potência do sinal foi utilizado o software MATLAB 6.5.1. Para análise estatística, foram utilizados os testes de Friedman e ANOVA two-way. RESULTADOS: A isquemia promoveu redução significativa (pOBJECTIVE: To analyze the effect of induced ischemia on the parameters of electromyographic signals and the strength of the wrist extensor muscle group (WEMG in healthy women. METHODS: Thirteen right-handed sedentary subjects aged 23.38±2.32 years old, with body mass index (BMI of 20.68±1.87kg/m², took part. To determine WEMG strength, three maximal voluntary isometric contractions (MVIC were performed using a load cell for 15 seconds, with 2 minutes intervals between contractions. The entire

Recombinant Uncarboxylated Osteocalcin Per Se Enhances Mouse Skeletal Muscle Glucose Uptake in both Extensor Digitorum Longus and Soleus Muscles

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Xuzhu Lin

2017-11-01

Full Text Available Emerging evidence suggests that undercarboxylated osteocalcin (ucOC improves muscle glucose uptake in rodents. However, whether ucOC can directly increase glucose uptake in both glycolytic and oxidative muscles and the possible mechanisms of action still need further exploration. We tested the hypothesis that ucOC per se stimulates muscle glucose uptake via extracellular signal-regulated kinase (ERK, adenosine monophosphate-activated protein kinase (AMPK, and/or the mechanistic target of rapamycin complex 2 (mTORC2-protein kinase B (AKT-AKT substrate of 160 kDa (AS160 signaling cascade. Extensor digitorum longus (EDL and soleus muscles from male C57BL/6 mice were isolated, divided into halves, and then incubated with ucOC with or without the pretreatment of ERK inhibitor U0126. ucOC increased muscle glucose uptake in both EDL and soleus. It also enhanced phosphorylation of ERK2 (Thr202/Tyr204 and AS160 (Thr642 in both muscle types and increased mTOR phosphorylation (Ser2481 in EDL only. ucOC had no significant effect on the phosphorylation of AMPKα (Thr172. The inhibition of ucOC-induced ERK phosphorylation had limited effect on ucOC-stimulated glucose uptake and AS160 phosphorylation in both muscle types, but appeared to inhibit the elevation in AKT phosphorylation only in EDL. Taken together, ucOC at the physiological range directly increased glucose uptake in both EDL and soleus muscles in mouse. The molecular mechanisms behind this ucOC effect on muscle glucose uptake seem to be muscle type-specific, involving enhanced phosphorylation of AS160 but limitedly modulated by ERK phosphorylation. Our study suggests that, since ucOC increases muscle glucose uptake without insulin, it could be considered as a potential agent to improve muscle glucose uptake in insulin resistant conditions.

Comparison of the effect of selected muscle groups fatigue on postural control during bipedal stance in healthy young women.

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Shirazi, Zahra Rojhani; Jahromi, Fatemeh Nikhalat

2013-09-01

The maintenance of balance is an essential requirement for the performance of daily tasks and sporting activities and muscular fatigue is a factor to impair postural control, so this study was done to compare the effect of selected muscle groups fatigue on postural control during bipedal stance in healthy subjects. Fifteen healthy female students (24.3 ± 2.6 years) completed three testing session with a break period of at least 2 days. During each session, postural control was assessed during two 30-s trials of bipedal stance with eyes close before and after the fatigue protocol. Fatigue protocols were performed by 60% of their unfatigued Maximum Voluntary Contraction of unilateral ankle plantar flexors, bilateral lumbar extensors and bilateral neck extensors. One of the three fatigue protocols was performed on each session. The result showed that fatigue had a significant effect on COP velocity and it increase COP velocity but there was not found any difference in postural sway between muscle groups. Localized muscle fatigue caused deficits in postural control regardless of the location of fatigue. Authors suggest the possibility of the contributions of central mechanisms to postural deficits due to fatigue and it seems that difference was not between muscle groups due to central fatigue.

Lean and Obese Zucker Rat Extensor Digitorum Longus Muscle high-frequency electrical stimulation (HFES Data: Regulation of p70S6kinase Associated Proteins

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Kevin M. Rice

2018-02-01

Full Text Available Anaerobic exercise has been advocated as a prescribed treatment for the management of diabetes: however, alterations in exercise-induced signaling remain largely unexplored in the diabetic muscle. Here, we compare the basal and the in situ contraction-induced phosphorylation of the AKT, GSK3beta, mTor, p70s6K, Pten, and Shp2 in the lean and obese (fa/fa Zucker rat Extensor Digitorum Longus (EDL muscle following a single bout of contractile stimuli. This article represents data associated with prior publications from our lab (Katta et al., 2009a, 2009b; Tullgren et al., 1991 [1–3] and concurrent Data in Brief articles (Ginjupalli et al., 2017a, 2017b; Rice et al., 2017a, 2017b [4–7]. Keywords: Diabetes, Skeletal muscle, High-frequency electrical stimulation (HFES, Zucker rat, Extensor Digitorum Longus, p70s6k

The effects of a muscle resistance program on the functional capacity, knee extensor muscle strength and plasma levels of IL-6 and TNF-alpha in pre-frail elderly women: a randomized crossover clinical trial--a study protocol.

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Lustosa, Lygia P; Coelho, Fernanda M; Silva, Juscelio P; Pereira, Daniele S; Parentoni, Adriana N; Dias, João M D; Dias, Rosangela C; Pereira, Leani S M

2010-07-28

With the increase in the elderly population, a growing number of chronic degenerative diseases and a greater dependency on caregivers have been observed. Elderly persons in states of frailty remain more susceptible to significant health complications. There is evidence of an inverse relationship between plasma levels of inflammatory mediators and levels of functionality and muscle strength, suggesting that muscle-strengthening measures can aid in inflammatory conditions. The purpose of this study will be verified the effect of a muscle-strengthening program with load during a ten-week period in pre-frail elderly women with attention to the following outcomes: (1) plasma levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha), (2) functional capacity and (3) knee extensor muscle strength. The study design is a randomized crossover clinical trial evaluating 26 elderly women (regardless of their race and/or social condition) who are community residents, older than 65, and classified as pre-frail according to the criteria previously described by Fried et al. (2004). All subjects will be assessed using the Timed up and go and 10-Meter Walk Test functional tests. The plasma levels of IL-6 and TNF-alpha will be assessed by ELISA (enzyme-linked immunosorbent assay) with high sensitivity kits (QuantikineHS, R&D Systems Minneapolis, MN, U.S.). Knee extensor muscle strength will be assessed using the Byodex System 3 Pro(R) isokinetic dynamometer at angular speeds of 60 and 180 degrees/s. The intervention will consist of strengthening exercises of the lower extremities at 50 to 70% of 1RM (maximal resistance) three times per week for ten weeks. The volunteers will be randomized into two groups: group E, the intervention group, and group C, the control group that did not initiate any new activities during the initial study period (ten weeks). After the initial period, group C will begin the intervention and group E will maintain everyday activities without

Validity and reliability of an instrumented leg-extension machine for measuring isometric muscle strength of the knee extensors.

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Ruschel, Caroline; Haupenthal, Alessandro; Jacomel, Gabriel Fernandes; Fontana, Heiliane de Brito; Santos, Daniela Pacheco dos; Scoz, Robson Dias; Roesler, Helio

2015-05-20

Isometric muscle strength of knee extensors has been assessed for estimating performance, evaluating progress during physical training, and investigating the relationship between isometric and dynamic/functional performance. To assess the validity and reliability of an adapted leg-extension machine for measuring isometric knee extensor force. Validity (concurrent approach) and reliability (test and test-retest approach) study. University laboratory. 70 healthy men and women aged between 20 and 30 y (39 in the validity study and 31 in the reliability study). Intraclass correlation coefficient (ICC) values calculated for the maximum voluntary isometric torque of knee extensors at 30°, 60°, and 90°, measured with the prototype and with an isokinetic dynamometer (ICC2,1, validity study) and measured with the prototype in test and retest sessions, scheduled from 48 h to 72 h apart (ICC1,1, reliability study). In the validity analysis, the prototype showed good agreement for measurements at 30° (ICC2,1 = .75, SEM = 18.2 Nm) and excellent agreement for measurements at 60° (ICC2,1 = .93, SEM = 9.6 Nm) and at 90° (ICC2,1 = .94, SEM = 8.9 Nm). Regarding the reliability analysis, between-days' ICC1,1 were good to excellent, ranging from .88 to .93. Standard error of measurement and minimal detectable difference based on test-retest ranged from 11.7 Nm to 18.1 Nm and 32.5 Nm to 50.1 Nm, respectively, for the 3 analyzed knee angles. The analysis of validity and repeatability of the prototype for measuring isometric muscle strength has shown to be good or excellent, depending on the knee joint angle analyzed. The new instrument, which presents a relative low cost and easiness of transportation when compared with an isokinetic dynamometer, is valid and provides consistent data concerning isometric strength of knee extensors and, for this reason, can be used for practical, clinical, and research purposes.

Muscle fatigue in relation to forearm pain and tenderness among professional computer users

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Thomsen, GF; Johnson, PW; Svendsen, Susanne Wulff

2007-01-01

ABSTRACT: BACKGROUND: To examine the hypothesis that forearm pain with palpation tenderness in computer users is associated with increased extensor muscle fatigue. METHODS: Eighteen persons with pain and moderate to severe palpation tenderness in the extensor muscle group of the right forearm...... response was not explained by differences in the MVC or body mass index. CONCLUSION: Computer users with forearm pain and moderate to severe palpation tenderness had diminished forearm extensor muscle fatigue response. Additional studies are necessary to determine whether this result reflects an adaptive...... and twenty gender and age matched referents without such complaints were enrolled from the Danish NUDATA study of neck and upper extremity disorders among technical assistants and machine technicians. Fatigue of the right forearm extensor muscles was assessed by muscle twitch forces in response to low...

Muscular hypertrophy and atrophy in normal rats provoked by the administration of normal and denervated muscle extracts.

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Agüera, Eduardo; Castilla, Salvador; Luque, Evelio; Jimena, Ignacio; Leiva-Cepas, Fernando; Ruz-Caracuel, Ignacio; Peña, José

2016-12-01

This study was conducted to determine the effects of extracts obtained from both normal and denervated muscles on different muscle types. Wistar rats were used and were divided into a control group and four experimental groups. Each experimental group was treated intraperitoneally during 10 consecutive days with a different extract. These extracts were obtained from normal soleus muscle, denervated soleus, normal extensor digitorum longus, and denervated extensor digitorum longus. Following treatment, the soleus and extensor digitorum longus muscles were obtained for study under optic and transmission electron microscope; morphometric parameters and myogenic responses were also analyzed. The results demonstrated that the treatment with normal soleus muscle and denervated soleus muscle extracts provoked hypertrophy and increased myogenic activity. In contrast, treatment with extracts from the normal and denervated EDL had a different effect depending on the muscle analyzed. In the soleus muscle it provoked hypertrophy of type I fibers and increased myogenic activity, while in the extensor digitorum longus atrophy of the type II fibers was observed without changes in myogenic activity. This suggests that the muscular responses of atrophy and hypertrophy may depend on different factors related to the muscle type which could be related to innervation.

Anatomía arterial de los colgajos musculares de extensor carpi radialis longus y extensor carpi radialis brevis para su uso en transferencia muscular funcional libre Arterial anatomy of the extensor carpi radialis longus and extensor carpi radialis brevis muscle flaps related to its use in free functioning muscle transfer

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A. Rodríguez Lorenzo

2008-09-01

ón anatómica del nervio radial con el pedículo del ECRL hace que no sea posible su transferencia como colgajo libre sin sacrificar la rama motora del nervio radial en la mayor parte de los casos.The arterial anatomy of the Extensor Carpi Radialis Longus and Brevis (ECRL, ECRB flaps is herein described in order to provide the vascular basis to be used as free muscle transfer for facial reanimation. We used 29 fresh above-elbow human arms injected by means of two diferent techniques.Latex-injection was performed in 18 arms and the modified lead oxide-gelatine injection technique was performed in 11 arms. The ECRL and ECRB with their pedicles were dissected, photodocumented and radiographied.The number, length and calibers of the muscle pedicles were recorded. The intramuscular vascular pattern and the relations of the main pedicles of the muscles with the radial nerve were also noted. Two vascular patterns were found following the Mathes and Nahai Classification of the Vascular Anatomy of the Muscles (number of pedicles and its dominance: Type I (37,9% of ECRL and 20,7% of ECRB dissections and Type II (62,1% of ECRL and 79,3% of ECRB dissections. The dominant pedicle for the ECRL (with an average caliber of 1,73 mm and an average length of pedicle of 32,32 mm is a branch of the radial recurrent artery in 100% of the dissections and the dominant pedicle for the ECRB (with an average caliber of 1,11 mm and an average length of pedicle of 27,77 mm a branch of the radial artery in 68,9% of the dissections and a branch of radial recurrent artery in 31,1% of the cases. As a conclusion, ECRL and ECRB muscle flaps present two types of vascular patterns: type I and type II.Type II pattern is the most common in our study. The anatomical features of both muscles (vascular basis,presence of an important fascial layer, contour and length of the muscle, make them reliable as free muscles flaps for facial reanimation, however, the relation between the dominant pedicle for the ECRL

Variant Branching Pattern of Dorsalis Pedis Artery Accompanied with Anomalous Presence of Extensor Hallucis Brevis Muscle

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Ashwini Aithal Padur

2017-10-01

Full Text Available During routine dissection, we came across multiple variations in the dorsum of the right foot. Dorsalis pedis artery (DPA presented with an unusual branching pattern. The arcuate artery was completely absent, and hence three tarsal branches arose from lateral side of DPA. The first branch continued as first dorsal metatarsal artery, the second branch continued as the second dorsal metatarsal artery, and the third branch continued as third dorsal metatarsal artery which also provided a small twig to the fourth intermetatarsal space as the fourth dorsal metatarsal artery. We also observed the unique presence of extensor hallucis brevis muscle with the origin from the medial part of superior surface of the calcaneus and inserted to proximal phalanx of great toe. Since the DPA was just beneath this muscle, anomalous presence of the muscle may lead to compression of DPA. Awareness regarding such variations is critical for angiographers, vascular surgeons, reconstructive and plastic surgeons.

Effectiveness of water-based Liuzijue exercise on respiratory muscle strength and peripheral skeletal muscle function in patients with COPD

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Wu W

2018-05-01

Full Text Available Weibing Wu,1,* Xiaodan Liu,2,* Jingxin Liu,1 Peijun Li,1 Zhenwei Wang3 1Department of Sports Medicine, Shanghai University of Sport, 2School of Rehabilitation Medicine, Shanghai University of Traditional Chinese Medicine, 3Department of Respiratory Medicine, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai, People’s Republic of China *These authors contributed equally to this work Objects: The purpose of this study was to quantitatively assess the effects of water-based Liuzijue exercise on patients with COPD and compare it with land-based Liuzijue exercise.Materials and methods: Participants were randomly allocated to one of three groups: the water-based Liuzijue exercise group (WG, the land-based Liuzijue exercise group (LG, and the control group (CG. CG participants accepted no exercise intervention, while training groups performed Liuzijue exercise according to Health Qigong Liuzijue (People’s Republic of China in different environments for 60-min sessions twice a week for 3 months.Results: Of the 50 patients enrolled, 45 (90% completed the 3-month intervention. The CG showed decreased expiratory muscle strength, extensor and flexor endurance ratio (ER of the elbow joints and flexor peak torque (PT, total work (TW, and ER of the knee joints (p<0.05. Both training groups showed improved respiratory muscle strength, which differed from the CG (p<0.001. In addition, extensor and flexor TW of the elbow joints in the training groups were increased (p<0.01, and the WG differed from the CG in extensor TW and ER and flexor TW (p<0.01, while the LG differed from the CG in flexor TW and extensor ER (p<0.05. PT, PT/body weight (BW, and TW in the knee joint extensor in the training groups were increased as well (PT and PT/BW: p<0.05, TW: p<0.01, and the WG differed from the CG in terms of knee joints outcomes, while the LG differed from the CG in flexor TW only (p<0.05.Conclusion: Water-based Liuzijue exercise has

[Statistical (Poisson) motor unit number estimation. Methodological aspects and normal results in the extensor digitorum brevis muscle of healthy subjects].

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Murga Oporto, L; Menéndez-de León, C; Bauzano Poley, E; Núñez-Castaín, M J

Among the differents techniques for motor unit number estimation (MUNE) there is the statistical one (Poisson), in which the activation of motor units is carried out by electrical stimulation and the estimation performed by means of a statistical analysis based on the Poisson s distribution. The study was undertaken in order to realize an approximation to the MUNE Poisson technique showing a coprehensible view of its methodology and also to obtain normal results in the extensor digitorum brevis muscle (EDB) from a healthy population. One hundred fourteen normal volunteers with age ranging from 10 to 88 years were studied using the MUNE software contained in a Viking IV system. The normal subjects were divided into two age groups (10 59 and 60 88 years). The EDB MUNE from all them was 184 49. Both, the MUNE and the amplitude of the compound muscle action potential (CMAP) were significantly lower in the older age group (page than CMAP amplitude ( 0.5002 and 0.4142, respectively pphisiology of the motor unit. The value of MUNE correlates better with the neuromuscular aging process than CMAP amplitude does.

The effects of a muscle resistance program on the functional capacity, knee extensor muscle strength and plasma levels of IL-6 and TNF-α in pre-frail elderly women: a randomized crossover clinical trial - a study protocol

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Dias João MD

2010-07-01

Full Text Available Abstract Background With the increase in the elderly population, a growing number of chronic degenerative diseases and a greater dependency on caregivers have been observed. Elderly persons in states of frailty remain more susceptible to significant health complications. There is evidence of an inverse relationship between plasma levels of inflammatory mediators and levels of functionality and muscle strength, suggesting that muscle-strengthening measures can aid in inflammatory conditions. The purpose of this study will be verified the effect of a muscle-strengthening program with load during a ten-week period in pre-frail elderly women with attention to the following outcomes: (1 plasma levels of interleukin-6 (IL-6 and tumor necrosis factor alpha (TNF-α, (2 functional capacity and (3 knee extensor muscle strength. Methods/Design The study design is a randomized crossover clinical trial evaluating 26 elderly women (regardless of their race and/or social condition who are community residents, older than 65, and classified as pre-frail according to the criteria previously described by Fried et al. (2004. All subjects will be assessed using the Timed up and go and 10-Meter Walk Test functional tests. The plasma levels of IL-6 and TNF-α will be assessed by ELISA (enzyme-linked immunosorbent assay with high sensitivity kits (Quantikine®HS, R&D Systems Minneapolis, MN, U.S.. Knee extensor muscle strength will be assessed using the Byodex System 3 Pro® isokinetic dynamometer at angular speeds of 60 and 180°/s. The intervention will consist of strengthening exercises of the lower extremities at 50 to 70% of 1RM (maximal resistance three times per week for ten weeks. The volunteers will be randomized into two groups: group E, the intervention group, and group C, the control group that did not initiate any new activities during the initial study period (ten weeks. After the initial period, group C will begin the intervention and group E will

Effect of Body Mass Index on Postural Balance and Muscle Strength in Children Aged 8-10 years

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Lucky Prasetiowati

2017-04-01

Full Text Available Background:Childhood overweight and obesity, which are considered as global epidemic, can be assessed using Body Mass Index (BMI. BMI difference can lead to anatomic changes due to an increased body load. This increase might also affect motor performance, including changes in postural balance and muscle strength. Aims and Objectives: to explain the influence of BMI on postural balance and lower limb muscle strength and to assess the correlation between those two variables in children aged 8-10 years. Material and methods:The sample consisted of 63 children aged 8-10 years, which were divided in 3 groups: BMI-normal, BMI-overweight, and BMI-obese. The postural balance was assessed using single leg balance test on MatScan and the Center Of Pressure (COP area was recorded. Isometric muscle strength of hip extensor and knee extensor were measured using a hand-held dynamometer. Results: Obese children had significantly largerCOP area than overweight (p = 0.004 and normal weight children (p = 0.000.There were no significant differences in hip extensor muscle strength between obese children with overweight and normal weight children (p=0.527. The absolute knee extensor muscle strength in obese group was significantly higher than the overweight and normal group (p = 0.003. However the relative muscle strength of lower limb for obese children was significantly lower than for normal weight. There was no significant correlation between absolute hip extensor and knee extensor muscles strength with COP area. Conclusion: Obese children have decreased postural balance and increased absolute knee extensormuscle strength significantly when compared to overweight and normal children. There is no significant correlation between postural balance and muscle strength.

Strength deficits identified with concentric action of the hip extensors and eccentric action of the hamstrings predispose to hamstring injury in elite sprinters.

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Sugiura, Yusaku; Saito, Tomoyuki; Sakuraba, Keishoku; Sakuma, Kazuhiko; Suzuki, Eiichi

2008-08-01

Prospective cohort study. In this prospective cohort study of elite sprinters, muscle strength of the hip extensors, as well as of the knee extensors and flexors, was measured to determine a possible relationship between strength deficits and subsequent hamstring injury within 12 months of testing. The method used for testing muscle strength simulated the specific muscle action during late swing and early contact phases when sprinting. There have been no prospective studies in elite sprinters that examine the concentric and eccentric isokinetic strength of the hip extensors and the quadriceps and hamstring muscles in a manner that reflects their actions in late swing or early contact phases of sprinting. Consequently, the causal relationship between hip and thigh muscle strength and hamstring injury in elite sprinters may not be fully understood. Isokinetic testing was performed on 30 male elite sprinters to assess hip extensors, quadriceps, and hamstring muscle strength. The occurrence of hamstring injury among the subjects was determined during the year following the muscle strength measurements. The strength of the hip extensors, quadriceps, and hamstring muscles, as well as the hamstrings-quadriceps and hip extensors- quadriceps ratios were compared. Hamstring injury occurred in 6 subjects during the 1-year period. Isokinetic testing at a speed of 60 degrees /s revealed weakness of the injured limb with eccentric action of the hamstring muscles and during concentric action of the hip extensors. When performing a side-to-side comparison for the injured sprinters, the hamstring injury always occurred on the weaker side. Differences in the hamstrings-quadriceps and hip extensors-quadriceps strength ratios were also evident between uninjured and injured limbs, and this was attributable to deficits in hamstring strength. Hamstring injury in elite sprinters was associated with weakness during eccentric action of the hamstrings and weakness during concentric action of

Muscle power is an important measure to detect deficits in muscle function in hip osteoarthritis: a cross-sectional study.

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Bieler, Theresa; Magnusson, Stig Peter; Christensen, Helle Elisabeth; Kjaer, Michael; Beyer, Nina

2017-07-01

To investigate between-leg differences in hip and thigh muscle strength and leg extensor power in patients with unilateral hip osteoarthritis. Further, to compare between-leg differences in knee extensor strength and leg extensor power between patients and healthy peers. Seventy-two patients (60-87 years) with radiographic and symptomatic hip osteoarthritis not awaiting hip replacement and 35 healthy peers (63-82 years) were included. Hip and thigh muscle strength and leg extensor power were measured in patients and knee extensor strength and leg extensor power in healthy. The symptomatic extremity in patients was significantly (p hip muscles (8-17%), knee extensors (11%) and leg extensor power (19%). Healthy older adults had asymmetry in knee extensor strength (6%, p hip osteoarthritis. Implications for Rehabilitation Even in patients with mild symptoms not awaiting hip replacement a generalized muscle weakening of the symptomatic lower extremity seems to be present. Between-leg differences in leg extensor power (force × velocity) appears to be relatively large (19%) in patients with unilateral hip osteoarthritis in contrast to healthy peers who show no asymmetry. Compared to muscle strength the relationship between functional performance and leg extensor power seems to be stronger, and more strongly related to power of the symptomatic lower extremity. Our results indicate that exercise interventions focusing on improving leg extensor power of the symptomatic lower extremity and reducing asymmetry may be beneficial for patients with mild symptoms not awaiting hip replacement.

Four cases of variations in the forearm extensor musculature in a study of hundred limbs and review of literature

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Rao Mohandas

2006-01-01

Full Text Available All surgeons must bear in mind the existence of muscular variations when performing common tendon transfers. Presence of additional bellies and tendons of existing muscles or presence of additional muscles in unusual locations might misguide a surgeon, during surgery and also during diagnosis. In the present paper we are reporting four cases of variations encountered during the study of extensor muscles of the forearm in 100 limbs. In Case 1, additional bellies of extensor carpi radialis longus and extensor carpi radialis brevis and multiple tendons of insertion of abductor pollicis longus were observed in a single limb. In Case 2, an additional belly of the abductor pollicis longus was observed. In Case 3, a short muscle on the dorsum of the hand going to the index finger [extensor indicis brevis (EIB] was found in addition to the normal extensor indicis (EI. It was also observed that some of the most superficial fleshy fibers of EIB were getting inserted into the tendon of EI. In Case 4, a rare incidence of extensor digiti medii proprius was observed. Further, the related literature is reviewed and the clinical and surgical importance of these muscular variations in diagnosis and proper planning of treatment is discussed.

Bilateral assessment of knee muscle relationships in healthy adults

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Gislaine Regina Santos dos Santos

2014-09-01

Full Text Available Asymmetric performance of flexor and extensor muscles of the knee may be a risk factor for knee injuries, especially the anterior cruciate ligament. Additionally, asymmetries in power and work may have correlations with fatigue and performance during functional tasks. Among untrained individuals, such asymmetries may be of potential interest for training prescription. Here, we investigated the bilateral performance of knee flexors and extensors muscle groups of untrained individuals. We quantified the torque-angle and torque-velocity relationships, as well as work, power and asymmetry indexes in 20 untrained male (25 ± 4 years old; height 1.74 ± 0.05 m; body mass 76 ± 9 kg. No significant asymmetry was observed for torque-angle and torque-velocity relationships, work and power output for knee flexor and extensor muscle groups (p < .05. Our results suggest that untrained male present symmetry in the knee flexion and extension bilateral performance. Changes in this behavior due to physical training must be monitored.

Effects of strength training program on hip extensors and knee extensors strength of lower limb in children with spastic diplegic cerebral palsy.

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Aye, Thanda; Thein, Soe; Hlaing, Thaingi

2016-01-01

[Purpose] The purpose of this study was to determine whether strength training programs for hip extensors and knee extensors improve gross motor function of children with cerebral palsy in Myanmar. [Subjects and Methods] Forty children (25 boys and 15 girls, mean age: 6.07 ± 2.74 years) from National Rehabilitation Hospital, Yangon, Myanmar, who had been diagnosed with spastic diplegic cerebral palsy, Gross Motor Classification System I and II participated in a 6-week strength training program (45 minutes per day, 3 days per week) on hip and knee extensors. Assessment was made, before and after intervention, of the amount of training weight in pounds, as well as Gross Motor Function Measure (GMFM) dimensions D (standing) and E (walking, running, jumping). [Results] All scores had increased significantly after the strength-training program. [Conclusion] A simple method of strength-training program for hip and knee extensors might lead to improved muscle strength and gross motor function in children with spastic diplegic cerebral palsy.

Comparative anatomy of the cheek muscles within the Centromochlinae subfamily (Ostariophysi, Siluriformes, Auchenipteridae).

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Sarmento-Soares, Luisa Maria; Porto, Marcovan

2006-02-01

Glanidium melanopterum Miranda Ribeiro, a typical representative of the subfamily Centromochlinae (Siluriformes: Auchenipteridae), is herein described myologically and compared to other representative species within the group, Glanidium ribeiroi, G. leopardum, Tatia neivai, T. intermedia, T. creutzbergi, Centromochlus heckelii, and C. existimatus. The structure of seven pairs of striated cephalic muscles was compared anatomically: adductor mandibulae, levator arcus palatini, dilatator operculi, adductor arcus palatini, extensor tentaculi, retractor tentaculi, and levator operculi. We observed broad adductor mandibulae muscles in both Glanidium and Tatia, catfishes with depressed heads and smaller eyes. Similarities between muscles were observed: the presence of a large aponeurotic insertion for the levator arcus palatini muscle; an adductor arcus palatini muscle whose origin spread over the orbitosphenoid, pterosphenoid, and parasphenoid; and the extensor tentaculi muscle broadly attached to the autopalatine. There is no retractor tentaculi muscle in either the Glanidium or Tatia species. On the other hand, in Centromochlus, with forms having large eyes and the tallest head, the adductor mandibulae muscles are slim; there is a thin aponeurotic or muscular insertion for the levator arcus palatini muscle; the adductor arcus palatini muscle originates from a single osseous process, forming a keel on the parasphenoid; the extensor tentaculi muscle is loosely attached to the autopalatine, permitting exclusive rotating and sliding movements between this bone and the maxillary. The retractor tentaculi muscle is connected to the maxilla through a single tendon, so that both extensor and retractor tentaculi muscles contribute to a wide array of movements of the maxillary barbels. A discussion on the differences in autopalatine-maxillary movements among the analyzed groups is given. (c) 2005 Wiley-Liss, Inc.

Lean muscle volume of the thigh has a stronger relationship with muscle power than muscle strength in women with knee osteoarthritis.

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Davison, Michael J; Maly, Monica R; Keir, Peter J; Hapuhennedige, Sandani M; Kron, Amie T; Adachi, Jonathan D; Beattie, Karen A

2017-01-01

Thigh lean muscle and intramuscular fat have been implicated in the impairment of physical function observed in people with knee osteoarthritis. We investigated the relationships of quadriceps and hamstrings intramuscular fat fraction and lean muscle volume with muscle power and strength, controlling for neuromuscular activation, and physical performance in women with knee OA. Women (n=20) 55years or older with symptomatic, radiographic knee osteoarthritis underwent a 3.0T magnetic resonance imaging scan of the thigh of their most symptomatic knee. Axial fat-separated images were analyzed using software to quantify intramuscular fat and lean muscle volumes of the quadriceps and hamstrings. To quantify strength and power of the knee extensors and flexors, participants performed maximum voluntary isometric contraction and isotonic knee extensions and flexions, respectively. Electromyography of the quadriceps and hamstrings was measured. Participants also completed five physical performance tests. Quadriceps and hamstrings lean muscle volumes were related to isotonic knee extensor (B=0.624; p=0.017) and flexor (B=1.518; p=0.032) power, but not knee extensor (B=0.001; p=0.615) or flexor (B=0.001; p=0.564) isometric strength. Intramuscular fat fractions were not related to isotonic knee extensor or flexor power, nor isometric strength. No relationships were found between intramuscular fat or lean muscle volume and physical performance. Muscle power may be more sensitive than strength to lean muscle mass in women with knee osteoarthritis. Thigh lean muscle mass, but neither intramuscular nor intermuscular fat, is related to knee extensor and flexor power in women with knee osteoarthritis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lower extremity muscle functions during full squats.

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Robertson, D G E; Wilson, Jean-Marie J; St Pierre, Taunya A

2008-11-01

The purpose of this research was to determine the functions of the gluteus maximus, biceps femoris, semitendinosus, rectus femoris, vastus lateralis, soleus, gastrocnemius, and tibialis anterior muscles about their associated joints during full (deep-knee) squats. Muscle function was determined from joint kinematics, inverse dynamics, electromyography, and muscle length changes. The subjects were six experienced, male weight lifters. Analyses revealed that the prime movers during ascent were the monoarticular gluteus maximus and vasti muscles (as exemplified by vastus lateralis) and to a lesser extent the soleus muscles. The biarticular muscles functioned mainly as stabilizers of the ankle, knee, and hip joints by working eccentrically to control descent or transferring energy among the segments during scent. During the ascent phase, the hip extensor moments of force produced the largest powers followed by the ankle plantar flexors and then the knee extensors. The hip and knee extensors provided the initial bursts of power during ascent with the ankle extensors and especially a second burst from the hip extensors adding power during the latter half of the ascent.

Do oarsmen have asymmetries in the strength of their back and leg muscles?

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Parkin, S; Nowicky, A V; Rutherford, O M; McGregor, A H

2001-07-01

The aim of this study was to establish whether asymmetry of the strength of the leg and trunk musculature is more prominent in rowers than in controls. Nineteen oarsmen and 20 male controls matched for age, height and body mass performed a series of isokinetic and isometric strength tests on an isokinetic dynamometer. These strength tests focused on the trunk and leg muscles. Comparisons of strength were made between and within groups for right and left symmetry patterns, hamstring: quadriceps ratios, and trunk flexor and extensor ratios. The results revealed no left and right asymmetries in either the knee extensor or flexor strength parameters (including both isometric and isokinetic measures). Knee extensor strength was significantly greater in the rowing population, but knee flexor strength was similar between the two groups. No difference was seen between the groups for the hamstring: quadriceps strength ratio. In the rowing population, stroke side had no influence on leg strength. No differences were observed in the isometric strength of the trunk flexors and extensors between groups, although EMG activity was significantly higher in the rowing population. Patterns of asymmetry of muscle activity were observed between the left and right erector spinae muscles during extension, which was significantly related to rowing side (P low back pain in oarsmen.

Effects of chronic administration of clenbuterol on contractile properties and calcium homeostasis in rat extensor digitorum longus muscle.

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Sirvent, Pascal; Douillard, Aymerick; Galbes, Olivier; Ramonatxo, Christelle; Py, Guillaume; Candau, Robin; Lacampagne, Alain

2014-01-01

Clenbuterol, a β2-agonist, induces skeletal muscle hypertrophy and a shift from slow-oxidative to fast-glycolytic muscle fiber type profile. However, the cellular mechanisms of the effects of chronic clenbuterol administration on skeletal muscle are not completely understood. As the intracellular Ca2+ concentration must be finely regulated in many cellular processes, the aim of this study was to investigate the effects of chronic clenbuterol treatment on force, fatigue, intracellular calcium (Ca2+) homeostasis and Ca2+-dependent proteolysis in fast-twitch skeletal muscles (the extensor digitorum longus, EDL, muscle), as they are more sensitive to clenbuterol-induced hypertrophy. Male Wistar rats were chronically treated with 4 mg.kg-1 clenbuterol or saline vehicle (controls) for 21 days. Confocal microscopy was used to evaluate sarcoplasmic reticulum Ca2+ load, Ca2+-transient amplitude and Ca2+ spark properties. EDL muscles from clenbuterol-treated animals displayed hypertrophy, a shift from slow to fast fiber type profile and increased absolute force, while the relative force remained unchanged and resistance to fatigue decreased compared to control muscles from rats treated with saline vehicle. Compared to control animals, clenbuterol treatment decreased Ca2+-transient amplitude, Ca2+ spark amplitude and frequency and the sarcoplasmic reticulum Ca2+ load was markedly reduced. Conversely, calpain activity was increased by clenbuterol chronic treatment. These results indicate that chronic treatment with clenbuterol impairs Ca2+ homeostasis and this could contribute to the remodeling and functional impairment of fast-twitch skeletal muscle.

The impact of type 1 diabetes and diabetic polyneuropathy on muscle strength and fatigability.

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Orlando, Giorgio; Balducci, Stefano; Bazzucchi, Ilenia; Pugliese, Giuseppe; Sacchetti, Massimo

2017-06-01

Although it is widely accepted that diabetic polyneuropathy (DPN) is linked to a marked decline in neuromuscular performance, information on the possible impact of type 1 diabetes (T1D) on muscle strength and fatigue remains unclear. The purpose of this study was to investigate the effects of T1D and DPN on strength and fatigability in knee extensor muscles. Thirty-one T1D patients (T1D), 22 T1D patients with DPN (DPN) and 23 matched healthy control participants (C) were enrolled. Maximal voluntary contraction (MVC) and endurance time at an intensity level of 50% of the MVC were assessed at the knee extensor muscles with an isometric dynamometer. Clinical characteristics of diabetic patients were assessed by considering a wide range of vascular and neurological parameters. DPN group had lower knee extensor muscles strength than T1D (-19%) and the C group (-37.5%). T1D group was 22% weaker when compared to the C group. Lower body muscle fatigability of DPN group was 22 and 45.5% higher than T1D and C group, respectively. T1D group possessed a higher fatigability (29.4%) compared to C group. A correlation was found between motor and sensory nerve conduction velocity and muscle strength and fatigability. Patients with T1D are characterised by both a higher fatigability and a lower muscle strength, which are aggravated by DPN. Our data suggest that factors other than nervous damage play a role in the pathogenesis of such defect.

Comparison of the electrical activity in upper trapezius and wrist extensor muscles during two typewriting conditions

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João Carlos Comel

Full Text Available Introduction The proper use of the position of the arm and wrist while typing may reduce muscle overload and prevent musculoskeletal disorders.Objective To evaluate the electromyographic activity of upper trapezius and wrist extensor muscles during two typewriting conditions.Materials and methods : Six healthy females (Xage = 42 years,SD= 10, (Xheight = 1.65m, SD = 0.05 and (Xweight = 71kg, SD = 16 participated in this study. The task was performed with a newly developed arm support and without the support. A perceived exertion scale was used with all subjects. An ANOVA with repeated measures was used to verify differences in perceived exertion and root mean square (RMS.Results There were no statistically significant differences for the RMS between the typewriting tasks. The condition without arm support presented a significantly greater mean velocity and amount of words typed (P= 0.02; P= 0.03 and there was a significant difference in perceived exertion during the condition without arm support (P= 0.03. Electromyographic activity did not present differences.Conclusion The muscle electrical activity was not altered regardless the arm support and occurred the improvement of the perceived exertion after 10 minutes of typing without support. Long-term studies are needed.

[Reconstruction of the extensor pollicis longus tendon by transposition of the extensor indicis tendon].

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Loos, A; Kalb, K; Van Schoonhoven, J; Landsleitner Dagger, B

2003-12-01

Rupture of the extensor pollicis longus-tendon (EPL) is a frequent complication after distal radius fractures. Other traumatic and non-traumatic reasons for this tendon lesion are known, including a theory about a disorder in the blood supply to the tendon itself. We examined 40 patients after reconstruction of the EPL-tendon in a mean follow-up time of 30 months. All patients were clinically examined and a DASH questionnaire was answered by all patients. The method to reconstruct the EPL-tendon was the transposition of the extensor indicis-tendon. After the operations the thumb was put in a splint for four weeks in a "hitch-hiker's-position". 31 ruptures of the tendon (77.5 %) were a result of trauma. In 20 of them (50 %) a distal radius fracture had occurred. Clinical examination included measurements of the movement of the thumb- and index-finger joints, the grip strength and the maximal span of the hand. Significant differences were not found. The isolated extension of the index finger was possible in all patients. But it was reduced in ten cases which represent 25 %. Our results were evaluated by the Geldmacher score to evaluate the reconstruction of the EPL-tendon. 20 % excellent, 65 % good, 12.5 % fair and 2.5 % poor results were reached. The Geldmacher score was used critically. We suggest its modification for the evaluation of thumb abduction. The DASH score reached a functional value of ten points which represents a very good result. In conclusion the extensor indicis-transposition is a safe method to reconstruct the EPL-tendon. Its substantial advantage is taking a healthy muscle as the motor, thereby avoiding the risk of using a degenerated muscle in late tendon reconstruction. A powerful extension of the index finger will be maintained by physical education. Generally, the loss of the extension of the index finger is negligible. It does not disturb the patients. But it has to be discussed with the patient before the operation.

The Immediate Effect of Neuromuscular Joint Facilitation (NJF) Treatment on Hip Muscle Strength.

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Wang, Hongdan; Huo, Ming; Huang, Qiuchen; Li, Desheng; Maruyama, Hitoshi

2013-11-01

[Purpose] This study investigated the change in hip muscle strength of younger persons after neuromuscular joint facilitation (NJF) treatment. [Subjects] The subjects were 45 healthy young people, who were divided into two groups: a NJF group and a proprioceptive neuromuscular facilitation (PNF) group. The NJF group consisted of 21 subjects (11 males, 10 females), and the PNF group consisted of 24 subjects (11 males, 13 females). [Methods] Participants in the NJF group received NJF treatment. We measured the maximal flexor strength and the maximal extensor strength during isokinetic movement of the hip joint before and after intervention in both groups. The angular velocities used were 60°/sec and 180°/sec. [Results] The NJF group showed significant increases in the maximal flexor strength and the maximal extensor strength after the intervention at each angular velocity. In the PNF group, the maximal flexor strength of 60°/sec and the maximal extensor strength of 180°/sec were significant increases. [Conclusion] These results suggest that there is an immediate effect of NJF intervention on hip muscle strength.

Isometric elbow extensors strength in supine- and prone-lying positions.

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Abdelzaher, Ibrahim E; Ababneh, Anas F; Alzyoud, Jehad M

2013-01-01

The purpose of this study was to compare isometric strength of elbow extensors measured in supine- and prone-lying positions at elbow flexion angles of 45 and 90 degrees. Twenty-two male subjects under single-blind procedures participated in the study. Each subject participated in both supine-lying and prone-lying measuring protocols. Calibrated cable tensiometer was used to measure isometric strength of the right elbow extensors and a biofeedback electromyography was used to assure no substitution movements from shoulder girdle muscles. The mean values of isometric strength of elbow extensors measured from supine-lying position at elbow flexion angles of 45 and 90 degrees were 11.1  ±  4.2 kg and 13.1  ±  4.6 kg, while those measured from prone-lying position were 9.9  ±  3.6 kg and 12  ±  4.2 kg, respectively. There is statistical significant difference between the isometric strength of elbow extensors measured from supine-lying position at elbow flexion angles of 45 and 90 degrees compared to that measured from prone-lying position (p  isometric strength of elbow extensors since supine-lying starting position is better than prone-lying starting position.

Fatty infiltrate in the cervical extensor muscles is not a feature of chronic, insidious-onset neck pain

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Elliott, J. [Division of Physiotherapy, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane (Australia); Department of Physical Therapy, Rueckert-Hartman School for Health Professions, Regis University, Denver, Colorado (United States); Centre for Magnetic Resonance, University of Queensland, Brisbane (Australia)], E-mail: jelltt@regis.edu; Sterling, M. [Division of Physiotherapy, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane (Australia); Noteboom, J.T. [Department of Physical Therapy, Rueckert-Hartman School for Health Professions, Regis University, Denver, Colorado (United States); Darnell, R. [Division of Physiotherapy, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane (Australia); Galloway, G. [Centre for Magnetic Resonance, University of Queensland, Brisbane (Australia); Jull, G. [Division of Physiotherapy, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane (Australia)

2008-06-15

Aim: To investigate the presence of fatty infiltrate in the cervical extensor musculature in patients with insidious-onset neck pain to better understand the possible pathophysiology underlying such changes in chronic whiplash-associated disorders (WAD). Materials and methods: A sample of convenience of 23 women with persistent insidious-onset neck pain (mean age 29.2 {+-} 6.9 years) was recruited for the study. Magnetic resonance imaging (MRI) was used to quantify fatty infiltration in the cervical extensor musculature. Quantitative Sensory Testing (QST; pressure and thermal pain thresholds) was performed as sensory features are present in chronic whiplash. Self-reported pain and disability, as well as psychological distress, were measured using the Neck Disability Index (NDI) and the General Health Questionnaire-28 (GHQ-28), respectively. Results: Measures were compared with those of a previous dataset of chronic whiplash patients (n = 79, mean age 29.7 {+-} 7.8 years). Using a classification tree, insidious-onset neck pain was clearly identified from whiplash (p < 0.001), based on the presence of MRI fatty infiltrate in the cervical extensor musculature (0/102 individuals) and altered temperature thresholds (cold; 3/102 individuals). Conclusion: Fatty infiltrates in the cervical extensor musculature and widespread hyperalgesia were not features of the insidious-onset neck pain group in this study; whereas these features have been identified in patients with chronic WAD. This novel finding may enable a better understanding of the underlying pathophysiological processes in patients with chronic whiplash.

Fatty infiltrate in the cervical extensor muscles is not a feature of chronic, insidious-onset neck pain

International Nuclear Information System (INIS)

Elliott, J.; Sterling, M.; Noteboom, J.T.; Darnell, R.; Galloway, G.; Jull, G.

2008-01-01

Aim: To investigate the presence of fatty infiltrate in the cervical extensor musculature in patients with insidious-onset neck pain to better understand the possible pathophysiology underlying such changes in chronic whiplash-associated disorders (WAD). Materials and methods: A sample of convenience of 23 women with persistent insidious-onset neck pain (mean age 29.2 ± 6.9 years) was recruited for the study. Magnetic resonance imaging (MRI) was used to quantify fatty infiltration in the cervical extensor musculature. Quantitative Sensory Testing (QST; pressure and thermal pain thresholds) was performed as sensory features are present in chronic whiplash. Self-reported pain and disability, as well as psychological distress, were measured using the Neck Disability Index (NDI) and the General Health Questionnaire-28 (GHQ-28), respectively. Results: Measures were compared with those of a previous dataset of chronic whiplash patients (n = 79, mean age 29.7 ± 7.8 years). Using a classification tree, insidious-onset neck pain was clearly identified from whiplash (p < 0.001), based on the presence of MRI fatty infiltrate in the cervical extensor musculature (0/102 individuals) and altered temperature thresholds (cold; 3/102 individuals). Conclusion: Fatty infiltrates in the cervical extensor musculature and widespread hyperalgesia were not features of the insidious-onset neck pain group in this study; whereas these features have been identified in patients with chronic WAD. This novel finding may enable a better understanding of the underlying pathophysiological processes in patients with chronic whiplash

The effect of knee extensor open kinetic chain resistance training in the ACL-injured knee.

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Barcellona, Massimo G; Morrissey, Matthew C; Milligan, Peter; Clinton, Melissa; Amis, Andrew A

2015-11-01

To investigate the effect of different loads of knee extensor open kinetic chain resistance training on anterior knee laxity and function in the ACL-injured (ACLI) knee. Fifty-eight ACLI subjects were randomised to one of three (12-week duration) training groups. The STAND group trained according to a standardised rehabilitation protocol. Subjects in the LOW and HIGH group trained as did the STAND group but with the addition of seated knee extensor open kinetic chain resistance training at loads of 2 sets of 20 repetition maximum (RM) and 20 sets of 2RM, respectively. Anterior knee laxity and measurements of physical and subjective function were performed at baseline, 6 and 12 weeks. Thirty-six subjects were tested at both baseline and 12 weeks (STAND n = 13, LOW n = 11, HIGH n = 12). The LOW group demonstrated a reduction in 133 N anterior knee laxity between baseline and 12 weeks testing when compared to the HIGH and the STAND groups (p = 0.009). Specifically, the trained-untrained knee laxity decreased an average of approximately 5 mm in the LOW group while remaining the same in the other two groups. Twelve weeks of knee extensor open kinetic chain resistance training at loads of 2 sets of 20RM led to a reduction in anterior knee laxity in the ACLI knee. This reduction in laxity does not appear to offer any significant short-term functional advantages when compared to a standard rehabilitation protocol. These results indicate that knee laxity can be decreased with resistance training of the thigh muscles. Randomised controlled trial, Level II.

Surgical Treatment of Traumatic Myositis Ossificans of the Extensor Carpi Radialis Muscle in a Dog.

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Morton, Bridget A; Hettlich, Bianca F; Pool, Roy R

2015-07-01

To report clinical signs, diagnostic imaging findings, and outcome in a dog with traumatic myositis ossificans of the origin of the extensor carpi radialis muscle. Clinical report. An 8-month-old intact female Irish Setter Dog. After radiographic and computed tomographic evaluation of an osseous proliferation arising from the cranial cortex of the right distal humeral diaphysis, the protruding bone was surgically removed and evaluated by histopathology. Traumatic myositis ossificans was successfully treated with surgical removal of the osseous proliferation resulting in improved postoperative range of motion of the right elbow joint. There was no evidence of lameness or abnormal bone regrowth associated with the surgical site radiographically at follow up. Surgical removal of a traumatic myositis ossificans lesion resulted in full return to function in a young, competitive show dog. © Copyright 2014 by The American College of Veterinary Surgeons.

Activation of plantar flexor muscles is constrained by multiple muscle synergies rather than joint torques.

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Takahito Suzuki

Full Text Available Behavioral evidence has suggested that a small number of muscle synergies may be responsible for activating a variety of muscles. Nevertheless, such dimensionality reduction may also be explained using the perspective of alternative hypotheses, such as predictions based on linear combinations of joint torques multiplied by corresponding coefficients. To compare the explanatory capacity of these hypotheses for describing muscle activation, we enrolled 12 male volunteers who performed isometric plantar flexor contractions at 10-100% of maximum effort. During each plantar flexor contraction, the knee extensor muscles were isometrically contracted at 0%, 50%, or 100% of maximum effort. Electromyographic activity was recorded from the vastus lateralis, medial gastrocnemius (MG, lateral gastrocnemius (LG, and soleus muscles and quantified using the average rectified value (ARV. At lower plantar flexion torque, regression analysis identified a clear linear relationship between the MG and soleus ARVs and between the MG and LG ARVs, suggesting the presence of muscle synergy (r2 > 0.65. The contraction of the knee extensor muscles induced a significant change in the slope of this relationship for both pairs of muscles (MG × soleus, P = 0.002; MG × LG, P = 0.006. Similarly, the slope of the linear relationship between the plantar flexion torque and the ARV of the MG or soleus changed significantly with knee extensor contraction (P = 0.031 and P = 0.041, respectively. These results suggest that muscle synergies characterized by non-mechanical constraints are selectively recruited according to whether contraction of the knee extensor muscles is performed simultaneously, which is relatively consistent with the muscle synergy hypothesis.

Heterogeneous recruitment of quadriceps muscle portions and fibre types during moderate intensity knee-extensor exercise: effect of thigh occlusion

DEFF Research Database (Denmark)

Krustrup, Peter; Söderlund, Karin; Relu, Mihai U.

2009-01-01

temperature increase (DeltaT(m)) in RF was 0.52+/-0.09 degrees C, which was 57% and 73% higher (Pmuscle CP in slow twitch (ST) and fast......The involvement of quadriceps femoris muscle portions and fibre type recruitment was studied during submaximal knee-extensor exercise without and with thigh occlusion (OCC) and compared with responses during intense exercise. Six healthy male subjects performed 90-s of moderate exercise without...... twitch (FT) fibres was 81% and 91% of resting levels, respectively, with lower (Pfibres had CP levels below mean-1 SD, respectively, with corresponding values for FT fibres being 41...

Seasonal variation in isokinetic strength of knee flexors and extensors in soccer players

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Michal Lehnert

2015-06-01

Full Text Available BACKGROUND: Muscle strength is an important factor in soccer from the performance and health perspective. There is a lack of knowledge about changes in muscle strength of the knee flexors and extensors and their ratios during annual training cycle. OBJECTIVES: The aim of this study was to evaluate the seasonal variability of the observed parameters of isokinetic strength of the knee flexors and extensors in soccer players, U19, from the performance and health perspective. METHODS: The strength of the knee flexors and extensors was measured in players U19 category (n = 9; the average age 18.5 ±0.4 years on the isokinetic dynamometer IsoMed 2000 in angular velocity 60° × s-1. Measurement was performed in concentric/concentric and excentric/excentric mode of muscle action at the beginning of the winter preparatory period, at the end of the preparatory period and at the end of the spring competitive period. Monitored parameters were absolute peak torque (PT, conventional H/Q ratio (H/QCON, functional H/Q ratio (H/QFUN and functional H/Q ratio in range 10-30° of knee flexion (H/QFUN_10-30. RESULTS: Significant change in PT (p < .05 was noted only in cases of the knee extensors of the nondominant leg in the concentric mode. The evaluation of imbalance of the knee flexors and extensors by H/QCON and H/QFUN ratios did not show any significant changes, but there was found a significant decrease of the H/QFUN_10-30 ratio in the dominant leg between measurements at the beginning and at the end of the winter preparatory period. CONCLUSIONS: The results of the current study indicate that throughout the monitored periods of the annual training cycle desirable changes in knee flexors and extensors strength did not occur. The values suggest the disruption of the dynamic stabilization of the knee joint and increase in injury risk. Different dynamics of the three observed ratios confirmed that they provide different information about the physical fitness of

Work-related pain in extrinsic finger extensor musculature of instrumentalists is associated with intracellular pH compartmentation during exercise.

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Angel Moreno-Torres

Full Text Available BACKGROUND: Although non-specific pain in the upper limb muscles of workers engaged in mild repetitive tasks is a common occupational health problem, much is unknown about the associated structural and biochemical changes. In this study, we compared the muscle energy metabolism of the extrinsic finger extensor musculature in instrumentalists suffering from work-related pain with that of healthy control instrumentalists using non-invasive phosphorus magnetic resonance spectroscopy ((31P-MRS. We hypothesize that the affected muscles will show alterations related with an impaired energy metabolism. METHODOLOGY/PRINCIPAL FINDINGS: We studied 19 volunteer instrumentalists (11 subjects with work-related pain affecting the extrinsic finger extensor musculature and 8 healthy controls. We used (31P-MRS to find deviations from the expected metabolic response to exercise in phosphocreatine (PCr, inorganic phosphate (Pi, Pi/PCr ratio and intracellular pH kinetics. We observed a reduced finger extensor exercise tolerance in instrumentalists with myalgia, an intracellular pH compartmentation in the form of neutral and acid compartments, as detected by Pi peak splitting in (31P-MRS spectra, predominantly in myalgic muscles, and a strong association of this pattern with the condition. CONCLUSIONS/SIGNIFICANCE: Work-related pain in the finger extrinsic extensor muscles is associated with intracellular pH compartmentation during exercise, non-invasively detectable by (31P-MRS and consistent with the simultaneous energy production by oxidative metabolism and glycolysis. We speculate that a deficit in energy production by oxidative pathways may exist in the affected muscles. Two possible explanations for this would be the partial and/or local reduction of blood supply and the reduction of the muscle oxidative capacity itself.

Work-Related Pain in Extrinsic Finger Extensor Musculature of Instrumentalists Is Associated with Intracellular pH Compartmentation during Exercise

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Moreno-Torres, Angel; Rosset-Llobet, Jaume; Pujol, Jesus; Fàbregas, Sílvia; Gonzalez-de-Suso, Jose-Manuel

2010-01-01

Background Although non-specific pain in the upper limb muscles of workers engaged in mild repetitive tasks is a common occupational health problem, much is unknown about the associated structural and biochemical changes. In this study, we compared the muscle energy metabolism of the extrinsic finger extensor musculature in instrumentalists suffering from work-related pain with that of healthy control instrumentalists using non-invasive phosphorus magnetic resonance spectroscopy (31P-MRS). We hypothesize that the affected muscles will show alterations related with an impaired energy metabolism. Methodology/Principal Findings We studied 19 volunteer instrumentalists (11 subjects with work-related pain affecting the extrinsic finger extensor musculature and 8 healthy controls). We used 31P-MRS to find deviations from the expected metabolic response to exercise in phosphocreatine (PCr), inorganic phosphate (Pi), Pi/PCr ratio and intracellular pH kinetics. We observed a reduced finger extensor exercise tolerance in instrumentalists with myalgia, an intracellular pH compartmentation in the form of neutral and acid compartments, as detected by Pi peak splitting in 31P-MRS spectra, predominantly in myalgic muscles, and a strong association of this pattern with the condition. Conclusions/Significance Work-related pain in the finger extrinsic extensor muscles is associated with intracellular pH compartmentation during exercise, non-invasively detectable by 31P-MRS and consistent with the simultaneous energy production by oxidative metabolism and glycolysis. We speculate that a deficit in energy production by oxidative pathways may exist in the affected muscles. Two possible explanations for this would be the partial and/or local reduction of blood supply and the reduction of the muscle oxidative capacity itself. PMID:20161738

ALTERATION OF MUSCLE FUNCTION AFTER ELECTRICAL STIMULATION BOUT OF KNEE EXTENSORS AND FLEXORS

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Marc Vanderthommen

2012-12-01

Full Text Available The purpose was to study the effects on muscle function of an electrical stimulation bout applied unilaterally on thigh muscles in healthy male volunteers. One group (ES group, n = 10 received consecutively 100 isometric contractions of quadriceps and 100 isometric contractions of hamstrings (on-off ratio 6-6 s induced by neuromuscular electrical stimulations (NMES. Changes in muscle torque, muscle soreness (0-10 VAS, muscle stiffness and serum creatine kinase (CK activity were assessed before the NMES exercise (pre-ex as well as 24h (d+1, 48h (d+2 and 120h (d+5 after the bout. A second group (control group, n = 10 were submitted to the same test battery than the ES group and with the same time-frame. The between-group comparison indicated a significant increase in VAS scores and in serum levels of CK only in the ES group. In the ES group, changes were more pronounced in hamstrings than in quadriceps and peaked at d+2 (quadriceps VAS scores = 2.20 ± 1.55 a.u. (0 at pre-ex; hamstrings VAS scores = 3.15 ± 2.14 a.u. (0 at pre-ex; hip flexion angle = 62 ± 5° (75 ± 6° at pre-ex; CK activity = 3021 ± 2693 IU·l-1 (136 ± 50 IU·l-1 at pre-ex. The results of the present study suggested the occurrence of muscle damage that could have been induced by the peculiar muscle recruitment in NMES and the resulting overrated mechanical stress. The sensitivity to the damaging effects of NMES appeared higher in the hamstrings than in quadriceps muscles

The Effect of Ratio of Contraction to Relaxation Durations in PNF Exercises on the Muscle Strength and Range of Motion of Hip Joint

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Hossein Rashedi

2015-09-01

Full Text Available Objective: The aim of the present study was to compare the effect of ratios of contraction- Relaxation on the muscle strength and range of motion of hip joint in PNF exercises. Methods: Thirty nine nonathletic male students (Mean±SD; age, 13±1.2 years; body mass, 55±9.8 kg were assigned .Three groups designated as I, II and III groups. The ratios of contraction to relaxation periods for groups were 1, 2 and 3 respectively. Training program included three sessions per week (CR-PNF for 6 weeks. Measurements of hip extensors muscles stretch and strength were performed at the beginning and at the end of training using an inclinometer (during leg raise test and dynamometer. Data were analyzed using dependent samples t-test and one-way ANOVA. Results: The results of the present study showed significant increases in hip extensor muscles flexibility and strength for three groups. This increase the in the strength in group I equaled 6 kg, in group II 4 kg and in group III 7 kg. The amount of increase in the hip extensor muscles flexibility in group I, II and II were 15, 8 and 12 degrees, respectively. The increase in these two variables was significant and similar in all three groups. Conclusion: Different contraction to relaxation ratio normally, 0.5, 1 and 2, did not show any meaningful differences on hip extensor muscular strength and hip range of motion.

Bioenergetics and ATP Synthesis during Exercise: Role of Group III/IV Muscle Afferents.

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Broxterman, Ryan M; Layec, Gwenael; Hureau, Thomas J; Morgan, David E; Bledsoe, Amber D; Jessop, Jacob E; Amann, Markus; Richardson, Russell S

2017-12-01

The purpose of this study was to investigate the role of the group III/IV muscle afferents in the bioenergetics of exercising skeletal muscle beyond constraining the magnitude of metabolic perturbation. Eight healthy men performed intermittent isometric knee-extensor exercise to task failure at ~58% maximal voluntary contraction under control conditions (CTRL) and with lumbar intrathecal fentanyl to attenuate group III/IV leg muscle afferents (FENT). Intramuscular concentrations of phosphocreatine (PCr), inorganic phosphate (Pi), diprotonated phosphate (H2PO4), adenosine triphosphate (ATP), and pH were determined using phosphorous magnetic resonance spectroscopy (P-MRS). The magnitude of metabolic perturbation was significantly greater in FENT compared with CTRL for [Pi] (37.8 ± 16.8 vs 28.6 ± 8.6 mM), [H2PO4] (24.3 ± 12.2 vs 17.9 ± 7.1 mM), and [ATP] (75.8% ± 17.5% vs 81.9% ± 15.8% of baseline), whereas there was no significant difference in [PCr] (4.5 ± 2.4 vs 4.4 ± 2.3 mM) or pH (6.51 ± 0.10 vs 6.54 ± 0.14). The rate of perturbation in [PCr], [Pi], [H2PO4], and pH was significantly faster in FENT compared with CTRL. Oxidative ATP synthesis was not significantly different between conditions. However, anaerobic ATP synthesis, through augmented creatine kinase and glycolysis reactions, was significantly greater in FENT than in CTRL, resulting in a significantly greater ATP cost of contraction (0.049 ± 0.016 vs 0.038 ± 0.010 mM·min·N). Group III/IV muscle afferents not only constrain the magnitude of perturbation in intramuscular Pi, H2PO4, and ATP during small muscle mass exercise but also seem to play a role in maintaining efficient skeletal muscle contractile function in men.

Decreased torque and electromyographic activity in the extensor thigh muscles in chondromalacia patellae.

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Väätäinen, U; Airaksinen, O; Jaroma, H; Kiviranta, I

1995-01-01

The alterations in thigh muscle properties of chondromalacia patellae patients during isometric and dynamic endurance tests were studied using a variokinetic knee testing system linked to surface EMG. A total of 41 patients (chondromalacia group) with arthroscopically certified chondromalacia of the patella were studied. The control group consisted of 31 healthy adult volunteers with no history of knee pain or trauma. Peak torque values were 21% (p chondromalacia group than in the control group. The decrease in the ratio between integrated EMG (IEMG) and measured force were found in all parts of the quadriceps femoris muscle in patients with chondromalacia of the patella in isometric extension. No change in the normalized IEMG levels of the thigh muscles were found between chondromalacia patients and controls in dynamic endurance test. The severity of the chondromalacia of the patella did not affect the level of electromyographic activation in thigh muscles. The ratio of normalized EMG levels of vastus medialis and vastus lateralis did not differ between the groups. The present study showed that chondromalacia patellae patients have reduced force and electromyographic activation levels of quadriceps femoris muscle. Especially, the explosive strength of the quadriceps femoris muscle is reduced.

Relationship between the Modified Modified Ashworth Scale and the Biomechanical Measure in Assessing Knee Extensor Muscle Spasticity in Patients with Post-Stroke Hemiparesia:A Pilot Study

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N. Nakhostin Ansari

2014-07-01

Full Text Available Introduction & Objective: The Modified Modified Ashworth Scale (MMAS is a clinical meas-ure that has been recently developed for the assessment of muscle spasticity. There is a dearth of research on the validity of the MMAS. The aim of the present study was to investi-gate the relationship between the MMAS and the biomechanical measure of work-velocity slope in assessing knee extensor muscle spasticity in patients with hemiparesia. Materials & Methods: Fourteen patients with post-stroke hemiparesia were included in this cross sectional study. Knee extensor spasticity was assessed with MMAS. An isokinetic dy-namometer was used to impose knee passive flexion with the angular velocity of 10, 30, 60, and 90 °/Sec to measure Torque-angle data. Work (Joule was calculated at each velocity to determine the slope of the work-velocity curves as the biomechanical measure of muscle spasticity. Results: The mean work decreased as the velocity increased but was not statistically signifi-cant (P = 0.07. The mean slope was – 0.35 [J /(°/Sec]. There was no significant correlation between the MMAS and the work-velocity slope (r =0.31, P = 0.28. Conclusion: There was no significant relationship between the MMAS and the biomechanical measure of work-velocity slope. Further studies with larger sample size are suggested. (Sci J Hamadan Univ Med Sci 2014; 21 (2: 131-136

Sex Comparison of Knee Extensor Size, Strength and Fatigue Adaptation to Sprint Interval Training.

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Bagley, Liam; Al-Shanti, Nasser; Bradburn, Steven; Baig, Osamah; Slevin, Mark; McPhee, Jamie S

2018-03-12

Regular sprint interval training (SIT) improves whole-body aerobic capacity and muscle oxidative potential, but very little is known about knee extensor anabolic or fatigue resistance adaptations, or whether effects are similar for males and females. The purpose of this study was to compare sex-related differences in knee extensor size, torque-velocity relationship and fatigability adaptations to 12 weeks SIT. Sixteen males and fifteen females (mean (SEM) age: 41 (±2.5) yrs) completed measurements of total body composition assessed by DXA, quadriceps muscle cross-sectional area (CSAQ) assessed by MRI, the knee extensor torque-velocity relationship (covering 0 - 240°·sec) and fatigue resistance, which was measured as the decline in torque from the first to the last of 60 repeated concentric knee extensions performed at 180°·sec. SIT consisted of 4 x 20 second sprints on a cycle ergometer set at an initial power output of 175% of power at VO2max, three times per week for 12 weeks. CSAQ increased by 5% (p=0.023) and fatigue resistance improved 4.8% (p=0.048), with no sex differences in these adaptations (sex comparisons: p=0.140 and p=0.282, respectively). Knee extensor isometric and concentric torque was unaffected by SIT in both males and females (p>0.05 for all velocities). 12 weeks SIT, totalling 4 minutes very intense cycling per week, significantly increased fatigue resistance and CSAQ similarly in males and females, but did not significantly increase torque in males or females. These results suggest that SIT is a time-effective training modality for males and females to increase leg muscle size and fatigue resistance.

Magnetic resonance imaging analysis of the upper cervical spine extensor musculature in an asymptomatic cohort: an index of fat within muscle

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Elliott, J.M.; Galloway, G.J.; Jull, G.A.; Noteboom, J.T.; Centeno, C.J.; Gibbon, W.W.

2005-01-01

AIM: To establish a simple method to quantify muscle/fat constituents in cervical muscles of asymptomatic women using magnetic resonance imaging (MRI), and to determine whether there is an age effect within a defined age range. MATERIALS AND METHODS: MRI of the upper cervical spine was performed for 42 asymptomatic women aged 18-45 years. The muscle and fat signal intensities on axial spin echo T1-weighted images were quantitatively classified by taking a ratio of the pixel intensity profiles of muscle against those of intermuscular fat for the rectus capitis posterior major and minor and inferior obliquus capitis muscles bilaterally. Inter- and intra-examiner agreement was scrutinized. RESULTS: The average relative values of fat within the upper cervical musculature compared with intermuscular fat indicated that there were only slight variations in indices between the three sets of muscles. There was no significant correlation between age and fat indices. There were significant differences for the relative fat within the muscle compared with intermuscular fat and body mass index for the right rectus capitis posterior major and right and left inferior obliquus capitis muscles (p=0.032). Intraclass correlation coefficients for intraobserver agreement ranged from 0.94 to 0.98. Inter-rater agreement of the measurements ranged from 0.75 to 0.97. CONCLUSION: A quantitative measure of muscle/fat constituents has been developed, and results of this study indicate that relative fatty infiltration is not a feature of age in the upper cervical extensor muscles of women aged 18-45 years

Magnetic resonance imaging analysis of the upper cervical spine extensor musculature in an asymptomatic cohort: an index of fat within muscle

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Elliott, J.M. [Division of Physiotherapy, University of Queensland, Brisbane, QLD (Australia)]. E-mail: jimelliott@plbb.net; Galloway, G.J. [Center for Magnetic Resonance, University of Queensland, Brisbane, QLD (Australia); Jull, G.A. [Division of Physiotherapy, University of Queensland, Brisbane, QLD (Australia); Noteboom, J.T. [Department of Physical Therapy, Regis University, Denver, CO, USA (United States); Centeno, C.J. [Centeno Clinic, Westminster, CO, USA (United States); Gibbon, W.W. [Department of Radiology, School of Medicine, University of Queensland, Brisbane, QLD (Australia)

2005-03-01

AIM: To establish a simple method to quantify muscle/fat constituents in cervical muscles of asymptomatic women using magnetic resonance imaging (MRI), and to determine whether there is an age effect within a defined age range. MATERIALS AND METHODS: MRI of the upper cervical spine was performed for 42 asymptomatic women aged 18-45 years. The muscle and fat signal intensities on axial spin echo T1-weighted images were quantitatively classified by taking a ratio of the pixel intensity profiles of muscle against those of intermuscular fat for the rectus capitis posterior major and minor and inferior obliquus capitis muscles bilaterally. Inter- and intra-examiner agreement was scrutinized. RESULTS: The average relative values of fat within the upper cervical musculature compared with intermuscular fat indicated that there were only slight variations in indices between the three sets of muscles. There was no significant correlation between age and fat indices. There were significant differences for the relative fat within the muscle compared with intermuscular fat and body mass index for the right rectus capitis posterior major and right and left inferior obliquus capitis muscles (p=0.032). Intraclass correlation coefficients for intraobserver agreement ranged from 0.94 to 0.98. Inter-rater agreement of the measurements ranged from 0.75 to 0.97. CONCLUSION: A quantitative measure of muscle/fat constituents has been developed, and results of this study indicate that relative fatty infiltration is not a feature of age in the upper cervical extensor muscles of women aged 18-45 years.

Prevalence of and referred pain from myofascial trigger points in the forearm muscles in patients with lateral epicondylalgia.

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Fernández-Carnero, Josué; Fernández-de-Las-Peñas, César; de la Llave-Rincón, Ana Isabel; Ge, Hong-You; Arendt-Nielsen, Lars

2007-05-01

Referred pain and pain characteristics evoked from the extensor carpi radialis brevis, extensor carpi radialis longus, extensor digitorum communis, and brachioradialis muscles was investigated in 20 patients with lateral epicondylalgia (LE) and 20-matched controls. Both groups were examined for the presence of myofascial trigger points (TrPs) in a blinded fashion. The quality and location of the evoked referred pain, and the pressure pain threshold (PPT) at the lateral epicondyle on the right upper extremity (symptomatic side in patients, and dominant-side on controls) were recorded. Several lateral elbow pain parameters were also evaluated. Within the patient group, the elicited referred pain by manual exploration of 13 out of 20 (65%) extensor carpi radialis brevis muscles, 12/20 (70%) extensor carpi radialis longus muscles, 10/20 (50%) brachioradialis muscles, and 5/20 (25%) extensor digitorum communis muscles, shares similar pain patterns as their habitual lateral elbow and forearm pain. The mean number of muscles with TrPs for each patient was 2.9 [95% confidence interval (CI) 1,4] of which 2 (95% CI 1,3) were active, and 0.9 (95% CI 0,2) were latent TrPs. Control participants only had latent TrPs (mean: 0.4; 95% CI 0,2). TrP occurrence between the 2 groups was significantly different for active TrPs (P0.05). The referred pain pattern was larger in patients than in controls, with pain referral to the lateral epicondyle (proximally) and to the dorso-lateral aspect of the forearm in the patients, and confined to the dorso-lateral aspect of the forearm in the controls. Patients with LE showed a significant (Plateral epicondyle was negatively correlated with both the total number of TrPs (rs=-0.63; P=0.003) and the number of active TrPs (rs=-0.5; P=0.02): the greater the number of active TrPs, the lower the PPT at the lateral epicondyle. Our results suggest that in patients with LE, the evoked referred pain and its sensory characteristics shared similar patterns

Transcranial direct current stimulation does not affect lower extremity muscle strength training in healthy individuals

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Maeda, Kazuhei; Yamaguchi, Tomofumi; Tatemoto, Tsuyoshi

2017-01-01

The present study investigated the effects of anodal transcranial direct current stimulation (tDCS) on lower extremity muscle strength training in 24 healthy participants. In this triple-blind, sham-controlled study, participants were randomly allocated to the anodal tDCS plus muscle strength...... training (anodal tDCS) group or sham tDCS plus muscle strength training (sham tDCS) group. Anodal tDCS (2 mA) was applied to the primary motor cortex of the lower extremity during muscle strength training of the knee extensors and flexors. Training was conducted once every 3 days for 3 weeks (7 sessions......). Knee extensor and flexor peak torques were evaluated before and after the 3 weeks of training. After the 3-week intervention, peak torques of knee extension and flexion changed from 155.9 to 191.1 Nm and from 81.5 to 93.1 Nm in the anodal tDCS group. Peak torques changed from 164.1 to 194.8 Nm...

Trajectory of self-reported pain and function and knee extensor muscle strength in young patients undergoing arthroscopic surgery for meniscal tears

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Thorlund, Jonas Bloch; Østengaard, Lasse; Cardy, Nathan

2017-01-01

. PATIENTS AND INTERVENTION: People aged 30 years or younger undergoing surgery for a meniscal tear. OUTCOMES: and comparator: (1) Self-reported pain and function in patients undergoing meniscal surgery compared to a non-operative control group (2). Knee extensor strength in the leg undergoing surgery...... the trajectory of self-reported pain and function in patients undergoing arthroscopic surgery compared with non-operative treatments for young patients with meniscal tears. Knee extensor strength seemed to be impaired up to 12 months after surgery in young patients undergoing surgery for meniscal tears...

Relations Between Lower Body Isometric Muscle Force Characteristics and Start Performance in Elite Male Sprint Swimmers

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Igor Beretić

2013-12-01

Full Text Available The aim of the present study was twofold. The first aim was to examine the influence of absolute and relative lower body muscle force on kinematic component which determine the start performance. The second aim was to create multiregressional model which could use as a tool for swimming coaches with the purpose to start performance control and improvement. Twenty seven high-level trained male competitive swimmers all members of the Serbian National Youth and Senior Swimming Team (Age = 21.1 ± 4.3 yrs., Height = 1. 89 ± 0.10 m, Weight = 81.6 ± 8.4 kg, 50m freestyle - long course = 24.36 ± 0.86 s performed two trials of standing leg extensors isometric muscle force testing and three swimming start trials corresponding to 10m distance. The average start time significantly correlated with variables of leg extensors maximum voluntary force (Fmax, r = -0.559, p = 0.002, leg extensors relative muscle voluntary force (Frel, r = -0.727, p < 0.001, leg extensors specific rate of force development (RFD50%, r = -0.338, p = 0.047 and leg extensors relative value of specific rate of force development (RFD50%rel, r = -0.402, p = 0.040. Regression equation for t10m prediction was defined by following variables: maximum voluntary isometric force of leg extensors muscles at absolute and relative level (Fmax and Frel, as well as a specific rate of force development of the same muscle groups (RFD50% and RFD50%rel at absolute and relative level too with 74.4% of explained variance. Contractile abilities indicators of the leg extensors muscles included consideration: Fmax, RFD50%, Frel and RFD50%rel showed significant correlation with swimming start times on 10m. Additionally, the results suggest that swimmers, who possess greater isometric maximum force and specific rate of force development at absolute and relative levels, tend to be able to swim faster on initial 10m swim start perforamnce.

Effects of training and weight support on muscle activation in Parkinson's disease.

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Rose, Martin H; Løkkegaard, Annemette; Sonne-Holm, Stig; Jensen, Bente R

2013-12-01

The aim of this study was to investigate the effect of high-intensity locomotor training on knee extensor and flexor muscle activation and adaptability to increased body-weight (BW) support during walking in patients with Parkinson's disease (PD). Thirteen male patients with idiopathic PD and eight healthy participants were included. The PD patients completed an 8-week training program on a lower-body, positive-pressure treadmill. Knee extensor and flexor muscles activation during steady treadmill walking (3 km/h) were measured before, at the mid-point, and after training. Increasing BW support decreased knee extensor muscle activation (normalization) and increased knee flexor muscle activation (abnormal) in PD patients when compared to healthy participants. Training improved flexor peak muscle activation adaptability to increased (BW) support during walking in PD patients. During walking without BW support shorter knee extensor muscle off-activation time and increased relative peak muscle activation was observed in PD patients and did not improve with 8 weeks of training. In conclusion, patients with PD walked with excessive activation of the knee extensor and flexor muscles when compared to healthy participants. Specialized locomotor training may facilitate adaptive processes related to motor control of walking in PD patients. Copyright © 2013 Elsevier Ltd. All rights reserved.

Relationship between lower extremity isometric muscle strength and standing balance in patients with multiple sclerosis.

Science.gov (United States)

Citaker, Seyit; Guclu-Gunduz, Arzu; Yazici, Gokhan; Bayraktar, Deniz; Nazliel, Bijen; Irkec, Ceyla

2013-01-01

Muscle strength and standing balance decrease in patients with Multiple Sclerosis (MS). The aim of the present study was to investigate the relationship between the lower extremity isometric muscle strength and standing balance in patients with MS. Forty-seven patients with MS and 10 healthy volunteers were included. Neurological disability level was assessed using Expanded Disability Status Scale (EDSS). Isometric strength of seven lower extremity muscles (hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor) was assessed using hand-held dynamometer. Duration of static one-leg standing balance was measured using digital chronometer. Hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor isometric muscle strength, and duration of one-leg standing balance were decreased in patients with MS when compared with controls (p isometric muscle strength and EDSS level was related duration of one-leg standing balance in patients with MS. All assessed lower extremity isometric muscle strength (except ankle dorsal flexor) was related with EDSS. Hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor isometric muscle strength decreases in ambulatory MS patients. Lower extremity muscle weakness and neurological disability level are related with imbalance in MS population. Hip and knee region muscles weakness increases the neurological disability level. For the better balance and decrease neurological disability level whole lower extremity muscle strengthening should be included in rehabilitation programs.

Muscle power is an important measure to detect deficits in muscle function in hip osteoarthritis

DEFF Research Database (Denmark)

Bieler, Theresa; Magnusson, Stig Peter; Christensen, Helle Elisabeth

2017-01-01

that exercise interventions focusing on improving leg extensor power of the symptomatic lower extremity and reducing asymmetry may be beneficial for patients with hip osteoarthritis. Implications for Rehabilitation Even in patients with mild symptoms not awaiting hip replacement a generalized muscle weakening......: The symptomatic extremity in patients was significantly (p asymmetry in knee extensor strength (6%, p ... in patients, but had no asymmetry in leg extensor power. CONCLUSIONS: Patients had generalized weakening of the affected lower extremity and numerically the largest asymmetry was evident for leg extensor power. In contrast, healthy peers had no asymmetry in leg extensor power. These results indicate...

Musculoskeletal Geometry, Muscle Architecture and Functional Specialisations of the Mouse Hindlimb (Open Access)

Science.gov (United States)

2016-04-26

example, studies in cats [18], guinea pigs [16] and rabbits [19] have shown that the hamstring muscles, a bi-articular group of muscles which act around...energy in compliant tendons [20, 21], whereas others, such as the hamstrings (hip extensors and knee flexors), function to produce fast contractions

Sex Differences in Neuromuscular Fatigability of the Knee Extensors Post-Stroke

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Meghan Kirking

2017-01-01

Full Text Available Background and Purpose: Despite the implications of optimizing strength training post-stroke, little is known about the differences in fatigability between men and women with chronic stroke. The purpose of this study was to determine the sex differences in knee extensor muscle fatigability and potential mechanisms in individuals with stroke. Methods: Eighteen participants (10 men, eight women with chronic stroke (≥6 months and 23 (12 men, 11 women nonstroke controls participated in the study. Participants performed an intermittent isometric contraction task (6 s contraction, 3 s rest at 30% of maximal voluntary contraction (MVC torque until failure to maintain the target torque. Electromyography was used to determine muscle activation and contractile properties were assessed with electrical stimulation of the quadriceps muscles. Results: Individuals with stroke had a briefer task duration (greater fatigability than nonstroke individuals (24.1 ± 17 min vs. 34.9 ± 16 min. Men were more fatigable than women for both nonstroke controls and individuals with stroke (17.9 ± 9 min vs. 41.6 ± 15 min. Individuals with stroke had less fatigue-related changes in muscle contractile properties and women with stroke differed in their muscle activation strategy during the fatiguing contractions. Conclusions: Men and women fatigue differently post-stroke and this may be due to the way they neurally activate muscle groups.

Isokinetic dynamometry of knee flexors and extensors: comparative study among non-athletes, jumper athletes and runner athletes

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Siqueira Cássio Marinho

2002-01-01

Full Text Available Participation in intensive sports activities leads to muscular specializations that may generate alterations in involved articular forces and cause static (posture and dynamic changes (alterations of articular stability, coordination, etc.. Prevention of injury requires specific functional muscular evaluation in all athletes and for any kind of sport. OBJECTIVE: To dynamically evaluate, through isokinetic tests, the peak torque, total work, and average power of the knee flexor and extensor muscles of jumper and runner athletes and compare them to those of a non-athletic population, evaluating dominance and balance between agonistic and antagonistic muscle groups. RESULTS: In the non-athlete group, we noted a higher asymmetry between the dominant and nondominant members. The jumpers had the highest values of the evaluated parameters of all groups, whereas parameters for the runners were intermediate between non-athletes and jumpers.

The identification of fall history using maximal and rapid isometric torque characteristics of the hip extensors in healthy, recreationally active elderly females: a preliminary investigation.

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Palmer, Ty B; Thiele, Ryan M; Williams, Katherine B; Adams, Bailey M; Akehi, Kazuma; Smith, Douglas B; Thompson, Brennan J

2015-08-01

Maximal and rapid torque characteristics of the hip extensor muscles play an important role in fall prevention and other balance-related performances; however, few studies have investigated the ability of these variables at identifying fall-history status in healthy, recreationally active elderly adults. This study aimed to examine the effectiveness of maximal and rapid isometric torque characteristics of the hip extensor muscles to differentiate between healthy, recreationally active elderly females with (fallers) and without (non-fallers) a history a falls. Six elderly female fallers (mean ± SD: age = 73 ± 7 year; mass = 68 ± 16 kg; height = 160 ± 5 cm) and nine elderly female non-fallers (age = 71 ± 7 year; mass = 66 ± 16 kg; height = 157 ± 6 cm) performed two isometric maximal voluntary contractions (MVCs) of the hip extensor muscles. Peak torque (PT) and absolute and relative rate of torque development (RTD) at the early (0-50 ms) and late (100-200 ms) phases of muscle contraction were examined during each MVC. Absolute and relative RTD at 0-50 ms were greater (P = 0.039 and 0.011, respectively) in the non-fallers compared to the fallers. However, no group-related differences (P = 0.160-0.573) were observed for PT nor absolute and relative RTD at 100-200 ms. Early rapid strength production of the hip extensor muscles may be a sensitive and effective measure for discriminating between elderly females of different fall histories. These findings may provide important insight regarding implications for the assessment of fall risk and in the development of proper training programs aimed at minimizing the occurrence of falls and other balance-related injuries in the elderly.

Sexual dimorphism of extensor carpi radialis muscle size, isometric force, relaxation rate and stamina during the breeding season of the frog Rana temporaria Linnaeus 1758.

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Navas, Carlos A; James, Rob S

2007-02-01

Mating success of individual male frogs within explosive breeding species can depend on their ability to compete for a mate and to hold onto that mate during amplexus. Such importance of amplexus has resulted in the evolution of sexual dimorphism in the morphology and contractile characteristics of the anuran forelimb muscles used during amplexus. The aims of our study were to use an explosive breeding frog (Rana temporaria) during the breeding season to compare extensor carpi radialis (ECR) muscle length, mass, isometric activation times, relaxation times, absolute force, relative force (stress) and fatigue between male and female frogs. We found that ECR muscle mass and length were greater (tenfold and 1.4-fold, respectively), absolute tetanic muscle force and relative tetanic force (stress) were greater (16-fold and 2.2-fold, respectively) and relaxation times were slower in males than in females. Male ECR muscles incompletely relaxed during fatigue tests and showed less fatigue than female muscles. These sex differences are likely to be beneficial to the male frogs in allowing them to produce relatively high absolute muscle forces for prolonged periods of time to hold onto their mate during amplexus.

Effects of Different Types of Exercise on Body Composition, Muscle Strength, and IGF-1 in the Elderly with Sarcopenic Obesity.

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Chen, Hung-Ting; Chung, Yu-Chun; Chen, Yu-Jen; Ho, Sung-Yen; Wu, Huey-June

2017-04-01

To investigate the influence of resistance training (RT), aerobic training (AT), or combination training (CT) interventions on the body composition, muscle strength performance, and insulin-like growth factor 1 (IGF-1) of patients with sarcopenic obesity. Randomized controlled trial. Community center and research center. Sixty men and women aged 65-75 with sarcopenic obesity. Participants were randomly assigned to RT, AT, CT, and control (CON) groups. After training twice a week for 8 weeks, the participants in each group ceased training for 4 weeks before being examined for the retention effects of the training interventions. The body composition, grip strength, maximum back extensor strength, maximum knee extensor muscle strength, and blood IGF-1 concentration were measured. The skeletal muscle mass (SMM), body fat mass, appendicular SMM/weight %, and visceral fat area (VFA) of the RT, AT, and CT groups were significantly superior to those of the CON group at both week 8 and week 12. Regarding muscle strength performance, the RT group exhibited greater grip strength at weeks 8 and 12 as well as higher knee extensor performance at week 8 than that of the other groups. At week 8, the serum IGF-1 concentration of the RT group was higher than the CON group, whereas the CT group was superior to the AT and CON groups. Older adults with sarcopenic obesity who engaged in the RT, AT, and CT interventions demonstrated increased muscle mass and reduced total fat mass and VFA compared with those without training. The muscle strength performance and serum IGF-1 level in trained groups, especially in the RT group, were superior to the control group. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Comparison of thoracic kyphosis degree, trunk muscle strength and joint position sense among healthy and osteoporotic elderly women: a cross-sectional preliminary study.

Science.gov (United States)

Granito, Renata Neves; Aveiro, Mariana Chaves; Renno, Ana Claudia Muniz; Oishi, Jorge; Driusso, Patricia

2012-01-01

Increased thoracic kyphosis is one of the most disfiguring consequences of osteoporotic spine fractures in the elderly. However, mechanisms involved in the increasing of the kyphosis degree among osteoporotic women are not completely understood. Then, the aims of this cross-sectional preliminary study were comparing thoracic kyphosis degree, trunk muscle peak torque and joint position sense among healthy and osteoporotic elderly women and investigating possible factors affecting the kyphosis degree. Twenty women were selected for 2 groups: healthy (n=10) and osteoporotic (n=10) elderly women. Bone mineral density (BMD), thoracic kyphosis degree, trunk muscles peak torque and joint position sense were measured. Differences among groups were analyzed by Student's Test T for unpaired data. Correlations between variables were performed by Pearson's coefficient correlation. The level of significance used for all comparisons was 5% (p≤0.05). We observed that the osteoporotic women demonstrated a significantly higher degree of kyphosis and lower trunk extensor muscle peak torque. Moreover, it was found that the BMD had a negative correlation with the thoracic kyphosis degree. Kyphosis degree showed a negative correlation between extensor muscle strength and joint position sense index. This study suggests that lower BMD may be associated to higher degree of kyphosis degree, lower trunk extensors muscle strength and an impaired joint position sense. It is also suggested that lower extensor muscle strength may be a factor that contributes to the increasing in kyphosis thoracic degree. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Congenital hypertrophy of multiple intrinsic muscles of the foot.

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Shiraishi, Tomohiro; Park, Susam; Niu, Atushi; Hasegawa, Hiromi

2014-12-01

Congenital hypertrophy of a single intrinsic muscle of the foot is rare, and as far as we know, only six cases have been reported. We describe a case of congenital anomaly that showed hypertrophy of multiple intrinsic muscles of the foot; the affected muscles were all the intrinsic muscles of the foot except the extensor digitorum brevis or extensor hallucis. Other tissues such as adipose tissue, nervous tissue, or osseous tissue showed no abnormalities. To reduce the volume of the foot we removed parts of the enlarged muscles.

Acute effects of maximal isometric muscle action of the elbow extensors on contralateral dynamic task of the elbow flexors: a pilot study

Directory of Open Access Journals (Sweden)

Cauê V La Scala Teixeira

2017-12-01

Full Text Available ABSTRACT Aim the aim was to investigate the influence of a maximal isometric muscle action of the elbow extensors on the contralateral dynamic task of the elbow flexors. Methods Seventeen recreationally trained men (23.3 ± 4.9 yrs, BMI: 24.8 ± 2.2 Kg/m² underwent two randomized different testing sessions separated by one week. In the control session (CON all subjects performed a maximum number of repetitions test (RMs at 75%1RM using the right elbow flexors. The experimental session (EXP was similar to the CON; however, all subjects were instructed to perform RMs at 75%1RM by using the right elbow flexors and maintaining the maximal voluntary contraction of the left elbow extensors during the test. RMs, rating of perceived exertion (RPE, and training volume (TV were measured and compared between sessions. Results The EXP showed a significant 10.4% increase on the RMs (13.8 vs. 12.5, p < 0.001, d = 0.44 and 12.1% increase in TV (238.0 vs. 212.4 kg, p < 0.001, d = 0.43 than CON. No differences were observed for RPE between sessions. Conclusion The maximum voluntary contraction of the left elbow extensors increased the RMs of the contralateral elbow flexors, reflecting a higher TV, and no differences in the RPE. Our results suggest that the investigated method may be a viable and practical alternative to increase the acute strength performance of elbow flexors when using submaximal loads.

Recovery in mechanical muscle strength following resurfacing vs standard total hip arthroplasty - a randomised clinical trial

DEFF Research Database (Denmark)

Jensen, Carsten; Aagaard, Per; Overgaard, S

2011-01-01

rather than implant design per se. Thus, the present data failed to support the hypothesis that R-THA would result in an enhanced strength rehabilitation compared to S-THA. Further, between-limb asymmetry remained present for hip flexors and adductors after 52 wks. Trial registration: NCT01229293....... randomised into (A) standard total hip arthroplasty (S-THA) and (B) resurfacing total hip arthroplasty (R-THA). Pre-surgery assessment and follow-up were conducted (8, 26 and 52 wks). Maximal isometric muscle strength (Nm) and between-limb asymmetry for the knee extensors/flexors, hip adductors....../abductors, hip extensors/flexors were analysed. RESULTS: Maximal knee extensor and hip abductor strength were higher in S-THA than R-THA at 52 wks post-surgery (P ≤ 0.05) and hip extensors tended to be higher in S-THA at 52 wks (P = 0.06). All muscle groups showed substantial between-limb strength asymmetry (7...

Utilization of stored elastic energy in leg extensor muscles by men and women.

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Komi, P V; Bosco, C

1978-01-01

An alternating cycle of eccentric-concentric contractions in locomotion represents a sequence when storage and utilization of elastic energy takes place. It is possible that this storage capacity and its utilization depends on the imposed stretch loads in activated muscles, and that sex differences may be present in these phenomena. To investigate these assumed differences, subjects from both sexes and of good physical condition performed vertical jumps on the force-platform from the following experimental conditions: squatting jump (SJ) from a static starting position; counter-movement jump (CMJ) from a free standing position and with a preparatory counter-movement; drop jumps (DJ) from the various heights (20 to 100 cm) on to the platform followed immediately by a vertical jump. In all subjects the SJ, in which condition no appreciable storage of elastic energy takes place, produced the lowest height of rise of the whole body center of gravity (C.G.). The stretch load (drop height) influenced the performance so that height of rise of C. of G. increased when the drop height increased from 26 up to 62 cm (males) and from 20 to 50 cm (females). In all jumping conditions the men jumped higher than the women. However, examination of the utilization of elastic energy indicated that in CMJ the female subjects were able to utilize most (congruent to 90%) of the energy produced in the prestretching phase. Similarly, in DJ the overall change in positive energy over SJ condition was higher in women as compared to men. Thus the results suggest that although the leg extensor muscles of the men subjects could sustain much higher stretch loads, the females may be able to utilize a greater portion of the stored elastic energy in jumping activities.

Impact of high intensity exercise on muscle morphology in EAE rats

DEFF Research Database (Denmark)

Wens, I; Dalgas, U; Verboven, K

2015-01-01

paralysis (experiment 2, n=40), isokinetic foot extensor strength, cross sectional area (CSA) of tibialis anterior (TA), extensor digitorum longus (EDL) and soleus (SOL) and brain-derived neurotrophic factor (BDNF) levels were assessed. EAE reduced muscle fiber CSA of TA, EDL and SOL. In general, exercise......The impact of high-intensity exercise on disease progression and muscle contractile properties in experimental autoimmune encephalomyelitis (EAE) remains unclear. Control (CON) and EAE rats were divided into sedentary and exercise groups. Before onset (experiment 1, n=40) and after hindquarter...... was not able to affect CSA, whereas it delayed hindquarter paralysis peak. CON muscle work peaked and declined, while it remained stable in EAE. BDNF-responses were not affected by EAE or exercise. In conclusion, EAE affected CSA-properties of TA, EDL and SOL, which could, partly, explain the absence of peak...

The effect of basketball training on the muscle strength of adults with mental retardation.

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Tsimaras, Vasilios K; Samara, Christina A; Kotzamanidou, Marianna C; Bassa, Eleni I; Fotiadou, Eleni G; Kotzamanidis, Christos M

2009-12-01

The purpose of this study was to evaluate the effect of basketball training on the muscle strength of adults with mental retardation (MR). Twenty-four adults with and without MR were separated into 3 groups. Eight adults (mean age 25.4 years) with normal IQ constituted the control group (NIQ). Eight adults (mean age 26.5 years) with MR and all participating in a 4-year systematic basketball exercise program constituted the trained group (MR-T), and 8 adults (mean age 25.3 years) with MR exercised occasionally for recreational reasons formed the MR-R group. Parameters measured were isometric and isokinetic concentric and eccentric muscle strength. All subjects performed a leg strength test on a Cybex Norm isokinetic dynamometer. Analysis of variance was used to examine mean differences between the values of the 3 groups. A significance level of 0.05 was used for all tests. The NIQ group showed a statistically significant difference in all measured values compared to the MR groups. The MR-T group presented higher absolute and relative torque scores for both knee extensors and flexors than the MR-R group, whereas the MR-R group presented statistically higher antagonistic activity for both knee extensors and flexors than the MR-T group. In addition, both MR groups presented statistically higher antagonistic activity for both knee extensors and flexors compared to the NIQ group. Data support participation on a systematic and well-designed basketball training program to improve muscle strength levels of adults with MR. Participation in basketball without necessarily focusing on developing specific fitness components may be an effective training strategy for the promotion of strength of adults with MR.

Paraspinal muscle morphometry in cervical spondylotic myelopathy and its implications in clinicoradiological outcomes following central corpectomy: clinical article.

Science.gov (United States)

Thakar, Sumit; Mohan, Dilip; Furtado, Sunil V; Sai Kiran, Narayanam Anantha; Dadlani, Ravi; Aryan, Saritha; Rao, Arun S; Hegde, Alangar S

2014-08-01

The objective of this study was to assess the cross-sectional areas (CSAs) of the superficial, deep flexor (DF), and deep extensor (DE) paraspinal muscles in patients with cervical spondylotic myelopathy (CSM), and to evaluate their correlations with functional status and sagittal spinal alignment changes following central corpectomy with fusion and plating. In this retrospective study of 67 patients who underwent central corpectomy with fusion and plating for CSM, the CSAs of the paraspinal muscles were calculated on the preoperative T2-weighted axial MR images and computed as ratios with respect to the corresponding vertebral body areas (VBAs) and as flexor/extensor CSA ratios. These ratios were then compared with those in the normative population and analyzed with respect to various clinicoradiological factors, including pain status, Nurick grade, and segmental angle change at follow-up (SACF). The mean CSA values for all muscle groups and the DF/DE ratio were significantly lower in the study cohort compared with an age- and sex-matched normative study group (p < 0.001). Among various independent variables tested in a multivariate regression analysis, increasing age and female sex significantly predicted a lower total extensor CSA/VBA ratio (p < 0.001), while a longer duration of symptoms significantly predicted a greater total flexor/total extensor CSA ratio (p = 0.02). In patients undergoing single-level corpectomy, graft subsidence had a positive correlation with SACF in all patients (p < 0.05), irrespective of the preoperative segmental angle and curvature, while in patients undergoing 2-level corpectomy, graft subsidence demonstrated such a correlation only in the subgroup with lordotic curvatures (p = 0.02). Among the muscle area ratios, the DF/DE ratio demonstrated a negative correlation with SACF in the subgroup with preoperative straight or kyphotic segmental angles (p = 0.04 in the single corpectomy group, p = 0.01 in the 2-level corpectomy group

Isokinetic trunk muscle performance in pre-teens and teens with and without back pain.

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Bernard, J-C; Boudokhane, S; Pujol, A; Chaléat-Valayer, E; Le Blay, G; Deceuninck, J

2014-02-01

To assess with an isokinetic dynamometer the force and endurance of the spinal flexor and extensor muscles in pre-teens or teens aged 11 to 13 and 14 to 16 years with and without low back pain (LBP). The control group and the LBP group were homogeneous in terms of age, weight, height and Body Mass Index (BMI). Assessment was carried out with the isokinetic dynamometer Cybex Norm®. The spinal flexors and extensors were explored concentrically at speeds of 60°, 90° and 120°/sec. The parameters chosen were: maximal moment of force (MMF), mean power (MP), total work (TW), F/E ratios (between the flexors and the extensors for the aforesaid parameters). In the LBP groups, clinical information (pain, extensibility of the spinal and sub-pelvic muscles, sports practice) and sagittal radiological data were all measured. While no significant difference in isokinetic performance was found between asymptomatic and LBP children in the 11-to-13-year-old group, the isokinetic performances of the LBP children were influenced positively by BMI value, number of hours of physical activity and radiologic value of the lumbar lordosis. As regards these pre-teens, assessment with an isokinetic dynamometer does not highlight muscle characteristics that might explain LBP occurrence. As regards the 14-to-16-year-old group, muscle strength has been found to be correlated with age. LBP teens were showed to have weaker extensors and stronger flexors than the healthy teens. It is with regard to this age group that assessment with an isokinetic dynamometer clearly yields interesting results. Since we have yet to standardize our evaluation criteria (working speed, number of trials…), it is difficult to compare our results with those reported in the literature. This is a preliminary study involving a relatively low number of patients. That said, given the fact that numerous parameters are connected with the age and height of the subjects, assessment with an isokinetic dynamometer can be

Effects of training and weight support on muscle activation in Parkinson's disease

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Rose, Martin Høyer; Løkkegaard, Annemette; Sonne-Holm, Stig

2013-01-01

The aim of this study was to investigate the effect of high-intensity locomotor training on knee extensor and flexor muscle activation and adaptability to increased body-weight (BW) support during walking in patients with Parkinson's disease (PD). Thirteen male patients with idiopathic PD and eight...... healthy participants were included. The PD patients completed an 8-week training program on a lower-body, positive-pressure treadmill. Knee extensor and flexor muscles activation during steady treadmill walking (3km/h) were measured before, at the mid-point, and after training. Increasing BW support...... decreased knee extensor muscle activation (normalization) and increased knee flexor muscle activation (abnormal) in PD patients when compared to healthy participants. Training improved flexor peak muscle activation adaptability to increased (BW) support during walking in PD patients. During walking without...

Intramuscular fatty acid metabolism in contracting and non-contracting human skeletal muscle

DEFF Research Database (Denmark)

Sacchetti, M; Saltin, B; Osada, T

2002-01-01

The present study was undertaken to investigate the fate of blood-borne non-esterified fatty acids (NEFA) entering contracting and non-contracting knee extensor muscles of healthy young individuals. [U-(13)C]-palmitate was infused into a forearm vein during 5 h of one-legged knee extensor exercis...... and degraded and that the metabolic fate of plasma NEFA entering the muscle is influenced by muscle contraction, so that a higher proportion is directed towards oxidation at the expense of storage in mTAG.......The present study was undertaken to investigate the fate of blood-borne non-esterified fatty acids (NEFA) entering contracting and non-contracting knee extensor muscles of healthy young individuals. [U-(13)C]-palmitate was infused into a forearm vein during 5 h of one-legged knee extensor exercise.......05) in the contracting muscle, whereas it was unchanged in the non-contracting muscle. The uptake of plasma NEFA, as well as the proportion directed towards oxidation, was higher in the exercising compared to the non-exercising leg, whereas the rate of palmitate incorporation into mTAG was fourfold lower (0.70 +/- 0...

Skeletal muscle glucose uptake during dynamic exercise in humans

DEFF Research Database (Denmark)

Richter, Erik; Kiens, Bente; Saltin, Bengt

1988-01-01

uptake was not compensated for by increased uptake of free fatty acids but was accompanied by decreases in plasma insulin and increases in plasma epinephrine and norepinephrine. During work with large muscle masses, arterial lactate increased to approximately 6 mM, and net leg lactate release reverted......To study the role of muscle mass in glucoregulation, six subjects worked with the knee extensors of one leg on a specially constructed cycle ergometer. The knee extensors of one leg worked either alone or in combination with the knee extensors of the other leg and/or with the arms. Substrate usage...... to net lactate uptake. Decreased glucose uptake could not be explained by decreased perfusion. It is concluded that thigh muscle glucose uptake is affected by the size of the total muscle mass engaged in exercise. The decrease in thigh glucose uptake, when arm cranking was added and O2 uptake...

Monosynaptic Ia projections from intrinsic hand muscles to forearm motoneurones in humans.

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Marchand-Pauvert, V; Nicolas, G; Pierrot-Deseilligny, E

2000-05-15

Heteronymous Ia excitatory projections from intrinsic hand muscles to human forearm motoneurones (MNs) were investigated. Changes in firing probability of single motor units (MUs) in the flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), flexor digitorum superficialis (FDS), extensor carpi radialis (ECR), extensor carpi ulnaris (ECU) and extensor digitorum communis (EDC) were studied after electrical stimuli were applied to the median and ulnar nerve at wrist level and to the corresponding homonymous nerve at elbow level. Homonymous facilitation, occurring at the same latency as the H reflex, and therefore attributed to monosynaptic Ia EPSPs, was found in all the sampled units. In many MUs an early facilitation was also evoked by heteronymous low-threshold afferents from intrinsic hand muscles. The low threshold (between 0.5 and 0.6 times motor threshold (MT)) and the inability of a pure cutaneous stimulation to reproduce this effect indicate that it is due to stimulation of group I muscle afferents. Evidence for a similar central delay (monosynaptic) in heteronymous as in homonymous pathways was accepted when the difference in latencies of the homonymous and heteronymous peaks did not differ from the estimated supplementary afferent conduction time from wrist to elbow level by more than 0.5 ms (conduction velocity in the fastest Ia afferents between wrist and elbow levels being equal to 69 m s-1). A statistically significant heteronymous monosynaptic Ia excitation from intrinsic hand muscles supplied by both median and ulnar nerves was found in MUs belonging to all forearm motor nuclei tested (although not in ECU MUs after ulnar stimulation). It was, however, more often found in flexors than in extensors, in wrist than in finger muscles and in muscles operating in the radial than in the ulnar side. It is argued that the connections of Ia afferents from intrinsic hand muscles to forearm MNs, which are stronger and more widely distributed than in the cat

Effect of a step-training program on muscle strength in older women

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Daniela Coelho Zazá

2010-04-01

Full Text Available Step-training is associated with strength improvement of the lower limbs. Muscle strength is a critical component for the maintenance of functional capacity. The objective of the present study was to determine the effect of 6 weeks of step-training on work and power of the lower limbs in older women. Thirteen healthy and active women volunteered to participate in the study. All subjects underwent step-training classes three times per week for 60 min. Strength variables of the knee extensor and flexor muscles were measured with a Biodex System 3 Pro isokinetic dynamometer. Muscle work and power were assessed at an angular velocity of 60 and 180°/s. A significant difference (p<0.05 in knee flexor muscle work was observed between pre- and post-test at 60 and 180°/s. There was a significant difference (p<0.05 in knee extensor muscle work between pre- and post-test at 60°/s. Significant differences were observed between pre- and post-test values of knee flexor muscle power at 60°/s (p<0.05 and knee extensor muscle power at 60 and 180°/s (p<0.05. In conclusion, step-training can be recommended as an alternative physical activity to increase strength performance (work and power of the knee extensor and flexor muscles in older subjects.

Extramuscular myofascial force transmission within the rat anterior tibial compartment: Proximodistal differences in muscle force

NARCIS (Netherlands)

Huijing, P.A.J.B.M.; Baan, G.C.

2001-01-01

Intramuscular connective tissues are continuous to extramuscular connective tissues. If force is transmitted there, differences should be present between force at proximal and distal attachments of muscles. Extensor digitorum longus (EDL), tibialis anterior (TA), and extensor hallucis longus muscles

Does mental exertion alter maximal muscle activation?

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Vianney eRozand

2014-09-01

Full Text Available Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 minutes each: i high mental exertion (incongruent Stroop task, ii moderate mental exertion (congruent Stroop task, iii low mental exertion (watching a movie. In each condition, mental exertion was combined with ten intermittent maximal voluntary contractions of the knee extensor muscles (one maximal voluntary contraction every 3 minutes. Neuromuscular function was assessed using electrical nerve stimulation. Maximal voluntary torque, maximal muscle activation and other neuromuscular parameters were similar across mental exertion conditions and did not change over time. These findings suggest that mental exertion does not affect neuromuscular function during intermittent maximal voluntary contractions of the knee extensors.

Effect of voluntary vs. artificial activation on the relationship of muscle torque to speed

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Dudley, Gary A.; Harris, Robert T.; Duvoisin, Marc R.; Hather, Bruce M.; Buchanan, Paul

1990-01-01

The suggestion by Phillips and Petrofsky (1980) and Wickiewicz et al. (1984) that artificial activation of the knee extensor muscles should result in greater relative changes in torque than those evident with maximal voluntary activation is examined by investigating the speed-torque relationship of the right knee extensor muscle group in eight human subjects in whom activation was achieved by 'maximal' voluntary effort or by electrical stimulation. Torque was measured at a specific knee angle during isokinetic concentric or eccentric actions at velocities between 0.17 and 3.66 rad/s and during isometric actions. It is shown that, with artificial activation, the relative changes in both eccentric and concentric torque were greater as the speed increased; the speed-torque relationship was independed of the extent of activation and was similar to that of an isolated muscle. On the other hand, activation by the central nervous system during maximal effort depended on the speed and the type of muscle action performed.

Relationships of muscle strength and bone mineral density in ambulatory children with cerebral palsy.

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Chen, C-L; Lin, K-C; Wu, C-Y; Ke, J-Y; Wang, C-J; Chen, C-Y

2012-02-01

This work explores the relationships of muscle strength and areal bone mineral density (aBMD) in ambulatory children with cerebral palsy (CP). The knee extensor strength, but not motor function, was related to aBMD. Thus, muscle strength, especially antigravity muscle strength, was more associated with aBMD in these children than motor function. Muscle strength is related to bone density in normal children. However, no studies have examined these relationships in ambulatory children with CP. This work explores the relationships of muscle strength and aBMD in ambulatory children with CP. Forty-eight ambulatory children with spastic CP, aged 5-15 years, were classified into two groups based on Gross Motor Function Classification System levels: I (n = 28) and II (n = 20). Another 31 normal development (ND) children were recruited as the comparison group for the aBMD. Children with CP underwent assessments of growth, lumbar and distal femur aBMD, Gross Motor Function Measure-66 (GMFM-66), and muscle strength of knee extensor and flexor by isokinetic dynamometer. The distal femur aBMD, but not lumbar aBMD, was lower in children with CP than in ND children (p antigravity muscle strength, were more associated with the bone density of ambulatory children with CP than motor function. The data may allow clinicians for early identifying the ambulatory CP children of potential low bone density.

Validity of trunk extensor and flexor torque measurements using isokinetic dynamometry.

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Guilhem, Gaël; Giroux, Caroline; Couturier, Antoine; Maffiuletti, Nicola A

2014-12-01

This study aimed to evaluate the validity and test-retest reliability of trunk muscle strength testing performed with a latest-generation isokinetic dynamometer. Eccentric, isometric, and concentric peak torque of the trunk flexor and extensor muscles was measured in 15 healthy subjects. Muscle cross sectional area (CSA) and surface electromyographic (EMG) activity were respectively correlated to peak torque and submaximal isometric torque for erector spinae and rectus abdominis muscles. Reliability of peak torque measurements was determined during test and retest sessions. Significant correlations were consistently observed between muscle CSA and peak torque for all contraction types (r=0.74-0.85; Ptorque (r ⩾ 0.99; Ptorque between test and retest ranged from -3.7% to 3.7% with no significant mean directional bias. Overall, our findings establish the validity of torque measurements using the tested trunk module. Also considering the excellent test-retest reliability of peak torque measurements, we conclude that this latest-generation isokinetic dynamometer could be used with confidence to evaluate trunk muscle function for clinical or athletic purposes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Corticospinal excitability of the ankle extensor muscles is enhanced in ballet dancers.

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Saito, Sakiko; Obata, Hiroki; Endoh, Takashi; Kuno-Mizumura, Mayumi; Nakazawa, Kimitaka

2014-09-01

We tested the corticospinal excitability of the soleus muscle in ballet dancers to clarify whether the presumed long-term repetition of the specific plantarflexion results in changes of excitability in this neural pathway. We compared motor evoked potentials of the soleus muscle at rest and during isometric contraction of the plantar flexors in dancers and non-dancers. The amplitudes of motor evoked potentials elicited by transcranial magnetic stimulation during contraction were examined against the background electromyographic activity. A regression line was calculated for each subject. Results showed that the slope of the regression line is significantly greater in the dancer group than in the control group, suggesting that the corticospinal tract of ballet dancers has adapted to long-term repetition of plantarflexion in daily ballet training.

Bilateral movements increase sustained extensor force in the paretic arm.

Science.gov (United States)

Kang, Nyeonju; Cauraugh, James H

2018-04-01

Muscle weakness in the extensors poststroke is a common motor impairment. Unfortunately, research is unclear on whether bilateral movements increase extensor force production in the paretic arm. This study investigated sustained force production while stroke individuals maximally extended their wrist and fingers on their paretic arm. Specifically, we determined isometric force production in three conditions: (a) unilateral paretic arm, (b) unilateral nonparetic arm, and (c) bilateral (both arms executing the same movement simultaneously). Seventeen chronic stroke patients produced isometric sustained force by executing wrist and fingers extension in unilateral and bilateral contraction conditions. Mean force, force variability (coefficient of variation), and signal-to-noise ratio were calculated for each contraction condition. Analysis of two-way (Arm × Type of Condition: 2 × 2; Paretic or Nonparetic Arm × Unilateral or Bilateral Conditions) within-subjects ANOVAs revealed that the bilateral condition increased sustained force in the paretic arm, but reduced sustained force in the nonparetic arm. Further, although the paretic arm exhibited more force variability and less signal-to-noise ratio than the nonparetic arm during a unilateral condition, there were no differences when participants simultaneously executed isometric contractions with both arms. Our unique findings indicate that bilateral contractions transiently increased extensor force in the paretic arm. Implications for Rehabilitation Bilateral movements increased isometric wrsit extensor force in paretic arms and redcued force in nonparetic arms versus unilateral movements. Both paretic and nonparetic arms produced similar force variability and signal-to-noise ratio during bilateral movements. Increased sustained force in the paretic arm during the bilateral condition indicates that rehabilitation protocols based on bilateral movements may be beneficial for functional recovery.

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 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

Back extensor muscle endurance test scores in coal miners in Australia

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Stewart, M.; Latimer, J.; Jamieson, M. [University of Sydney, Sydney, NSW (Australia). Faculty of Health and Science, School of Physiotherapy

2003-06-01

Low back pain is a common complaint among those working in the Australian coal mining industry. One test that may be predictive of first-time episodes of low back pain is the Biering-Sorensen test of back extensor endurance strength. While this test has been evaluated in overseas sedentary populations, normative data and the discriminative ability of the test have not been evaluated with coal miners. Eighty-eight coal miners completed a questionnaire for known risk factors for low back pain, performed the Biering-Sorensen test, and undertook a test of aerobic fitness. Data analysis was performed to describe the groups and to determine whether any significant difference existed between those with a past history of low back pain and those without. Significantly lower than expected holding times were found in this group of coal miners (mean 113 s). This result was significantly lower than demonstrated in previous studies. When holding times for those with a past history of low back pain were compared with times for those with no history of low back pain, the difference was not statistically significant, nor was there a significant difference in fitness between those with a past history of low back pain and those without. It is concluded that coal miners in Australia have lower than normal Biering-Sorensen holding times. This lower back holding time does not differ between coal miners with a past history of low back pain and those without.

Asymmetry of neck motion and activation of the cervical paraspinal muscles during prone neck extension in subjects with unilateral posterior neck pain.

Science.gov (United States)

Park, Kyue-Nam; Kwon, Oh-Yun; Kim, Su-Jung; Kim, Si-Hyun

2017-01-01

Although unilateral posterior neck pain (UPNP) is more prevalent than central neck pain, little is known about how UPNP affects neck motion and the muscle activation pattern during prone neck extension. To investigate whether deviation in neck motion and asymmetry of activation of the bilateral cervical paraspinal muscles occur during prone neck extension in subjects with UPNP compared to subjects without UPNP. This study recruited 20 subjects with UPNP and 20 age- and sex-matched control subjects without such pain. Neck motion and muscle onset time during prone neck extension were measured using a three-dimensional motion-analysis system and surface electromyography. The deviation during prone neck extension was greater in the UPNP group than in the controls (p cervical extensor muscle activation in the UPNP group was significantly delayed on the painful side during prone neck extension (p cervical extensors, triggering a need for specific evaluation and exercises in the management of patients with UPNP.

Protein degradation in skeletal muscle during experimental hyperthyroidism in rats and the effect of beta-blocking agents.

Science.gov (United States)

Angerås, U; Hasselgren, P O

1987-04-01

beta-Blocking agents are increasingly used in the management of hyperthyroid patients. The effect of this treatment on increased muscle protein breakdown in the hyperthyroid state is not known. In the present study, experimental hyperthyroidism was induced in rats by daily ip injections of T3 (100 micrograms/100 g BW) during a 10-day period. Control animals received corresponding volumes of solvent. In groups of rats the selective beta-1-blocking agent metoprolol or the nonselective beta-blocker propranolol was infused by miniosmotic pumps implanted sc on the backs of the animals. Protein degradation was measured in incubated intact soleus and extensor digitorum longus muscles by determining tyrosine release into the incubation medium. The protein degradation rate in incubated extensor digitorum longus and soleus muscles was increased by 50-60% during T3 treatment. Metoprolol or propranolol did not influence muscle protein breakdown in either T3-treated or control animals. The results suggest that T3-induced increased muscle proteolysis is not mediated by beta-receptors, and muscle weakness and wasting in hyperthyroidism might not be affected by beta-blockers.

The Effect of Dry Needling of the Trigger Points of Shoulder Muscles on Pain and Grip Strength in Patients with Lateral Epicondylitis: A Pilot Study

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Alireza Kheradmandi

2015-09-01

Full Text Available Background: Lateral epicondylitis, also known as tennis elbow, is the most common overuse syndrome of the elbow. The severity of pain may not be directly caused by tendinopathy of wrist extensors since trigger points of the shoulder muscles have a referral zone in the arm and elbow. Therefore the aim of this study was to evaluate the effect of dry needling of shoulder myofascial trigger points on wrist extensors muscles pain and function. Methods: Fourteen female patients with tennis elbow (aged 20 - 45 years old were recruited after primary evaluation by an orthopedist. They entered the study if they had pain in the lateral aspect of elbow of the dominant hand for more than 3 months along with the presence of myofascial trigger points in any muscles of supra spinatus, infra spinatus, sub scapularis or scalenes. Pain pressure threshold, maximal grip force and pain intensity of the hand extensors on lateral epicondyle of elbow were measured before and after treatment. Pain intensity was measured on a one to ten scale of visual analogue scale (VAS. A hand dynamometer used to measure the maximal grip force value of the affected hand in 0˚shoulder flexion/ abduction, 90˚ elbow extension and mid-poison of forearm in sitting position. A pressure algometer was applied on hand extensor muscles to define their trigger point sensitivity. For the control group, treatment regimens consisted of routine physical therapy of tennis elbow. This regime was accompanied by dry needling of mentioned muscles for the intervention group. Wilcoxon and Mann-Whitney non-parametric tests were used for statistical analysis. Results: Comparison of the results after intervention showed that the patients’ pain significantly decreased in both groups (P<0.001; but the patient’s PPT and grip force significantly increased solely in the intervention group (P<0.05. Mann Whitney test showed significant pain differences in both groups (P=0.001. The comparison of differences

Effects of squat lift training and free weight muscle training on maximum lifting load and isolinetic peak torque of young adults without impairments.

Science.gov (United States)

Yeung, S S; Ng, G Y

2000-06-01

Manual lifting is a frequent cause of back injury, and there is no evidence as to which training mode can provide the best training effect for lifting performance and muscle force. The purpose of this study was to examine the effects of a squat lift training and a free weight muscle training program on the maximum lifting load and isokinetic peak torque in subjects without known neuromuscular or musculoskeletal impairments. Thirty-six adults (20 male, 16 female) without known neuromuscular or musculoskeletal impairments participated. The subjects' mean age was 21.25 years (SD=1.16, range=20-24). Subjects were divided into 3 groups. Subjects in group 1 (n=12) performed squat lift training. Subjects in group 2 (n=12) participated in free weight resistance training of their shoulder abductors, elbow flexors, knee extensors and trunk extensors. Subjects in group 3 (n=12) served as controls. The maximum lifting load and isokinetic peak torques of the trunk extensors, knee extensors, elbow flexors, and shoulder abductors of each subject were measured before and after the study. Training was conducted on alternate days for 4 weeks, with an initial load of 80% of each subject's maximum capacity and with the load increased by 5% weekly. All groups were comparable for all measured variables before the study. After 4 weeks, subjects in groups 1 and 2 demonstrated more improvement in maximum lifting load and isokinetic peak torque of the back extensors compared with the subjects in group 3, but the 2 training groups were not different. The findings demonstrate that both squat lift and free weight resistance training are equally effective in improving the lifting load and isokinetic back extension performance of individuals without impairments.

Balance and Muscle Strength in Elderly Women Who Dance Samba.

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Marcos Maurício Serra

Full Text Available Considering the growth of the aging population, and the increasing risk for falls and related morbidity, it is vital to seek efficient, comprehensive, and culturally relevant prevention programs for elderly people to reduce risks for falls. The aim of the present study was to evaluate the postural balance and muscle strength among women participating in the "Wing of Baianas" in the carnival parades. One hundred and ten women, with an average age of 67.4±5.9 years, were divided into two groups: Baianas group-elderly participants of the carnival parades in the "Wing of Baianas", and a Control group of women who do not dance samba. Assessments included a physical activity questionnaire, isokinetic muscle strength testing for the knee extensors and flexors, and a postural balance assessment completed on a force platform. There were no differences between groups, for postural balance outcomes, during the eyes open condition; however, with eyes closed, there was a significant effect between groups (Baianas vs Control in all variables. The Baianas group showed less medio-lateral displacement (p < 0.04; and anteroposterior displacement (p < 0.007; larger amplitudes of medio-lateral displacement (p < 0.001; and anteroposterior displacement (p < 0.001; increased mean velocity (p < 0.01; and elliptical area (p < 0.01 There were no differences in the isokinetic peak torque corrected by body weight, total work and flexor/extensor ratio. Participation in the Wing of Baianas is associated with better balance with closed eyes, but there were no differences between dancers and non-dancers for muscle strength.

Ischemia Increases the Twitch Latent Period in the Soleus and Extensor Carpi Radialis Longus Muscles from Adult Rats.

Science.gov (United States)

Morales, Camilo; Fierro, Leonardo

2017-10-01

Complete ischemia and reperfusion effects on twitch force (∫(F·t)), twitch latent period (TLP), maximal rate of rise of twitch tension (δF/δt) max , and twitch maximum relaxation rate (TMRR) were assessed. We divided 36 adult rats into four groups; two control groups (n = 9), a group undergoing 1 hour of ischemia followed by 1 hour of reperfusion (n = 9), and one group exposed to 2 hours of ischemia followed by 1 hour of reperfusion (n = 9). We have induced twitch contractions every 10 minutes in the soleus and the extensor carpi radialis longus (ECRL). Twitch contractions were recorded and then analyzed for ∫(F·t), TLP, (δF/δt) max , and TMRR. During 1 hour and 40 minutes of ischemia, TLP increased to 179 ± 24% (p values.

Knee extensor strength and body weight in adolescent men and the risk of knee osteoarthritis by middle age

DEFF Research Database (Denmark)

Turkiewicz, Aleksandra; Timpka, Simon; Thorlund, Jonas Bloch

2017-01-01

be attributed to knee injury and adult occupation. CONCLUSION: Higher knee extensor strength in adolescent men was associated with increased risk of knee OA by middle age, challenging the current tenet of low muscle strength being a risk factor for OA. We confirmed higher weight to be a strong risk factor......OBJECTIVES: To assess the extent to which knee extensor strength and weight in adolescence are associated with knee osteoarthritis (OA) by middle age. METHODS: We studied a cohort of 40 121 men who at age 18 years in 1969/1970 underwent mandatory conscription in Sweden. We retrieved data...

Atualização da anatomia do mecanismo extensor do joelho com uso de técnica de visualização tridimensional Updating of the anatomy of the extensor mechanism of the knee using a three-dimensional viewing technique

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Diego Costa Astur

2011-10-01

Full Text Available O mecanismo extensor do joelho é uma estrutura complexa formada pelo músculo e tendão quadricipital, a patela, o tendão patelar e os ligamentos que os circundam e auxiliam na estabilização do joelho. Através do uso de técnica de visualização tridimensional de imagens do aparelho extensor do joelho pretendemos mostrar de forma didática as estruturas que compõem este complexo ósteo-músculo-ligamentar. Dissecção anatômica do joelho com ênfase nas estruturas do seu mecanismo extensor foi realizada seguida de fotografias com câmera e lentes adequadas para simulação da visão humana através de técnica de construção de imagem tridimensional. Em seguida, com a ajuda de software apropriado, as duas imagens da mesma estrutura de diferentes ângulos simulando a visão humana são sobrepostas com adição de camada polarizante, concluindo a construção da imagem anaglífica. As principais estruturas do mecanismo extensor do joelho podem ser observadas com efeito tridimensional. Dentre os principais benefícios relacionados a esta técnica, destacamos, além do ensino e estudo da anatomia musculoesquelética, o potencial uso em treinamento de procedimentos cirúrgicos e a realização de imagens em exames diagnósticos.The knee extensor mechanism is a complex structure formed by the quadriceps muscle and tendon, the patella, the patellar tendon and the ligaments that surround and help stabilize the knee. Through using a three-dimensional viewing technique on images of the knee extensor apparatus, we aimed to didactically show the structures that compose this bone-muscle-ligament complex. Anatomical dissection of the knee with emphasis on the structures of its extensor mechanism was performed, followed by taking photographs using a camera and lenses suitable for simulating human vision, through a technique for constructing three-dimensional images. Then, with the aid of appropriate software, pairs of images of the same structure from

Longitudinal, lateral and transverse axes of forearm muscles influence the crosstalk in the mechanomyographic signals during isometric wrist postures.

Science.gov (United States)

Islam, Md Anamul; Sundaraj, Kenneth; Ahmad, R Badlishah; Sundaraj, Sebastian; Ahamed, Nizam Uddin; Ali, Md Asraf

2014-01-01

In mechanomyography (MMG), crosstalk refers to the contamination of the signal from the muscle of interest by the signal from another muscle or muscle group that is in close proximity. The aim of the present study was two-fold: i) to quantify the level of crosstalk in the mechanomyographic (MMG) signals from the longitudinal (Lo), lateral (La) and transverse (Tr) axes of the extensor digitorum (ED), extensor carpi ulnaris (ECU) and flexor carpi ulnaris (FCU) muscles during isometric wrist flexion (WF) and extension (WE), radial (RD) and ulnar (UD) deviations; and ii) to analyze whether the three-directional MMG signals influence the level of crosstalk between the muscle groups during these wrist postures. Twenty, healthy right-handed men (mean ± SD: age = 26.7±3.83 y; height = 174.47±6.3 cm; mass = 72.79±14.36 kg) participated in this study. During each wrist posture, the MMG signals propagated through the axes of the muscles were detected using three separate tri-axial accelerometers. The x-axis, y-axis, and z-axis of the sensor were placed in the Lo, La, and Tr directions with respect to muscle fibers. The peak cross-correlations were used to quantify the proportion of crosstalk between the different muscle groups. The average level of crosstalk in the MMG signals generated by the muscle groups ranged from: 34.28-69.69% for the Lo axis, 27.32-52.55% for the La axis and 11.38-25.55% for the Tr axis for all participants and their wrist postures. The Tr axes between the muscle groups showed significantly smaller crosstalk values for all wrist postures [F (2, 38) = 14-63, pmovement research, especially for the examination of muscle mechanics during various types of the wrist postures.

THE RELATIONSHIP BETWEEN TRUNK MUSCLES ENDURANCE AND NORMAL BMI AMONG UNIVERSITY STUDENTS WITH SEDENTARY LIFESTYLE

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Karthikeyan Selvaganapathy

2017-12-01

Full Text Available Background: The most important trunk stabilizers are the trunk flexors and extensors. The isometric endurance of the trunk muscles is an essential element for mechanical support of the spine in all positions. The study objectives were to find out the trunk flexors and extensors endurance, its relationship with normal BMI and to find out the ratio of trunk flexors to extensors endurance. Methods: In this correlation study, 50 subjects were selected by convenience sampling method on the basis of inclusion and exclusion criteria from Asia metropolitan university, Malaysia. The trunk flexors and extensors endurance were assessed by Kraus- Weber and Sorenson test respectively. Paired 't' test and Spearman correlation test were used for data analysis. Results: There was a significant difference (p 0.01 and TEE, rs (50 = -0.162, p >0.01 but there was a significant strong positive relationship between TFE and TEE, rs (50 = 0.68, p < 0.01. The ratio of trunk flexors to extensors was 0.61. Conclusion: The trunk extensors endurance is higher than trunk flexors endurance and BMI has no relationship with trunk flexors and extensors muscle endurance. The ratio of trunk flexors to extensors endurance value is low

Wrist muscle activity of khatrah approach in Mameluke technique using traditional bow archery

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Ariffin, Muhammad Shahimi; Rambely, Azmin Sham; Ariff, Noratiqah Mohd

2018-04-01

An investigation of khatrah technique in archery was carried out. An electromyography (EMG) experiment was conducted towards six wrist muscles which are flexor carpi radialis, extensor carpi ulnaris and extensor digitorum communis for both arms. The maximum voluntary contraction (MVC) and activity data were recorded. The bow arm produced a higher muscle force compared to draw arm muscles during release phase. However, the muscle forces produced by bow arm had a consistency in term of pattern throughout the phases. In conclusion, the forces generated by the professional archer produced a force benchmark at the wrist joint to alleviate the risk of injury.

The interaction between the vastus medialis and vastus intermedius and its influence on the extensor apparatus of the knee joint.

Science.gov (United States)

Grob, Karl; Manestar, Mirjana; Filgueira, Luis; Kuster, Markus S; Gilbey, Helen; Ackland, Timothy

2018-03-01

extension. The interaction between the VM and VI, with responsibility for the extension of the knee joint and influence on the patellofemoral function, leads readily to an understanding of common clinical problems found at the knee joint as it attempts to meet contradictory demands for both mobility and stability. Surgery or trauma in the anteromedial aspect of the quadriceps muscle group might alter a delicate interplay between the VM and VI. This would affect the extensor apparatus as a whole.

A comparison of débridement with and without anconeus muscle flap for treatment of refractory lateral epicondylitis.

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Ruch, David S; Orr, Steven B; Richard, Marc J; Leversedge, Fraser J; Mithani, Suhail K; Laino, Daniel K

2015-02-01

Lateral epicondylitis is a common condition encountered by orthopedic surgeons. Whereas the majority of patients improve with conservative management, a small percentage will require surgery. The purpose of this study was to compare the clinical outcomes of surgical débridement of the common extensor origin alone with débridement combined with rotation of an anconeus muscle flap in patients who failed to respond to conservative management of chronic lateral epicondylitis. Fifty-seven patients who failed to respond to a minimum of 5 months of conservative treatment for lateral epicondylitis were retrospectively reviewed. Patients in group 1 were treated with open débridement of the common extensor origin. Patients in group 2 were treated with open débridement combined with rotation of an anconeus muscle flap. Outcome measures included elbow range of motion, grip strength, visual analog scale (VAS) for pain score, and Disabilities of the Arm, Shoulder, and Hand (DASH) score. Statistical analyses were performed by Student's t test with 95% confidence intervals. At final follow-up, average DASH scores were significantly lower in group 2. There were no significant differences between the groups with regard to elbow range of motion or grip strength. VAS pain scores were significantly reduced in both groups. Preoperative VAS pain scores were significantly greater in group 2; however, at final follow-up, there was no significant difference between groups. There were no apparent complications in either group. In addition to débridement of the common extensor origin, the rotation of an anconeus muscle flap may improve outcomes in cases of lateral epicondylitis that require operative intervention. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

V1 and v2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion.

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Zhang, Jingming; Lanuza, Guillermo M; Britz, Olivier; Wang, Zhi; Siembab, Valerie C; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J; Frank, Eric; Goulding, Martyn

2014-04-02

Reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here, we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity. Copyright © 2014 Elsevier Inc. All rights reserved.

Corticospinal excitability changes following prolonged muscle tendon vibration

NARCIS (Netherlands)

Steyvers, M.; Levin, O.; Baelen, M.G.M. van; Swinnen, S.P.

2003-01-01

The present experiment addressed the time course of corticospinal excitability changes following interventional muscle tendon vibration. Using transcranial magnetic stimulation, motor evoked potentials of the flexor carpi radialis and extensor carpi radialis brevis muscle were recorded for a period

Customizing Extensor Reconstruction in Vascularized Toe Joint Transfers to Finger Proximal Interphalangeal Joints: A Strategic Approach for Correcting Extensor Lag.

Science.gov (United States)

Loh, Charles Yuen Yung; Hsu, Chung-Chen; Lin, Cheng-Hung; Chen, Shih-Heng; Lien, Shwu-Huei; Lin, Chih-Hung; Wei, Fu-Chan; Lin, Yu-Te

2017-04-01

Vascularized toe proximal interphalangeal joint transfer allows the restoration of damaged joints. However, extensor lag and poor arc of motion have been reported. The authors present their outcomes of treatment according to a novel reconstructive algorithm that addresses extensor lag and allows for consistent results postoperatively. Vascularized toe joint transfers were performed in a consecutive series of 26 digits in 25 patients. The average age was 30.5 years, with 14 right and 12 left hands. Reconstructed digits included eight index, 10 middle, and eight ring fingers. Simultaneous extensor reconstructions were performed and eight were centralization of lateral bands, five were direct extensor digitorum longus-to-extensor digitorum communis repairs, and 13 were central slip reconstructions. The average length of follow-up was 16.7 months. The average extension lag was 17.9 degrees. The arc of motion was 57.7 degrees (81.7 percent functional use of pretransfer toe proximal interphalangeal joint arc of motion). There was no significant difference in the reconstructed proximal interphalangeal joint arc of motion for the handedness (p = 0.23), recipient digits (p = 0.37), or surgical experience in vascularized toe joint transfer (p = 0.25). The outcomes of different techniques of extensor mechanism reconstruction were similar in terms of extensor lag, arc of motion, and reconstructed finger arc of motion compared with the pretransfer toe proximal interphalangeal joint arc of motion. With this treatment algorithm, consistent outcomes can be produced with minimal extensor lag and maximum use of potential toe proximal interphalangeal joint arc of motion. Therapeutic, IV.

Impact of fat mass distribution body shapes on muscles strength and the joints pain

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Zerf Mohammed

2016-01-01

Full Text Available Our study focuses on fat mass distribution body shapes type as measured to determine their effect on skeletal muscle strengthening lumbar extensors (upper and lower limbs where our background confirms that every girl has a natural body type of rectangle, apple, pear, or hourglass. It is good for her to know which type of body shape she is, so she can learn what exercises to do, whereas similar studies suggest that it is much better to challenge weight problems with exercise and dietary measures before resorting to figure shaping. For this purpose, our study was carried out with a total of thirty students, females listed in the Institute of Physical Education and Sport, University of Mostaganem, aged between 20 and 23 years; their homogeneity was based on age, sex, and academic specialty, classified based on the body mass index (BMI into two groups (normal and overweight and based on their body shape′s type into three groups (9 pear shape, 10 rectangle shape, and 11 hourglass shape as a protocol experimental to examine the impact of fat mass distribution body shapes type on lumbar extensor strength. Based on our data analysis, we confirm that the pear and the rectangle shape affect the strength lumbar extensors due to body weight distribution which increases the risks relating to the skeletal muscles. Weight gain is a factor contributing to the weakness of skeletal muscles. However, the body shape explains the anomalies of the distribution of fat mass and BMI risk observed in our sample in the lower and upper part of the body recorded by the values of Killy test and endurance of trunk, the case of the pear and the rectangle shape back pain, which are consisting in excess of the body fat distributed in comparison with less percentage of muscle mass. Whereas this difference can affect the pelvic position.

Near infrared spectroscopy of human muscles

Science.gov (United States)

Gasbarrone, R.; Currà, A.; Cardillo, A.; Bonifazi, G.; Serranti, S.

2018-02-01

Optical spectroscopy is a powerful tool in research and industrial applications. Its properties of being rapid, non-invasive and not destructive make it a promising technique for qualitative as well as quantitative analysis in medicine. Recent advances in materials and fabrication techniques provided portable, performant, sensing spectrometers readily operated by user-friendly cabled or wireless systems. We used such a system to test whether infrared spectroscopy techniques, currently utilized in many areas as primary/secondary raw materials sector, cultural heritage, agricultural/food industry, environmental remote and proximal sensing, pharmaceutical industry, etc., could be applied in living humans to categorize muscles. We acquired muscles infrared spectra in the Vis-SWIR regions (350-2500 nm), utilizing an ASD FieldSpec 4 Standard-Res Spectroradiometer with a spectral sampling capability of 1.4 nm at 350-1000 nm and 1.1 nm at 1001-2500 nm. After a preliminary spectra pre-processing (i.e. signal scattering reduction), Principal Component Analysis (PCA) was applied to identify similar spectral features presence and to realize their further grouping. Partial Least-Squares Discriminant Analysis (PLS-DA) was utilized to implement discrimination/prediction models. We studied 22 healthy subjects (age 25-89 years, 11 females), by acquiring Vis-SWIR spectra from the upper limb muscles (i.e. biceps, a forearm flexor, and triceps, a forearm extensor). Spectroscopy was performed in fixed limb postures (elbow angle approximately 90‡). We found that optical spectroscopy can be applied to study human tissues in vivo. Vis-SWIR spectra acquired from the arm detect muscles, distinguish flexors from extensors.

Avaliação da altura patelar em atletas com tendinopatia crônica do aparelho extensor do joelho Evaluation of the patellar height in athletes with diagnosed with chronic tendinopathy of the knee extensor mechanism

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Emerson Garms

2011-01-01

Full Text Available OBJETIVO: Avaliar radiograficamente a altura patelar de atletas com diagnóstico de tendinopatia crônica do aparelho extensor do joelho (TCAE. MÉTODOS: Na amostra foram avaliados radiograficamente 65 pacientes (110 joelhos com idade entre 15 e 40 anos e de diferentes modalidades esportivas com e sem diagnóstico de tendinopatia crônica do aparelho extensor do joelho (jumper's knee. Os atletas foram divididos em dois grupos: aqueles com diagnóstico de TCAE (grupo 1: 38 atletas - 56 joelhos e um grupo que denominamos de controle (grupo 2: 27 atletas - 54 joelhos. RESULTADOS: No grupo 1 tivemos 18 atletas que apresentavam a doença bilateralmente na ocasião dos exames. Para a medida da altura patelar utilizamos os índices radiográficos de Insall e Salvati e Blackburne e Peel. CONCLUSÃO: A presença de patela alta no grupo de atletas com tendinopatia crônica do aparelho extensor do joelho foi significante maior do que a observada no grupo controle.OBJECTIVES: To carry out a radiographic evaluation of patellar height in athletes diagnosed with chronic tendinopathy of the knee extensor mechanism; METHODS: Radiographic assessments were carried out on 65 patients (110 knees aged between 15 and 40 years, who practiced different kinds of sports, some with of chronic tendinopathy of the knee extensor mechanism (jumper's knee and others without. The athletes were divided into two groups: those with diagnosed "jumper's knee" (group 1:38 athletes - 56 knees and a control group (group 2:27 athletes - 54 knees. In group 1, 18 of the athletes presented the condition in both knees on examination. The height of the patella was measured using the Insall-Salvati and Blackburne-Peel x-ray methods. CONCLUSION: The presence of a high patella in the group of athletes with chronic tendinopathy of the knee extensor mechanism was significantly higher than in the control group.

Enhanced spinal excitation from ankle flexors to knee extensors during walking in stroke patients

DEFF Research Database (Denmark)

Achache, V.; Mazevet, D.; Iglesias, C.

2010-01-01

: The spinal, presumed group II, excitation from ankle dorsiflexors to knee extensors is particularly enhanced during post-stroke walking probably due to plastic adaptations in the descending control. SIGNIFICANCE: This adaptation may help to stabilize the knee in early stance when the patients have recover......OBJECTIVES: It is still unclear to what an extent altered reflex activity contributes to gait deficit following stroke. Spinal group I and group II excitations from ankle dorsiflexors to knee extensors were investigated during post-stroke walking. METHODS: Electrical stimulation was applied...... ankle dorsiflexor functions....

Asymmetry of Muscle Strength in Elite Athletes

Science.gov (United States)

Drid, Patrik; Drapsin, Miodrag; Trivic, Tatjana; Lukac, Damir; Obadov, Slavko; Milosevic, Zoran

2009-01-01

"Study aim": To determine muscle strength variables in elite judoists and wrestlers since thigh muscle strength and bilaterally balanced flexor-to-extensor ratio minimise injury risk and are desirable for achieving sport successes. "Material and methods": Judoists, wrestlers and untrained subjects, 10 each, were subjected to isokinetic strength…

Fatigue effects on tracking performance and muscle activity

NARCIS (Netherlands)

Huysmans, M.A.; Hoozemans, M.J.M.; van der Beek, A.J.; de Looze, M.P.; van Dieen, J.H.

2008-01-01

It has been suggested that fatigue affects proprioception and consequently movement accuracy, the effects of which may be counteracted by increased muscle activity. To determine the effects of fatigue on tracking performance and muscle activity in the M. extensor carpi radialis (ECR), 11 female

Sonography findings in tears of the extensor pollicis longus tendon and correlation with CT, MRI and surgical findings

International Nuclear Information System (INIS)

Ruiz Santiago, Fernando; Garofano Plazas, Pilar; Fernandez, Juan Miguel Tristan

2008-01-01

We present our experience in the diagnosis of extensor pollicis longus tendon tears using different imaging methods. In the past 2 years, 12 patients (7 males, 5 females) with extension deficit of distal phalanx of thumb were diagnosed with extensor pollicis longus tendon (EPL) rupture by means of different imaging methods. The ultrasound pattern consisted of a gap between tendon stumps occupied by a continuous (eight cases) or discontinuous (four cases) attenuated hypoechoic string. In nine cases, the tendon ends were identified as a thickened stump-like structure. In the other three cases, tendon stumps were attenuated and mixed with atrophic muscle or wrist subcutaneous fat. All ultrasound findings were confirmed by CT, MR and/or surgical findings

Longitudinal, lateral and transverse axes of forearm muscles influence the crosstalk in the mechanomyographic signals during isometric wrist postures.

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Md Anamul Islam

Full Text Available In mechanomyography (MMG, crosstalk refers to the contamination of the signal from the muscle of interest by the signal from another muscle or muscle group that is in close proximity.The aim of the present study was two-fold: i to quantify the level of crosstalk in the mechanomyographic (MMG signals from the longitudinal (Lo, lateral (La and transverse (Tr axes of the extensor digitorum (ED, extensor carpi ulnaris (ECU and flexor carpi ulnaris (FCU muscles during isometric wrist flexion (WF and extension (WE, radial (RD and ulnar (UD deviations; and ii to analyze whether the three-directional MMG signals influence the level of crosstalk between the muscle groups during these wrist postures.Twenty, healthy right-handed men (mean ± SD: age = 26.7±3.83 y; height = 174.47±6.3 cm; mass = 72.79±14.36 kg participated in this study. During each wrist posture, the MMG signals propagated through the axes of the muscles were detected using three separate tri-axial accelerometers. The x-axis, y-axis, and z-axis of the sensor were placed in the Lo, La, and Tr directions with respect to muscle fibers. The peak cross-correlations were used to quantify the proportion of crosstalk between the different muscle groups.The average level of crosstalk in the MMG signals generated by the muscle groups ranged from: 34.28-69.69% for the Lo axis, 27.32-52.55% for the La axis and 11.38-25.55% for the Tr axis for all participants and their wrist postures. The Tr axes between the muscle groups showed significantly smaller crosstalk values for all wrist postures [F (2, 38 = 14-63, p<0.05, η2 = 0.416-0.769].The results may be applied in the field of human movement research, especially for the examination of muscle mechanics during various types of the wrist postures.

Effects of whole-body vibration on muscle architecture, muscle strength, and balance in stroke patients: a randomized controlled trial.

Science.gov (United States)

Marín, Pedro J; Ferrero, Cristina M; Menéndez, Héctor; Martín, Juan; Herrero, Azael J

2013-10-01

The aim of the present study was to analyze the effects of whole-body vibration on lower limb muscle architecture, muscle strength, and balance in stroke patients during a period of 3 mos. The inclusion criteria were having had ischemic or hemorrhagic stroke at least 6 mos before the study and a National Institutes of Health Stroke Scale score of greater than 1 and less than 20. The patients were randomly divided into two groups: an experimental group (n = 11, six men and five women; age, 62.4 ± 10.7 yrs; height, 1.64 ± 0.07 m; mass, 69.4 ± 12.9 kg) and a sham group (n = 9, five men and four women; age, 64.4 ± 7.6 yrs; height, 1.62 ± 0.07 m; mass, 75.0 ± 15.8 kg). The experimental group received a whole-body vibration treatment, with an increase in frequency, sets, and time per set during 17 sessions. The sham group performed the same exercises as that of the experimental group but was not exposed to vibration. Outcome variables included the muscle architecture (the rectus femoris, the vastus lateralis, and the medial gastrocnemius), the maximal isometric voluntary contraction of the knee extensors, and the Berg Balance Scale. There were no significant differences between the groups on the primary outcomes of lower limb muscle architecture, muscle strength, and balance. It seems that whole-body vibration exercise does not augment the increase in neuromuscular performance and lower limb muscle architecture induced by isometric exercise alone in stroke patients.

Reliability and Validity of a New Method for Isometric Back Extensor Strength Evaluation Using A Hand-Held Dynamometer.

Science.gov (United States)

Park, Hee-Won; Baek, Sora; Kim, Hong Young; Park, Jung-Gyoo; Kang, Eun Kyoung

2017-10-01

To investigate the reliability and validity of a new method for isometric back extensor strength measurement using a portable dynamometer. A chair equipped with a small portable dynamometer was designed (Power Track II Commander Muscle Tester). A total of 15 men (mean age, 34.8±7.5 years) and 15 women (mean age, 33.1±5.5 years) with no current back problems or previous history of back surgery were recruited. Subjects were asked to push the back of the chair while seated, and their isometric back extensor strength was measured by the portable dynamometer. Test-retest reliability was assessed with intraclass correlation coefficient (ICC). For the validity assessment, isometric back extensor strength of all subjects was measured by a widely used physical performance evaluation instrument, BTE PrimusRS system. The limit of agreement (LoA) from the Bland-Altman plot was evaluated between two methods. The test-retest reliability was excellent (ICC=0.82; 95% confidence interval, 0.65-0.91). The Bland-Altman plots demonstrated acceptable agreement between the two methods: the lower 95% LoA was -63.1 N and the upper 95% LoA was 61.1 N. This study shows that isometric back extensor strength measurement using a portable dynamometer has good reliability and validity.

The neuromechanical functional contractile properties of the thigh muscles measured using tensiomyography in male athletes and non-athletes

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Toskić Lazar

2016-01-01

Full Text Available Involuntary neuromechanical muscle contractile properties, especially of the extensor muscles and knee joint flexors as the largest muscle groups of the caudal part of the body, play an important role in both everyday movement and sport. Based on these data we can obtain important information on the functional properties of muscles. The basic means of evaluation of the functional involuntary neuromechanical muscles contractile properties is the non-invasive tensiomyographic method (TMG. The aim of this study was to determine the differences between the involuntary neuromechanical contractile properties of the thigh muscles measured using the TMG method on a sample of male athletes and non-athletes. The sample of participants was made up of 17 athletes and 10 non-athletes. By applying the multivariate analysis of variance (MANOVA and the t-test, we achieved results which indicate that of the overall 30 variables, a difference was determined among 13 of them. Most of the differences were determined for the extensor muscles of the right knee, especially of the rectus femoris muscle. It was also shown that in addition to the main knee joint extensor muscle (rectus femoris the main knee joint flexor muscle (biceps femoris also takes part in the definition of the difference between athletes and non-athletes. The results have shown that the following variables: contraction time (Tc and delay contraction time (Td are the functional parameters for which the highest difference between athletes and non-athletes were determined (from t = -2.284, p < 0.05 for the vastus lateralis of the right leg to t = -4.018, p < 0.01 for the rectus femoris of the left leg. These results have shown that it is possible to determine the differences in the functional involuntary neuromechanical contractile properties of the thigh muscles among trained and untrained individuals using the tensiomyographic method, but at the same time indicated that these differences were very

Training and muscle ammonia and amino acid metabolism in humans during prolonged exercise

DEFF Research Database (Denmark)

Graham, T E; Turcotte, L P; Kiens, Bente

1995-01-01

We studied the responses of NH3 and amino acids (AA) to prolonged exercise (3 h) in trained (Tr; n = 6) and untrained (Utr; n = 6) men. Each subject exercised the knee extensor muscles of one leg at 60% of maximum capacity. Thigh blood flow and femoral arteriovenous differences (0, 30, 60, 120, 150......, and 180 min) as well as muscle biopsies (0, 120, and 180 min) were taken for NH3 and AA measurements. In both groups, muscle Glu decreased (P ....4 +/- 6.8 mmol/kg wet wt in Tr and Utr, respectively. Tr had greater (P muscle Tau, Phe, Ala, and Glu. Both groups had a large Glu uptake and effluxes of NH3, Gln, and Ala as well as essential AA. The latter implies that there was a net protein catabolism. The efflux of NH3 and Gln was much...

Evaluation of cranial tibial and extensor carpi radialis reflexes before and after anesthetic block in cats.

Science.gov (United States)

Tudury, Eduardo Alberto; de Figueiredo, Marcella Luiz; Fernandes, Thaiza Helena Tavares; Araújo, Bruno Martins; Bonelli, Marília de Albuquerque; Diogo, Camila Cardoso; Silva, Amanda Camilo; Santos, Cássia Regina Oliveira; Rocha, Nadyne Lorrayne Farias Cardoso

2017-02-01

Objectives This study aimed to test the extensor carpi radialis and cranial tibial reflexes in cats before and after anesthetic block of the brachial and lumbosacral plexus, respectively, to determine whether they depend on a myotatic reflex arc. Methods Fifty-five cats with a normal neurologic examination that were referred for elective gonadectomy were divided into group 1 (29 cats) for testing the extensor carpi radialis reflex, and group 2 (26 cats) for testing the cranial tibial reflex. In group 1, the extensor carpi radialis reflex was tested after anesthetic induction and 15 mins after brachial plexus block with lidocaine. In group 2, the cranial tibial, withdrawal and patellar reflexes were elicited in 52 hindlimbs and retested 15 mins after epidural anesthesia. Results In group 1, before the anesthetic block, 55.17% of the cats had a decreased and 44.83% had a normal extensor carpi radialis reflex. After the block, 68.96% showed a decreased and 27.59% a normal reflex. No cat had an increased or absent reflex before anesthetic block. In group 2, prior to the anesthetic block, 15.38% of the cats had a decreased cranial tibial reflex and 84.62% had a normal response, whereas after the block it was decreased in 26.92% and normal in 73.08% of the cats. None of the cats had an increased or absent reflex. Regarding the presence of both reflexes before and after anesthetic block, there was no significant difference at 1% ( P = 0.013). Conclusions and relevance The extensor carpi radialis and cranial tibial reflexes in cats are not strictly myotatic reflexes, as they are independent of the reflex arc, and may be idiomuscular responses. Therefore, they are not reliable for neurologic examination in this species.

Muscle thickness and muscle quality measured by ultrasound: influence of different sites of measurement DOI: 10.5007/1980-0037.2011v13n2p87

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Ronei Silveira Pinto

2011-03-01

Full Text Available The aims of this study were: a to investigate differences in muscle thickness (MT measured by ultrasound and muscle quality (MQ at three sites in the elbow flexors and knee extensors, and b to correlate MT with isometric force production of the elbow flexors and knee extensors. Sixty-nine young male subjects participated in this study. The isometric force production values of the elbow flexors and knee extensors were obtained at 90° and 60°, respectively. MT was assessed at three sites in the elbow flexors (proximal – BB1, middle – BB2, and distal – BB3 and knee extensors (proximal – RI1, middle – RI2, and distal – RI3. Differences between the three measurements of MT and MQ were evaluated by one-way repeated measures ANOVA. Pearson’s correlation test was used to assess the correlation between MT and isometric force. The level of significance was set at p<0.05. The results showed significant differences (p<0.001 between the three MT and MQ sites in the elbow flexors (BB1, BB2, BB3 and in the knee extensors (RI1, RI2, RI3. The correlation between BB1, BB2 and BB3 and force production was r=0.57, r=0.52 and r=0.59, respectively (p<0.05. In the knee extensors, the correlation between RI1, RI2 and RI3 and force production was r=0.47, r=0.51 and r=0.53, respectively (p<0.01. There were significant differences in MQ between elbow flexors (p<0.001 and knee extensors (p<0.001. The present results showed that the site of measurement has a significant influence on MT and MQ. Furthermore, MT was positively correlated with isometric force production in the elbow flexors and knee extensors.

Resistance training improves muscle strength and functional capacity in multiple sclerosis

DEFF Research Database (Denmark)

Dalgas, U; Stenager, E; Jakobsen, J

2009-01-01

strength and functional capacity in patients with multiple sclerosis, the effects persisting after 12 weeks of self-guided physical activity. Level of evidence: The present study provides level III evidence supporting the hypothesis that lower extremity progressive resistance training can improve muscle......OBJECTIVE: To test the hypothesis that lower extremity progressive resistance training (PRT) can improve muscle strength and functional capacity in patients with multiple sclerosis (MS) and to evaluate whether the improvements are maintained after the trial. METHODS: The present study was a 2-arm...... and was afterward encouraged to continue training. After the trial, the control group completed the PRT intervention. Both groups were tested before and after 12 weeks of the trial and at 24 weeks (follow-up), where isometric muscle strength of the knee extensors (KE MVC) and functional capacity (FS; combined score...

Relation between knee extensors' strength, postural stability and variability of centre of pressure displacement during gait in adult women

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Eliza C. de Souza

2017-03-01

Full Text Available Background: It has been shown that variability of walking is related to fall risk similarly as postural control and muscle strength. Joint potential of this group of variables for fall risk assessment is promising, however research interested in relations between them is lacking. Objective: The aim of this study was to investigate the relation between knee extensors' strength, centre of pressure (COP velocity during one-leg stance and variability of COP displacement during various phases of gait cycle in middle-age women. Methods: A single group of 40 healthy women (age 56 ± 4.2 years took part in the study. For assessment of knee extensors' strength (peak torque and average work during concentric and eccentric contractions an isokinetic dynamometer was used. Mean velocity of COP during one-leg stance in anterior-posterior (AP and medial-lateral (ML directions was assessed on a force plate on a rigid surface with eyes open (two 30 s trials. Variability of COP displacement was assessed for loading response, midstance, terminal stance and preswing gait cycle phases (determined by vertical ground reaction force in AP and ML directions. It was measured by two force plates positioned in the middle of an 8 m walkway (5 trials at a self-selected speed. For statistical analysis of relationships between variables Pearson correlation was applied. Results: Our results showed significant correlations between eccentric peak torque and COP velocity in AP direction during one-leg stance, eccentric and concentric peak torque and COP variability during loading response in both ML and AP directions and during terminal stance in AP direction. Conclusion: Loading response and terminal stance seems to be more related to knee extensors' strength. Variables derived from postural stability assessment during one-leg stance are independent from variables derived from assessment of COP displacement variability during walking.

Protein hydrolysates and recovery of muscle damage following eccentric exercise

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Dale M.J.

2015-01-01

Full Text Available Background: A whey protein hydrolysate (NatraBoost XR; WPHNB has been shown to speed repair muscle damage. We sought to determine whether this benefit is specific to this hydrolysate to evaluate a marker for quality control. Methods: Three hydrolysates of the same whey protein isolate (WPI were prepared (WPHNB, WPH1 and WPH2. Isometric knee extensor strength was measured in 39 sedentary male participants before and after 100 maximal eccentric contractions of the knee extensors to induce muscle damage. Participants were then randomised to consume 250 ml of flavoured water (FW, n=9, or 250 ml of FW containing 25 g of either NatraBoost XR (n=3, WPH1 (n=9, WPH2 (n=9 or WPI (n=9. Strength was reassessed over the next seven days while the supplements were consumed daily. Fibroblasts were cultured for 48 hr in the presence of the different hydrolysates, WPI, saline or fetal bovine serum to ascertain effects on cell proliferation. Results: Strength was reduced in all treatment groups after eccentric exercise (P<0.001. Strength recovered steadily over 7 days in the FW, WPI, WPH1 and WPH2 treatment groups (P<0.001, with no difference between treatments (P=0.87. WPHNB promoted faster strength recovery compared with the other treatments (P<0.001. Fibroblast proliferation was greater with WPHNB compared with saline, WPI or the other hydrolysates (P<0.001. Conclusions: Promoting recovery from muscle damage seems unique to WPHNB. In vitro fibroblast proliferation may be a useful marker for quality control. It is not clear whether effects on fibroblast proliferation contribute to the in vivo effect of WPHNB on muscle damage.

Synergy of EMG patterns in gait as an objective measure of muscle selectivity in children with spastic cerebral palsy.

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Zwaan, Esther; Becher, Jules G; Harlaar, Jaap

2012-01-01

Selective motor control (SMC) is an important determinant of functioning in cerebral palsy (CP). Currently its assessment is based on subjective clinical tests with a low sensitivity. Electromyography (EMG) profiles during gait represent muscle coordination and might be used to assess SMC. EMG measurements during gait were processed into a measure of extensor synergy and thigh synergy. This was obtained in two groups of children with CP, and 30 typically developing children. Extensor synergy in CP was higher (0.95) than in healthy children (0.77), thigh synergy was almost equal in both groups. GMFM scores in the first group of 39 children with CP did not correlate to EMG based synergy measures. In a second group of 38 children with CP, a clear relation of clinical SMC score with extensor synergy was found, but only a weak relation with thigh synergy. Although an extensor synergy was validated at group level, our results present no convincing evidence for the use of EMG during gait to assess SMC in individual subjects with CP. Since gait involves both synergistic and selective contractions, the inherent motor control properties of this task will not allow for an assessment of selectivity comparable to the ability to perform isolated movements. Nevertheless, our results support the sensitive nature of EMG to represent an aberrant motor control in CP. Copyright © 2011 Elsevier B.V. All rights reserved.

Impact of high intensity exercise on muscle morphology in EAE rats

DEFF Research Database (Denmark)

Wens, I; Dalgas, U; Verboven, K

2015-01-01

paralysis (experiment 2, n=40), isokinetic foot extensor strength, cross sectional area (CSA) of tibialis anterior (TA), extensor digitorum longus (EDL) and soleus (SOL) and brain-derived neurotrophic factor (BDNF) levels were assessed. EAE reduced muscle fiber CSA of TA, EDL and SOL. In general, exercise...... was not able to affect CSA, whereas it delayed hindquarter paralysis peak. CON muscle work peaked and declined, while it remained stable in EAE. BDNF-responses were not affected by EAE or exercise. In conclusion, EAE affected CSA-properties of TA, EDL and SOL, which could, partly, explain the absence of peak...

Knee extensor strength and body weight in adolescent men and the risk of knee osteoarthritis by middle age.

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Turkiewicz, Aleksandra; Timpka, Simon; Thorlund, Jonas Bloch; Ageberg, Eva; Englund, Martin

2017-10-01

To assess the extent to which knee extensor strength and weight in adolescence are associated with knee osteoarthritis (OA) by middle age. We studied a cohort of 40 121 men who at age 18 years in 1969/1970 underwent mandatory conscription in Sweden. We retrieved data on isometric knee extensor strength, weight, height, smoking, alcohol consumption, parental education and adult occupation from Swedish registries. We identified participants diagnosed with knee OA or knee injury from 1987 to 2010 through the National Patient Register. We estimated the HR of knee OA using multivariable-adjusted Cox proportional regression model. To assess the influence of adult knee injury and occupation, we performed a formal mediation analysis. The mean (SD) knee extensor strength was 234 (47) Nm, the mean (SD) weight was 66 (9.3) kg. During 24 years (median) of follow-up starting at the age of 35 years, 2049 persons were diagnosed with knee OA. The adjusted HR (95% CI) of incident knee OA was 1.12 (1.06 to 1.18) for each SD of knee extensor strength and 1.18 (1.15 to 1.21) per 5 kg of body weight. Fifteen per cent of the increase in OA risk due to higher knee extensor strength could be attributed to knee injury and adult occupation. Higher knee extensor strength in adolescent men was associated with increased risk of knee OA by middle age, challenging the current tenet of low muscle strength being a risk factor for OA. We confirmed higher weight to be a strong risk factor for knee OA. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effect of exercise-induced enhancement of the leg-extensor muscle-tendon unit capacities on ambulatory mechanics and knee osteoarthritis markers in the elderly.

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Karamanidis, Kiros; Oberländer, Kai Daniel; Niehoff, Anja; Epro, Gaspar; Brüggemann, Gert-Peter

2014-01-01

Leg-extensor muscle weakness could be a key component in knee joint degeneration in the elderly because it may result in altered muscular control during locomotion influencing the mechanical environment within the joint. This work aimed to examine whether an exercise-induced enhancement of the triceps surae (TS) and quadriceps femoris (QF) muscle-tendon unit (MTU) capacities would affect mechanical and biological markers for knee osteoarthritis in the elderly. Twelve older women completed a 14-week TS and QF MTU exercise intervention, which had already been established as increasing muscle strength and tendon stiffness. Locomotion mechanics and serum cartilage oligomeric matrix protein (COMP) levels were examined during incline walking. MTU mechanical properties were assessed using simultaneously ultrasonography and dynamometry. Post exercise intervention, the elderly had higher TS and QF contractile strength and tendon-aponeurosis stiffness. Regarding the incline gait task, the subjects demonstrated a lower external knee adduction moment and lower knee adduction angular impulse during the stance phase post-intervention. Furthermore, post-intervention compared to pre-intervention, the elderly showed lower external hip adduction moment, but revealed higher plantarflexion pushoff moment. The changes in the external knee adduction moment were significantly correlated with the improvement in ankle pushoff function. Serum COMP concentration increased in response to the 0.5-h incline walking exercise with no differences in the magnitude of increment between pre- and post-intervention. This work emphasizes the important role played by the ankle pushoff function in knee joint mechanical loading during locomotion, and may justify the inclusion of the TS MTU in prevention programs aiming to positively influence specific mechanical markers for knee osteoarthritis in the elderly. However, the study was unable to show that COMP is amenable to change in the elderly following a

Isometric hip muscle strength in posttraumatic below-knee amputees

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Jandrić Slavica

2007-01-01

Full Text Available Background/Aim. Traumas and war injuries, next to chronic occlusive artery disease and diabetes mellitus-derived complications, are the most frequent cause of the lower limbs amputation. They affect mostly younger population that need a higher level of activities as compared with the elderly. Medical rehabilitation is very significant for the muscle performance improvement in this population providing their social reintegration. The aim of this study was to investigate the effect of below-knee amputation on the hip isometric muscle strength and effect of rehabilitation on improvement of hip muscle strength in below-knee amputees, secondary to war wounding. Methods. Forty below-knee amputees (after war wounding, average age 35.6±10.6 years, that were included in primary rehabilitation program with prosthetics, were examined. Objective parameters were used to evaluate therapeutical effects. Isometric muscle strength of hip flexors, extensors, abductors and adductors was measured by dynamometer and expressed in Newton (N at admission, control and discharge for each patient. Average length of the treatment was 51 ± 34.1 days. Results. For isometric hip flexors (t = - 1.99346, p < 0.05, extensors (t = -4.629073, p < 0.001, abductors (t = -4.9408, p < 0.001 and adductors (t = -2.00228, p < 0.05, muscle strength was significantly less on the amputated than on nonamputated side. The highest differences in muscle strength between amputated and nonamputated limbs were noted for hip abductors (26.6% and extensors (23.3%. There was significant improvement of mean values of strength for all examined hip muscles after rehabilitation and prosthetics for both legs in comparison to beginning of the therapy. The hip abductor on the amputated side was for 19.4% weaker after rehabilitation in comparison to the nonamputated limb. Conclusion. Decreases of isometric muscle strength in all examined hip muscles were observed, more in the amputated limb. Rehabilitation

A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

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Randolph, Matthew E.; Pavlath, Grace K.

2015-01-01

The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies (MDs), such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some MDs. The biology of muscle stem cells varies depending on the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease. PMID:26500547

RELATIONSHIP BETWEEN ISOMETRIC THIGH MUSCLE STRENGTH AND MINIMAL CLINICALLY IMPORTANT DIFFERENCES (MCIDS) IN KNEE FUNCTION IN OSTEOARTHRITIS – DATA FROM THE OSTEOARTHRITIS INITIATIVE

Science.gov (United States)

Ruhdorfer, Anja; Wirth, Wolfgang; Eckstein, Felix

2014-01-01

Objective To determine the relationship between thigh muscle strength and clinically relevant differences in self-assessed lower limb function. Methods Isometric knee extensor and flexor strength of 4553 Osteoarthritis Initiative participants (2651 women/1902 men) was related to Western Ontario McMasters Universities (WOMAC) physical function scores by linear regression. Further, groups of Male and female participant strata with minimal clinically important differences (MCIDs) in WOMAC function scores (6/68) were compared across the full range of observed values, and to participants without functional deficits (WOMAC=0). The effect of WOMAC knee pain and body mass index on the above relationships was explored using stepwise regression. Results Per regression equations, a 3.7% reduction in extensor and a 4.0% reduction in flexor strength were associated with an MCID in WOMAC function in women, and a 3.6%/4.8% reduction in men. For strength divided by body weight, reductions were 5.2%/6.7% in women and 5.8%/6.7% in men. Comparing MCID strata across the full observed range of WOMAC function confirmed the above estimates and did not suggest non-linear relationships across the spectrum of observed values. WOMAC pain correlated strongly with WOMAC function, but extensor (and flexor) muscle strength contributed significant independent information. Conclusion Reductions of approximately 4% in isometric muscle strength and of 6% in strength/weight were related to a clinically relevant difference in WOMAC functional disability. Longitudinal studies will need to confirm these relationships within persons. Muscle extensor (and flexor) strength (per body weight) provided significant independent information in addition to pain in explaining variability in lower limb function. PMID:25303012

Effects of High-Intensity Blood Flow Restriction Exercise on Muscle Fatigue

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Neto Gabriel R.

2014-07-01

Full Text Available Strength training combined with blood flow restriction (BFR have been used to improve the levels of muscle adaptation. The aim of this paper was to investigate the acute effect of high intensity squats with and without blood flow restriction on muscular fatigue levels. Twelve athletes (aged 25.95 ± 0.84 years were randomized into two groups: without Blood Flow Restriction (NFR, n = 6 and With Blood Flow Restriction (WFR, n = 6 that performed a series of free weight squats with 80% 1-RM until concentric failure. The strength of the quadriceps extensors was assessed in a maximum voluntary isometric contraction integrated to signals from the surface electromyogram. The average frequency showed significant reductions in the WFR group for the vastus lateralis and vastus medialis muscles, and intergroup only for the vastus medialis. In conclusion, a set of squats at high intensity with BFR could compromise muscle strength immediately after exercise, however, differences were not significant between groups.

L-carnitine pretreatment protects slow-twitch skeletal muscles in a rat model of ischemia-reperfusion injury.

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Demirel, Mert; Kaya, Burak; Cerkez, Cem; Ertunc, Mert; Sara, Yildirim

2013-10-01

Ischemia-reperfusion (I/R) injury negatively affects the outcome of surgical interventions for amputated or severely traumatized extremities. This study aimed to evaluate the protective role of l-carnitine on the contractile properties of fast-twitch (extensor digitorum longus [EDL]) and slow-twitch (soleus [SOL]) skeletal muscles following I/R-induced injury in a rat model. Rats were divided into 4 groups (1) saline pretreatment, (2) l-carnitine pretreatment, (3) saline pretreatment and I/R, and (4) l-carnitine pretreatment and I/R. Twitch and tetanic contractions in the EDL and SOL muscles in each group were recorded. Additionally, a fatigue protocol was performed in these muscles. Twitch and tetanic contraction amplitudes were lower in the EDL and SOL muscles in which I/R was induced (P contraction amplitude in the SOL muscles following I/R (P muscles. l-Carnitine pretreatment did not alter the fatigue response in any of the muscles.

The Fate of the Iliopsoas Muscle in Long-term Follow-up After Open Reduction With a Medial Approach in Developmental Dysplasia of the Hip. Part 2: Isokinetic Muscle Strength Evaluation.

Science.gov (United States)

Yilmaz, Serdar; Aksahin, Ertugrul; Ersoz, Murat; Bicimoglu, Ali

2017-09-01

The impact on long-term weakness of hip flexion of complete iliopsoas tenotomy during open reduction of developmental hip dysplasia with a medial approach has not yet been fully clarified. The purpose of this study was to investigate the isokinetic muscle strength (IMS) of hip flexor and extensor muscles in these patients and also to analyze the effect of spontaneous reattachment of the iliopsoas muscle on IMS measurements. The study included 20 patients. Earlier magnetic resonance imaging examination of all the patients revealed spontaneous reattachment of the iliopsoas in 18 (90%) patients. IMS measurements were performed at 60 and 150 degrees/s. The peak torque, total work (TW), average power (AP), work fatigue, and agonist to antagonist muscle ratio of the operated and nonoperated hips were recorded separately for flexors and extensors. The effect of iliopsoas reattachment on IMS was also evaluated. The mean follow-up period was 16.65±2.16 (13 to 20) years. Total work (P=0.013) and average power (P=0.009) of the flexor muscles and work fatigue of the extensor muscles (P=0.030) of the operated hip were significantly decreased when compared with the nonoperated hips at 150 degrees/s. There was no significant difference between the flexor muscles of the operated and nonoperated hips (Phips. Flexor muscle strength was decreased in the operated hip against low resistance in long-term follow-up after iliopsoas tenotomy. This may reflect that hip muscle strength was decreased after prolonged activities such as sports. However, in forceful activities flexor muscle strength was retained due to iliopsoas reattachment. On the basis of this study we thought that spontaneous reattachment of the iliopsoas tendon substantially preserves muscle strength. Nonetheless possible efforts should be made to surgically reattach the psoas tendon to preserve strength of the muscle. Therapeutic level IV.

The Effects of High-Intensity versus Low-Intensity Resistance Training on Leg Extensor Power and Recovery of Knee Function after ACL-Reconstruction

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Theresa Bieler

2014-01-01

Full Text Available Objective. Persistent weakness is a common problem after anterior cruciate ligament- (ACL- reconstruction. This study investigated the effects of high-intensity (HRT versus low-intensity (LRT resistance training on leg extensor power and recovery of knee function after ACL-reconstruction. Methods. 31 males and 19 females were randomized to HRT (n=24 or LRT (n=26 from week 8–20 after ACL-reconstruction. Leg extensor power, joint laxity, and self-reported knee function were measured before and 7, 14, and 20 weeks after surgery. Hop tests were assessed before and after 20 weeks. Results. Power in the injured leg was 90% (95% CI 86–94% of the noninjured leg, decreasing to 64% (95% CI 60–69% 7 weeks after surgery. During the resistance training phase there was a significant group by time interaction for power (P=0.020. Power was regained more with HRT compared to LRT at week 14 (84% versus 73% of noninjured leg, resp.; P=0.027 and at week 20 (98% versus 83% of noninjured leg, resp.; P=0.006 without adverse effects on joint laxity. No other between-group differences were found. Conclusion. High-intensity resistance training during rehabilitation after ACL-reconstruction can improve muscle power without adverse effects on joint laxity.

Muscle protein analysis. II. Two-dimensional electrophoresis of normal and diseased human skeletal muscle

Energy Technology Data Exchange (ETDEWEB)

Giometti, C.S. (Argonne National Lab., IL); Barany, M.; Danon, M.J.; Anderson, N.G.

1980-07-01

High-resolution two-dimensional electrophoresis was used to analyze the major proteins of normal and pathological human-muscle samples. The normal human-muscle pattern contains four myosin light chains: three that co-migrate with the myosin light chains from rabbit fast muscle (extensor digitorum longus), and one that co-migrates with the light chain 2 from rabbit slow muscle (soleus). Of seven Duchenne muscular dystrophy samples, four yielded patterns with decreased amounts of actin and myosin relative to normal muscle, while three samples gave patterns comparable to that for normal muscle. Six samples from patients with myotonic dystrophy also gave normal patterns. In nemaline rod myopathy, in contrast, the pattern was deficient in two of the fast-type myosin light chains.

Proximo-distal organization and fibre type regionalization in rat hindlimb muscles

NARCIS (Netherlands)

Wang, LC; Kernell, D

Five muscles of the rat's lower hindlimb were compared with regard to their histochemical fibre type distribution at seven different proximo-distal levels. The muscles were: extensor digitorum longus (ED), flexor digitorum and hallucis longus (FD), gastrocnemius medialis (GM), peroneus longus (PE)

Effects of aging on muscle mechanical function and muscle fiber morphology during short-term immobilization and subsequent retraining

DEFF Research Database (Denmark)

Hvid, Lars; Aagaard, Per; Justesen, Lene

2010-01-01

Very little attention has been given to the combined effects of aging and disuse as separate factors causing deterioration in muscle mechanical function. Thus the purpose of this study was to investigate the effects of 2 wk of immobilization followed by 4 wk of retraining on knee extensor muscle...... to the deleterious effects of short-term muscle disuse on muscle fiber size and rapid force capacity than YM. Furthermore, OM seems to require longer time to recover and regain rapid muscle force capacity, which may lead to a larger risk of falling in aged individuals after periods of short-term disuse....

Relationship between isometric thigh muscle strength and minimum clinically important differences in knee function in osteoarthritis: data from the osteoarthritis initiative.

Science.gov (United States)

Ruhdorfer, Anja; Wirth, Wolfgang; Eckstein, Felix

2015-04-01

To determine the relationship between thigh muscle strength and clinically relevant differences in self-assessed lower leg function. Isometric knee extensor and flexor strength of 4,553 Osteoarthritis Initiative participants (2,651 women and 1,902 men) was related to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function scores by linear regression. Further, groups of male and female participant strata with minimum clinically important differences (MCIDs) in WOMAC function scores (6 of 68 units) were compared across the full range of observed values and to participants without functional deficits (WOMAC score 0). The effect of WOMAC knee pain and body mass index on the above relationships was explored using stepwise regression. Per regression equations, a 3.7% reduction in extensor strength and a 4.0% reduction in flexor strength were associated with an MCID in WOMAC function in women, and, respectively, a 3.6% and 4.8% reduction in men. For strength divided by body weight, reductions were 5.2% and 6.7%, respectively, in women and 5.8% and 6.7%, respectively, in men. Comparing MCID strata across the full observed range of WOMAC function confirmed the above estimates and did not suggest nonlinear relationships across the spectrum of observed values. WOMAC pain correlated strongly with WOMAC function, but extensor (and flexor) muscle strength contributed significant independent information. Reductions of approximately 4% in isometric muscle strength and of 6% in strength per body weight were related to a clinically relevant difference in WOMAC functional disability. Longitudinal studies will need to confirm these relationships within persons. Muscle extensor (and flexor) strength (per body weight) provided significant independent information in addition to pain in explaining variability in lower leg function. Copyright © 2015 by the American College of Rheumatology.

Does muscle morphology change in chronic neck pain patients? - A systematic review.

Science.gov (United States)

De Pauw, R; Coppieters, I; Kregel, J; De Meulemeester, K; Danneels, L; Cagnie, B

2016-04-01

Neck pain is a common disabling worldwide health problem with a high socio-economic burden. Changes underlying the transition to, or the maintenance of a chronic state are still barely understood. Increasing evidence suggests that morphological muscle changes, including changes in cross-sectional area (CSA) or fatty infiltration, play a role in chronic neck pain. However, a structured overview of the current evidence of morphological changes is lacking. To systematically review the morphological muscle changes in patients with chronic neck pain, including those with whiplash-associated disorders (WAD) and chronic idiopathic neck pain. A systematic review using the PRISMA-guidelines. Fourteen of 395 papers were included after extensive screening. Most studies were of moderate methodological quality. A higher CSA was found in all flexor muscles in both patients with WAD and patients with chronic idiopathic neck pain, except for the deeper flexor muscles in patients with chronic idiopathic neck pain. The cervical extensor muscles show an increased CSA at the highest cervical segments in patients with WAD, while most studies in patients with chronic idiopathic neck pain report a decreased CSA in all extensor muscles. Fatty infiltration, which could be accountable for an increased CSA, of both cervical extensors and flexors seems to occur only in patients with WAD. Some evidence is available for changes in muscle morphology, however more high quality prospective and cross-sectional research is needed to confirm these changes and to identify potential underlying causes that need yet to be discovered. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effects of knee extensor eccentric training on functional tests in healthy subjects Os efeitos do treino isocinético excêntrico dos extensores do joelho nos testes funcionais em sujeitos saudáveis

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Heleodório H. Santos

2010-08-01

Full Text Available BACKGROUND: It is well known that eccentric training increases muscle strength and promotes greater neural activation, and therefore has been used in the recovery of knee extensors. The hypothesis of this study was that there would be a strong correlation between knee extensor torque and functional tests. OBJECTIVES: To investigate the relationship between knee extensor peak torque and functional tests of agility (runs and propulsion (hop for distance after short-term isokinetic eccentric training. METHODS: Twenty healthy and active male undergraduate students (age 22.5±2.1 years; height 1.72±0.10 m; weight 67.8±9.5 kg; body mass index: 22.5±2.0 kg/m², with no abnormalities or history of injury of the limbs, performed an isokinetic assessment of the knee extensors and flexors and also functional tests before and after isokinetic training, which consisted of 3 sets of 10 MVECs at 30º/s, with 3 minutes of rest between sets, twice a week for 6 weeks. RESULTS: The eccentric training increased the extensor peak torque (16, 27 and 17%; PCONTEXTUALIZAÇÃO: Sabe-se que o treino excêntrico aumenta a força muscular, promovendo uma maior ativação neural e, portanto, tem sido usado na recuperação do torque extensor. A hipótese deste estudo foi a de que possa existir uma forte correlação entre o torque extensor do joelho e os testes funcionais. OBJETIVOS: Correlacionar o torque extensor do joelho com os testes funcionais de agilidade (corridas e impulsão (saltos em distância após o treino isocinético excêntrico de curta duração. MÉTODOS: Vinte homens universitários, ativos e saudáveis (22,5±2,1 anos; 1,72±0,10 m; 67,8±9,5 kg; IMC 22,5±2,0 kg/m², sem reportar anormalidades ou história de lesão no membro inferior, realizaram avaliação isocinética do torque extensor e flexor do joelho e testes funcionais antes e depois do treino isocinético que consistiu em três séries de 10 CEVM a 30º/s, com 3 minutos de repouso entre as

Effect of simultaneous stretching of the wrist and finger extensors for lateral epicondylitis: a gross anatomical study of the tendinous origins of the extensor carpi radialis brevis and extensor digitorum communis.

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Shirato, Rikiya; Wada, Takuro; Aoki, Mitsuhiro; Iba, Kousuke; Kanaya, Kohei; Fujimiya, Mineko; Yamashita, Toshihiko

2015-11-01

Pulling the wrist into flexion with the elbow in extension and forearm in pronation has been used as the stretching technique of wrist extensors for lateral epicondylitis. Simultaneous stretching of the fingers in addition to the wrist flexion has also been applied. However, the mechanism of this simultaneous stretching has not been clarified. This study is designed to clarify the mechanism underlying this simultaneous stretching technique based on the anatomical features of the origins of the extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC). Thirty-nine arms from formalin-embalmed Japanese human specimens were dissected. The features of the origins of the ECRB and EDC were macroscopically observed, and the locations of each origin on the lateral epicondyle were measured. The ECRB had a long and wide, purely tendinous origin which originated from the anterior slope of the lateral epicondyle. The tendinous origin of the index finger of the EDC (EDC-IF) arose from the posterior aspect of the ECRB tendinous origin, with a coexisting muscular portion observed at the level of the proximal forearm. The middle finger of the EDC (EDC-MF) had a short tendinous origin with an associated muscular portion and originated proximo-laterally to the origin of the ECRB on the lateral epicondyle. In addition, the muscular origin of the EDC-MF arose on the superficial and posterior aspect of the ECRB tendinous origin. In contrast, the ring and little fingers of the EDC originated from the tendinous septum of the extensor digiti minimi and extensor carpi ulnaris, and had no connection with the ECRB tendinous origin. On the basis of our anatomical findings, simultaneous stretching of the wrist extensors by wrist, index and middle fingers flexion could provide stretching force to both the tendinous origins of the ECRB and EDC through the EDC-IF and EDC-MF.

Muscle Recruitment and Coordination following Constraint-Induced Movement Therapy with Electrical Stimulation on Children with Hemiplegic Cerebral Palsy: A Randomized Controlled Trial.

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Kaishou Xu

Full Text Available To investigate changes of muscle recruitment and coordination following constraint-induced movement therapy, constraint-induced movement therapy plus electrical stimulation, and traditional occupational therapy in treating hand dysfunction.In a randomized, single-blind, controlled trial, children with hemiplegic cerebral palsy were randomly assigned to receive constraint-induced movement therapy (n = 22, constraint-induced movement therapy plus electrical stimulation (n = 23, or traditional occupational therapy (n = 23. Three groups received a 2-week hospital-based intervention and a 6-month home-based exercise program following hospital-based intervention. Constraint-induced movement therapy involved intensive functional training of the involved hand during which the uninvolved hand was constrained. Electrical stimulation was applied on wrist extensors of the involved hand. Traditional occupational therapy involved functional unimanual and bimanual training. All children underwent clinical assessments and surface electromyography (EMG at baseline, 2 weeks, 3 and 6 months after treatment. Surface myoelectric signals were integrated EMG, root mean square and cocontraction ratio. Clinical measures were grip strength and upper extremity functional test.Constraint-induced movement therapy plus electrical stimulation group showed both a greater rate of improvement in integrated EMG of the involved wrist extensors and cocontraction ratio compared to the other two groups at 3 and 6 months, as well as improving in root mean square of the involved wrist extensors than traditional occupational therapy group (p<0.05. Positive correlations were found between both upper extremity functional test scores and integrated EMG of the involved wrist as well as grip strength and integrated EMG of the involved wrist extensors (p<0.05.Constraint-induced movement therapy plus electrical stimulation is likely to produce the best outcome in improving muscle recruitment

Relationship between Joint Position Sense, Force Sense, and Muscle Strength and the Impact of Gymnastic Training on Proprioception

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Bartłomiej Niespodziński

2018-01-01

Full Text Available The aims of this study were (1 to assess the relationship between joint position (JPS and force sense (FS and muscle strength (MS and (2 to evaluate the impact of long-term gymnastic training on particular proprioception aspects and their correlations. 17 elite adult gymnasts and 24 untrained, matched controls performed an active reproduction (AR and passive reproduction (PR task and a force reproduction (FR task at the elbow joint. Intergroup differences and the relationship between JPS, FS, and MS were evaluated. While there was no difference in AR or PR between groups, absolute error in the control group was higher during the PR task (7.15 ± 2.72° than during the AR task (3.1 ± 1.93°. Mean relative error in the control group was 61% higher in the elbow extensors than in the elbow flexors during 50% FR, while the gymnast group had similar results in both reciprocal muscles. There was no linear correlation between JPS and FS in either group; however, FR was negatively correlated with antagonist MS. In conclusion, this study found no evidence for a relationship between the accuracy of FS and JPS at the elbow joint. Long-term gymnastic training improves the JPS and FS of the elbow extensors.

Variations of anatomy on MRI of the first extensor compartment of the wrist and association with DeQuervain tenosynovitis

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Chang, Connie Y.; Kheterpal, Arvin B.; Terneria Vicentini, Joao Rafael; Huang, Ambrose J. [Massachusetts General Hospital, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States)

2017-08-15

To study anatomical variations on MRI of the first extensor compartment of the wrist in DeQuervain tenosynovitis (DQT). A retrospective search for DQT patients yielded 47 subjects (51 ± 15 years, 36 female, 11 male). The age-matched control group (normal first extensor compartment) was 49 ± 15 years (29 female, 18 male). Two independent readers reviewed: the number of abductor pollicis longus (APL) tendon slips, tendon sheath septations (compartmentalization), and APL and EPB cross-sectional area (CSA) at the radial styloid. A tendon slip was defined as a discrete structure for ≥5 contiguous slices with its own insertion. The distribution of APL tendon slips was different for the DQT and control groups (Reader 1/Reader 2: P = 0.0001 and 0.001). The most common arrangement for both groups was two APL tendon slips. One tendon slip was less common (P = 0.03 and 0.1) and compartmentalization was more common (P = 0.003; < 0.0001) for the DQT group than the control group. There was no difference in tendon slip insertions on one or multiple bones (P = 0.1; 0.7). APL and EPB compartment CSAs were also higher for the DQT group (combined first extensor compartment area: 21.3 ± 7.6 mm{sup 2}; 21.0 ± 7.1) than the control group (17.2 ± 3.8; 17.1 ± 3.9) (P = 0.002; 0.002). We found a statistically significantly increased proportion of supernumerary tendon slips and compartmentalization of the first extensor compartment in patients with DQT and greater CSA of the first extensor compartment at the radial styloid, consistent with previous anatomical, surgical, and ultrasound studies. (orig.)

Determining physiological cross-sectional area of extensor carpi radialis longus and brevis as a whole and by regions using 3D computer muscle models created from digitized fiber bundle data.

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Ravichandiran, Kajeandra; Ravichandiran, Mayoorendra; Oliver, Michele L; Singh, Karan S; McKee, Nancy H; Agur, Anne M R

2009-09-01

Architectural parameters and physiological cross-sectional area (PCSA) are important determinants of muscle function. Extensor carpi radialis longus (ECRL) and brevis (ECRB) are used in muscle transfers; however, their regional architectural differences have not been investigated. The aim of this study is to develop computational algorithms to quantify and compare architectural parameters (fiber bundle length, pennation angle, and volume) and PCSA of ECRL and ECRB. Fiber bundles distributed throughout the volume of ECRL (75+/-20) and ECRB (110+/-30) were digitized in eight formalin embalmed cadaveric specimens. The digitized data was reconstructed in Autodesk Maya with computational algorithms implemented in Python. The mean PCSA and fiber bundle length were significantly different between ECRL and ECRB (p < or = 0.05). Superficial ECRL had significantly longer fiber bundle length than the deep region, whereas the PCSA of superficial ECRB was significantly larger than the deep region. The regional quantification of architectural parameters and PCSA provides a framework for the exploration of partial tendon transfers of ECRL and ECRB.

Tennis in hot and cool conditions decreases the rapid muscle torque production capacity of the knee extensors but not of the plantar flexors

Science.gov (United States)

Girard, Olivier; Racinais, Sébastien; Périard, Julien D

2014-01-01

Objectives To assess the time course of changes in rapid muscle force/torque production capacity and neuromuscular activity of lower limb muscles in response to prolonged (∼2 h) match-play tennis under heat stress. Methods The rates of torque development (RTD) and electromyographic activity (EMG; ie, root mean square) rise were recorded from 0 to 30, –50, –100 and –200 ms during brief (3–5 s) explosive maximal isometric voluntary contractions (MVC) of the knee extensors (KE) and plantar flexors (PF), along with the peak RTD within the entirety of the torque-time curve. These values were recorded in 12 male tennis players before (prematch) and after (postmatch, 24 and 48 h) match-play in HOT (∼37°C) and COOL (∼22°C) conditions. Results The postmatch core temperature was greater in the HOT (∼39.4°C) vs COOL (∼38.7°C) condition (ptorque. Furthermore, the rate of KE EMG activity rise remained unchanged. Conversely, the PF contractile RTD and rate of EMG activity rise were unaffected by the exercise or environmental conditions. Conclusions In the KE, a reduction in maximal torque production capacity following prolonged match-play tennis appears to account for the decrease in the rate of torque development, independent of environmental conditions, while remaining unchanged in the PF. PMID:24668381

One session of partial-body cryotherapy (-110 °C) improves muscle damage recovery.

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Ferreira-Junior, J B; Bottaro, M; Vieira, A; Siqueira, A F; Vieira, C A; Durigan, J L Q; Cadore, E L; Coelho, L G M; Simões, H G; Bemben, M G

2015-10-01

To evaluate the effects of a single session of partial-body cryotherapy (PBC) on muscle recovery, 26 young men performed a muscle-damaging protocol that consisted of five sets of 20 drop jumps with 2-min rest intervals between sets. After the exercise, the PBC group (n = 13) was exposed to 3 min of PBC at -110 °C, and the control group (n = 13) was exposed to 3 min at 21 °C. Anterior thigh muscle thickness, isometric peak torque, and muscle soreness of knee extensors were measured pre, post, 24, 48, 72, and 96 h following exercise. Peak torque did not return to baseline in control group (P  0.05). Peak torque was also higher after PBC at 72 and 96 h compared with control group (P < 0.05). Muscle thickness increased after 24 h in the control group (P < 0.05) and was significantly higher compared with the PBC group at 24 and 96 h (P < 0.05). Muscle soreness returned to baseline for the PBC group at 72 h compared with 96 h for controls. These results indicate that PBC after strenuous exercise may enhance recovery from muscle damage. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Modulation of recurrent inhibition from knee extensors to ankle motoneurones during human walking

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Lamy, Jean-Charles; Iglesias, Caroline; Lackmy, Alexandra

2008-01-01

The neural control for muscle coordination during human locomotion involves spinal and supraspinal networks, but little is known about the exact mechanisms implicated. The present study focused on modulation of heteronymous recurrent inhibition from knee extensors to ankle motoneurones at different...... times in the gait cycle, when quadriceps (Quad) muscle activity overlaps that in tibialis anterior (TA) and soleus (Sol). The effects of femoral nerve stimulation on ankle motoneurones were investigated during treadmill walking and during tonic co-contraction of Quad and TA/Sol while standing. Recurrent...... inhibition of TA motoneurones depended on the level of background EMG, and was similar during walking and standing for matched background EMG levels. On the other hand, recurrent inhibition in Sol was reduced in early stance, with respect to standing, and enhanced in late stance. Reduced inhibition in Sol...

Characteristics and preliminary observations of the influence of electromyostimulation on the size and function of human skeletal muscle during 30 days of simulated microgravity

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Duvoisin, Marc R.; Convertino, Victor A.; Buchanan, Paul; Gollnick, Philip A.; Dudley, Gary A.

1989-01-01

The effect of transcutaneous electromyostimulation (EMS) on the development of atrophy and the loss of strength in lower limb musculature in humans exposed to microgravity was determined in three subjects who received EMS twice daily in a 3-d on/1-d off cycle on their dominant leg during 30 days of bedrest. The output waveform from the stimulator was sequenced to the knee extensors, knee flexors, ankle extensors, and ankle flexors, and caused three isometric contractions of each muscle group per minute. It was found that, in the dominant leg, EMS acted to attenuate the changes caused by bedrest, such as reductions in the leg volume, muscle compartment size, cross-sectional area of slow- and fast-twitch fibers, strength, and aerobic enzyme activities, and an increase in leg compliance.

Spontaneous Extensor Tendon Rupture in the Rheumatoid Wrist: Risk Factors and Preventive Role of Extended Tenosynovectomy.

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Hsueh, Jung-Hua; Liu, Wen-Chung; Yang, Kuo-Chung; Hsu, Kuei-Chang; Lin, Cheng-Ta; Chen, Lee-Wei

2016-03-01

Spontaneous extensor tendon rupture is often seen in rheumatoid arthritis (RA) patients, but the risk factors are not clearly defined. We therefore collected the data of RA patients with previous extensor tendon rupture and those with tenosynovitis and analyzed the relationship between extended tenosynovectomy and spontaneous extensor tendon rupture. We retrospectively reviewed 17 spontaneous extensor tendon rupture episodes in 15 RA patients and 14 tenosynovitis episodes that required tenosynovectomy in 12 RA patients from 1997 to 2013. Correlations between the incidence of tendon rupture, X-ray findings, and clinical findings in the affected wrists before tendon rupture were analyzed statistically using the test for proportion. The following parameters were significantly correlated with spontaneous extensor tendon rupture: disease duration longer than 8 years, persistent tenosynovitis longer than 1 year duration, and Larsen grade greater than 4 (P = 0.02, 0.03, and 0.01, respectively). Dislocation of the distal end of the ulna, carpal collapse, and the scallop sign on X-ray contributed to a higher spontaneous extensor tendon rupture rate among RA patients (P = 0.01, 0.05, and 0.03, respectively). Extended tenosynovectomy was performed on 14 wrists in 12 RA patients with persistent tenosynovitis longer than 6 months, and Larsen grade did not deteriorate in this group compared with those who did not undergo the surgery. No spontaneous extensor tendon rupture occurred following the surgery. Risk factors of spontaneous extensor tendon rupture included disease duration longer than 8 years, persistent tenosynovitis longer than 1 year, and wrist Larsen grade greater than 4. Dislocation of the distal end of the ulna, carpal collapse, and the scallop sign on X-ray indicated a higher probability of extensor tendon rupture. Rheumatologists should consult with hand surgeons promptly to preserve hand function before tendon rupture. Prophylactic extended tenosynovectomy

The Effect of an Isometric Hip Muscle Strength Training Protocol on Valgus Angle During a Drop Vertical Jump in Competitive Female Volleyball Players

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Kaitlin M. Jackson

2017-10-01

Full Text Available Background: Hip muscle weakness is associated with higher peak knee valgus angles (VA during drop vertical jumps (DVJ and linked to ACL injury risk. Objective: To determine if isometric strengthening (IST of the hip extensor, abductor, and external rotator muscle groups would reduce VA exhibited during a DVJ. Methodology:  Fourteen female volleyball players (7 training (TG, 7 control (CG, VA≥9˚ during DVJ participated. Pre- and post-test gluteal, quadriceps and hamstring strength were measured with a digital force gauge. Three-dimensional kinematics were collected during 15 DVJ trials. TG participated in a 6-week IST program that targeted the hip extensor, abductor, and external rotator muscle groups. Two-way mixed ANOVAs compared mean differences of VA and strength. Single-participant analyses examined if athlete-specific adaptations went undetected in the analyses of aggregated data. Results: TG hip extension, abduction, and knee flexion strength increased, respectively, by 20.5%, 27.5% and 23.5% (P<0.05. No group-level changes in VA were detected. Unilateral VA decreased for 5 TG participants, and bilateral VA decreased in 2 TG participants. Conclusions: IST increased isometric hip muscle strength, but its effect on VA is inconclusive based on group-level analyses. Using single-participant designs, future studies should assess IST and/or dynamic resistance/neuromuscular training in a larger sample to determine its effect on ACL injury risk factors.

Exercise induced effects on muscle function and range of motion in patients with hip osteoarthritis

DEFF Research Database (Denmark)

Bieler, Theresa; Siersma, Volkert; Magnusson, S Peter

2018-01-01

BACKGROUND AND PURPOSE: Patients with hip osteoarthritis have impairments in muscle function (muscle strength and power) and hip range of motion (ROM), and it is commonly believed that effective clinical management of osteoarthritis should address these impairments to reduce pain and disability......-two patients were randomized to either 4 months of physiotherapist-supervised, moderate, progressive, strength training (n = 50), physiotherapist-supervised NW (n = 50), or unsupervised HBE (n = 52). Maximal isometric hip and thigh muscle strength and leg extensor power and active hip ROM were assessed...... at baseline 2, 4, and 12 months. RESULTS: Intention-to-treat-analyses did not show any significant between-group differences for improvements in muscle strength and power or ROM at any time points. Short-term significant (p

Direct effects of FGF21 on glucose uptake in human skeletal muscle

DEFF Research Database (Denmark)

Mashili, Fredirick L; Austin, Reginald L; Deshmukh, Atul S

2011-01-01

21 were determined in normal glucose tolerant (n = 40) and type 2 diabetic (T2D; n = 40) subjects. We determined whether FGF21 has direct effects on glucose metabolism in cultured myotubes (n = 8) and extensor digitorum longus skeletal muscle. RESULTS: Serum FGF21 levels increased 20% in T2D versus...... normal glucose tolerant subjects (p muscle mRNA expression was unaltered. Fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), waist circumference, and body mass index (BMI) significantly correlated with serum FGF21 levels in T2D (p ... and insulin-stimulated glucose uptake in human myotubes, coincident with increased glucose transporter 1 mRNA, and enhanced glucose transporter 1 abundance at the plasma membrane. In isolated extensor digitorum longus muscle, FGF21 potentiated insulin-stimulated glucose transport, without altering...

Does metabosensitive afferent fibers activity differ from slow- and fast-twitch muscles?

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Caron, Guillaume; Decherchi, Patrick; Marqueste, Tanguy

2015-09-01

This study was designed to investigate the metabosensitive afferent response evoked by electrically induced fatigue (EIF), lactic acid (LA) and potassium chloride (KCl) in three muscle types. We recorded the activity of groups III-IV afferents originating from soleus, gastrocnemius and tibialis anterior muscles. Our data showed a same pattern of response in the three muscles after chemical injections, i.e., a bell curve with maximal discharge rate at 1 mM for LA injections and a linear relationship between KCl concentrations and the afferent discharge rate. Furthermore, a stronger response was recorded after EIF in the gastrocnemius muscle compared to the two other muscles. The change in afferent discharge after 1 mM LA injection was higher for the gastrocnemius muscle compared to the response obtained with the corresponding concentration applied in the two other muscles, whereas changes to KCl injections did not dramatically differ between the three muscles. We conclude that anatomical (mass, phenotype, vascularization, receptor and afferent density…) and functional (flexor vs. extensor) differences between muscles could explain the amplitude of these responses.

Muscle oxygen kinetics at onset of intense dynamic exercise in humans

DEFF Research Database (Denmark)

Bangsbo, J; Krustrup, P; González-Alonso, J

2000-01-01

The present study examined the onset and the rate of rise of muscle oxidation during intense exercise in humans and whether oxygen availability limits muscle oxygen uptake in the initial phase of intense exercise. Six subjects performed 3 min of intense one-legged knee-extensor exercise [65.3 +/-...

Relationship between muscle strength parameters and functional capacity in persons with mild to moderate degree multiple sclerosis

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Kjølhede, Tue; Vissing, Kristian; Langeskov-Christensen, Daniel

2015-01-01

BACKGROUND: Maximal muscle strength has been shown to be an important predictor of functional capacity for persons with multiple sclerosis (PwMS). Another muscle strength parameter known to be important for functional capacity in other patient groups is rate of force development (RFD) in knee...... is the better predictor of walking performance in persons with mild to moderate multiple sclerosis. RFD, although also important for functional capacity, is a less strong predictor. Maximal strength of the knee extensors, rather than the knee flexors, predicted performance in the stairclimb and 5STS tests....

Transfer of extensor digiti minimi and extensor carpi ulnaris nerve branches to the intrinsic motor nerve branches: A histological study on cadaver.

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Namazi, H; Haji Vandi, S

2017-06-01

In cases of high ulnar and median nerve palsy, result of nerve repair in term of intrinsic muscle recovery is unsatisfactory. Distal nerve transfer can alleviate the regeneration time and improve the results. Transfer of the extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU) nerve branches to the deep branch of ulnar nerve (DBUN)/recurrent branch of median nerve (RMN) at wrist had been used to restore intrinsic hand function but, incomplete recovery occurred. The axon count at the donor nerve has a strong influence on the final results. This cadaveric study aims to analyses the histology of this nerve transfer to evaluate whether these donor nerves are suitable for this transfer or another donor nerve may be considered. Ten cadaveric upper limbs dissected to identify the location of the EDM, ECU, RMN and DBUN. Surface area, fascicle count, and axon number was determined by histological methods. The mean of axon number in the EDM, ECU, RMN and DBUN branches was 5931, 7355, 30960 and 35426, respectively. In this study, the number of axons in the EDM and ECU branches was 37% (13281/35426) of that in the DBUN. Also, the number of axons in the EDM and ECU branches was 42% (13281/30960) of that in the RMN. The axon count data showed an unfavorable match between the EDM, ECU and DBUN/RMN. Therefore, it is suggested that another donor nerve with higher axon number to be considered. Cadaver study (histological study). Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Analysis of postural control and muscular performance in young and elderly women in different age groups.

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Gomes, Matheus M; Reis, Júlia G; Carvalho, Regiane L; Tanaka, Erika H; Hyppolito, Miguel A; Abreu, Daniela C C

2015-01-01

muscle strength and power are two factors affecting balance. The impact of muscle strength and power on postural control has not been fully explored among different age strata over sixty. the aim of the present study was to assess the muscle strength and power of elderly women in different age groups and determine their correlation with postural control. eighty women were divided into four groups: the young 18-30 age group (n=20); the 60-64 age group (n=20); the 65-69 age group (n=20); and the 70-74 age group (n=20). The participants underwent maximum strength (one repetition maximum or 1-RM) and muscle power tests to assess the knee extensor and flexor muscles at 40%, 70%, and 90% 1-RM intensity. The time required by participants to recover their balance after disturbing their base of support was also assessed. the elderly women in the 60-64, 65-69, and 70-74 age groups exhibited similar muscle strength, power, and postural control (p>0.05); however, these values were lower than those of the young group (ppostural control performance (ppostural control shown by these women.

The intra- and inter-rater reliability of five clinical muscle performance tests in patients with and without neck pain

Science.gov (United States)

2013-01-01

Background This study investigates the reliability of muscle performance tests using cost- and time-effective methods similar to those used in clinical practice. When conducting reliability studies, great effort goes into standardising test procedures to facilitate a stable outcome. Therefore, several test trials are often performed. However, when muscle performance tests are applied in the clinical setting, clinicians often only conduct a muscle performance test once as repeated testing may produce fatigue and pain, thus variation in test results. We aimed to investigate whether cervical muscle performance tests, which have shown promising psychometric properties, would remain reliable when examined under conditions similar to those of daily clinical practice. Methods The intra-rater (between-day) and inter-rater (within-day) reliability was assessed for five cervical muscle performance tests in patients with (n = 33) and without neck pain (n = 30). The five tests were joint position error, the cranio-cervical flexion test, the neck flexor muscle endurance test performed in supine and in a 45°-upright position and a new neck extensor test. Results Intra-rater reliability ranged from moderate to almost perfect agreement for joint position error (ICC ≥ 0.48-0.82), the cranio-cervical flexion test (ICC ≥ 0.69), the neck flexor muscle endurance test performed in supine (ICC ≥ 0.68) and in a 45°-upright position (ICC ≥ 0.41) with the exception of a new test (neck extensor test), which ranged from slight to moderate agreement (ICC = 0.14-0.41). Likewise, inter-rater reliability ranged from moderate to almost perfect agreement for joint position error (ICC ≥ 0.51-0.75), the cranio-cervical flexion test (ICC ≥ 0.85), the neck flexor muscle endurance test performed in supine (ICC ≥ 0.70) and in a 45°-upright position (ICC ≥ 0.56). However, only slight to fair agreement was found for the neck extensor test (ICC�

Exercise induces transient transcriptional activation of the PGC-1a gene in human skeletal muscle

DEFF Research Database (Denmark)

Pilegaard, Henriette; Saltin, Bengt; Neufer, P. Darrell

2003-01-01

Endurance exercise training induces mitochondrial biogenesis in skeletal muscle. The peroxisome proliferator activated receptor co-activator 1a (PGC-1a) has recently been identified as a nuclear factor critical for coordinating the activation of genes required for mitochondrial biogenesis in cell...... culture and rodent skeletal muscle. To determine whether PGC-1a transcription is regulated by acute exercise and exercise training in human skeletal muscle, seven male subjects performed 4 weeks of one-legged knee extensor exercise training. At the end of training, subjects completed 3 h of two......-legged knee extensor exercise. Biopsies were obtained from the vastus lateralis muscle of both the untrained and trained legs before exercise and after 0, 2, 6 and 24 h of recovery. Time to exhaustion (2 min maximum resistance), as well as hexokinase II (HKII), citrate synthase and 3-hydroxyacyl...

Effects of Ving Tsun Chinese Martial Art Training on Upper Extremity Muscle Strength and Eye-Hand Coordination in Community-Dwelling Middle-Aged and Older Adults: A Pilot Study

Science.gov (United States)

Ng, Shamay S. M.; Cheng, Yoyo T. Y.; Yu, Esther Y. T.; Chow, Gary C. C.; Chak, Yvonne T. C.; Chan, Ivy K. Y.; Zhang, Joni; Macfarlane, Duncan

2016-01-01

Objectives. To evaluate the effects of Ving Tsun (VT) martial art training on the upper extremity muscle strength and eye-hand coordination of middle-aged and older adults. Methods. This study used a nonequivalent pretest-posttest control group design. Forty-two community-dwelling healthy adults participated in the study; 24 (mean age ± SD = 68.5 ± 6.7 years) underwent VT training for 4 weeks (a supervised VT session twice a week, plus daily home practice), and 18 (mean age ± SD = 72.0 ± 6.7 years) received no VT training and acted as controls. Shoulder and elbow isometric muscle strength and eye-hand coordination were evaluated using the Lafayette Manual Muscle Test System and a computerized finger-pointing test, respectively. Results. Elbow extensor peak force increased by 13.9% (P = 0.007) in the VT group and the time to reach peak force decreased (9.9%) differentially in the VT group compared to the control group (P = 0.033). For the eye-hand coordination assessment outcomes, reaction time increased by 2.9% in the VT group and decreased by 5.3% in the control group (P = 0.002). Conclusions. Four weeks of VT training could improve elbow extensor isometric peak force and the time to reach peak force but not eye-hand coordination in community-dwelling middle-aged and older adults. PMID:27525020

Effects of Ving Tsun Chinese Martial Art Training on Upper Extremity Muscle Strength and Eye-Hand Coordination in Community-Dwelling Middle-Aged and Older Adults: A Pilot Study.

Science.gov (United States)

Fong, Shirley S M; Ng, Shamay S M; Cheng, Yoyo T Y; Wong, Janet Y H; Yu, Esther Y T; Chow, Gary C C; Chak, Yvonne T C; Chan, Ivy K Y; Zhang, Joni; Macfarlane, Duncan; Chung, Louisa M Y

2016-01-01

Objectives. To evaluate the effects of Ving Tsun (VT) martial art training on the upper extremity muscle strength and eye-hand coordination of middle-aged and older adults. Methods. This study used a nonequivalent pretest-posttest control group design. Forty-two community-dwelling healthy adults participated in the study; 24 (mean age ± SD = 68.5 ± 6.7 years) underwent VT training for 4 weeks (a supervised VT session twice a week, plus daily home practice), and 18 (mean age ± SD = 72.0 ± 6.7 years) received no VT training and acted as controls. Shoulder and elbow isometric muscle strength and eye-hand coordination were evaluated using the Lafayette Manual Muscle Test System and a computerized finger-pointing test, respectively. Results. Elbow extensor peak force increased by 13.9% (P = 0.007) in the VT group and the time to reach peak force decreased (9.9%) differentially in the VT group compared to the control group (P = 0.033). For the eye-hand coordination assessment outcomes, reaction time increased by 2.9% in the VT group and decreased by 5.3% in the control group (P = 0.002). Conclusions. Four weeks of VT training could improve elbow extensor isometric peak force and the time to reach peak force but not eye-hand coordination in community-dwelling middle-aged and older adults.

Effects of Ving Tsun Chinese Martial Art Training on Upper Extremity Muscle Strength and Eye-Hand Coordination in Community-Dwelling Middle-Aged and Older Adults: A Pilot Study

Directory of Open Access Journals (Sweden)

Shirley S. M. Fong

2016-01-01

Full Text Available Objectives. To evaluate the effects of Ving Tsun (VT martial art training on the upper extremity muscle strength and eye-hand coordination of middle-aged and older adults. Methods. This study used a nonequivalent pretest-posttest control group design. Forty-two community-dwelling healthy adults participated in the study; 24 (mean age ± SD = 68.5±6.7 years underwent VT training for 4 weeks (a supervised VT session twice a week, plus daily home practice, and 18 (mean age ± SD = 72.0±6.7 years received no VT training and acted as controls. Shoulder and elbow isometric muscle strength and eye-hand coordination were evaluated using the Lafayette Manual Muscle Test System and a computerized finger-pointing test, respectively. Results. Elbow extensor peak force increased by 13.9% (P=0.007 in the VT group and the time to reach peak force decreased (9.9% differentially in the VT group compared to the control group (P=0.033. For the eye-hand coordination assessment outcomes, reaction time increased by 2.9% in the VT group and decreased by 5.3% in the control group (P=0.002. Conclusions. Four weeks of VT training could improve elbow extensor isometric peak force and the time to reach peak force but not eye-hand coordination in community-dwelling middle-aged and older adults.

Open extensor tendon injuries: an epidemiologic study.

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Patillo, Dominic; Rayan, Ghazi M

2012-01-01

To report the epidemiology, mechanism, anatomical location, distribution, and severity of open extensor tendon injuries in the digits, hand, and forearm as well as the frequency of associated injuries to surrounding bone and soft tissue. Retrospective chart review was conducted for patients who had operative repair of open digital extensor tendon injuries in all zones within an 11-year period. Data was grouped according to patient characteristics, zone of injury, mechanism of injury, and presence of associated injury. Statistical analysis was used to determine the presence of relevant associations. Eighty-six patients with 125 severed tendons and 105 injured digits were available for chart reviews. Patients were predominantly males (83%) with a mean age of 34.2 years and the dominant extremity was most often injured (60%). The thumb was the most commonly injured (25.7%), followed by middle finger (24.8), whereas small finger was least affected (10.5%). Sharp laceration was the most common mechanism of injury (60%), and most of these occurred at or proximal to the metacarpophalangeal joints. Most saw injuries occurred distal to the metacarpophalangeal joint. Zone V was the most commonly affected in the fingers (27%) while zone VT was the most commonly affected in the thumb (69%). Associated injuries to bone and soft tissue occurred in 46.7% of all injuries with saw and crush/avulsions being predictive of fractures and damage to the underlying joint capsule. The extensor mechanism is anatomically complex, and open injuries to the dorsum of the hand, wrist, and forearm, especially of crushing nature and those inflicted by saws, must be thoroughly evaluated. Associated injuries should be ruled out in order to customize surgical treatment and optimize outcome.

Low back pain characterized by muscle resistance and occupational factors associated with nursing

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Rafael de Souza Petersen

2014-06-01

Full Text Available OBJECTIVE: to identify the occupational factors associated with low back pain using a surveillance tool and to characterize the low back pain by the resistance of the extensor muscles of the vertebral column among nursing professionals at an Intensive Care Unit.METHODS: Cross-sectional study. The workers answered a questionnaire about occupational factors and participated in a resistance test of the extensor muscles of the vertebral column. Associations were established through Student's T-test or Mann-Whitney's U-test and correlations using Pearson's test.RESULTS: Out of 48 participants, 32 (67% suffered from low pain. For the resistance test, the subjects suffering from low back pain endured less time in comparison with asymptomatic subjects, but without significant differences (p=0.147. The duration of the pain episode showed a significant negative correlation (p=0.016 with the results of the resistance test though. The main factors identified as causes of low back pain were biomechanical and postural elements, conditions of the muscle structure and physical and organizational conditions.CONCLUSIONS: the main occupational factors associated with the low back pain were the posture and the characteristics of the physical and organizational conditions. In addition, the extensor muscles of the column showed a trend towards lesser resistance for workers in pain. This evidence is important when considering prevention and treatment strategies.

The influence of resistance exercise with emphasis on specific contractions (concentric vs. eccentric on muscle strength and post-exercise autonomic modulation: a randomized clinical trial

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Mariana O. Gois

2014-01-01

Full Text Available Background: Compared to eccentric contractions, concentric contractions result in higher cardiovascular stress. However, we do not know how these two types of contractions influence cardiac autonomic modulation during the post-exercise recovery period. Objective: to compare the effect of resistance training that is performed with concentric vs. eccentric emphasis on muscle strength and on post-exercise recovery which was assessed by examining heart rate variability (HRV, for the knee extensor muscle group in young healthy adults. Methods: For this study, 105 men between 18 and 30 years of age were randomized into 4 groups: concentric control (CONCC, eccentric control (ECCC, concentric training (CONCT and eccentric training (ECCT. The CONCC and ECCC groups underwent one session of resistance exercise (RE using the knee extensor muscle group (3 sets of 1 repetition at 100% of the maximal repetition [1MR] and the CONCT and ECCT groups performed 10 training sessions. The HRV was analyzed at baseline and across four recovery periods (T1, T2, T3 and T4. Results: The ECCT group exhibited increased muscle strength at the end of the study. Regarding cardiac autonomic modulation, the CONCC and ECCC groups exhibited increases in overall variability (SDNN and SD2 at T1 compared to baseline, and the ECCT group demonstrated increases in variables reflecting vagal modulation and the recovery process (RMSSD, SD1 and HF [ms2] at T1, T2 and T4 compared to baseline. Conclusions: Resistance training with emphasis on eccentric contractions promoted strength gain and an increase in cardiac vagal modulation during recovery compared to baseline.

Accuracy of High-Resolution Ultrasonography in the Detection of Extensor Tendon Lacerations.

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Dezfuli, Bobby; Taljanovic, Mihra S; Melville, David M; Krupinski, Elizabeth A; Sheppard, Joseph E

2016-02-01

Lacerations to the extensor mechanism are usually diagnosed clinically. Ultrasound (US) has been a growing diagnostic tool for tendon injuries since the 1990s. To date, there has been no publication establishing the accuracy and reliability of US in the evaluation of extensor mechanism lacerations in the hand. The purpose of this study is to determine the accuracy of US to detect extensor tendon injuries in the hand. Sixteen fingers and 4 thumbs in 4 fresh-frozen and thawed cadaveric hands were used. Sixty-eight 0.5-cm transverse skin lacerations were created. Twenty-seven extensor tendons were sharply transected. The remaining skin lacerations were used as sham dissection controls. One US technologist and one fellowship-trained musculoskeletal radiologist performed real-time dynamic US studies in and out of water bath. A second fellowship trained musculoskeletal radiologist subsequently reviewed the static US images. Dynamic and static US interpretation accuracy was assessed using dissection as "truth." All 27 extensor tendon lacerations and controls were identified correctly with dynamic imaging as either injury models that had a transected extensor tendon or sham controls with intact extensor tendons (sensitivity = 100%, specificity = 100%, positive predictive value = 1.0; all significantly greater than chance). Static imaging had a sensitivity of 85%, specificity of 89%, and accuracy of 88% (all significantly greater than chance). The results of the dynamic real time versus static US imaging were clearly different but did not reach statistical significance. Diagnostic US is a very accurate noninvasive study that can identify extensor mechanism injuries. Clinically suspected cases of acute extensor tendon injury scanned by high-frequency US can aid and/or confirm the diagnosis, with dynamic imaging providing added value compared to static. Ultrasonography, to aid in the diagnosis of extensor mechanism lacerations, can be successfully used in a reliable and

Tuberculosis tenosynovitis of the extensor tendons of the wrist

OpenAIRE

Mrabet, Dalila; Ouenniche, Kmar; Mizouni, Habiba; Ounaies, Mouna; Khémiri, Chékib; Sahli, Héla; Sellami, Slaheddine

2011-01-01

Mycobacterial tuberculous tenosynovitis of the extensor tendon sheath is an extremely rare manifestation of extrapulmonary tuberculosis. The diagnosis may be easily delayed because of its non-specific clinical signs. We report a new case of tuberculous tenosynovitis of the extensor without concomitant pulmonary tuberculosis or documented immunodeficiency.

Relation between the Disability of the Arm, Shoulder and Hand Score and Muscle Strength in Post-Cardiac Surgery Patients.

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Izawa, Kazuhiro P; Kasahara, Yusuke; Hiraki, Koji; Hirano, Yasuyuki; Watanabe, Satoshi

2017-11-27

Background: The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire is a valid and reliable patient-reported outcome measure. DASH can be assessed by self-reported upper extremity disability and symptoms. We aimed to examine the relationship between the physiological outcome of muscle strength and the DASH score after cardiac surgery. Methods: This cross-sectional study assessed 50 consecutive cardiac patients that were undergoing cardiac surgery. Physiological outcomes of handgrip strength and knee extensor muscle strength and the DASH score were measured at one month after cardiac surgery and were assessed. Results were analyzed using Spearman correlation coefficients. Results: The final analysis comprised 43 patients (men: 32, women: 11; age: 62.1 ± 9.1 years; body mass index: 22.1 ± 4.7 kg/m²; left ventricular ejection fraction: 53.5 ± 13.7%). Respective handgrip strength, knee extensor muscle strength, and DASH score were 27.4 ± 8.3 kgf, 1.6 ± 0.4 Nm/kg, and 13.3 ± 12.3, respectively. The DASH score correlated negatively with handgrip strength ( r = -0.38, p = 0.01) and with knee extensor muscle strength ( r = -0.32, p = 0.04). Conclusion: Physiological outcomes of both handgrip strength and knee extensor muscle strength correlated negatively with the DASH score. The DASH score appears to be a valuable tool with which to assess cardiac patients with poor physiological outcomes, particularly handgrip strength as a measure of upper extremity function, which is probably easier to follow over time than lower extremity function after patients complete cardiac rehabilitation.

Relation between the Disability of the Arm, Shoulder and Hand Score and Muscle Strength in Post-Cardiac Surgery Patients

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Kazuhiro P. Izawa

2017-11-01

Full Text Available Background: The Disabilities of the Arm, Shoulder, and Hand (DASH questionnaire is a valid and reliable patient-reported outcome measure. DASH can be assessed by self-reported upper extremity disability and symptoms. We aimed to examine the relationship between the physiological outcome of muscle strength and the DASH score after cardiac surgery. Methods: This cross-sectional study assessed 50 consecutive cardiac patients that were undergoing cardiac surgery. Physiological outcomes of handgrip strength and knee extensor muscle strength and the DASH score were measured at one month after cardiac surgery and were assessed. Results were analyzed using Spearman correlation coefficients. Results: The final analysis comprised 43 patients (men: 32, women: 11; age: 62.1 ± 9.1 years; body mass index: 22.1 ± 4.7 kg/m2; left ventricular ejection fraction: 53.5 ± 13.7%. Respective handgrip strength, knee extensor muscle strength, and DASH score were 27.4 ± 8.3 kgf, 1.6 ± 0.4 Nm/kg, and 13.3 ± 12.3, respectively. The DASH score correlated negatively with handgrip strength (r = −0.38, p = 0.01 and with knee extensor muscle strength (r = −0.32, p = 0.04. Conclusion: Physiological outcomes of both handgrip strength and knee extensor muscle strength correlated negatively with the DASH score. The DASH score appears to be a valuable tool with which to assess cardiac patients with poor physiological outcomes, particularly handgrip strength as a measure of upper extremity function, which is probably easier to follow over time than lower extremity function after patients complete cardiac rehabilitation.

Spinal mobility and trunk muscle strength in elite hockey players.

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Lindgren, S; Twomey, L

1988-01-01

Elite hockey players of both sexes from the Australian Institute of Sport were assessed for lumbar spine mobility, trunk flexion and back extensor muscle strength, hamstring flexibility and postural characteristics over a two year period. All the athletes were more mobile in rotation than the 'normal' West Australian population, and demonstrated flexible hamstrings and powerful back extensor muscles; trunk flexion was less strong initially, but improved after intervention in the form of a specific exercise programme, over the measurement period. A questionnaire disclosed that low back pain is a common complaint of hockey players, but rarely required intensive physical and medical treatment. The term 'hockey player's back' has been coined in recognition of the long flat thoracolumbar spine frequently noted in these subjects. Copyright © 1988 Australian Physiotherapy Association. Published by . All rights reserved.

Effect of ascorbic acid on fatigue of skeletal muscle fibres in long term cold exposed sprague dawley rats

International Nuclear Information System (INIS)

Rashid, A.; Ayub, M.

2011-01-01

On exposure to prolonged cold temperature, the body responds for effective heat production both by shivering and non-shivering thermo genesis. Cold exposure increases the production of reactive oxygen species which influence the sarcoplasmic reticulum Ca/sup ++/ release from the skeletal muscles and affect their contractile properties. The role of ascorbic acid supplementation on force of contraction during fatigue of cold exposed skeletal muscles was evaluated in this study. Method: Ninety healthy, male Sprague Dawley rats were randomly divided into three groups of control, cold exposed, and cold exposed with ascorbic acid 500 mg/L supplementation mixed in drinking water. Group II and III were given cold exposure by keeping their cages in ice-filled tubs for 1 hr/day for one month. After one month, the extensor digitorum longus muscle was dissected out and force of contraction during fatigue in the skeletal muscle fibres was analysed on a computerised data acquisition system. Results: The cold exposed group showed a significant delay in the force of contraction during fatigue of skeletal muscle fibres compared to control group. Group III showed easy fatigability and a better force of contraction than the cold exposed group. Conclusions: Ascorbic acid increases the force of contraction and decreases resistance to fatigue in the muscles exposed to chronic cold. (author)

A randomized controlled trial on the effects of combined aerobic-resistance exercise on muscle strength and fatigue, glycemic control and health-related quality of life of type 2 diabetes patients.

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Tomas-Carus, Pablo; Ortega-Alonso, Alfredo; Pietilainen, Kirsi H; Santos, Vitoria; Goncalves, Helena; Ramos, Jorge; Raimundo, Armando

2016-05-01

The aim of this paper was to evaluate the effects of a 12-weeks combined aerobic-resistance exercise therapy on fatigue and isokinetic muscle strength, glycemic control and health-related quality of life (HRQoL) in moderately affected type 2 diabetes (T2DM) patients. A randomized controlled trial design was employed. Forty-three T2DM patients were assigned to an exercise group (N.=22), performing 3 weekly sessions of 60 minutes of combined aerobic-resistance exercise for 12-weeks; or a no exercise control group (N.=21). Both groups were evaluated at a baseline and after 12-weeks of exercise therapy for: 1) muscle strength and fatigue by isokinetic dynamometry; 2) plasma glycated hemoglobin A1C (HbA1C); and 3) HRQoL utilizing the SF-36 questionnaire. The exercise therapy led to improvements in muscle fatigue in knee extensors (-55%) and increased muscle strength in knee flexors and extensors (+15 to +30%), while HbA1C decreased (-18%). In addition, the exercising patients showed sizeable improvements in HRQoL: physical function (+53%), vitality (+21%) and mental health (+40%). Twelve-weeks of combined aerobic-resistance exercise was highly effective to improve muscle strength and fatigue, glycemic control and several aspects of HRQoL in T2DM patients. These data encourage the use of aerobic and resistance exercise in the good clinical care of T2DM.

Capacity of small groups of muscles to accomplish precision grasping tasks.

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Towles, Joseph D; Valero-Cuevas, Francisco J; Hentz, Vincent R

2013-01-01

An understanding of the capacity or ability of various muscle groups to generate endpoint forces that enable grasping tasks could provide a stronger biomechanical basis for the design of reconstructive surgery or rehabilitation for the treatment of the paralyzed or paretic hand. We quantified two-dimensional endpoint force distributions for every combination of the muscles of the index finger, in cadaveric specimens, to understand the capability of muscle groups to produce endpoint forces that accomplish three common types of grasps-tripod, tip and lateral pinch-characterized by a representative level of Coulomb friction. We found that muscle groups of 4 or fewer muscles were capable of generating endpoint forces that enabled performance of each of the grasping tasks examined. We also found that flexor muscles were crucial to accomplish tripod pinch; intrinsic muscles, tip pinch; and the dorsal interosseus muscle, lateral pinch. The results of this study provide a basis for decision making in the design of reconstructive surgeries and rehabilitation approaches that attempt to restore the ability to perform grasping tasks with small groups of muscles.

Dissociation between lactate and proton exchange in muscle during intense exercise in man

DEFF Research Database (Denmark)

Bangsbo, Jens; Juel, Carsten; Hellsten, Ylva

1997-01-01

1. Transport of lactate, H+ and fluid across muscle sarcolemma was studied in contracting muscles under varying blood acid-base conditions. 2. Subjects performed two-legged submaximal knee-extensor exercise for 29-35 min consisting of warming up for 5 min followed by 10 min of leg exercise (L1...

Neck Pain Following Cervical Laminoplasty: Does Preservation of the C2 Muscle Attachments and/or C7 Matter?

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Riew, K. Daniel; Raich, Annie L.; Dettori, Joseph R.; Heller, John G.

2013-01-01

Study Design Systematic review. Objective In patients aged 18 years or older, with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament (OPLL), does sparing the C2 muscle attachments and/or C7-preserving cervical laminoplasty lead to reduced postoperative axial pain compared with conventional C3 to C7 laminoplasty? Do these results vary based on early active postoperative cervical motion? Methods A systematic review of the English-language literature was undertaken for articles published between 1970 and August 17, 2012. Electronic databases and reference lists of key articles were searched to identify studies evaluating C2/C3- or C7-preserving cervical laminoplasty for the treatment of cervical spondylotic myelopathy (CSM) or OPLL in adults. Studies involving traumatic onset, cervical fracture, infection, deformity, or neoplasms were excluded, as were noncomparative studies. Two independent reviewers assessed the level of evidence quality using the grading of recommendations assessment, development and evaluation (GRADE) system, and disagreements were resolved by consensus. Results We identified 11 articles meeting our inclusion criteria. Only the randomized controlled trial (RCT) showed no significant difference in late axial pain (at 12 months) when C7 spinous muscle preservation was compared with no preservation. However, seven other retrospective cohort studies showed significant pain relief in the preserved group compared with the nonpreserved group. The preservation group included those with preservation of the C7 spinous process and/or attached muscles, the deep extensor muscles, or C2 muscle attachment and/or C3 laminectomy (as opposed to laminoplasty). One study that included preservation of either the C2 or C7 posterior paraspinal muscles found that only preservation of the muscles attached to C2 resulted in reduced postoperative pain. Another study that included preservation of either the C7 spinous process or

Muscle power is an independent determinant of pain and quality of life in knee osteoarthritis

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OBJECTIVE: This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. METHODS: Baseli...

Effects of branched-chain amino acids supplementation on both plasma amino acids concentration and muscle energetics changes resulting from muscle damage: A randomized placebo controlled trial.

Science.gov (United States)

Fouré, Alexandre; Nosaka, Kazunori; Gastaldi, Marguerite; Mattei, Jean-Pierre; Boudinet, Hélène; Guye, Maxime; Vilmen, Christophe; Le Fur, Yann; Bendahan, David; Gondin, Julien

2016-02-01

Branched-chain amino acids promote muscle-protein synthesis, reduce protein oxidation and have positive effects on mitochondrial biogenesis and reactive oxygen species scavenging. The purpose of the study was to determine the potential benefits of branched-chain amino acids supplementation on changes in force capacities, plasma amino acids concentration and muscle metabolic alterations after exercise-induced muscle damage. (31)P magnetic resonance spectroscopy and biochemical analyses were used to follow the changes after such damage. Twenty six young healthy men were randomly assigned to supplemented branched-chain amino acids or placebo group. Knee extensors maximal voluntary isometric force was assessed before and on four days following exercise-induced muscle damage. Concentrations in phosphocreatine [PCr], inorganic phosphate [Pi] and pH were measured during a standardized rest-exercise-recovery protocol before, two (D2) and four (D4) days after exercise-induced muscle damage. No significant difference between groups was found for changes in maximal voluntary isometric force (-24% at D2 and -21% at D4). Plasma alanine concentration significantly increased immediately after exercise-induced muscle damage (+25%) in both groups while concentrations in glycine, histidine, phenylalanine and tyrosine decreased. No difference between groups was found in the increased resting [Pi] (+42% at D2 and +34% at D4), decreased resting pH (-0.04 at D2 and -0.03 at D4) and the slower PCr recovery rate (-18% at D2 and -24% at D4). The damaged muscle was not able to get benefits out of the increased plasma branched-chain amino acids availability to attenuate changes in indirect markers of muscle damage and muscle metabolic alterations following exercise-induced muscle damage. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Effect of mental fatigue on induced tremor in human knee extensors.

Science.gov (United States)

Budini, Francesco; Lowery, Madeleine; Durbaba, Rade; De Vito, Giuseppe

2014-06-01

In this study, the effects of mental fatigue on mechanically induced tremor at both a low (3-6Hz) and high (8-12Hz) frequency were investigated. The two distinct tremor frequencies were evoked using two springs of different stiffness, during 20s sustained contractions of the knee extensor muscles at 30% maximum voluntary contraction (MVC) before and after 100min of a mental fatigue task, in 12 healthy (29±3.7years) participants. Mental fatigue resulted in a 6.9% decrease in MVC and in a 9.4% decrease in the amplitude of the agonist muscle EMG during sustained 30% MVC contractions in the induced high frequency only. Following the mental fatigue task, the coefficient of variation and standard deviation of the force signal decreased at 8-12Hz induced tremor by 31.7% and 35.2% respectively, but not at 3-6Hz induced tremor. Similarly, the maximum value and area underneath the peak in the power spectrum of the force signal decreased by 55.5% and 53.1% respectively in the 8-12Hz range only. In conclusion, mental fatigue decreased mechanically induced 8-12Hz tremor and had no effect on induced 3-6Hz tremor. We suggest that the reduction could be attributed to the decreased activation of the agonist muscles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Passive stiffness of rat skeletal muscle undernourished during fetal development

Directory of Open Access Journals (Sweden)

Ana Elisa Toscano

2010-01-01

Full Text Available OBJECTIVES: The aim of the study was to investigate the effect of fetal undernutrition on the passive mechanical properties of skeletal muscle of weaned and young adult rats. INTRODUCTION: A poor nutrition supply during fetal development affects physiological functions of the fetus. From a mechanical point of view, skeletal muscle can be also characterized by its resistance to passive stretch. METHODS: Male Wistar rats were divided into two groups according to their mother's diet during pregnancy: a control group (mothers fed a 17% protein diet and an isocaloric low-protein group (mothers fed a 7.8% protein diet. At birth, all mothers received a standardized meal ad libitum. At the age of 25 and 90 days, the soleus muscle and extensor digitorum longus (EDL muscles were removed in order to test the passive mechanical properties. A first mechanical test consisted of an incremental stepwise extension test using fast velocity stretching (500 mm/s enabling us to measure, for each extension stepwise, the dynamic stress (σd and the steady stress (σs. A second test consisted of a slow velocity stretch in order to calculate normalized stiffness and tangent modulus from the stress-strain relationship. RESULTS: The results for the mechanical properties showed an important increase in passive stiffness in both the soleus and EDL muscles in weaned rat. In contrast, no modification was observed in young adult rats. CONCLUSIONS: The increase in passive stiffness in skeletal muscle of weaned rat submitted to intrauterine undernutrition it is most likely due to changes in muscle passive stiffness.

Electrophysiological, histochemical, and hormonal adaptation of rat muscle after prolonged hindlimb suspension

Science.gov (United States)

Kourtidou-Papadeli, Chrysoula; Kyparos, Antonios; Albani, Maria; Frossinis, Athanasios; Papadelis, Christos L.; Bamidis, Panagiotis; Vivas, Ana; Guiba-Tziampiri, Olympia

2004-05-01

The perspective of long-duration flights for future exploration, imply more research in the field of human adaptation. Previous studies in rat muscles hindlimb suspension (HLS), indicated muscle atrophy and a change of fibre composition from slow-to-fast twitch types. However, the contractile responses to long-term unloading is still unclear. Fifteen adult Wistar rats were studied in 45 and 70 days of muscle unweighting and soleus (SOL) muscle as well as extensor digitorum longus (EDL) were prepared for electrophysiological recordings (single, twitch, tetanic contraction and fatigue) and histochemical stainings. The loss of muscle mass observed was greater in the soleus muscle. The analysis of electrophysiological properties of both EDL and SOL showed significant main effects of group, of number of unweighting days and fatigue properties. Single contraction for soleus muscle remained unchanged but there was statistically significant difference for tetanic contraction and fatigue. Fatigue index showed a decrease for the control rats, but increase for the HLS rats. According to the histochemical findings there was a shift from oxidative to glycolytic metabolism during HLS. The data suggested that muscles atrophied, but they presented an adaptation pattern, while their endurance in fatigue was decreased.

Peak torque and muscle balance in the knees of young U-15 and U-17 soccer athletes playing various tactical positions.

Science.gov (United States)

Chiamonti Bona, Cleiton; Tourinho Filho, Hugo; Izquierdo, Mikel; Pires Ferraz, Ricardo M; Marques, Mário C

2017-01-01

Soccer is a sport that is practiced worldwide and has been investigated in its various aspects, particularly muscle strength, which is an essential motor skill for sports performance. The objective of this study was to investigate the peak torque and muscle balance on the knee extensor and flexor of young soccer players in the tactical positions of goalkeeper, defender, full back, midfielder, defensive midfielder and striker, as well as to determine which field position has the highest peak torque. Forty-nine male players were recruited and divided into two categories during the preparatory period of the season: the Under-15 (U-15) group (N.=23, mean age 14.7±0.5 years, body mass 58.2±10.5 kg, body height 168.5±7.6 cm), and the Under-17 (U-17) group (N.=26, mean age 16.8±0.4 years, body mass 69.2±7.9 kg, body height 176.2±6.6 cm). The U-17 athletes presented a higher peak torque in all the movements of flexion and extension in the two angular velocities (i.e. 60°/s and 300°/s), but only the dominant knee extensor at 300°/s was significantly different between the two categories as well as the percentage change in peak torque compared between U-15 and U-17 was always above 20%. The peak torque variation in the U-17 category (i.e. mostly above 20%) highlights a higher peak torque compared to U-15 athletes. The muscular deficit of the two categories presented a low average of 10-15%, indicating a good muscle balance between knee extensors and flexors. Finally, goalkeepers and defenders achieved the highest peak torque amongst the field positions.

Relationships between lower limb muscle architecture and activities and participation of children with cerebral palsy.

Science.gov (United States)

Ko, In-Hee; Kim, Jung-Hee; Lee, Byoung-Hee

2013-01-01

The purpose of this study was to determine the effects of the structure of skeletal muscle of lower extremities on function, activity, and participation of children with cerebral palsy. The subjects were 38 hospitalized patients and 13 infants with normal development. The following clinical measures were used for assessment of activity daily living and functional level of gross motor: Gross Motor Function Classification System (GMFCS), Gross Motor Function Measure (GMFM), Wee Functional Independence Measure (WeeFIM), International Classification of Functioning Child and Youth (ICF CY). Muscle thickness and strength of knee extensor and ankle extensor were collected using ultrasonography and manual muscle tester. Following the results of ICF CY evaluation for body function, activity, learning and application of knowledge, communication and environmental factors showed a decline (Psocial acknowledgement (Pfunction, daily activity and participation; the score of ICF-CY was shown to decline due to the high score for differences in thickness of muscle, muscle strength, WeeFIM, and GMFM. The thickness and muscle strength of lower extremities affect main functions of the body and improvement of muscle strength of lower extremities may have positive effects on social standards such as activity and participation of cerebral palsy.

Distribution of skeletal muscle involvement in autosomal recessive distal muscular dystrophy

International Nuclear Information System (INIS)

Mizusawa, Hidehiro; Nakanishi, Takao; Kobayashi, Fumie.

1987-01-01

Distribution of skeletal muscle involvement in 5 cases with autosomal recessive distal muscular dystrophy was studied clinically and by computed tomography (CT). Manual muscle test showed muscle involvement with a predilection for flexors in the lower leg and adductors in the thigh. Flexion and extension of the thigh and the lower leg was impaired to similar degree. In progressed cases, neck flexors and trunk muscles were also affected mildly. CT disclosed more clearly the preferential involvement of flexors in the lower leg, and involvement of both hamstrings · adductors group and extensors group of the thigh to similar degree. However, m. popliteus was curiously well preserved. In addition, there was a stage showing high density and hypertrophy of m. sartorius, m. gracilis, m. adductor, m. biceps femoris, m. semimenbranosus, m. semitendinosus or m. rectus femoris, which in thought to be compensatory hypertrophy. M. gluteus minimus in the pelvic girdle and m. dorsi proprii in the trunk were also liable to be affected. The CT findings are regarded as characteristic features noted clearly before muscle weakness and atrophy become apparent clinically. CT is very useful for distinguishing distal muscular dystrophy from rimmed vacuolar distal myopathy in which m. quadriceps femoris and flexors of the lower leg are usually well preserved without compensatory hypertrophy on CT. (author)

Ulnar-sided pain due to extensor carpi ulnaris tendon subluxation: a case report

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Cift Hakan

2012-11-01

Full Text Available Abstract Introduction We present the case of a patient with extensor carpi ulnaris tendon subluxation who was first treated for distal radioulnar joint sprain. Case presentation A 25-year-old Caucasian man was seen at our policlinic one month after he had fallen on his outstretched hand. A diagnosis of extensor carpi ulnaris subluxation was made clinically but we also had the magnetic resonance imaging scan of the patient’s wrist which displayed an increased signal on T2-weighted images consistent with inflammation around the extensor carpi ulnaris tendon. The extensor carpi ulnaris tendon was found to be dislocating during supination and relocating during pronation. The sheath was reconstructed using extensor retinaculum due to attenuation of subsheath. Conclusion There was no recurrent dislocation of the extensor carpi ulnaris tendon of the patient at his last follow up 12 months after the operation.

ASSOCIATION OF ISOMETRIC STRENGTH OF HIP AND KNEE MUSCLES WITH INJURY RISK IN HIGH SCHOOL CROSS COUNTRY RUNNERS.

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Luedke, Lace E; Heiderscheit, Bryan C; Williams, D S Blaise; Rauh, Mitchell J

2015-11-01

High school cross country runners have a high incidence of overuse injuries, particularly to the knee and shin. As lower extremity strength is modifiable, identification of strength attributes that contribute to anterior knee pain (AKP) and shin injuries may influence prevention and management of these injuries. To determine if a relationship existed between isometric hip abductor, knee extensor and flexor strength and the incidence of AKP and shin injury in high school cross country runners. Sixty-eight high school cross country runners (47 girls, 21 boys) participated in the study. Isometric strength tests of hip abductors, knee extensors and flexors were performed with a handheld dynamometer. Runners were prospectively followed during the 2014 interscholastic cross country season for occurrences of AKP and shin injury. Bivariate logistic regression was used to examine risk relationships between strength values and occurrence of AKP and shin injury. During the season, three (4.4%) runners experienced AKP and 13 (19.1%) runners incurred a shin injury. Runners in the tertiles indicating weakest hip abductor (chi-square = 6.140; p=0.046), knee extensor (chi-square = 6.562; p=0.038), and knee flexor (chi-square = 6.140; p=0.046) muscle strength had a significantly higher incidence of AKP. Hip and knee muscle strength was not significantly associated with shin injury. High school cross country runners with weaker hip abductor, knee extensor and flexor muscle strength had a higher incidence of AKP. Increasing hip and knee muscle strength may reduce the likelihood of AKP in high school cross country runners. 2b.

Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles.

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Liu, An-Tang; Liu, Ben-Li; Lu, Li-Xuan; Chen, Gang; Yu, Da-Zhi; Zhu, Lie; Guo, Rong; Dang, Rui-Shan; Jiang, Hua

2014-07-01

The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm(2)), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm(2)). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18-0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the 'design' of their

Architectural properties of the neuromuscular compartments in selected forearm skeletal muscles

Science.gov (United States)

Liu, An-Tang; Liu, Ben-Li; Lu, Li-Xuan; Chen, Gang; Yu, Da-Zhi; Zhu, Lie; Guo, Rong; Dang, Rui-Shan; Jiang, Hua

2014-01-01

The purposes f this study were to (i) explore the possibility of splitting the selected forearm muscles into separate compartments in human subjects; (ii) quantify the architectural properties of each neuromuscular compartment; and (iii) discuss the implication of these properties in split tendon transfer procedures. Twenty upper limbs from 10 fresh human cadavers were used in this study. Ten limbs of five cadavers were used for intramuscular nerve study by modified Sihler's staining technique, which confirmed the neuromuscular compartments. The other 10 limbs were included for architectural analysis of neuromuscular compartments. The architectural features of the compartments including muscle weight, muscle length, fiber length, pennation angle, and sarcomere length were determined. Physiological cross-sectional area and fiber length/muscle length ratio were calculated. Five of the selected forearm muscles were ideal candidates for splitting, including flexor carpi ulnaris, flexor carpi radials, extensor carpi radialis brevis, extensor carpi ulnaris and pronator teres. The humeral head of pronator teres contained the longest fiber length (6.23 ± 0.31 cm), and the radial compartment of extensor carpi ulnaris contained the shortest (2.90 ± 0.28 cm). The ulnar compartment of flexor carpi ulnaris had the largest physiological cross-sectional area (5.17 ± 0.59 cm2), and the ulnar head of pronator teres had the smallest (0.67 ± 0.06 cm2). Fiber length/muscle length ratios of the neuromuscular compartments were relatively low (average 0.27 ± 0.09, range 0.18–0.39) except for the ulnar head of pronator teres, which had the highest one (0.72 ± 0.05). Using modified Sihler's technique, this research demonstrated that each compartment of these selected forearm muscles has its own neurovascular supply after being split along its central tendon. Data of the architectural properties of each neuromuscular compartment provide insight into the ‘design’ of their

Trunk muscle activity is modified in osteoporotic vertebral fracture and thoracic kyphosis with potential consequences for vertebral health.

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Alison M Greig

Full Text Available This study explored inter-relationships between vertebral fracture, thoracic kyphosis and trunk muscle control in elderly people with osteoporosis. Osteoporotic vertebral fractures are associated with increased risk of further vertebral fractures; but underlying mechanisms remain unclear. Several factors may explain this association, including changes in postural alignment (thoracic kyphosis and altered trunk muscle contraction patterns. Both factors may increase risk of further fracture because of increased vertebral loading and impaired balance, which may increase falls risk. This study compared postural adjustments in 24 individuals with osteoporosis with and without vertebral fracture and with varying degrees of thoracic kyphosis. Trunk muscle electromyographic activity (EMG associated with voluntary arm movements was recorded and compared between individuals with and without vertebral fracture, and between those with low and high thoracic kyphosis. Overall, elderly participants in the study demonstrated co-contraction of the trunk flexor and extensor muscles during forwards arm movements, but those with vertebral fractures demonstrated a more pronounced co-contraction than those without fracture. Individuals with high thoracic kyphosis demonstrated more pronounced alternating flexor and extensor EMG bursts than those with less kyphosis. Co-contraction of trunk flexor and extensor muscles in older individuals contrasts the alternating bursts of antagonist muscle activity in previous studies of young individuals. This may have several consequences, including altered balance efficacy and the potential for increased compressive loads through the spine. Both of these outcomes may have consequences in a population with fragile vertebrae who are susceptible to fracture.

The Effects of Vibration and Muscle Fatigue on Trunk Sensorimotor Control in Low Back Pain Patients.

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Jean-Alexandre Boucher

Full Text Available Changes in sensorimotor function and increased trunk muscle fatigability have been identified in patients with chronic low back pain (cLBP. This study assessed the control of trunk force production in conditions with and without local erector spinae muscle vibration and evaluated the influence of muscle fatigue on trunk sensorimotor control.Twenty non-specific cLBP patients and 20 healthy participants were asked to perform submaximal isometric trunk extension torque with and without local vibration stimulation, before and after a trunk extensor muscle fatigue protocol. Constant error (CE, variable error (VE as well as absolute error (AE in peak torque were computed and compared across conditions. Trunk extensor muscle activation during isometric contractions and during the fatigue protocol was measured using surface electromyography (sEMG.Force reproduction accuracy of the trunk was significantly lower in the patient group (CE = 9.81 ± 2.23 Nm; AE = 18.16 ± 3.97 Nm than in healthy participants (CE = 4.44 ± 1.68 Nm; AE = 12.23 ± 2.44 Nm. Local erector spinae vibration induced a significant reduction in CE (4.33 ± 2.14 Nm and AE (13.71 ± 3.45 Nm mean scores in the patient group. Healthy participants conversely showed a significant increase in CE (8.17 ± 2.10 Nm and AE (16.29 ± 2.82 Nm mean scores under vibration conditions. The fatigue protocol induced erector spinae muscle fatigue as illustrated by a significant decrease in sEMG median time-frequency slopes. Following the fatigue protocol, patients with cLBP showed significant decrease in sEMG root mean square activity at L4-5 level and responded in similar manner with and without vibration stimulation in regard to CE mean scores.Patients with cLBP have a less accurate force reproduction sense than healthy participants. Local muscle vibration led to significant trunk neuromuscular control improvements in the cLBP patients before and after a muscle fatigue protocol. Muscle vibration

The Effects of Vibration and Muscle Fatigue on Trunk Sensorimotor Control in Low Back Pain Patients

Science.gov (United States)

Abboud, Jacques; Nougarou, François; Normand, Martin C.

2015-01-01

Introduction Changes in sensorimotor function and increased trunk muscle fatigability have been identified in patients with chronic low back pain (cLBP). This study assessed the control of trunk force production in conditions with and without local erector spinae muscle vibration and evaluated the influence of muscle fatigue on trunk sensorimotor control. Methods Twenty non-specific cLBP patients and 20 healthy participants were asked to perform submaximal isometric trunk extension torque with and without local vibration stimulation, before and after a trunk extensor muscle fatigue protocol. Constant error (CE), variable error (VE) as well as absolute error (AE) in peak torque were computed and compared across conditions. Trunk extensor muscle activation during isometric contractions and during the fatigue protocol was measured using surface electromyography (sEMG). Results Force reproduction accuracy of the trunk was significantly lower in the patient group (CE = 9.81 ± 2.23 Nm; AE = 18.16 ± 3.97 Nm) than in healthy participants (CE = 4.44 ± 1.68 Nm; AE = 12.23 ± 2.44 Nm). Local erector spinae vibration induced a significant reduction in CE (4.33 ± 2.14 Nm) and AE (13.71 ± 3.45 Nm) mean scores in the patient group. Healthy participants conversely showed a significant increase in CE (8.17 ± 2.10 Nm) and AE (16.29 ± 2.82 Nm) mean scores under vibration conditions. The fatigue protocol induced erector spinae muscle fatigue as illustrated by a significant decrease in sEMG median time-frequency slopes. Following the fatigue protocol, patients with cLBP showed significant decrease in sEMG root mean square activity at L4-5 level and responded in similar manner with and without vibration stimulation in regard to CE mean scores. Conclusions Patients with cLBP have a less accurate force reproduction sense than healthy participants. Local muscle vibration led to significant trunk neuromuscular control improvements in the cLBP patients before and after a muscle

Muscle glycogen content and glucose uptake during exercise in humans: influence of prior exercise and dietary manipulation

DEFF Research Database (Denmark)

Steensberg, Adam; van Hall, Gerrit; Keller, Charlotte

2002-01-01

on two occasions: one after 60 min of two-legged cycling (16 h prior to the experimental trial) followed by a high carbohydrate diet (HCHO) and the other after the same exercise followed by a low carbohydrate diet (LCHO) (Series 2). Muscle glycogen was decreased by 40 % when comparing the pre-exercised......There are many factors that can influence glucose uptake by contracting skeletal muscle during exercise and although one may be intramuscular glycogen content, this relationship is at present not fully elucidated. To test the hypothesis that muscle glycogen concentration influences glucose uptake...... during exercise, 13 healthy men were studied during two series of experiments. Seven men completed 4 h of two-legged knee extensor exercise 16 h after reducing of muscle glycogen by completing 60 min of single-legged cycling (Series 1). A further six men completed 3 h of two-legged knee extensor exercise...

Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI.

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Fernandez-Gonzalo, R; Tesch, P A; Linnehan, R M; Kreider, R B; Di Salvo, V; Suarez-Arrones, L; Alomar, X; Mendez-Villanueva, A; Rodas, G

2016-06-01

This study used functional magnetic resonance imaging (fMRI) to compare individual muscle use in exercises aimed at preventing hamstring injuries. Thirty-six professional soccer players were randomized into 4 groups, each performing either Nordic hamstring, flywheel leg curl, Russian belt or conic-pulley exercise. MRIs were performed before and immediately after a bout of 4 sets of 8 repetitions. Pre-post exercise differences in contrast shift (T2) were analyzed for the long (BFLh) and short head (BFSh) of biceps femoris, semitendinosus (ST), semimembranosus (SM) and gracilis (GR) muscles. Flywheel leg curl increased (Phamstring, GR (39%), ST (16%) and BFSh (14%) showed increased T2 (Phamstring and GR muscle use. However, no single exercise executed was able to increase T2 of all hamstring and synergist muscles analyzed. It is therefore suggested that multiple exercises must be carried out to bring in, and fully activate all knee flexors and hip extensors. © Georg Thieme Verlag KG Stuttgart · New York.

Unaccustomed eccentric contractions impair plasma K+ regulation in the absence of changes in muscle Na+,K+-ATPase content.

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Craig A Goodman

Full Text Available The Na+,K+-ATPase (NKA plays a fundamental role in the regulation of skeletal muscle membrane Na+ and K+ gradients, excitability and fatigue during repeated intense contractions. Many studies have investigated the effects of acute concentric exercise on K+ regulation and skeletal muscle NKA, but almost nothing is known about the effects of repeated eccentric contractions. We therefore investigated the effects of unaccustomed maximal eccentric knee extensor contractions on K+ regulation during exercise, peak knee extensor muscle torque, and vastus lateralis muscle NKA content and 3-O-MFPase activity. Torque measurements, muscle biopsies, and venous blood samples were taken before, during and up to 7 days following the contractions in six healthy adults. Eccentric contractions reduced peak isometric muscle torque immediately post-exercise by 26±11% and serum creatine kinase concentration peaked 24 h post-exercise at 339±90 IU/L. During eccentric contractions, plasma [K+] rose during Set 1 and remained elevated at ∼4.9 mM during sets 4-10; this was despite a decline in work output by Set 4, which fell by 18.9% at set 10. The rise in plasma [K+] x work(-1 ratio was elevated over Set 2 from Set 4- Set 10. Eccentric contractions had no effect on muscle NKA content or maximal in-vitro 3-O-MFPase activity immediately post- or up to 7 d post-exercise. The sustained elevation in plasma [K+] despite a decrease in work performed by the knee extensor muscles suggests an impairment in K+ regulation during maximal eccentric contractions, possibly due to increased plasma membrane permeability or to excitation-contraction uncoupling.

Effects of a Worksite Supervised Adapted Physical Activity Program on Trunk Muscle Endurance, Flexibility, and Pain Sensitivity Among Vineyard Workers.

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Balaguier, Romain; Madeleine, Pascal; Rose-Dulcina, Kévin; Vuillerme, Nicolas

2017-01-01

In viticulture, the prevalence of low back pain is particularly high among vineyard workers exposed to sustained and awkward postures. One promising setting for low back pain prevention resides in the implementation of workplace physical activity. This nonrandomized pilot study aims at evaluating the effects of a worksite supervised adapted physical activity program among 17 vineyard workers volunteered to enter either an intervention group (n = 10) or a control group (n = 7).The intervention group followed a physical activity program for 8 weeks involving (1) 15 minutes of warm-up every working day and (2) two weekly 1-hour adapted physical activity sessions targeting trunk muscle endurance and flexibility. The control group was advised to continue normal physical activity. Evaluations were carried out at weeks 0, 4, 8, and 12. Physical capacity was assessed using flexibility tests for the trunk, along with trunk muscle flexor and extensor endurance tests. Finally, pain sensitivity was evaluated by assessing pressure pain thresholds over 14 anatomical locations in the low back region. For the intervention group, the endurance of the trunk extensor and flexor significantly increased from baseline to week 8 as well as the pressure pain thresholds. No change was observed for the control group over the same period. These encouraging results in combination with the high adherence rate set interesting foundations for the promotion of worksite supervised adapted physical activity and, most likely, offer a new promising approach to prevent low back pain among vineyard workers.

Musculoskeletal Geometry, Muscle Architecture and Functional Specialisations of the Mouse Hindlimb.

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James P Charles

Full Text Available Mice are one of the most commonly used laboratory animals, with an extensive array of disease models in existence, including for many neuromuscular diseases. The hindlimb is of particular interest due to several close muscle analogues/homologues to humans and other species. A detailed anatomical study describing the adult morphology is lacking, however. This study describes in detail the musculoskeletal geometry and skeletal muscle architecture of the mouse hindlimb and pelvis, determining the extent to which the muscles are adapted for their function, as inferred from their architecture. Using I2KI enhanced microCT scanning and digital segmentation, it was possible to identify 39 distinct muscles of the hindlimb and pelvis belonging to nine functional groups. The architecture of each of these muscles was determined through microdissections, revealing strong architectural specialisations between the functional groups. The hip extensors and hip adductors showed significantly stronger adaptations towards high contraction velocities and joint control relative to the distal functional groups, which exhibited larger physiological cross sectional areas and longer tendons, adaptations for high force output and elastic energy savings. These results suggest that a proximo-distal gradient in muscle architecture exists in the mouse hindlimb. Such a gradient has been purported to function in aiding locomotor stability and efficiency. The data presented here will be especially valuable to any research with a focus on the architecture or gross anatomy of the mouse hindlimb and pelvis musculature, but also of use to anyone interested in the functional significance of muscle design in relation to quadrupedal locomotion.

Predicting the Functional Roles of Knee Joint Muscles from Internal Joint Moments

DEFF Research Database (Denmark)

Flaxman, Teresa E; Alkjær, Tine; Simonsen, Erik B

2017-01-01

INTRODUCTION: Knee muscles are commonly labeled as flexors or extensors and aptly stabilize the knee against sagittal plane loads. However, how these muscles stabilize the knee against adduction-abduction and rotational loads remains unclear. Our study sought 1) to classify muscle roles as they r...... on its role in maintaining knee joint stability in the frontal and transverse loading planes. This is useful for delineating the roles of biarticular knee joint muscles and could have implications in robotics, musculoskeletal modeling, sports sciences, and rehabilitation....

Neck muscle endurance and head posture: A comparison between adolescents with and without neck pain.

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Oliveira, Ana Carolina; Silva, Anabela G

2016-04-01

The main aims of this study were to compare the neck flexor and extensor endurance and forward head posture between adolescents with and without neck pain. The secondary aims were to explore potential associations between muscles endurance, head posture and neck pain characteristics and to assess intra-rater reliability of the measurements used. Adolescents with neck pain (n = 35) and age-matched asymptomatic adolescents (n = 35) had their forward head posture, neck flexor endurance and neck extensor endurance measured using clinical tests. Intra-rater reliability was also assessed. Forward head posture and neck flexor and extensor endurance tests showed moderate to almost perfect intra-rater reliability (ICC between 0.58 and 0.88). Adolescents with neck pain showed significantly less forward head posture (neck pain = 46.62 ± 4.92; asymptomatic = 44.18°± 3.64°, p > 0.05) and less neck flexor (neck pain = 24.50 ± 23.03s; asymptomatic = 35.89 ± 21.53s, p > 0.05) and extensor endurance (neck pain = 12.6.64 ± 77.94s; asymptomatic = 168.66 ± 74.77s, p > 0.05) than asymptomatic adolescents. Results suggest that changes in posture and neck muscle endurance are a feature of adolescents with neck pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Course of Serum Inflammatory Biomarkers Following Whiplash Injury and Their Relationship to Sensory and Muscle Measures: a Longitudinal Cohort Study

Science.gov (United States)

Sterling, Michele; Elliott, James M.; Cabot, Peter J.

2013-01-01

Tissue damage or pathological alterations are not detectable in the majority of people with whiplash associated disorders (WAD). Widespread hyperalgisa, morphological muscle changes and psychological distress are common features of WAD. However little is known about the presence of inflammation and its association with symptom persistence or the clinical presentation of WAD. This study aimed to prospectively investigate changes in serum inflammatory biomarker levels from the acute (3 months) stages of whiplash injury. It also aimed to determine relationships between biomarker levels and hyperalgesia, fatty muscle infiltrates of the cervical extensors identified on MRI and psychological factors. 40 volunteers with acute WAD and 18 healthy controls participated. Participants with WAD were classified at 3 months as recovered/mild disability or having moderate/severe disability using the Neck Disability Index. At baseline both WAD groups showed elevated serum levels of CRP but by 3 months levels remained elevated only in the moderate/severe group. The recovered/mild disability WAD group had higher levels of TNF-α at both time points than both the moderate/severe WAD group and healthy controls. There were no differences found in serum IL-1β. Moderate relationships were found between hyperalgesia and CRP at both time points and between hyperalgesia and IL-1β 3 months post injury. There was a moderate negative correlation between TNF-α and amount of fatty muscle infiltrate and pain intensity at 3 months. Only a weak relationship was found between CRP and pain catastrophising and no relationship between biomarker levels and posttraumatic stress symptoms. The results of the study indicate that inflammatory biomarkers may play a role in outcomes following whiplash injury as well as being associated with hyperalgesia and fatty muscle infiltrate in the cervical extensors. PMID:24147095

The course of serum inflammatory biomarkers following whiplash injury and their relationship to sensory and muscle measures: a longitudinal cohort study.

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Michele Sterling

Full Text Available Tissue damage or pathological alterations are not detectable in the majority of people with whiplash associated disorders (WAD. Widespread hyperalgisa, morphological muscle changes and psychological distress are common features of WAD. However little is known about the presence of inflammation and its association with symptom persistence or the clinical presentation of WAD. This study aimed to prospectively investigate changes in serum inflammatory biomarker levels from the acute (3 months stages of whiplash injury. It also aimed to determine relationships between biomarker levels and hyperalgesia, fatty muscle infiltrates of the cervical extensors identified on MRI and psychological factors. 40 volunteers with acute WAD and 18 healthy controls participated. Participants with WAD were classified at 3 months as recovered/mild disability or having moderate/severe disability using the Neck Disability Index. At baseline both WAD groups showed elevated serum levels of CRP but by 3 months levels remained elevated only in the moderate/severe group. The recovered/mild disability WAD group had higher levels of TNF-α at both time points than both the moderate/severe WAD group and healthy controls. There were no differences found in serum IL-1β. Moderate relationships were found between hyperalgesia and CRP at both time points and between hyperalgesia and IL-1β 3 months post injury. There was a moderate negative correlation between TNF-α and amount of fatty muscle infiltrate and pain intensity at 3 months. Only a weak relationship was found between CRP and pain catastrophising and no relationship between biomarker levels and posttraumatic stress symptoms. The results of the study indicate that inflammatory biomarkers may play a role in outcomes following whiplash injury as well as being associated with hyperalgesia and fatty muscle infiltrate in the cervical extensors.

MUSCLE WEAKNESS, FATIGUE, AND TORQUE VARIABILITY: EFFECTS OF AGE AND MOBILITY STATUS

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KENT-BRAUN, JANE A.; CALLAHAN, DAMIEN M.; FAY, JESSICA L.; FOULIS, STEPHEN A.; BUONACCORSI, JOHN P.

2013-01-01

Introduction Whereas deficits in muscle function, particularly power production, develop in old age and are risk factors for mobility impairment, a complete understanding of muscle fatigue during dynamic contractions is lacking. We tested hypotheses related to torque-producing capacity, fatigue resistance, and variability of torque production during repeated maximal contractions in healthy older, mobility-impaired older, and young women. Methods Knee extensor fatigue (decline in torque) was measured during 4 min of dynamic contractions. Torque variability was characterized using a novel 4-component logistic regression model. Results Young women produced more torque at baseline and during the protocol than older women (P torque variability differed by group (P = 0.022) and was greater in older impaired compared with young women (P = 0.010). Conclusions These results suggest that increased torque variability may combine with baseline muscle weakness to limit function, particularly in older adults with mobility impairments. PMID:23674266

The Effects of Long-Term Experimental Diabetes Mellitus Type I on Skeletal Muscle Regeneration Capacity

OpenAIRE

Jerković, Romana; Bosnar, Alan; Jurišić-Eržen, Dubravka; Ažman, Josip; Starčević-Klasan, Gordana; Peharec, Stanislav; Čoklo, Miran

2009-01-01

Muscle fibers are dynamic structures capable of altering their phenotype under various pathological conditions. The aim of the present study was to investigate the influence of long-lasting diabetes mellitus on the process of muscle regeneration in the skeletal muscle. Wistar rats were made diabetic by a single intraperitoneal injection of streptozotocin (STZ). The regeneration process in the skeletal muscle was induced in slow (m. soleus, SOL) and fast (m. extensor digitorum longus, EDL) mus...

Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans

DEFF Research Database (Denmark)

Krustrup, Peter; Secher, Niels; Relu, Mihai U.

2008-01-01

We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W...... without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P fibres, whereas in CON, CP decreased (P ... at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation....

Overload-induced skeletal muscle hypertrophy is not impaired in STZ-diabetic rats

Science.gov (United States)

Fortes, Marco Aurélio S; Pinheiro, Carlos Hermano J; Guimarães-Ferreira, Lucas; Vitzel, Kaio F; Vasconcelos, Diogo A A; Curi, Rui

2015-01-01

The aim of this study was to evaluate the effect of overload-induced hypertrophy on extensor digitorum longus (EDL) and soleus muscles of streptozotocin-induced diabetic rats. The overload-induced hypertrophy and absolute tetanic and twitch forces increases in EDL and soleus muscles were not different between diabetic and control rats. Phospho-Akt and rpS6 contents were increased in EDL muscle after 7 days of overload and returned to the pre-overload values after 30 days. In the soleus muscle, the contents of total and phospho-Akt and total rpS6 were increased in both groups after 7 days. The contents of total Akt in controls and total rpS6 and phospho-Akt in the diabetic rats remained increased after 30 days. mRNA expression after 7 days of overload in the EDL muscle of control and diabetic animals showed an increase in MGF and follistatin and a decrease in myostatin and Axin2. The expression of FAK was increased and of MuRF-1 and atrogin-1 decreased only in the control group, whereas Ankrd2 expression was enhanced only in diabetic rats. In the soleus muscle caused similar changes in both groups: increase in FAK and MGF and decrease in Wnt7a, MuRF-1, atrogin-1, and myostatin. Differences between groups were observed only in the increased expression of follistatin in diabetic animals and decreased Ankrd2 expression in the control group. So, insulin deficiency does not impair the overload-induced hypertrophic response in soleus and EDL muscles. However, different mechanisms seem to be involved in the comparable hypertrophic responses of skeletal muscle in control and diabetic animals. PMID:26197932

Loss of knee extensor torque complexity during fatiguing isometric muscle contractions occurs exclusively above the critical torque.

Science.gov (United States)

Pethick, Jamie; Winter, Samantha L; Burnley, Mark

2016-06-01

The complexity of knee extensor torque time series decreases during fatiguing isometric muscle contractions. We hypothesized that because of peripheral fatigue, this loss of torque complexity would occur exclusively during contractions above the critical torque (CT). Nine healthy participants performed isometric knee extension exercise (6 s of contraction, 4 s of rest) on six occasions for 30 min or to task failure, whichever occurred sooner. Four trials were performed above CT (trials S1-S4, S1 being the lowest intensity), and two were performed below CT (at 50% and 90% of CT). Global, central, and peripheral fatigue were quantified using maximal voluntary contractions (MVCs) with femoral nerve stimulation. The complexity of torque output was determined using approximate entropy (ApEn) and the detrended fluctuation analysis-α scaling exponent (DFA-α). The MVC torque was reduced in trials below CT [by 19 ± 4% (means ± SE) in 90%CT], but complexity did not decrease [ApEn for 90%CT: from 0.82 ± 0.03 to 0.75 ± 0.06, 95% paired-samples confidence intervals (CIs), 95% CI = -0.23, 0.10; DFA-α from 1.36 ± 0.01 to 1.32 ± 0.03, 95% CI -0.12, 0.04]. Above CT, substantial reductions in MVC torque occurred (of 49 ± 8% in S1), and torque complexity was reduced (ApEn for S1: from 0.67 ± 0.06 to 0.14 ± 0.01, 95% CI = -0.72, -0.33; DFA-α from 1.38 ± 0.03 to 1.58 ± 0.01, 95% CI 0.12, 0.29). Thus, in these experiments, the fatigue-induced loss of torque complexity occurred exclusively during contractions performed above the CT. Copyright © 2016 the American Physiological Society.

Relations between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy

NARCIS (Netherlands)

Eken, Maaike M.; Houdijk, Han; Doorenbosch, Caroline A. M.; Kiezebrink, Francisca E. M.; van Bennekom, Coen A. M.; Harlaar, Jaap; Dallmeijer, Annet J.

2016-01-01

To investigate the relation between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy (CP) and peers with typical development. In this case-control study, knee extensor muscle endurance was estimated from

Relations between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy

NARCIS (Netherlands)

Eken, Maaike M; Houdijk, Han; Doorenbosch, Caroline A M; Kiezebrink, Francisca E.M.; van Bennekom, Coen A.M.; Harlaar, Jaap; Dallmeijer, Annet J.

2016-01-01

Aim: To investigate the relation between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy (CP) and peers with typical development. Method: In this case–control study, knee extensor muscle endurance was

Hyperparathyroidism-related extensor tenosynovitis at the wrist: a general review of the literature.

Science.gov (United States)

Ichihara, Satoshi; Hidalgo-Diaz, Juan Jose; Prunières, Guillaume; Facca, Sybille; Bodin, Frédéric; Boucher, Stéphanie; Liverneaux, Philippe

2015-07-01

Extensor tenosynovitis often occurs accompanying with rheumatoid arthritis, gout, trauma, mycobacterium and dialysis-related amyloidosis. However, there is no recognition of extensor tenosynovitis accompanying with hyperparathyroidism. The purpose of this general review was to describe the clinical condition and to report the results of surgical intervention in the extensor tenosynovitis at the wrist related to hyperparathyroidism. Hyperparathyroidism is thought to be a rare disease in adult. Although renal symptoms are the commonest symptom, musculoskeletal complaints also occur in hyperparathyroidism. From our general review, hyperparathyroidism deserves consideration in the differential diagnosis of extensor tenosynovitis at the wrist.

F response and H reflex analysis of physiological unity of gravity and antigravity muscles in man.

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García, H A; Fisher, M A

1977-01-01

Observational differences between reflex (H reflex) and antidromic (F response) activation of segmental motoneurons by a peripheral electrical stimulus are described. In contrast to H reflexes, the percentage of F responses found after a series of stimuli is directly related to the pick-up field of the recording electrode consistent with this response being due to the variable activation of a small fraction of the available motoneuron pool. Despite the differing physiological mechanisms, both F responses and H reflexes can be used to demonstrate similar relative "central excitatory states" for antigravity muscles (i.e. extensors in the lower extremity and flexors in the upper extremity) and their antagonist gravity muscles. H reflexes were elicited not only in their usual location in certain antigravity muscles but also in unusual locations by length/tension changes in agonist and antagonist groups as well as by passive stretch. The data argue for the physiological unity of similarly acting gravity and antigravity muscles as well as supporting a meaningful role of group II afferents in normal segmental motoneuron pool excitability.

Decreased neck muscle strength in patients with the loss of cervical lordosis.

Science.gov (United States)

Alpayci, Mahmut; Şenköy, Emre; Delen, Veysel; Şah, Volkan; Yazmalar, Levent; Erden, Metin; Toprak, Murat; Kaplan, Şeyhmus

2016-03-01

The loss of cervical lordosis is associated with some negative clinical outcomes. No previous study has examined cervical muscle strength, specifically in patients with the loss of cervical lordosis. This study aims to investigate whether there is weakness of the cervical muscles or an imbalance between cervical flexor and extensor muscle strength in patients with the loss of cervical lordosis compared with healthy controls matched by age, gender, body mass index (BMI), and employment status. Thirty-two patients with the loss of cervical lordosis (23 F, 9 M) and 31 healthy volunteers (23 F, 8 M) were included in the study. Maximal isometric neck extension and flexion strength, and the strength ratio between extension and flexion were used as evaluation parameters. All measurements were conducted by a blinded assessor using a digital force gauge. The participants were positioned on a chair in a neutral cervical position and without the trunk inclined during measurements. Maximal isometric neck extension and flexion strength values were significantly lower in the patients versus healthy controls (Plordosis have reduced neck muscle strength, especially in the extensors. These findings may be beneficial for optimizing cervical exercise prescriptions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterisation of myosin heavy chain gene variants in the fast and slow muscle fibres of gammarid amphipods.

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Whiteley, N M; Magnay, J L; McCleary, S J; Nia, S Khazraee; El Haj, A J; Rock, J

2010-10-01

Recent molecular work has revealed a large diversity of myosin heavy chain (MyHC) gene variants in the abdominal musculature of gammarid amphipods. An unusual truncated MyHC transcript from the loop 1 region (Variant A(3)) was consistently observed in multiple species and populations. The current study aimed to determine whether this MyHC variant is specific to a particular muscle fibre type, as a change in net charge to the loop 1 region of Variant A(3) could be functionally significant. The localisation of different fibre types within the abdominal musculature of several gammarid species revealed that the deep flexor and extensor muscles are fast-twitch muscle fibres. The dorsal superficial muscles were identified as slow fibres and the muscles extrinsic to the pleopods were identified as intermediate fibres. Amplification of loop 1 region mRNA from isolated superficial extensor and deep flexor muscles, and subsequent liquid chromatography and sequence analysis revealed that Variant A(3) was the primary MyHC variant in slow muscles, and the conserved A(1) sequence was the primary variant in fast muscles. The specific role of Variant A(3) in the slow muscles remains to be investigated. 2010 Elsevier Inc. All rights reserved.

Joint Moment-Angle Properties of the Hip Extensors in Subjects With and Without Patellofemoral Pain.

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Kindel, Curtis; Challis, John

2018-04-01

Strength deficits of hip extension in individuals with patellofemoral syndrome are commonly reported in literature. No literature to date has examined these deficits with variable positions of the knee and hip; altering knee angle alters the length and therefore potentially the force produced by the biarticular muscles. Beyond strength, neuromuscular control can also be assessed through the analysis of isometric joint moment steadiness. Subjects consisted of a group of individuals with patellofemoral syndrome (n = 9), and a group of age- and size-matched controls with no symptoms (n = 9). Maximum isometric joint moments for hip extension were measured at 4 points within the joint's range of motion, at 2 different knee positions (0° and 90°) for each group. The joint moment signals were analyzed by computing signal Coefficient of Variation (CV). The results indicate that no significant differences were found between the groups of subjects for the hip extension moments when the knee was extended. However, there was a significant difference between the groups for the joint moments of hip extension with the knee flexed at all 4 hip positions. Results also showed hip extension CV values to be significantly higher in the patellofemoral group compared with the control group, indicating greater signal noise and therefore poorer neuromuscular control of the hip extensor musculature. This study demonstrated that individuals with patellofemoral syndrome have reduced hip extension strength and reduced neuromuscular control with the knee flexed compared with a control group. These results have implications for the etiology of patellofemoral syndrome and its rehabilitation.

A Survey On The Effects Of Iontophoresis Of Piroxicam Gel On Pain And Knee Muscles Strengthn Patients With Knee Osteoarthritis

Directory of Open Access Journals (Sweden)

Asghar RezaSoltani

2012-04-01

Full Text Available Background and Aim: Knee osteoarthritis is the most common cause of disability in many societies. Therapeutic measures such as using anti-inflammation drugs and physiotherapy programs have been used to suppress knee pain and improve knee joint function in patients with knee osteoarthritis. The aim of this study was to compare the effects of iontophoresis of piroxicam gel, galvanic current with or without piroxicam gel on pain, functional ability and knee muscle strength in patients with knee osteoarthritis.Materials and Method: This study was a clinical trial conducted in Akhtar hospital. Forty two female patients (mean age 58.52 years old with knee osteoarthritis participated in this study. The protocol was performed in Physiotherapy Clinic of Mazandaran Medical University, Mazandaran, Iran. All patients were randomly assigned to three groups. Iontophoresis of piroxicam gel was applied for group 1 (n=14, proxicam gel for group 2 (n=14 and galvanic current for group 3 (n=14. The procedure was carried out for 20-minutes, three times a week and for two following weeks. Knee pain and functional ability were estimated by knee injury and osteoarthritis outcome score (KOOS questioner and the strength of knee extensor and flexor muscles by an isometric device just before the first treatment and immediately after the last treatment times.Results: A significant decrease in pain and a significant increase in functional ability and the strength of knee extensor muscles were resulted in all studied groups (P < 0.05. According to ANOVA test, the level of the percentage difference which was computed for KOOS and knee muscle strength before and after treatments was significantly higher in group 1 than the other two (P < 0.01.Conclusion: Pain and knee functional ability were significantly improved in patients in all three methods. But iontophoresis of piroxicam gel appeared to be more effective in relieving pain and improving knee functional abilities than the

Changes in muscle cross-sectional area, muscle force, and jump performance during 6 weeks of progressive whole-body vibration combined with progressive, high intensity resistance training

Science.gov (United States)

Rosenberger, A.; Beijer, Å.; Johannes, B.; Schoenau, E.; Mester, J.; Rittweger, J.; Zange, J.

2017-01-01

Objectives: We hypothesized that progressive whole-body vibration (WBV) superimposed to progressive high intensity resistance training has greater effects on muscle cross-sectional area (CSA), muscle force of leg muscles, and jump performance than progressive high intensity resistance training alone. Methods: Two groups of healthy male subjects performed either 6 weeks of Resistive Vibration Exercise (RVE, squats and heel raises with WBV, n=13) or Resistive Exercise (RE, squats and heel raises without WBV, n=13). Squats under RVE required indispensable weight loading on the forefoot to damp harmful vibrations to the head. Time, intervention, and interaction effects were analyzed. Results: After 6 weeks of training, knee extensor CSA, isometric knee extension force, and counter movement jump height increased equally in both groups (time effect, P<0.001, P≤0.02, and P≤0.03, respectively), whereas only in RVE ankle plantar flexor CSA and isometric ankle plantar flexion force reached significance or a tendency, respectively, (time effect, P=0.015 and P=0.069, respectively; intervention effect also for the latter, P=0.006). Drop jump contact time did significantly more improve in RVE (interaction effect, P=0.042). Conclusions: RVE showed better training effects than RE only in plantar flexor muscles. RVE seems to be suitable in professional sports with a special focus on calf muscles. PMID:28574410

Effect of spaceflight on the isotonic contractile properties of single skeletal muscle fibers in the rhesus monkey

Science.gov (United States)

Fitts, R. H.; Romatowski, J. G.; Blaser, C.; De La Cruz, L.; Gettelman, G. J.; Widrick, J. J.

2000-01-01

Experiments from both Cosmos and Space Shuttle missions have shown weightlessness to result in a rapid decline in the mass and force of rat hindlimb extensor muscles. Additionally, despite an increased maximal shortening velocity, peak power was reduced in rat soleus muscle post-flight. In humans, declines in voluntary peak isometric ankle extensor torque ranging from 15-40% have been reported following long- and short-term spaceflight and prolonged bed rest. Complete understanding of the cellular events responsible for the fiber atrophy and the decline in force, as well as the development of effective countermeasures, will require detailed knowledge of how the physiological and biochemical processes of muscle function are altered by spaceflight. The specific purpose of this investigation was to determine the extent to which the isotonic contractile properties of the slow- and fast-twitch fiber types of the soleus and gastrocnemius muscles of rhesus monkeys (Macaca mulatta) were altered by a 14-day spaceflight.

Differences in feedforward trunk muscle activity in subgroups of patients with mechanical low back pain.

Science.gov (United States)

Silfies, Sheri P; Mehta, Rupal; Smith, Sue S; Karduna, Andrew R

2009-07-01

To investigate alterations in trunk muscle timing patterns in subgroups of patients with mechanical low back pain (MLBP). Our hypothesis was that subjects with MLBP would demonstrate delayed muscle onset and have fewer muscles functioning in a feedforward manner than the control group. We further hypothesized that we would find differences between subgroups of our patients with MLBP, grouped according to diagnosis (segmental instability and noninstability). Case-control. Laboratory. Forty-three patients with chronic MLBP (25 instability, 18 noninstability) and 39 asymptomatic controls. Not applicable. Surface electromyography was used to measure onset time of 10 trunk muscles during a self-perturbation task. Trunk muscle onset latency relative to the anterior deltoid was calculated and the number of muscles functioning in feedforward determined. Activation timing patterns (Pfeedforward (P=.02; eta=.30; 1-beta=.83) were statistically different between patients with MLBP and controls. The control group activated the external oblique, lumbar multifidus, and erector spinae muscles in a feedforward manner. The heterogeneous MLBP group did not activate the trunk musculature in feedforward, but responded with significantly delayed activations. MLBP subgroups demonstrated significantly different timing patterns. The noninstability MLBP subgroup activated trunk extensors in a feedforward manner, similar to the control group, but significantly earlier than the instability subgroup. Lack of feedforward activation of selected trunk musculature in patients with MLBP may result in a period of inefficient muscular stabilization. Activation timing was more impaired in the instability than the noninstability MLBP subgroup. Training specifically for recruitment timing may be an important component of the rehabilitation program.

Surface electromyography based muscle fatigue analysis for stroke patients at different Brunnstrom stages.

Science.gov (United States)

Yinjun Tu; Zhe Zhang; Xudong Gu; Qiang Fang

2016-08-01

Muscle fatigue analysis has been an important topic in sport and rehabilitation medicine due to its role in muscle performance evaluation and pathology investigation. This paper proposes a surface electromyography (sEMG) based muscle fatigue analysis approach which was specifically designed for stroke rehabilitation applications. 14 stroke patients from 5 different Brunnstrom recovery stage groups were involved in the experiment and features including median frequency and mean power frequency were extracted from the collected sEMG samples for investigation. After signal decomposition, the decline of motor unit firing rate of patients from different groups had also been studied. Statistically significant presence of fatigue had been observed in deltoideus medius and extensor digitorum communis of patients at early recovery stages (P0.01). It had also been discovered that the motor unit firing frequency declines with a range positively correlated to the recovery stage during repetitive movements. Based on the experiment result, it can be verified that as the recovery stage increases, the central nervous system's control ability strengthens and the patient motion becomes more stable and resistive to fatigue.

Glucose uptake patterns in exercised skeletal muscles of elite male long-distance and short-distance runners.

Science.gov (United States)

Tai, Suh-Jun; Liu, Ren-Shyan; Kuo, Ya-Chen; Hsu, Chi-Yang; Chen, Chi-Hsien

2010-04-30

The aim of this study was to determine glucose uptake patterns in exercised skeletal muscles of elite male long-distance and short-distance runners. Positron emission tomography (PET) using 18F-fluoro-2-deoxyglucose (FDG) was performed to determine the patterns of glucose uptake in lower limbs of short-distance (SD group, n=8) and long-distance (LD group, n=8) male runners after a modified 20 min Bruce treadmill test. Magnetic resonance imaging (MRI) was used to delineate the muscle groups in lower limbs. Muscle groups from hip, knee, and ankle movers were measured. The total FDG uptake and the standard uptake value (SUV) for each muscle group were compared between the 2 groups. For the SD and LD runners, the 2 major muscle groups utilizing glucose during running were knee extensors and ankle plantarflexors, which accounted for 49.3 +/- 8.1% (25.1 +/- 4.7% and 24.2 +/- 6.0%) of overall lower extremity glucose uptake for SD group, and 51.3 +/- 8.0% (27.2 +/- 2.7% and 24.0 +/- 8.1%) for LD group. No difference in muscle glucose uptake was noted for other muscle groups. For SD runners, the SUVs for the muscle groups varied from 0.49 +/- 0.27 for the ankle plantarflexors, to 0.20 +/- 0.08 for the hip flexor. For the LD runners, the highest and lowest SUVs were 0.43 +/- 0.15 for the ankle dorsiflexors and 0.21 +/- 0.19 for the hip. For SD and LD groups, no difference in muscle SUV was noted for the muscle groups. However, the SUV ratio between the ankle dorsiflexors and plantarflexors in the LD group was significantly greater than that in the SD group. We thus conclude that the major propelling muscle groups account for approximately 50% of lower limb glucose utilization during running. Thus, the other muscle groups involving maintenance of balance, limb deceleration, and shock absorption utilize an equal amount. This result provides a new insight into glucose distribution in skeletal muscle, suggesting that propellers and supporters are both energetically important

Isokinetic muscle performance of the hip and ankle muscles in women with fibromyalgia.

Science.gov (United States)

Yetişgin, Alparslan; Tiftik, Tülay; Kara, Murat; Karabay, İlkay; Akkuş, Selami; Ersöz, Murat

2016-06-01

To compare isokinetic muscle performances of a proximal (hip) and a distal (ankle) muscle of fibromyalgia syndrome (FMS) patients with those of age- and body mass index (BMI)-matched healthy subjects. Thirty female patients with FMS (mean age: 41.5 ± 6.7 years [range, 27-54]) and 30 age- (mean age: 40.6 ± 6.0 years [range, 27-54]) and BMI-matched female healthy controls were consecutively enrolled. Demographic and clinical characteristics of the subjects were recorded. Isokinetic measurements of hip and ankle flexion and extension at angular velocities of 60°/s and 180°/s, peak torques, flexor-extensor torque ratios, muscle fatigue resistance values and average power were obtained. Mean disease duration of FMS patients was 2.4 ± 1.9 years. Mean weight, height and BMI values were 70.4 ± 12.5 kg, 159.5 ± 6.0 cm and 27.7 ± 4.7 kg/m² (FMS patients) and 69.3 ± 10.1 kg, 161.7 ± 6.2 cm and 26.6 ± 4.3 kg/m² (control subjects), respectively (all P > 0.05). All isokinetic values were statistically decreased in the FMS group when compared with the control group, except for the peak torques at angular velocity of 180°/s on flexion of the hip and extension of the ankle and the total work and average power on extension of the ankle. We did not find any correlation between isokinetic values and disease related parameters of FMS patients. In the light of our results, we may conclude that muscle strength and muscle fatigue seem to decrease in FMS patients' both proximal and distal lower extremity muscles. © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

The role of propriospinal neuronal network in transmitting the alternating muscular activities of flexor and extensor in parkinsonian tremor.

Science.gov (United States)

Hao, M; He, X; Lan, N

2012-01-01

It has been shown that normal cyclic movement of human arm and resting limb tremor in Parkinson's disease (PD) are associated with the oscillatory neuronal activities in different cerebral networks, which are transmitted to the antagonistic muscles via the same spinal pathway. There are mono-synaptic and multi-synaptic corticospinal pathways for conveying motor commands. This study investigates the plausible role of propriospinal neuronal (PN) network in the C3-C4 levels in multi-synaptic transmission of cortical commands for oscillatory movements. A PN network model is constructed based on known neurophysiological connections, and is hypothesized to achieve the conversion of cortical oscillations into alternating antagonistic muscle bursts. Simulations performed with a virtual arm (VA) model indicate that without the PN network, the alternating bursts of antagonistic muscle EMG could not be reliably generated, whereas with the PN network, the alternating pattern of bursts were naturally displayed in the three pairs of antagonist muscles. Thus, it is suggested that oscillations in the primary motor cortex (M1) of single and double tremor frequencies are processed at the PN network to compute the alternating burst pattern in the flexor and extensor muscles.

Evidence for repetitive load in the trapezius muscle during a tapping task.

Science.gov (United States)

Tomatis, L; Müller, C; Nakaseko, M; Läubli, T

2012-08-01

Many studies describe the trapezius muscle activation pattern during repetitive key-tapping focusing on continuous activation. The objectives of this study were to determine whether the upper trapezius is phasically active during supported key tapping, whether this activity is cross-correlated with forearm muscle activity, and whether trapezius activity depends on key characteristic. Thirteen subjects (29.7 ± 11.4 years) were tested. Surface EMG of the finger's extensor and flexor and of the trapezius muscles, as well as the key on-off signal was recorded while the subject performed a 2-min session of key tapping at 4 Hz. The linear envelopes obtained were cut into single tapping cycles extending from one onset to the next onset signal and subsequently time-normalized. Effect size between mean range and maximal standard deviation was calculated to determine as to whether a burst of trapezius muscle activation was present. Cross-correlation was used to determine the time-lag of the activity bursts between forearm and trapezius muscles. For each person the mean and standard deviation of the cross-correlations coefficient between forearm muscles and trapezius were determined. Results showed a burst of activation in the trapezius muscle during most of the tapping cycles. The calculated effect size was ≥0.5 in 67% of the cases. Cross-correlation factors between forearm and trapezius muscle activity were between 0.75 and 0.98 for both extensor and flexor muscles. The cross-correlated phasic trapezius activity did not depend on key characteristics. Trapezius muscle was dynamically active during key tapping; its activity was clearly correlated with forearm muscles' activity.

Physiological Response to Static Muscle Contractions in Standing and Supine Positions

DEFF Research Database (Denmark)

Pedersen, Jens Meldgaard; Andersen, T. Bull

2013-01-01

The purpose of this study was to investigate the physiological responses to static muscle contractions in the standing position and the supine position. Eight subjects performed static contractions of the ankle extensors in both positions. Blood pressure (SBP and DBP), heart rate (HR...

Serum levo-carnitine levels and skeletal muscle functions in type 2 diabetes mellitus in rodents

International Nuclear Information System (INIS)

Aleem, S.B.; Hussain, M.M.; Farooq, Y.

2013-01-01

Objective: To study serum levo-carnitine (l-carnitine) levels and isometric contraction, force frequency relationship and fatigue of rodent skeletal muscles in type 2 diabetes mellitus. Study Design: Randomized controlled trial. Place and Duration of Study: Physiology Department, Army Medical College, Rawalpindi, from January 2009 to January 2010. Methodology: Sixty Sprague-Dawley rats were randomly divided into two groups; group I (control), fed on normal diet ad libitum and Group II (diabetic), fed on high fat diet and administered streptozocin to induce type 2 diabetes mellitus (T2DM). At 21st day, plasma glucose and TG/HDL ratio were measured to confirm the development of T2DM in group II. At 28th day, blood was drawn by intracardiac puncture to estimate serum levo-carnitine levels. Contractile functions of skeletal muscles were assessed by using iWorx AHK/214 physiological data acquisition unit. Simple muscle twitches, maximum isometric twitch tension (MITT), time-to-peak twitch tension (TPTT) and time-to-relax to 50% of the peak twitch tension (1/2RT) of extensor digitorum muscles were recorded. Muscles were stimulated at higher frequencies to determine maximum fused tetanic tension (MFTT), maximum fused tetanic tension after fatigue protocol (TTFP) and recovery from fatigue (RF). Results: Serum levo-carnitine level decreased significantly in the diabetic group. Both groups had similar MITT, TPTT and 1/2RT but decline in MFTT, TTFP and RF was significant in the diabetic rats. Conclusion: T2DM adversely affected serum levo-carnitine levels and the contractile functions of rodent skeletal muscle at high frequency stimulation. (author)

An electromyographic study of the effect of hand grip sizes on forearm muscle activity and golf performance.

Science.gov (United States)

Sorbie, Graeme G; Hunter, Henry H; Grace, Fergal M; Gu, Yaodong; Baker, Julien S; Ugbolue, Ukadike Chris

2016-01-01

The study describes the differences in surface electromyography (EMG) activity of two forearm muscles in the lead and trail arm at specific phases of the golf swing using a 7-iron with three different grip sizes among amateur and professional golfers. Fifteen right-handed male golfers performed five golf swings using golf clubs with three different grip sizes. Surface EMG was used to measure muscle activity of the extensor carpi radialis brevis (ECRB) and flexor digitorum superficialis (FDS) on both forearms. There were no significant differences in forearm muscle activity when using the three golf grips within the group of 15 golfers (p > 0.05). When using the undersize grip, club head speed significantly increased (p = 0.044). During the backswing and downswing phases, amateurs produced significantly greater forearm muscle activity with all three grip sizes (p < 0.05). In conclusion, forearm muscle activity is not affected by grip sizes. However, club head speed increases when using undersize grips.

Streptozotocin diabetes attenuates the effects of nondepolarizing neuromuscular relaxants on rat muscles.

Science.gov (United States)

Huang, Lina; Chen, Dan; Li, Shitong

2014-12-01

The hypothesis of this study was that diabetes-induced desensitization of rat soleus (SOL) and extensor digitorum longus (EDL) to non-depolarizing muscle relaxants (NDMRs) depends on the stage of diabetes and on the kind of NDMRs. We tested the different magnitude of resistance to vecuronium, cisatracurium, and rocuronium at different stages of streptozotocin (STZ)-induced diabetes by the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations from rats after 4 and 16 weeks of STZ treatment. The concentration-twitch tension curves were significantly shifted from those of the control group to the right in the diabetic groups. Concentration giving 50% of maximal inhibition (IC50) was larger in the diabetic groups for all the NDMRs. For rocuronium and cisatracurium in both SOL and EDL, IC50 was significantly larger in diabetic 16 weeks group than those in the diabetic 4 weeks group. For SOL/EDL, the IC50 ratios were significantly largest in the diabetic 16 weeks group, second largest in the diabetic 4 weeks group, and smallest for the control group. Diabetes-induced desensitization to NDMRs depended on the stage of diabetes and on the different kind of muscles observed while was independent on different kind of NDMRs. The resistance to NDMRs was stronger in the later stage of diabetes (16 versus 4 weeks after STZ treatment). Additionally, when monitoring in SOL, diabetes attenuated the actions of neuromuscular blockade more intensely than that in EDL. Nonetheless, the hyposensitivity to NDMRs in diabetes was not relevant for the kind of NDMRs.

Adding muscle where you need it: non-uniform hypertrophy patterns in elite sprinters.

Science.gov (United States)

Handsfield, G G; Knaus, K R; Fiorentino, N M; Meyer, C H; Hart, J M; Blemker, S S

2017-10-01

Sprint runners achieve much higher gait velocities and accelerations than average humans, due in part to large forces generated by their lower limb muscles. Various factors have been explored in the past to understand sprint biomechanics, but the distribution of muscle volumes in the lower limb has not been investigated in elite sprinters. In this study, we used non-Cartesian MRI to determine muscle sizes in vivo in a group of 15 NCAA Division I sprinters. Normalizing muscle sizes by body size, we compared sprinter muscles to non-sprinter muscles, calculated Z-scores to determine non-uniformly large muscles in sprinters, assessed bilateral symmetry, and assessed gender differences in sprinters' muscles. While limb musculature per height-mass was 22% greater in sprinters than in non-sprinters, individual muscles were not all uniformly larger. Hip- and knee-crossing muscles were significantly larger among sprinters (mean difference: 30%, range: 19-54%) but only one ankle-crossing muscle was significantly larger (tibialis posterior, 28%). Population-wide asymmetry was not significant in the sprint population but individual muscle asymmetries exceeded 15%. Gender differences in normalized muscle sizes were not significant. The results of this study suggest that non-uniform hypertrophy patterns, particularly large hip and knee flexors and extensors, are advantageous for fast sprinting. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Changes in maximum muscle strength and rapid muscle force characteristics after long-term special support and reconnaissance missions

DEFF Research Database (Denmark)

Christensen, Peter Astrup; Jacobsen, Jacob Ole; Thorlund, Jonas B

2008-01-01

PURPOSE: The purpose of the present study was to examine the impact of 8 days of immobilization during a Special Support and Reconnaissance mission (SSR) on muscle mass, contraction dynamics, maximum jump height/power, and body composition. METHODS: Unilateral maximal voluntary contraction, rate...... of force development, and maximal jump height were tested to assess muscle strength/power along with whole-body impedance analysis before and after SSR. RESULTS: Body weight, fat-free mass, and total body water decreased (4-5%) after SSR, along with impairments in maximal jump height (-8%) and knee...... extensor maximal voluntary contraction (-10%). Furthermore, rate of force development was severely affected (-15-30%). CONCLUSIONS: Eight days of immobilization during a covert SSR mission by Special Forces soldiers led to substantial decrements in maximal muscle force and especially in rapid muscle force...

Muscle performance following an acute bout of plyometric training combined with low or high intensity weight exercise.

Science.gov (United States)

Beneka, Anastasia G; Malliou, Paraskevi K; Missailidou, Victoria; Chatzinikolaou, Athanasios; Fatouros, Ioannis; Gourgoulis, Vassilios; Georgiadis, Elias

2013-01-01

To determine the time course of performance responses after an acute bout of plyometric exercise combined with high and low intensity weight training, a 3-group (including a control group), repeated-measures design was employed. Changes in performance were monitored through jumping ability by measuring countermovement and squat jumping, and strength performance assessment through isometric and isokinetic testing of knee extensors (at two different velocities). Participants in both experimental groups performed a plyometric protocol consisting of 50 jumps over 50 cm hurdles and 50 drop jumps from a 50 cm plyometric box. Additionally, each group performed two basic weight exercises consisting of leg presses and leg extensions at 90-95% of maximum muscle strength for the high intensity group and 60% of maximum muscle strength for the low intensity group. The results of the study suggest that an acute bout of intense plyometric exercise combined with weight exercise induces time-dependent changes in performance, which are also dependent on the nature of exercise protocol and testing procedures. In conclusion, acute plyometric exercise with weight exercise may induce a substantial decline in jumping performance for as long as 72 hours but not in other forms of muscle strength.

Kinesthetic perception based on integration of motor imagery and afferent inputs from antagonistic muscles with tendon vibration.

Science.gov (United States)

Shibata, E; Kaneko, F

2013-04-29

The perceptual integration of afferent inputs from two antagonistic muscles, or the perceptual integration of afferent input and motor imagery are related to the generation of a kinesthetic sensation. However, it has not been clarified how, or indeed whether, a kinesthetic perception would be generated by motor imagery if afferent inputs from two antagonistic muscles were simultaneously induced by tendon vibration. The purpose of this study was to investigate how a kinesthetic perception would be generated by motor imagery during co-vibration of the two antagonistic muscles at the same frequency. Healthy subjects participated in this experiment. Illusory movement was evoked by tendon vibration. Next, the subjects imaged wrist flexion movement simultaneously with tendon vibration. Wrist flexor and extensor muscles were vibrated according to 4 patterns such that the difference between the two vibration frequencies was zero. After each trial, the perceived movement sensations were quantified on the basis of the velocity and direction of the ipsilateral hand-tracking movements. When the difference in frequency applied to the wrist flexor and the extensor was 0Hz, no subjects perceived movements without motor imagery. However, during motor imagery, the flexion velocity of the perceived movement was higher than the flexion velocity without motor imagery. This study clarified that the afferent inputs from the muscle spindle interact with motor imagery, to evoke a kinesthetic perception, even when the difference in frequency applied to the wrist flexor and extensor was 0Hz. Furthermore, the kinesthetic perception resulting from integrations of vibration and motor imagery increased depending on the vibration frequency to the two antagonistic muscles. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Assessment of the Cross-Sectional Areas of the Psoas Major and Multifidus Muscles in Patients With Adult Spinal Deformity: A Case-Control Study.

Science.gov (United States)

Banno, Tomohiro; Yamato, Yu; Hasegawa, Tomohiko; Kobayashi, Sho; Togawa, Daisuke; Oe, Shin; Mihara, Yuki; Kurosu, Kenta; Yamamoto, Naoto; Matsuyama, Yukihiro

2017-08-01

This is a case-control study. The present study aimed to compare the cross-sectional areas of the psoas major and multifidus muscles between elderly patients with adult spinal deformity (ASD) and age-matched and body weight-matched controls, and to evaluate the associations between the cross-sectional areas of these muscles and the severity of spinal deformity. The study included 49 female kyphosis patients with mild scoliosis (Cobb angle muscles were calculated using preoperative L4/L5 axial computed tomography images. In group D, the following spinopelvic parameters were assessed: sagittal vertical axis, pelvic tilt, pelvic incidence, lumbar lordosis, and thoracic kyphosis. The relationships between the muscle cross-sectional areas and spinopelvic parameters were evaluated. The cross-sectional area of the multifidus muscle was lower in group D than in group C. However, the cross-sectional area of the psoas major muscle was not different between the 2 groups. In multiple regression analysis, the cross-sectional area of the multifidus muscle was significantly associated with all spinopelvic parameters. The cross-sectional area of the multifidus muscle might be lower in elderly patients with ASD than in controls. In the elderly population, the severity of sagittal spinal deformity might be correlated with the cross-sectional area of the multifidus muscle. Therefore, muscle imbalances between the flexors and extensors of the spine could participate in the pathology of ASD.

Greater glucose uptake heterogeneity in knee muscles of old compared to young men during isometric contractions detected by [18F]-FDG PET/CT

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Thorsten eRudroff

2014-05-01

Full Text Available We used positron emission tomography/computed tomography (PET/CT and [18F]-FDG to test the hypothesis that glucose uptake (GU heterogeneity in skeletal muscles as a measure of heterogeneity in muscle activity is greater in old than young men when they perform isometric contractions. Six young (26 ± 6 yrs and six old (77 ± 6 yrs men performed two types of submaximal isometric contractions that required either force or position control. [18F]-FDG was injected during the task and PET/CT scans were performed immediately after the task. Within-muscle heterogeneity of knee muscles was determined by calculating the coefficient of variation (CV of GU in PET image voxels within the muscles of interest. The average GU heterogeneity (mean ± SD for knee extensors and flexors was greater for the old (35.3 ± 3.3 % than the young (28.6 ± 2.4 % (P = 0.006. Muscle volume of the knee extensors were greater for the young compared to the old men (1016 ± 163 vs. 598 ± 70 cm3, P= 0.004. In a multiple regression model, knee extensor muscle volume was a predictor (partial r = - 0.87; P = 0.001 of GU heterogeneity for old men (R2 = 0.78; P < 0.001, and MVC force predicted GU heterogeneity for young men (partial r = - 0.95, P < 0.001. The findings demonstrate that glucose uptake is more spatially variable for old than young men and especially so for old men who exhibit greater muscle atrophy.

ASSOCIATION OF KNEE PAIN WITH A REDUCTION IN THIGH MUSCLE STRENGTH – A CROSS-SECTIONAL ANALYSIS INCLUDING 4553 OSTEOARTHRITIS INITIATIVE PARTICIPANTS

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Ruhdorfer, Anja; Wirth, Wolfgang; Eckstein, Felix

2016-01-01

Objective To cross-sectionally determine the quantitative relationship of age-adjusted, sex-specific isometric knee extensor and flexor strength to patient-reported knee pain. Methods Difference of thigh muscle strength by age, and that of age-adjusted strength per unit increase on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain scale, was estimated from linear regression analysis of 4553 Osteoarthritis Initiative participants (58% women). Strata encompassing the minimal clinically important difference (MCID) in knee pain were compared to evaluate a potentially non-linear relationship between WOMAC pain levels and muscle strength. Results In Osteoarthritis Initiative participants without pain, the age-related difference in isometric knee extensor strength was −9.0%/−8.2% (women/men) per decade, and that of flexor strength was −11%/−6.9%. Differences in age-adjusted strength values for each unit of WOMAC pain (1/20) amounted to −1.9%/−1.6% for extensor and −2.5%/−1.7% for flexor strength. Differences in torque/weight for each unit of WOMAC pain ranged from −3.3 to − 2.1%. There was no indication of a non-linear relationship between pain and strength across the range of observed WOMAC values, and similar results were observed in women and men. Conclusion Each increase by 1/20 units in WOMAC pain was associated with a ~2% lower age-adjusted isometric extensor and flexor strength in either sex. As a reduction in muscle strength is known to prospectively increase symptoms in knee osteoarthritis and as pain appears to reduce thigh muscle strength, adequate therapy of pain and muscle strength is required in knee osteoarthritis patients to avoid a vicious circle of self-sustaining clinical deterioration. PMID:27836675

The hip adductor muscle group in caviomorph rodents: anatomy and homology.

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García-Esponda, César M; Candela, Adriana M

2015-06-01

Anatomical comparative studies including myological data of caviomorph rodents are relatively scarce, leading to a lack of use of muscular features in cladistic and morphofunctional analyses. In rodents, the hip adductor muscles constitute an important group of the hindlimb musculature, having an important function during the beginning of the stance phase. These muscles are subdivided in several distinct ways in the different clades of rodents, making the identification of their homologies hard to establish. In this contribution we provide a detailed description of the anatomical variation of the hip adductor muscle group of different genera of caviomorph rodents and identify the homologies of these muscles in the context of Rodentia. On this basis, we identify the characteristic pattern of the hip adductor muscles in Caviomorpha. Our results indicate that caviomorphs present a singular pattern of the hip adductor musculature that distinguishes them from other groups of rodents. They are characterized by having a single m. adductor brevis that includes solely its genicular part. This muscle, together with the m. gracilis, composes a muscular sheet that is medial to all other muscles of the hip adductor group. Both muscles probably have a synergistic action during locomotion, where the m. adductor brevis reinforces the multiple functions of the m. gracilis in caviomorphs. Mapping of analyzed myological characters in the context of Rodentia indicates that several features are recovered as potential synapomorphies of caviomorphs. Thus, analysis of the myological data described here adds to the current knowledge of caviomorph rodents from anatomical and functional points of view, indicating that this group has features that clearly differentiate them from other rodents. Copyright © 2015 Elsevier GmbH. All rights reserved.

The effect of targeted exercise on knee-muscle function in patients with persistent hamstring deficiency following ACL reconstruction

DEFF Research Database (Denmark)

Bregenhof, Bo; Jørgensen, Uffe; Aagaard, Per

2018-01-01

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction, using hamstring auto-graft is a common surgical procedure, which often leads to persistent hamstring muscle-strength deficiency and reduced function. The purpose of this randomized controlled trial (RCT) is to investigate the effect...... at 12-24 months' post surgery, will be recruited through outpatient clinics and advertisements. Patients will be randomized to a 12-week progressive, strength and neuromuscular exercise group (SNG) with supervised training twice weekly or a control intervention (CON) consisting of a home-based, low......-intensity exercise program. Outcome measures include between-group change in maximal isometric knee-flexor strength (primary outcome) and knee-extensor muscle strength, hamstring-to-quadriceps strength ratios of the leg that has been operated on and Knee injury and Osteoarthritis Outcome Score (KOOS) (secondary...

Effects of aging on muscle mechanical function and muscle fiber morphology during short-term immobilization and subsequent retraining

DEFF Research Database (Denmark)

Hvid, Lars; Aagaard, Per; Justesen, Lene

2010-01-01

to the deleterious effects of short-term muscle disuse on muscle fiber size and rapid force capacity than YM. Furthermore, OM seems to require longer time to recover and regain rapid muscle force capacity, which may lead to a larger risk of falling in aged individuals after periods of short-term disuse.......Very little attention has been given to the combined effects of aging and disuse as separate factors causing deterioration in muscle mechanical function. Thus the purpose of this study was to investigate the effects of 2 wk of immobilization followed by 4 wk of retraining on knee extensor muscle...... mechanical function (e.g., maximal strength and rapid force capacity) and muscle fiber morphology in 9 old (OM: 67.3 ± 1.3 yr) and 11 young healthy men (YM: 24.4 ± 0.5 yr) with comparable levels of physical activity. Following immobilization, OM demonstrated markedly larger decreases in rapid force capacity...

Analysis of isokinetic muscle function and postural control in individuals with intermittent claudication

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Morgan Lanzarin

2016-02-01

Full Text Available BACKGROUND: Intermittent claudication (IC is a debilitating condition that mostly affects elderly people. IC is manifested by a decrease in ambulatory function. Individuals with IC present with motor and sensory nerve dysfunction in the lower extremities, which may lead to deficits in balance. OBJECTIVE: This study aimed to measure postural control and isokinetic muscle function in individuals with intermittent claudication. METHOD: The study included 32 participants of both genders, 16 IC participants (mean age: 64 years, SD=6 and 16 healthy controls (mean age: 67 years, SD=5, which were allocated into two groups: intermittent claudication group (ICG and control group (CG. Postural control was assessed using the displacement and velocity of the center of pressure (COP during the sensory organization test (SOT and the motor control test (MCT. Muscle function of the flexor and extensor muscles of the knee and ankle was measured by an isokinetic dynamometer. Independent t tests were used to calculate the between-group differences. RESULTS: The ICG presented greater displacement (p =0.027 and speed (p =0.033 of the COP in the anteroposterior direction (COPap during the MCT, as well as longer latency (p =0.004. There were no between-group differences during the SOT. The ICG showed decreased muscle strength and power in the plantar flexors compared to the CG. CONCLUSION: Subjects with IC have lower values of strength and muscle power of plantiflexores, as well as changes in postural control in dynamic conditions. These individuals may be more vulnerable to falls than healthy subjects.

Spontaneous Rupture of the Extensor Pollicis Longus Tendon due to Unusual Etiology

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Süleyman Taş

2014-03-01

Full Text Available Background: The etiology of spontaneous rupture of the extensor pollicis longus tendon includes systemic or local steroid injections, wrist fracture, tenosynovitis, synovitis, rheumatoid arthritis, and repetitive wrist motions. Case Report: We encountered a case of extensor pollicis longus tendon rupture with an unusual etiology, cow milking. In this case, transfer of the extensor indicis proprius tendon was performed successfully. At 1 year after surgery, extension of the thumb was sufficient. Conclusion: It appears that patients with occupations involving repetitive motions are at a high risk of closed tendon ruptures.

Role of Glucocorticoids in the Response to Unloading of Muscle Protein and Amino Acid Metabolism

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Tischler, M. E.; Jaspers, S. R.

1985-01-01

Intact control (weight bearing) and suspended rats gained weight at a similar rate during a 6 day period. Adrenaectomized (adx) weight bearing rats gained less weight during this period while adrenalectomized suspended rats showed no significant weight gain. Cortisol treatment of both of these groups of animals caused a loss of body weight. Results from these studies show several important findings: (1) Metabolic changes in the extensor digitorum longus muscle of suspended rats are due primarily to increased circulating gluccorticoids; (2) Metabolic changes in the soleus due to higher steroid levels are probably potentiated by greater numbers of receptors; and (3) Not all metabolic responses in the unloaded soleus muscle are due to direct action of elevated glucocorticoids or increased sensitivity to these hormones.

Unilateral microform cleft lip repair: application of muscle tension line group theory.

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Yin, Ningbei; Song, Tao; Wu, Jiajun; Chen, Bo; Ma, Hengyuan; Zhao, Zhenmin; Wang, Yongqian; Li, Haidong; Wu, Di

2015-03-01

In microform cleft lip repair, reconstructing the elaborate structures is difficult. We describe a new technique of unilateral microform cleft lip repair that is based on the muscle tension line group theory. According to the shape of Cupid bow, a different small incision is used without creating an obvious cutaneous scar. First, the nasolabial muscle around the nasal floor (the first auxiliary tension line group) is reconstructed, and then the orbicularis oris muscle around the philtrum (the second auxiliary tension line group) is reconstructed based on the muscle tension line group theory. From June 2006 to June 2012, the technique was used in 263 unilateral microform cleft lip repairs. For 18 months, 212 patients were followed up. The appearance of the nasal alar, nasal sill, philtrum, and Cupid bow peak improved. Most patients had a satisfactory appearance. Based on the muscle tension line group theory, using this technique offers the ability to adduct the nasal alar effectively to form a good nasal sill and philtrum.

Adaptation in properties of skeletal muscle to coronary artery occlusion/reperfusion in rats

International Nuclear Information System (INIS)

Ogoh, Shigehiko; Taguchi, Sadayoshi

2002-01-01

The present study was designed to determine if changes in function and metabolism of heart muscle induce alterations in characteristics of skeletal muscle. We investigated the histochemical and biochemical properties of soleus (SOL) and extensor digitorum longus (EDL) muscles in Wistar rats at the chronic phase after coronary artery occlusion/reperfusion. The size of myocardial infarct region was evaluated using a high resolution pinhole single photo emission computed tomography (SPECT) system. 4wk after left coronary artery occlusion/reperfusion, the SOL and EDL of hindlimb were dissected out and immersed in isopentane cooled with liquid nitrogen for subsequent histochemical and biochemical analysis. From SPECT imaging, the blood circulation was recovered, but the recovery of fatty acid metabolism was not observed in infarct region of heart. Citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HAD) activities in infarct region of heart were lower in the myocardial infarction (MI, n=6) group compared with that of age-matched sham-operated (Sham, n=6) group. In addition, heart muscle hypertrophy caused by the dysfunction in MI group was observed. In skeletal muscle, the atrophy and transition of fiber type distribution in MI group, reported in previous studies of heart failure, were not observed. However, the succinate dehydrogenase (SDH) activity in the slow twitch oxidative (SO) from SOL of MI group decreased by 9.8% and in the fast twitch oxidative glycolytic fibers (FOG), 8.0% as compared with sham group. Capillary density of the SO fibers from SOL of MI group also reduced by 18.5% and in the FOG fibers, 18.2% as compared with Sham group. Decreased capillary density in this study related significantly to decreased SDH activity of single muscle fibers in chronic phase of perfusion after surgical infarction. Our results make it clear that there is a difference in the reaction of skeletal muscle to coronary artery occlusion/reperfusion compared with chronic

Adaptation in properties of skeletal muscle to coronary artery occlusion/reperfusion in rats

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Ogoh, Shigehiko [Univ. of North Texas, Fort Worth, TX (United States). Health Science Center; Hirai, Taku [Kyoto Univ. (Japan). Graduate School of Medicine; Nohara, Ryuuji [Kitano Hospital, Osaka (Japan); Taguchi, Sadayoshi [Kyoto Univ. (Japan). Graduate School of Human and Environmental Studies

2002-10-01

The present study was designed to determine if changes in function and metabolism of heart muscle induce alterations in characteristics of skeletal muscle. We investigated the histochemical and biochemical properties of soleus (SOL) and extensor digitorum longus (EDL) muscles in Wistar rats at the chronic phase after coronary artery occlusion/reperfusion. The size of myocardial infarct region was evaluated using a high resolution pinhole single photo emission computed tomography (SPECT) system. 4wk after left coronary artery occlusion/reperfusion, the SOL and EDL of hindlimb were dissected out and immersed in isopentane cooled with liquid nitrogen for subsequent histochemical and biochemical analysis. From SPECT imaging, the blood circulation was recovered, but the recovery of fatty acid metabolism was not observed in infarct region of heart. Citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HAD) activities in infarct region of heart were lower in the myocardial infarction (MI, n=6) group compared with that of age-matched sham-operated (Sham, n=6) group. In addition, heart muscle hypertrophy caused by the dysfunction in MI group was observed. In skeletal muscle, the atrophy and transition of fiber type distribution in MI group, reported in previous studies of heart failure, were not observed. However, the succinate dehydrogenase (SDH) activity in the slow twitch oxidative (SO) from SOL of MI group decreased by 9.8% and in the fast twitch oxidative glycolytic fibers (FOG), 8.0% as compared with sham group. Capillary density of the SO fibers from SOL of MI group also reduced by 18.5% and in the FOG fibers, 18.2% as compared with Sham group. Decreased capillary density in this study related significantly to decreased SDH activity of single muscle fibers in chronic phase of perfusion after surgical infarction. Our results make it clear that there is a difference in the reaction of skeletal muscle to coronary artery occlusion/reperfusion compared with chronic

The minimum sit-to-stand height test: reliability, responsiveness and relationship to leg muscle strength.

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Schurr, Karl; Sherrington, Catherine; Wallbank, Geraldine; Pamphlett, Patricia; Olivetti, Lynette

2012-07-01

To determine the reliability of the minimum sit-to-stand height test, its responsiveness and its relationship to leg muscle strength among rehabilitation unit inpatients and outpatients. Reliability study using two measurers and two test occasions. Secondary analysis of data from two clinical trials. Inpatient and outpatient rehabilitation services in three public hospitals. Eighteen hospital patients and five others participated in the reliability study. Seventy-two rehabilitation unit inpatients and 80 outpatients participated in the clinical trials. The minimum sit-to-stand height test was assessed using a standard procedure. For the reliability study, a second tester repeated the minimum sit-to-stand height test on the same day. In the inpatient clinical trial the measures were repeated two weeks later. In the outpatient trial the measures were repeated five weeks later. Knee extensor muscle strength was assessed in the clinical trials using a hand-held dynamometer. The reliability for the minimum sit-to-stand height test was excellent (intraclass correlation coefficient (ICC) 0.91, 95% confidence interval (CI) 0.81-0.96). The standard error of measurement was 34 mm. Responsiveness was moderate in the inpatient trial (effect size: 0.53) but small in the outpatient trial (effect size: 0.16). A small proportion (8-17%) of variability in minimum sit-to-stand height test was explained by knee extensor muscle strength. The minimum sit-to-stand height test has excellent reliability and moderate responsiveness in an inpatient rehabilitation setting. Responsiveness in an outpatient rehabilitation setting requires further investigation. Performance is influenced by factors other than knee extensor muscle strength.

Baseline Mechanical and Neuromuscular Profile of Knee Extensor and Flexor Muscles in Professional Soccer Players at the Start of the Pre-Season

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García-García Oscar

2017-08-01

Full Text Available The aim of the study was to determine the mechanical and neuromuscular profile of knee extensor and flexor muscles in professional soccer players at the start of the pre-season, and to calculate percentages for symmetry, as well as examine differences according to the player’s positional role. The vastus medialis (VM, vastus lateralis (VL, rectus femoris (RF and biceps femoris (BF of 16 professional soccer players were evaluated by means of tensiomyography (TMG on the first day of the pre-season. A paired-samples t test (p < .05 was used to compare the dominant and non-dominant lower limb. One-way ANOVA was applied, with the positional role as an independent factor. No differences were observed between the dominant and non-dominant leg. The highest degree of symmetry corresponded to the VM (92.5 ± 2.7%, and the lowest to the BF (80.7 ± 10.9%. The positional role was associated with significant differences in some of the variables for the BF, RF and VM, although only the half-relaxation time in the BF and the time to sustain force in the VM differed across all the playing positions considered. TMG was shown to be a useful way of evaluating the neuromuscular characteristics of soccer players at the start of the pre-season, and of establishing baseline values for individual players.

Baseline Mechanical and Neuromuscular Profile of Knee Extensor and Flexor Muscles in Professional Soccer Players at the Start of the Pre-Season.

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García-García, Oscar; Serrano-Gómez, Virginia; Hernández-Mendo, Antonio; Morales-Sánchez, Verónica

2017-09-01

The aim of the study was to determine the mechanical and neuromuscular profile of knee extensor and flexor muscles in professional soccer players at the start of the pre-season, and to calculate percentages for symmetry, as well as examine differences according to the player's positional role. The vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF) and biceps femoris (BF) of 16 professional soccer players were evaluated by means of tensiomyography (TMG) on the first day of the pre-season. A paired-samples t test (p < .05) was used to compare the dominant and non-dominant lower limb. One-way ANOVA was applied, with the positional role as an independent factor. No differences were observed between the dominant and non-dominant leg. The highest degree of symmetry corresponded to the VM (92.5 ± 2.7%), and the lowest to the BF (80.7 ± 10.9%). The positional role was associated with significant differences in some of the variables for the BF, RF and VM, although only the half-relaxation time in the BF and the time to sustain force in the VM differed across all the playing positions considered. TMG was shown to be a useful way of evaluating the neuromuscular characteristics of soccer players at the start of the pre-season, and of establishing baseline values for individual players.

Effects of strength training, detraining and retraining in muscle strength, hypertrophy and functional tasks in older female adults.

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Correa, Cleiton S; Cunha, Giovani; Marques, Nise; Oliveira-Reischak, Ãlvaro; Pinto, Ronei

2016-07-01

Previous studies presented different results regarding the maintenance time of muscular adaptations after strength training and the ability to resume the gains on muscular performance after resumption of the training programme. This study aimed to verify the effect of strength training on knee extensors and elbow flexor muscle strength, rectus femoris muscle volume and functional performance in older female adults after 12 weeks of strength training, 1 year of detraining and followed by 12 weeks of retraining. Twelve sedentary older women performed 12 weeks of strength training, 1 year of detraining and 12 weeks of retraining. The strength training was performed twice a week, and the assessment was made four times: at the baseline, after the strength training, after the detraining and after the retraining. The knee extensor and elbow flexor strength, rectus femoris muscle volume and functional task were assessed. Strength of knee extensor and elbow flexor muscles, rectus femoris muscle volume and 30-s sit-to-stand increased from baseline to post-training (respectively, 40%, 70%, 38% and 46%), decreased after detraining (respectively, -36%, -64%, -35% and -43%) and increased again these parameters after retraining (35%, 68%, 36% and 42%). Strength training induces gains on strength and hypertrophy, also increased the performance on functional tasks after the strength training. The stoppage of the strength caused strength loss and reduction of functional performance. The resumption of the strength training promoted the same gains of muscular performance in older female adults. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Estimation of Muscle Force Based on Neural Drive in a Hemispheric Stroke Survivor.

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Dai, Chenyun; Zheng, Yang; Hu, Xiaogang

2018-01-01

Robotic assistant-based therapy holds great promise to improve the functional recovery of stroke survivors. Numerous neural-machine interface techniques have been used to decode the intended movement to control robotic systems for rehabilitation therapies. In this case report, we tested the feasibility of estimating finger extensor muscle forces of a stroke survivor, based on the decoded descending neural drive through population motoneuron discharge timings. Motoneuron discharge events were obtained by decomposing high-density surface electromyogram (sEMG) signals of the finger extensor muscle. The neural drive was extracted from the normalized frequency of the composite discharge of the motoneuron pool. The neural-drive-based estimation was also compared with the classic myoelectric-based estimation. Our results showed that the neural-drive-based approach can better predict the force output, quantified by lower estimation errors and higher correlations with the muscle force, compared with the myoelectric-based estimation. Our findings suggest that the neural-drive-based approach can potentially be used as a more robust interface signal for robotic therapies during the stroke rehabilitation.

Muscle fascicle behavior during eccentric cycling and its relation to muscle soreness.

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Peñailillo, Luis; Blazevich, Anthony J; Nosaka, Kazunori

2015-04-01

A single bout of eccentric exercise confers a protective effect against muscle damage and soreness in subsequent eccentric exercise bouts, but the mechanisms underpinning this effect are unclear. This study compared vastus lateralis (VL) muscle-tendon behavior between two eccentric cycling bouts to test the hypothesis that muscle-tendon behavior would be different between bouts and would be associated with the protective effect. Eleven untrained men (27.1 ± 7.0 yr) performed two bouts of eccentric cycling (ECC1 and ECC2) separated by 2 wk for 10 min at 65% of maximal concentric workload (191.9 ± 44.2 W) each. Muscle soreness (by visual analog scale) and maximal voluntary isometric contraction (MVC) torque of the knee extensors were assessed before and 1-2 d after exercise. Using ultrasonography, VL fascicle length and angle changes during cycling were assessed, and tendinous tissue (TT) length changes were estimated. VL EMG amplitude, crank torque, and knee joint angles were measured during cycling. Soreness was greater (P tendon behavior may be an important mechanism underpinning the protective effect.

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

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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.

Extensor Mechanism Disruption after Total Knee Arthroplasty: A Case Series and Review of Literature.

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Vaishya, Raju; Agarwal, Amit Kumar; Vijay, Vipul

2016-02-04

Extensor mechanism disruption following total knee arthroplasty (TKA) is a rare but devastating complication. These patients may require revision of the implants, but even then, it may not be possible to restore the normal function of the knee after the disruption. The patterns of extensor mechanism disruption can broadly be classified into three types: suprapatellar (quadriceps tendon rupture), transpatellar (patellar fracture), or infrapatellar (patellar tendon rupture). Infrapatellar tendon ruptures are the worst injuries, as they carry maximum morbidity and are challenging to manage. The disruption of the extensor mechanism may occur either intra-operatively or in the immediate postoperative period due to an injury. The treatment of extensor mechanism complications after TKA may include either nonsurgical management or surgical intervention in the form of primary repair or reconstruction with autogenous, allogeneic, or synthetic substitutes. We have provided an algorithm for the management of extensor mechanism disruption after TKA.

Energy conservation attenuates the loss of skeletal muscle excitability during intense contractions

DEFF Research Database (Denmark)

Macdonald, W A; Ørtenblad, N; Nielsen, Ole Bækgaard

2007-01-01

High-frequency stimulation of skeletal muscle has long been associated with ionic perturbations, resulting in the loss of membrane excitability, which may prevent action potential propagation and result in skeletal muscle fatigue. Associated with intense skeletal muscle contractions are large...... with control muscles, the resting metabolites ATP, phosphocreatine, creatine, and lactate, as well as the resting muscle excitability as measured by M-waves, were unaffected by treatment with BTS plus dantrolene. Following 20 or 30 s of continuous 60-Hz stimulation, BTS-plus-dantrolene-treated muscles showed...... changes in muscle metabolites. However, the role of metabolites in the loss of muscle excitability is not clear. The metabolic state of isolated rat extensor digitorum longus muscles at 30 degrees C was manipulated by decreasing energy expenditure and thereby allowed investigation of the effects of energy...

Inter-Tester Reliability and Precision of Manual Muscle Testing and Hand-Held Dynamometry in Lower Limb Muscles of Children with Spina Bifida

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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…

Neuromuscular adjustments of the quadriceps muscle after repeated cycling sprints.

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Olivier Girard

Full Text Available PURPOSE: This study investigated the supraspinal processes of fatigue of the quadriceps muscle in response to repeated cycling sprints. METHODS: Twelve active individuals performed 10 × 6-s "all-out" sprints on a cycle ergometer (recovery = 30 s, followed 6 min later by 5 × 6-s sprints (recovery = 30 s. Transcranial magnetic and electrical femoral nerve stimulations during brief (5-s and sustained (30-s isometric contractions of the knee extensors were performed before and 3 min post-exercise. RESULTS: Maximal strength of the knee extensors decreased during brief and sustained contractions (~11% and 9%, respectively; P0.05. While cortical voluntary activation declined (P 40% reduced (P<0.001 following exercise. CONCLUSION: The capacity of the motor cortex to optimally drive the knee extensors following a repeated-sprint test was shown in sustained, but not brief, maximal isometric contractions. Additionally, peripheral factors were largely involved in the exercise-induced impairment in neuromuscular function, while corticospinal excitability was well-preserved.

The Effects of a Motorized Aquatic Treadmill Exercise Program on Muscle Strength, Cardiorespiratory Fitness, and clinical function in Subacute Stroke Patients -- a Randomized Controlled Pilot Trial.

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Lee, So Young; Han, Eun Young; Kim, Bo Ryun; Im, Sang Hee

2018-03-12

The aim of this study was to assess the effects of a motorized aquatic treadmill exercise program improve the isometric strength of the knee muscles, cardiorespiratory fitness, arterial stiffness, motor function, balance, functional outcomes and quality of life in subacute stroke patients. Thirty-two patients were randomly assigned to 4-week training sessions of either aquatic therapy(n=19) or land-based aerobic exercise(n=18). Isometric strength was measured using an isokinetic dynamometer. Cardiopulmonary fitness was evaluated using a symptom-limited exercise tolerance test and by measuring brachial ankle pulse wave velocity. Moreover, motor function(Fugl-Meyer Assessment[FMA] and FMA-lower limb[FMA-LL]), balance(Berg Balance Scale[BBS]), Activities of daily living(Korean version of the Modified Barthel Index [K-MBI]), and Quality of life(EQ-5D index) were examined. There were no inter-group differences between demographic and clinical characteristics at baseline(p>0.05). The results shows significant improvements in peak oxygen consumption (p=0.02), maximal isometric strength of the bilateral knee extensors (paquatic therapy group. However, only significant improvements in maximal isometric strength in the knee extensors (p=0.03) and flexors (p=0.04) were found within the aquatic therapy group and control group. Water-based aerobic exercise performed on a motorized aquatic treadmill had beneficial effect on isometric muscle strength in the lower limb.

The effects of implant composition on extensor tenosynovitis in a canine distal radius fracture model.

Science.gov (United States)

Sinicropi, Stefano M; Su, Brian W; Raia, Frank J; Parisien, May; Strauch, Robert J; Rosenwasser, Melvin P

2005-03-01

Dorsal plating of distal radius fractures with titanium plates has resulted in clinically observed tenosynovitis and tendon rupture. The goal of this study was to investigate whether titanium-based implants result in more extensor tendon inflammation than matched stainless-steel implants in a canine fracture model. An osteotomy was created in the distal radius of 18 beagles and fixed with 2.7-mm 4-hole plates composed of commercially pure titanium, titanium alloy (Ti-Al6-V4), or 316L stainless steel. Animals were killed at an average of 4 months. Tendon gliding was assessed by applying a force at the extensor musculotendinous junction and noting gliding. Histologic grading (mild, moderate, severe) was based on cellular hypertrophy, hyperplasia, and leukocytic infiltration. Tendons glided freely in 100% stainless-steel specimens, 75% of titanium alloy, and 43% of commercially pure titanium groups. A severe inflammatory reaction was identified in 60% of the titanium alloy (Ti-A16-V4) group, 57% of the pure titanium group, and 0% of the stainless-steel group. Dorsal plating of the canine radius with commercially pure titanium or titanium alloy implants produced a greater inflammatory peritendinous response than matched stainless-steel implants.

Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans.

Science.gov (United States)

Krustrup, Peter; Secher, Niels H; Relu, Mihai U; Hellsten, Ylva; Söderlund, Karin; Bangsbo, Jens

2008-12-15

We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P fibres, whereas in CON, CP decreased (P fibres, respectively. From 127 s of exercise, muscle VO2 was higher (P muscle VO2 response was slower (P muscle homogenate CP was lowered (P muscle lactate production was similar in CUR and CON (37.8 +/- 4.1 versus 35.2 +/- 6.2 mmol). Estimated total muscle ATP turnover was 19% higher (P fibres are less efficient than ST fibres in vivo at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation.

Relation between functional mobility and dynapenia in institutionalized frail elderly.

Science.gov (United States)

Soares, Antonio Vinicius; Marcelino, Elessandra; Maia, Késsia Cristina; Borges, Noé Gomes

2017-01-01

To investigate the relation between functional mobility and dynapenia in institutionalized frail elderly. A descriptive, correlational study involving 26 institutionalized elderly men and women, mean age 82.3±6 years. The instruments employed were the Mini Mental State Examination, the Geriatric Depression Scale, the International Physical Activity Questionnaire, the Timed Up and Go test, a handgrip dynamometer and a portable dynamometer for large muscle groups (shoulder, elbow and hip flexors, knee extensors and ankle dorsiflexors). Significant negative correlation between functional mobility levels assessed by the Timed Up and Go test and dynapenia was observed in all muscle groups evaluated, particularly in knee extensors (r -0.65). A significant negative correlation between muscle strength, particularly knee extensor strength, and functional mobility was found in institutionalized elderly. Data presented indicate that the higher the muscle strength, the shorter the execution time, and this could demonstrate better performance in this functional mobility test.

Dynamic extensor brace for lateral epicondylitis.

NARCIS (Netherlands)

Faes, M.C.; Akker, B. van den; Lint, J.A. de; Kooloos, J.G.M.; Hopman, M.T.E.

2006-01-01

Lateral epicondylitis (tennis elbow) is a common, often disabling ailment. Based on the failure of current therapies, a new dynamic extensor brace has been developed. In this study, the effects of application of this brace for 3 months on the most important and disabling symptoms of patients with

Stronger back muscles reduce the incidence of vertebral fractures: a prospective 10 year follow-up of postmenopausal women.

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Sinaki, M; Itoi, E; Wahner, H W; Wollan, P; Gelzcer, R; Mullan, B P; Collins, D A; Hodgson, S F

2002-06-01

The long-term protective effect of stronger back muscles on the spine was determined in 50 healthy white postmenopausal women, aged 58-75 years, 8 years after they had completed a 2 year randomized, controlled trial. Twenty-seven subjects had performed progressive, resistive back-strengthening exercises for 2 years and 23 had served as controls. Bone mineral density, spine radiographs, back extensor strength, biochemical marker values, and level of physical activity were obtained for all subjects at baseline, 2 years, and 10 years. Mean back extensor strength (BES) in the back-exercise (BE) group was 39.4 kg at baseline, 66.8 kg at 2 years (after 2 years of prescribed exercises), and 32.9 kg at 10 years (8 years after cessation of the prescribed exercises). Mean BES in the control (C) group was 36.9 kg at baseline, 49.0 kg at 2 years, and 26.9 kg at 10 years. The difference between the two groups was still statistically significant at 10 year follow-up (p = 0.001). The difference in bone mineral density, which was not significant between the two groups at baseline and 2 year follow-up, was significant at 10 year follow-up (p = 0.0004). The incidence of vertebral compression fracture was 14 fractures in 322 vertebral bodies examined (4.3%) in the C group and 6 fractures in 378 vertebral bodies examined (1.6%) in the BE group (chi-square test, p = 0.0290). The relative risk for compression fracture was 2.7 times greater in the C group than in the BE group. To our knowledge, this is the first study reported in the literature demonstrating the long-term effect of strong back muscles on the reduction of vertebral fractures in estrogen-deficient women.

Effects of whole-body cryotherapy (-110 °C) on proprioception and indices of muscle damage.

Science.gov (United States)

Costello, J T; Algar, L A; Donnelly, A E

2012-04-01

The purpose of this study was to investigate the effects of whole-body cryotherapy (WBC) on proprioceptive function, muscle force recovery following eccentric muscle contractions and tympanic temperature (T(TY) ). Thirty-six subjects were randomly assigned to a group receiving two 3-min treatments of -110 ± 3 °C or 15 ± 3 °C. Knee joint position sense (JPS), maximal voluntary isometric contraction (MVIC) of the knee extensors, force proprioception and T(TY) were recorded before, immediately after the exposure and again 15 min later. A convenience sample of 18 subjects also underwent an eccentric exercise protocol on their contralateral left leg 24 h before exposure. MVIC (left knee), peak power output (PPO) during a repeated sprint on a cycle ergometer and muscles soreness were measured pre-, 24, 48 and 72h post-treatment. WBC reduced T(TY) , by 0.3 °C, when compared with the control group (P<0.001). However, JPS, MVIC or force proprioception was not affected. Similarly, WBC did not effect MVIC, PPO or muscle soreness following eccentric exercise. WBC, administered 24 h after eccentric exercise, is ineffective in alleviating muscle soreness or enhancing muscle force recovery. The results of this study also indicate no increased risk of proprioceptive-related injury following WBC. © 2011 John Wiley & Sons A/S.

Protein and amino acid metabolism in skeletal muscle

Energy Technology Data Exchange (ETDEWEB)

Wu, Guoyao.

1989-01-01

Isolated chick extensor digitorum communis (EDC) muscles and, in some experiments, rat skeletal muscles were used to study a number of aspects of protein and amino acid metabolism. (1) Chick EDC muscles synthesize and release large amounts of alanine and glutamine, which indirectly obtain their amino groups from branched-chain amino acids (BCAA). (2) Acetoacetate or DL-{beta}-hydroxybutyrate (4 mM) decrease (P < 0.01) alanine synthesis and BCAA transamination in EDC muscles from 24-h fasted chicks by decreasing (P < 0.01) intracellular concentrations of pyruvate due to inhibition of glycolysis. (3) Glutamine is extensively degraded in skeletal muscles from both chicks and rats, thus challenging the traditional view that glutamine oxidation is negligible in skeletal muscle. The cytosolic glutamine aminotransferases L and K in the rat and the mitochondrial phosphate-activated glutaminase in the chick play important roles in the conversion of glutamine to {alpha}-ketoglutarate for further oxidation. (4) Although methionine has been reported to be extensively transaminated in rat skeletal muscle preparations in the absence of other amino acids, transamination of methionine is absent or negligible in chick and rat skeletal muscles in the presence of physiological concentrations of amino acids. (5) Glutamine at 1.0-15 mM increases (P < 0.01) protein synthesis ({sup 3}H-phenylalanine incorporation), and at 10.0-15.0 mM decreases (P < 0.05) protein degradation ({sup 3}H-phenylalanine release from prelabelled protein in vivo) in EDC muscles from fed chicks as compared to muscles incubated in the absence of glutamine. (6) Acetoacetate or DL-{beta}-hydroxybutyrate (4 mM) has a small but significant inhibitory effect (P < 0.05) on the rate of protein synthesis, but has no effect (P > 0.05) on the rate of protein degradation in EDC muscles from fed chicks.

MRI of the tibioastragalus anticus of Gruber muscle: a rare accessory muscle and normal anatomical variant

Energy Technology Data Exchange (ETDEWEB)

Berkowitz, Yaron; Amiras, Dimitri [Imperial College Healthcare NHS Trust, London (United Kingdom); St Mary' s Hospital, Imaging Department, QEQM, London (United Kingdom); Mushtaq, Nadeem [Imperial College Healthcare NHS Trust, London (United Kingdom)

2016-06-15

We present the case of a 31-year-old man who sustained a hyperplantar flexion injury of his right ankle, and was evaluated using computed tomography and MRI to assess for osseous and ligamentous injury. The MRI and CT studies demonstrated a tibioastragalus anticus of Gruber (TAAG) muscle in the lower limb's anterior compartment. To our knowledge, the imaging of this muscle has not been previously described. The TAAG muscle arises from the lower third of the anterolateral tibia and the interosseous membrane. Its tendon passes laterally, deep to the tibialis anterior and extensor hallucis longus tendons, and inserts onto the anterior superolateral neck of the talus in a fan-like manner. Knowledge and recognition of this tendon are important for both diagnostic accuracy and surgical planning, and could potentially be used as a tendon transfer or graft in the appropriate clinical setting. The presence of this accessory muscle should not be confused with a pathological condition. (orig.)

Atrophy of foot muscles in diabetic patients can be detected with ultrasonography

DEFF Research Database (Denmark)

Severinsen, Kaare; Obel, Annette; Jakobsen, Johannes

2007-01-01

OBJECTIVE: To establish a bedside test with ultrasonography for evaluation of foot muscle atrophy in diabetic patients. RESEARCH DESIGN AND METHODS: Thickness and cross-sectional area (CSA) of the extensor digitorum brevis muscle (EDB) and of the muscles of the first interstitium (MILs) were...... determined in 26 diabetic patients and in 26 matched control subjects using ultrasonography. To estimate the validity, findings were related to the total volume of all foot muscles determined at magnetic resonance imaging (MRI-FM(vol)). Furthermore, the relations of ultrasonographic estimates to nerve...... than in nonneuropathic diabetic patients (5.8 +/- 2.1 vs. 7.5 +/- 1.7 mm [P foot muscles determined at ultrasonography is directly related to foot muscle volume determined by MRI and to various...

Contraction-mediated glycogenolysis in mouse skeletal muscle lacking creatine kinase: the role of phosphorylase b activation.

NARCIS (Netherlands)

Katz, A.; Andersson, D.C.; Yu, J.; Norman, B.; Sandstrom, M.E.; Wieringa, B.; Westerblad, H.

2003-01-01

Skeletal muscle that is deficient in creatine kinase (CK-/-) exhibits accelerated glycogenolysis during contraction. Understanding this phenomenon could provide insight into the control of glycogenolysis during contraction. Therefore, glycogen breakdown was investigated in isolated extensor

Curcumin and Piperine Supplementation and Recovery Following Exercise Induced Muscle Damage: A Randomized Controlled Trial

Directory of Open Access Journals (Sweden)

Barthélémy Delecroix, Abd Elbasset Abaïdia, Cédric Leduc, Brian Dawson, Grégory Dupont

2017-03-01

Full Text Available The aim of this study was to analyze the effects of oral consumption of curcumin and piperine in combination on the recovery kinetics after exercise-induced muscle damage. Forty-eight hours before and following exercise-induced muscle damage, ten elite rugby players consumed curcumin and piperine (experimental condition or placebo. A randomized cross-over design was performed. Concentric and isometric peak torque for the knee extensors, one leg 6 seconds sprint performance on a non-motorized treadmill, counter movement jump performance, blood creatine kinase concentration and muscle soreness were assessed immediately after exercise, then at 24h, 48h and 72h post-exercise. There were moderate to large effects of the exercise on the concentric peak torque for the knee extensors (Effect size (ES = -1.12; Confidence interval at 90% (CI90%: -2.17 to -0.06, the one leg 6 seconds sprint performance (ES=-1.65; CI90% = -2.51to -0.80 and the counter movement jump performance (ES = -0.56; CI90% = -0.81 to -0.32 in the 48h following the exercise. There was also a large effect of the exercise on the creatine kinase level 72h after the exercise in the control group (ES = 3.61; CI90%: 0.24 to 6.98. This decrease in muscle function and this elevation in creatine kinase indicate that the exercise implemented was efficient to induce muscle damage. Twenty four hours post-exercise, the reduction (from baseline in sprint mean power output was moderately lower in the experimental condition (-1.77 ± 7.25%; 1277 ± 153W in comparison with the placebo condition (-13.6 ± 13.0%; 1130 ± 241W (Effect Size = -1.12; Confidence Interval 90%=-1.86 to -0.86. However, no other effect was found between the two conditions. Curcumin and piperine supplementation before and after exercise can attenuate some, but not all, aspects of muscle damage.

Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases

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Yu-Zhou Guan

2015-01-01

Full Text Available Background: Single-fiber electromyography (SFEMG abnormality in the extensor digitorum communis (EDC was reported in ocular myasthenia gravis (OMG, which indicated subclinical involvement beyond extraocular muscles in OMG patients. The relationship between the abnormal findings of SFEMG in EDC and the probability for OMG to develop generalized myasthenia gravis (GMG is unknown. This retrospective study aimed to determine the predictive value of abnormality of SFEMG in EDC of OMG patients. Methods: One-hundred and two OMG patients underwent standard clinical diagnosis process and SFEMG test in EDC muscle when diagnosed and were clinically followed up for 5 years. The SFEMG data were compared between different clinical groups according to thymus status, onset age, and different outcome of OMG developing. Chances of progressing to GMG were compared between two different groups according to SFEMG and repetitive nerve stimulation (RNS results, acetylcholine receptor antibody (AchRAb titer, thymus status, and onset age. Results: Abnormal SFEMG results were observed in 84 (82.4% patients. The mean jitter, percentage of jitter >55 μs (%, and blocking were higher in OMG patients than in healthy volunteers. There were no statistical differences in jitter analysis between thymoma group and non-thymoma group (P = 0.65, or between the later OMG group and the later GMG group (P = 0.31, including mean jitter, percentage of jitter >55 μs (%, and blocking. Elderly group (≥45 years old had a higher mean jitter than younger group (t = 2.235, P = 0.028. Total 55 OMG developed GMG, including 47 in abnormal SFEMG group while 8 in normal SFEMG group. There was no statistical difference in the conversion rates between the two groups (χ2 = 0.790, P = 0.140. RNS abnormality, AchRab titer, or onset age had no correlation with OMG prognosis (P = 0.150, 0.070, 0.120, respectively while thymoma did (χ2 = 0.510, P = 0.020. Conclusion: SFEMG test in the EDC showed high

Whole-body electromyostimulation as a means to impact muscle mass and abdominal body fat in lean, sedentary, older female adults: subanalysis of the TEST-III trial

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Kemmler W

2013-10-01

Full Text Available Wolfgang Kemmler, Simon von StengelInstitute of Medical Physics, University of Erlangen-Nürnberg, Erlangen, GermanyBackground: The primary aim of this study was to determine the effect of 12 months of whole-body electromyostimulation (WB-EMS exercise on appendicular muscle mass and abdominal fat mass in subjects specifically at risk for sarcopenia and abdominal obesity, but unable or unwilling to exercise conventionally.Methods: Forty-six lean, nonsportive (<60 minutes of exercise per week, elderly women (aged 75 ± 4 years with abdominal obesity according to International Diabetes Federation criteria were randomly assigned to either a WB-EMS group (n=23 which performed 18 minutes of intermittent, bipolar WB-EMS (85 Hz three sessions in 14 days or an "active" control group (n=23. Whole-body and regional body composition was assessed by dual energy X-ray absorptiometry to determine appendicular muscle mass, upper leg muscle mass, abdominal fat mass, and upper leg fat mass. Maximum strength of the leg extensors was determined isometrically by force plates.Results: After 12 months, significant intergroup differences were detected for the primary endpoints of appendicular muscle mass (0.5% ± 2.0% for the WB-EMS group versus −0.8% ± 2.0% for the control group, P=0.025 and abdominal fat mass (−1.2% ± 5.9% for the WB-EMS group versus 2.4% ± 5.8% for the control group, P=0.038. Further, upper leg lean muscle mass changed favorably in the WB-EMS group (0.5% ± 2.5% versus −0.9% ± 1.9%, in the control group, P=0.033, while effects for upper leg fat mass were borderline nonsignificant (−0.8% ± 3.5% for the WB-EMS group versus 1.0% ± 2.6% for the control group, P=0.050. With respect to functional parameters, the effects for leg extensor strength were again significant, with more favorable changes in the WB-EMS group (9.1% ± 11.2% versus 1.0% ± 8.1% in the control group, P=0.010.Conclusion: In summary, WB-EMS showed positive effects on the

Scaling of Primate Forearm Muscle Architecture as It Relates to Locomotion and Posture.

Science.gov (United States)

Leischner, Carissa L; Crouch, Michael; Allen, Kari L; Marchi, Damiano; Pastor, Francisco; Hartstone-Rose, Adam

2018-03-01

It has been previously proposed that distal humerus morphology may reflect the locomotor pattern and substrate preferred by different primates. However, relationships between these behaviors and the morphological capabilities of muscles originating on these osteological structures have not been fully explored. Here, we present data about forearm muscle architecture in a sample of 44 primate species (N = 55 specimens): 9 strepsirrhines, 15 platyrrhines, and 20 catarrhines. The sample includes all major locomotor and substrate use groups. We isolated each antebrachial muscle and categorized them into functional groups: wrist and digital extensors and flexors, antebrachial mm. that do not cross the wrist, and functional combinations thereof. Muscle mass, physiological cross-sectional area (PCSA), reduced PCSA (RPCSA), and fiber length (FL) are examined in the context of higher taxonomic group, as well as locomotor/postural and substrate preferences. Results show that muscle masses, PCSA, and RPCSA scale with positive allometry while FL scales with isometry indicating that larger primates have relatively stronger, but neither faster nor more flexible, forearms across the sample. When accounting for variation in body size, we found no statistically significant difference in architecture among higher taxonomic groups or locomotor/postural groups. However, we found that arboreal primates have significantly greater FL than terrestrial ones, suggesting that these species are adapted for greater speed and/or flexibility in the trees. These data may affect our interpretation of the mechanisms for variation in humeral morphology and provide information for refining biomechanical models of joint stress and movement in extant and fossil primates. Anat Rec, 301:484-495, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Net joint moments and muscle activation in barbell squats without and with restricted anterior leg rotation.

Science.gov (United States)

Chiu, Loren Z F; vonGaza, Gabriella L; Jean, Liane M Y

2017-01-01

Muscle utilisation in squat exercise depends on technique. The purpose of this study was to compare net joint moments (NJMs) and muscle activation during squats without and with restricted leg dorsiflexion. Experienced men (n = 5) and women (n = 4) performed full squats at 80% one repetition maximum. 3D motion analysis, force platform and (EMG) data were collected. Restricting anterior leg rotation reduced anterior leg (P = 0.001) and posterior thigh (P squat depth, ankle plantar flexor (P squats. Hip extensor NJM (P = 0.14) was not different between squat types at maximum squat depth. Vastus lateralis (P > 0.05), vastus medialis (P > 0.05) and rectus femoris (P > 0.05) EMG were not different between squat types. Unrestricted squats have higher ankle plantar flexor and knee extensor NJM than previously reported from jumping and landing. However, ankle plantar flexor and knee extensor NJM are lower in restricted squats than previous studies of jumping and landing. The high NJM in unrestricted squat exercise performed through a full range of motion suggests this squat type would be more effective to stimulate adaptations in the lower extremity musculature than restricted squats.

Non-neural Muscle Weakness Has Limited Influence on Complexity of Motor Control during Gait

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Marije Goudriaan

2018-01-01

Full Text Available Cerebral palsy (CP and Duchenne muscular dystrophy (DMD are neuromuscular disorders characterized by muscle weakness. Weakness in CP has neural and non-neural components, whereas in DMD, weakness can be considered as a predominantly non-neural problem. Despite the different underlying causes, weakness is a constraint for the central nervous system when controlling gait. CP demonstrates decreased complexity of motor control during gait from muscle synergy analysis, which is reflected by a higher total variance accounted for by one synergy (tVAF1. However, it remains unclear if weakness directly contributes to higher tVAF1 in CP, or whether altered tVAF1 reflects mainly neural impairments. If muscle weakness directly contributes to higher tVAF1, then tVAF1 should also be increased in DMD. To examine the etiology of increased tVAF1, muscle activity data of gluteus medius, rectus femoris, medial hamstrings, medial gastrocnemius, and tibialis anterior were measured at self-selected walking speed, and strength data from knee extensors, knee flexors, dorsiflexors and plantar flexors, were analyzed in 15 children with CP [median (IQR age: 8.9 (2.2], 15 boys with DMD [8.7 (3.1], and 15 typical developing (TD children [8.6 (2.7]. We computed tVAF1 from 10 concatenated steps with non-negative matrix factorization, and compared tVAF1 between the three groups with a Mann-Whiney U-test. Spearman's rank correlation coefficients were used to determine if weakness in specific muscle groups contributed to altered tVAF1. No significant differences in tVAF1 were found between DMD [tVAF1: 0.60 (0.07] and TD children [0.65 (0.07], while tVAF1 was significantly higher in CP [(0.74 (0.09] than in the other groups (both p < 0.005. In CP, weakness in the plantar flexors was related to higher tVAF1 (r = −0.72. In DMD, knee extensor weakness related to increased tVAF1 (r = −0.50. These results suggest that the non-neural weakness in DMD had limited influence on

Experimental quadriceps muscle pain impairs knee joint control during walking

DEFF Research Database (Denmark)

Henriksen, Marius; Alkjaer, Tine; Lund, Hans

2007-01-01

Pain is a cardinal symptom in musculoskeletal diseases involving the knee joint, and aberrant movement patterns and motor control strategies are often present in these patients. However, the underlying neuromuscular mechanisms linking pain to movement and motor control are unclear. To investigate...... the functional significance of muscle pain on knee joint control during walking, three-dimensional gait analyses were performed before, during, and after experimentally induced muscle pain by means of intramuscular injections of hypertonic saline (5.8%) into vastus medialis (VM) muscle of 20 healthy subjects....... Isotonic saline (0.9%) was used as control. Surface electromyography (EMG) recordings of VM, vastus lateralis (VL), biceps femoris, and semitendinosus muscles were synchronized with the gait analyses. During experimental muscle pain, the loading response phase peak knee extensor moments were attenuated...

Differential partitioning of rumen-protected n-3 and n-6 fatty acids into muscles with different metabolism.

Science.gov (United States)

Wolf, C; Ulbrich, S E; Kreuzer, M; Berard, J; Giller, K

2018-03-01

Bioavailability of polyunsaturated fatty acids (PUFA) in ruminants is enhanced by their protection from ruminal biohydrogenation. Both n-3 and n-6 PUFA fulfil important physiological functions. We investigated potentially different incorporation patterns of these functional PUFA into three beef muscles with different activity characteristics. We supplemented 33 Angus heifers with rumen-protected oils characterized either by mainly C18:2 n-6 (linoleic acid (LA) in sunflower oil) or by C20:5 (eicosapentaenoic acid (EPA)) and C22:6 (docosahexaenoic acid (DHA)), both prevalent n-3 PUFA in fish oil. Contents and proportions of n-3 and n-6 PUFA of total fatty acids were elevated in the muscles of the respective diet group but they were partitioned differently into the muscles. For EPA and DHA, but not for LA, the diet effect was more distinct in the extensor carpi radialis compared to longissimus thoracis and biceps femoris. Partitioning of PUFA in metabolism could be related to muscle function. This has to be confirmed in other muscles, adipose tissues and organs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Brief Report: Loss of Muscle Strength Prior to Knee Replacement: A Question of Anatomic Cross-Sectional Area or Specific Strength?

Science.gov (United States)

Culvenor, Adam G; Hamler, Felix C; Kemnitz, Jana; Wirth, Wolfgang; Eckstein, Felix

2018-02-01

To determine whether loss in thigh muscle strength prior to knee replacement is caused by reductions of muscle strength in the anatomic cross-sectional area or by reductions of specific strength. All 100 of the participants in the Osteoarthritis Initiative who underwent knee replacement and whose medical records included data on thigh isometric muscle strength and magnetic resonance imaging (MRI) (58 women, and 42 men, mean ± SD age 65 ± 8 years, mean ± SD body mass index [BMI] 29 ± 5 kg/m 2 ) were matched with a control (no knee replacement) for age, sex, height, BMI, and radiographic severity. Thigh muscle anatomic cross-sectional area was determined by MRI at the research visit before knee replacement (time 0) and 2 years before time 0 (time -2). Specific strength (strength/anatomic cross-sectional area) was calculated, and the measures were compared by conditional logistic regression (i.e., odds ratio [OR] per standard deviation). ORs adjusted for pain (OR adj ) and 95% confidence intervals (95% CIs) were also calculated. Knee replacement cases had significantly smaller extensor (but not flexor) anatomic cross-sectional areas than controls at time 0 (women, OR adj 1.89 [95% CI 1.05-3.90]; men, OR adj 2.22 [95% CI 1.04-4.76]), whereas no significant differences were found at time -2. Women who had knee replacement showed lower levels of extensor specific strength than controls at time 0 (OR 1.59 [95% CI 1.02-2.50]), although this difference was not observed in men and did not maintain significance after adjustment for pain (OR adj 1.22 [95% CI 0.71-2.08]). Female cases lost significantly more extensor specific strength between time -2 and time 0 than controls (OR adj 3.76 [95% CI 1.04-13.60]), whereas no significant differences were noted at time -2, or in men. Prior to knee replacement, a significant reduction in knee extensor strength appears to occur in women through 2 mechanisms: one driven by pain (loss of specific strength) and one independent of pain

Does the mesodermal derangement in Chiari Type I malformation extend to the cervical spine? Evidence from an analytical morphometric study on cervical paraspinal muscles.

Science.gov (United States)

Thakar, Sumit; Kurudi Siddappa, Avinash; Aryan, Saritha; Mohan, Dilip; Sai Kiran, Narayanam Anantha; Hegde, Alangar S

2017-10-01

OBJECTIVE The mesodermal derangement in Chiari Type I malformation (CMI) has been postulated to encompass the cervical spine. The objectives of this study were to assess the cross-sectional areas (CSAs) of cervical paraspinal muscles (PSMs) in patients with CMI without syringomyelia, compare them with those in non-CMI subjects, and evaluate their correlations with various factors. METHODS In this retrospective study, the CSAs of cervical PSMs in 25 patients were calculated on T2-weighted axial MR images and computed as ratios with respect to the corresponding vertebral body areas. These values and the cervical taper ratios were then compared with those of age- and sex-matched non-CMI subjects and analyzed with respect to demographic data and clinicoradiological factors. RESULTS Compared with the non-CMI group, the mean CSA values for the rectus capitis minor and all of the subaxial PSMs were lower in the study group, and those of the deep extensors were significantly lower (p = 0.004). The cervical taper ratio was found to be significantly higher in the study cohort (p = 0.0003). A longer duration of symptoms and a steeper cervical taper ratio were independently associated with lower CSA values for the deep extensors (p = 0.04 and p = 0.03, respectively). The presence of neck pain was associated with a lower CSA value for the deep flexors (p = 0.03). CONCLUSIONS Patients with CMI demonstrate alterations in their cervical paraspinal musculature even in the absence of coexistent syringomyelia. Their deep extensor muscles undergo significant atrophic changes that worsen with the duration of their symptoms. This could be related to a significantly steeper cervical taper ratio that their cervical cords are exposed to. Neck pain in these patients is related to atrophy of their deep flexor muscles. A steeper cervical taper ratio and alterations in the PSMs could be additional indicators for surgery in patients with CMI without syringomyelia.

Low blood flow at onset of moderate intensity exercise does not limit muscle oxygen uptake

DEFF Research Database (Denmark)

Nyberg, Michael Permin; Mortensen, Stefan Peter; Saltin, Bengt

2010-01-01

The effect of low blood flow at onset of moderate intensity exercise on the rate of rise in muscle oxygen uptake was examined. Seven male subjects performed a 3.5 minute one-legged knee-extensor exercise bout (24+/-1 (+/-S.D.) W) without (CON) and with (double blockade; DB) arterial infusion of i....... Additionally, prostanoids and/or NO appear to play important roles in elevating skeletal muscle blood flow in the initial phase of exercise. Key words: Oxygen delivery, oxygen extraction, nitric oxide, prostanoids.......The effect of low blood flow at onset of moderate intensity exercise on the rate of rise in muscle oxygen uptake was examined. Seven male subjects performed a 3.5 minute one-legged knee-extensor exercise bout (24+/-1 (+/-S.D.) W) without (CON) and with (double blockade; DB) arterial infusion...... of inhibitors of nitric oxide synthase (NOS; L-NMMA) and cyclooxygenase (COX; indomethacin) in order to inhibit the synthesis of nitric oxide (NO) and prostanoids, respectively.. Leg blood flow and leg oxygen delivery throughout exercise was 25-50 % lower (P

Variant insertion of the fibularis tertius muscle is an evidence of the progressive evolutionary adaptation for the bipedal gait

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Rashmoni Jana

2011-10-01

Full Text Available Fibularis tertius (FT is often considered as part of extensor digitorum longus (EDL muscle. The muscle is absent in hominoid apes and with the acquisition of the bipedal gait; the muscle emerged as a recent addition in the human foot. From its various modes of insertions, it is evident that the muscles of the sole are in search of its distal attachment, which can best support the relatively weak human midfoot. We describe an unusual insertion of the muscle in support of this hypothesis.

Fatigue and muscle-tendon stiffness after stretch-shortening cycle and isometric exercise.

Science.gov (United States)

Toumi, Hechmi; Poumarat, Georges; Best, Thomas M; Martin, Alain; Fairclough, John; Benjamin, Mike

2006-10-01

The purpose of the present study was to compare vertical jump performance after 2 different fatigue protocols. In the first protocol, subjects performed consecutive sets of 10 repetitions of stretch-shortening cycle (SSC) contractions. In the second protocol, successive sets of 10 repetitions of isometric contractions were performed for 10 s with the knee at 90 degrees of flexion. The exercises were stopped when the subjects failed to reach 50% of their maximum voluntary isometric contractions. Maximal isometric force and maximal concentric power were assessed by performing supine leg presses, squat jumps, and drop jumps. Surface EMG was used to determine changes in muscle activation before and after fatigue. In both groups, the fatigue exercises reduced voluntary isometric force, maximal concentric power, and drop jump performance. Kinematic data showed a decrease in knee muscle-tendon stiffness accompanied by a lengthened ground contact time. EMG analysis showed that the squat and drop jumps were performed similarly before and after the fatigue exercise for both groups. Although it was expected that the stiffness would decrease more after SSC than after isometric fatigue (as a result of a greater alteration of the reflex sensitivity SSC), our results showed that both protocols had a similar effect on knee muscle stiffness during jumping exercises. Both fatigue protocols induced muscle fatigue, and the decrease in jump performance was linked to a decrease in the strength and stiffness of the knee extensor muscles.

Distribution of skeletal muscle involvement in autosomal recessive distal muscular dystrophy. A clinical and computed tomographic study

Energy Technology Data Exchange (ETDEWEB)

Mizusawa, Hidehiro; Nakanishi, Takao; Kobayashi, Fumie

1987-02-01

Distribution of skeletal muscle involvement in 5 cases with autosomal recessive distal muscular dystrophy was studied clinically and by computed tomography (CT). Manual muscle test showed muscle involvement with a predilection for flexors in the lower leg and adductors in the thigh. Flexion and extension of the thigh and the lower leg was impaired to similar degree. In progressed cases, neck flexors and trunk muscles were also affected mildly. CT disclosed more clearly the preferential involvement of flexors in the lower leg, and involvement of both hamstrings center dot adductors group and extensors group of the thigh to similar degree. However, m. popliteus was curiously well preserved. In addition, there was a stage showing high density and hypertrophy of m. sartorius, m. gracilis, m. adductor, m. biceps femoris, m. semimenbranosus, m. semitendinosus or m. rectus femoris, which in thought to be compensatory hypertrophy. M. gluteus minimus in the pelvic girdle and m. dorsi proprii in the trunk were also liable to be affected. The CT findings are regarded as characteristic features noted clearly before muscle weakness and atrophy become apparent clinically. CT is very useful for distinguishing distal muscular dystrophy from rimmed vacuolar distal myopathy in which m. quadriceps femoris and flexors of the lower leg are usually well preserved without compensatory hypertrophy on CT.

Distal intersection tenosynovitis of the wrist: a lesser-known extensor tendinopathy with characteristic MR imaging features

International Nuclear Information System (INIS)

Parellada, Antoni J.; Gopez, Angela G.; Morrison, William B.; Sweet, Stephanie; Leinberry, Charles F.; Reiter, Sean B.; Kohn, Mark

2007-01-01

To present the MRI imaging findings of extensor tenosynovitis at the distal intersection or crossover between the second (extensor carpi radialis longus (ECRL) and brevis (ECRB)) and third (extensor pollicis longus (EPL)) extensor compartment tendons, and the anatomical details that may play a role in the pathogenesis of this condition. The imaging studies and clinical records of five patients (three females and two males, with ages ranging between 22 and 78 years; mean age, 49 years) presenting with pain on the dorsal and radial aspect of the wrist were reviewed by two musculoskeletal radiologists in consensus. Three cases were identified serendipitously during routine clinical reading sessions; a follow-up computerized database search for additional cases reported in the prior two years yielded two additional cases. The overall number of cases screened was 1,031. The diagnosis of tendinopathy affecting the second and third compartment extensor tendons was made on the basis of MRI findings and clinical follow-up, or synovectomy. All patients showed signs of tenosynovitis: in four patients both the tendons of the second and third extensor compartments were affected; the fifth patient showed signs of tenosynovitis of the EPL tendon, and tendinosis of the extensor carpi radialis tendons. Three patients showed tenosynovitis proximal and distal to the point of intersection; and in two of them, a discrete point of constriction was appreciated at the crossover site in relation to the extensor retinaculum. Two patients showed tenosynovitis limited to the segment distal to the point of decussation. Tendinosis tended to follow the presence of tenosynovitis. In one of the patients, subtendinous reactive marrow edema in Lister's tubercle was noted. Distal intersection tenosynovitis may be related to the biomechanical pulley effect exerted by Lister's tubercle on the EPL tendon as it leaves the third compartment and crosses over the extensor carpi radialis tendons, as well as

Distal intersection tenosynovitis of the wrist: a lesser-known extensor tendinopathy with characteristic MR imaging features

Energy Technology Data Exchange (ETDEWEB)

Parellada, Antoni J. [DII - Diagnostic Imaging, Inc., Philadelphia, PA (United States); Frankford Hospitals - Torresdale Campus, Department of Radiology, Philadelphia, PA (United States); Gopez, Angela G.; Morrison, William B. [Thomas Jefferson University, Department of Radiology, Philadelphia, PA (United States); Sweet, Stephanie [Thomas Jefferson University, Philadelphia Hand Center, Philadelphia, PA (United States); Leinberry, Charles F. [Thomas Jefferson University, Department of Orthopedic Surgery - Hand Surgery, Philadelphia, PA (United States); Reiter, Sean B.; Kohn, Mark [DII - Diagnostic Imaging, Inc., Philadelphia, PA (United States)

2007-03-15

To present the MRI imaging findings of extensor tenosynovitis at the distal intersection or crossover between the second (extensor carpi radialis longus (ECRL) and brevis (ECRB)) and third (extensor pollicis longus (EPL)) extensor compartment tendons, and the anatomical details that may play a role in the pathogenesis of this condition. The imaging studies and clinical records of five patients (three females and two males, with ages ranging between 22 and 78 years; mean age, 49 years) presenting with pain on the dorsal and radial aspect of the wrist were reviewed by two musculoskeletal radiologists in consensus. Three cases were identified serendipitously during routine clinical reading sessions; a follow-up computerized database search for additional cases reported in the prior two years yielded two additional cases. The overall number of cases screened was 1,031. The diagnosis of tendinopathy affecting the second and third compartment extensor tendons was made on the basis of MRI findings and clinical follow-up, or synovectomy. All patients showed signs of tenosynovitis: in four patients both the tendons of the second and third extensor compartments were affected; the fifth patient showed signs of tenosynovitis of the EPL tendon, and tendinosis of the extensor carpi radialis tendons. Three patients showed tenosynovitis proximal and distal to the point of intersection; and in two of them, a discrete point of constriction was appreciated at the crossover site in relation to the extensor retinaculum. Two patients showed tenosynovitis limited to the segment distal to the point of decussation. Tendinosis tended to follow the presence of tenosynovitis. In one of the patients, subtendinous reactive marrow edema in Lister's tubercle was noted. Distal intersection tenosynovitis may be related to the biomechanical pulley effect exerted by Lister's tubercle on the EPL tendon as it leaves the third compartment and crosses over the extensor carpi radialis tendons

Type grouping in skeletal muscles after experimental reinnervation: another explanation

NARCIS (Netherlands)

Vleggeert-lankamp, C.L.A.M.; de Ruiter, G.C.W.; Wolfs, J.F.C.; Pêgo, A.P.; Feirabend, H.K.P.; Lakke, E.A.J.F.; Malessy, M.J.A.

2005-01-01

Type grouping signifies clustering of muscle fibres of the same metabolic type, and is a frequent finding in reinnervated muscles. To elucidate the mechanism behind it, the rat sciatic nerve was either autografted or grafted with hollow synthetic nerve grafts. Twelve weeks later the number and fibre

Interleukin-6 production in contracting human skeletal muscle is influenced by pre-exercise muscle glycogen content

DEFF Research Database (Denmark)

Steensberg, A; Febbraio, M A; Osada, T

2001-01-01

1. Prolonged exercise results in a progressive decline in glycogen content and a concomitant increase in the release of the cytokine interleukin-6 (IL-6) from contracting muscle. This study tests the hypothesis that the exercise-induced IL-6 release from contracting muscle is linked to the intram......1. Prolonged exercise results in a progressive decline in glycogen content and a concomitant increase in the release of the cytokine interleukin-6 (IL-6) from contracting muscle. This study tests the hypothesis that the exercise-induced IL-6 release from contracting muscle is linked...... to the intramuscular glycogen availability. 2. Seven men performed 5 h of a two-legged knee-extensor exercise, with one leg with normal, and one leg with reduced, muscle glycogen content. Muscle biopsies were obtained before (pre-ex), immediately after (end-ex) and 3 h into recovery (3 h rec) from exercise in both...... legs. In addition, catheters were placed in one femoral artery and both femoral veins and blood was sampled from these catheters prior to exercise and at 1 h intervals during exercise and into recovery. 3. Pre-exercise glycogen content was lower in the glycogen-depleted leg compared with the control...

Effects of Inclined Treadmill Walking on Pelvic Anterior Tilt Angle, Hamstring Muscle Length, and Trunk Muscle Endurance of Seated Workers with Flat-back Syndrome.

Science.gov (United States)

Kim, Min-Hee; Yoo, Won-Gyu

2014-06-01

[Purpose] This study investigated the effects of inclined treadmill walking on pelvic anterior tilt angle, hamstring muscle length, and back muscle endurance of seated workers with flat-back syndrome. [Subjects] Eight seated workers with flat-back syndrome who complained of low-back pain in the L3-5 region participated in this study. [Methods] The subjects performed a walking exercise on a 30° inclined treadmill. We measured the pelvic anterior tilt angle, hamstring muscle length, and back muscle endurance before and after inclined treadmill walking. [Results] Anterior pelvic tilt angle and active knee extension angle significantly increased after inclined treadmill walking. Trunk extensor and flexor muscle endurance times were also significantly increased compared to the baseline. [Conclusion] Inclined treadmill walking may be an effective approach for the prevention or treatment of low-back pain in flat-back syndrome.

Pulsed ultrasound therapy accelerates the recovery of skeletal muscle damage induced by Bothrops jararacussu venom

Directory of Open Access Journals (Sweden)

J. Saturnino-Oliveira

2012-06-01

Full Text Available We studied the effect of pulsed ultrasound therapy (UST and antibothropic polyvalent antivenom (PAV on the regeneration of mouse extensor digitorum longus muscle following damage by Bothrops jararacussu venom. Animals (Swiss male and female mice weighing 25.0 ± 5.0 g; 5 animals per group received a perimuscular injection of venom (1 mg/kg and treatment with UST was started 1 h later (1 min/day, 3 MHz, 0.3 W/cm², pulsed mode. Three and 28 days after injection, muscles were dissected and processed for light microscopy. The venom caused complete degeneration of muscle fibers. UST alone and combined with PAV (1.0 mL/kg partially protected these fibers, whereas muscles receiving no treatment showed disorganized fascicules and fibers with reduced diameter. Treatment with UST and PAV decreased the effects of the venom on creatine kinase content and motor activity (approximately 75 and 48%, respectively. Sonication of the venom solution immediately before application decreased the in vivo and ex vivo myotoxic activities (approximately 60 and 50%, respectively. The present data show that UST counteracts some effects of B. jararacussu venom, causing structural and functional improvement of the regenerated muscle after venom injury.

Stretch-stimulated glucose transport in skeletal muscle is regulated by Rac1.

Science.gov (United States)

Sylow, Lykke; Møller, Lisbeth L V; Kleinert, Maximilian; Richter, Erik A; Jensen, Thomas E

2015-02-01

Rac1 regulates stretch-stimulated (i.e. mechanical stress) glucose transport in muscle. Actin depolymerization decreases stretch-induced glucose transport in skeletal muscle. Rac1 is a required part of the mechanical stress-component of the contraction-stimulus to glucose transport in skeletal muscle. An alternative to the canonical insulin signalling pathway for glucose transport is muscle contraction/exercise. Mechanical stress is an integrated part of the muscle contraction/relaxation cycle, and passive stretch stimulates muscle glucose transport. However, the signalling mechanism regulating stretch-stimulated glucose transport is not well understood. We recently reported that the actin cytoskeleton regulating GTPase, Rac1, was activated in mouse muscle in response to stretching. Rac1 is a regulator of contraction- and insulin-stimulated glucose transport, however, its role in stretch-stimulated glucose transport and signalling is unknown. We therefore investigated whether stretch-induced glucose transport in skeletal muscle required Rac1 and the actin cytoskeleton. We used muscle-specific inducible Rac1 knockout mice as well as pharmacological inhibitors of Rac1 and the actin cytoskeleton in isolated soleus and extensor digitorum longus muscles. In addition, the role of Rac1 in contraction-stimulated glucose transport during conditions without mechanical load on the muscles was evaluated in loosely hanging muscles and muscles in which cross-bridge formation was blocked by the myosin ATPase inhibitors BTS and Blebbistatin. Knockout as well as pharmacological inhibition of Rac1 reduced stretch-stimulated glucose transport by 30-50% in soleus and extensor digitorum longus muscle. The actin depolymerizing agent latrunculin B similarly decreased glucose transport in response to stretching by 40-50%. Rac1 inhibition reduced contraction-stimulated glucose transport by 30-40% in tension developing muscle but did not affect contraction-stimulated glucose transport in

Comparison between parameters of muscle performance and inflammatory biomarkers of non-sarcopenic and sarcopenic elderly women

Directory of Open Access Journals (Sweden)

Lustosa LP

2017-08-01

Full Text Available Lygia Paccini Lustosa,1 Patrícia Parreira Batista,1 Daniele Sirineu Pereira,2 Leani Souza Máximo Pereira,1 Aline Scianni,1 Giane Amorim Ribeiro-Samora1 1Physical Therapy Department, Universidade Federal de Minas Gerais, Belo Horizonte, 2Physical Therapy Department, Universidade Federal de Alfenas, Alfenas, Brazil Background: Sarcopenia is a multifactorial geriatric syndrome with complex interrelationships. Increased plasma levels of inflammatory mediators increase the catabolic stimuli of the musculature, thereby causing a decrease in mass and muscular function. Objective: The objective of this study was to compare the performance of the knee extensors test (by isokinetic dynamometer and plasma levels of interleukin-6 (IL-6 and soluble receptors of tumor necrosis factor alpha (sTNFR1 between sarcopenics and non-sarcopenics community-dwelling elderly women residents of Brazil. Material and methods: The diagnosis of sarcopenia included measurements of body composition (by densitometry with dual energy source of X-ray, handgrip strength (by Jamar® dynamometer, and the usual gait velocity according to the recommendations of the European Working Group on Sarcopenia in Older People. In both sarcopenics and non-sarcopenics elderly women, we evaluated the muscle function by knee extensors test (using an isokinetic dynamometer Byodex System 4 Pro® at angular speeds of 60°/s and 180°/s and also we evaluated the plasma concentrations of IL-6 and sTNFR1. Comparisons of muscle performance between groups were carried out using mixed factorial ANOVA with post hoc Bonferroni test; sTNFR1 and IL-6 variables were analyzed by applying Mann–Whitney U test. Results: Statistical differences were observed between groups regarding muscle power (P=0.01, total work adjusted to body weight (P=0.01 at a rate of 180°/s, and plasma levels of sTNFR1 (P=0.01. Conclusion: Sarcopenic elder women showed lower performance of the lower limbs, especially at a higher speed

CT evaluation of the damaged upper limb muscle in patients with Duchenne type progressive muscular dystrophy (DMD)

International Nuclear Information System (INIS)

Saito, Hiroshi; Matsuke, Yutaka.

1992-01-01

In order to evaluate the changes of CT numbers and cross sectional areas of the muscles, we determined CT scores of the muscle. In twelve patients with Duchenne type progressive muscular dystrophy (DMD), we assessed the difference of CT scores of the muscle and the correlation between CT score of the muscle and 9-stage classification of upper extremities. CT scores of the subscapularis muscle and infraspinatus muscle were significantly lower than deltoideus muscle at the level of the shoulder, and flexor muscles showed also significantly lower than extensor muscles at the level of the upper extremity. Good correlations between CT score of the muscle and 9-stage classification of upper extremities were observed in the muscles of shoulder and upper arm. (author)

CT evaluation of the damaged upper limb muscle in patients with Duchenne type progressive muscular dystrophy (DMD)

Energy Technology Data Exchange (ETDEWEB)

Saito, Hiroshi (Anan Central Hospital, Tokushima (Japan)); Matsuke, Yutaka

1992-04-01

In order to evaluate the changes of CT numbers and cross sectional areas of the muscles, we determined CT scores of the muscle. In twelve patients with Duchenne type progressive muscular dystrophy (DMD), we assessed the difference of CT scores of the muscle and the correlation between CT score of the muscle and 9-stage classification of upper extremities. CT scores of the subscapularis muscle and infraspinatus muscle were significantly lower than deltoideus muscle at the level of the shoulder, and flexor muscles showed also significantly lower than extensor muscles at the level of the upper extremity. Good correlations between CT score of the muscle and 9-stage classification of upper extremities were observed in the muscles of shoulder and upper arm. (author).

Associations Between Balance and Muscle Strength, Power Performance in Male Youth Athletes of Different Maturity Status.

Science.gov (United States)

Hammami, Raouf; Chaouachi, Anis; Makhlouf, Issam; Granacher, Urs; Behm, David G

2016-11-01

Balance, strength and power relationships may contain important information at various maturational stages to determine training priorities. The objective was to examine maturity-specific relationships of static/dynamic balance with strength and power measures in young male athletes. Soccer players (N = 130) aged 10-16 were assessed with the Stork and Y balance (YBT) tests. Strength/power measures included back extensor muscle strength, standing long jump (SLJ), countermovement jump (CMJ), and 3-hop jump tests. Associations between balance with strength/power variables were calculated according to peak-height-velocity (PHV). There were significant medium-large sized correlations between all balance measures with back extensor strength (r = .486-.791) and large associations with power (r = .511-.827). These correlation coefficients were significantly different between pre-PHV and circa PHV as well as pre-PHV and post-PHV with larger associations in the more mature groups. Irrespective of maturity-status, SLJ was the best strength/power predictor with the highest proportion of variance (12-47%) for balance (i.e., Stork eyes opened) and the YBT was the best balance predictor with the highest proportion of variance (43-78%) for all strength/power variables. The associations between balance and muscle strength/power measures in youth athletes that increase with maturity may imply transfer effects from balance to strength/power training and vice versa in youth athletes.

The effects of low and moderate doses of caffeine supplementation on upper and lower body maximal voluntary concentric and eccentric muscle force.

Science.gov (United States)

Tallis, Jason; Yavuz, Harley C M

2018-03-01

Despite the growing quantity of literature exploring the effect of caffeine on muscular strength, there is a dearth of data that directly explores differences in erogenicity between upper and lower body musculature and the dose-response effect. The present study sought to investigate the effects of low and moderate doses of caffeine on the maximal voluntary strength of the elbow flexors and knee extensors. Ten nonspecifically strength-trained, recreationally active participants (aged 21 ± 0.3 years) completed the study. Using a randomised, counterbalanced, and double-blind approach, isokinetic concentric and eccentric strength was measured at 60 and 180°/s following administration of a placebo, 3 mg·kg -1 body mass caffeine, and 6 mg·kg -1 body mass caffeine. There was no effect of caffeine on the maximal voluntary concentric and eccentric strength of the elbow flexors, or the eccentric strength of the knee extensors. Both 3 and 6 mg·kg -1 body mass caffeine caused a significant increase in peak concentric force of the knee extensors at 180°/s. No difference was apparent between the 2 concentrations. Only 6 mg·kg -1 body mass caused an increase in peak concentric force during repeated contractions. The results infer that the effective caffeine concentration to evoke improved muscle performance may be related to muscle mass and contraction type. The present work indicates that a relatively low dose of caffeine treatment may be effective for improving lower body muscular strength, but may have little benefit for the strength of major muscular groups of the upper body.

Neck movement and muscle activity characteristics in female office workers with neck pain.

Science.gov (United States)

Johnston, V; Jull, G; Souvlis, T; Jimmieson, N L

2008-03-01

Cross-sectional study. To explore aspects of cervical musculoskeletal function in female office workers with neck pain. Evidence of physical characteristics that differentiate computer workers with and without neck pain is sparse. Patients with chronic neck pain demonstrate reduced motion and altered patterns of muscle control in the cervical flexor and upper trapezius (UT) muscles during specific tasks. Understanding cervical musculoskeletal function in office workers will better direct intervention and prevention strategies. Measures included neck range of motion; superficial neck flexor muscle activity during a clinical test, the craniocervical flexion test; and a motor task, a unilateral muscle coordination task, to assess the activity of both the anterior and posterior neck muscles. Office workers with and without neck pain were formed into 3 groups based on their scores on the Neck Disability Index. Nonworking women without neck pain formed the control group. Surface electromyographic activity was recorded bilaterally from the sternocleidomastoid, anterior scalene (AS), cervical extensor (CE) and UT muscles. Workers with neck pain had reduced rotation range and increased activity of the superficial cervical flexors during the craniocervical flexion test. During the coordination task, workers with pain demonstrated greater activity in the CE muscles bilaterally. On completion of the task, the UT and dominant CE and AS muscles demonstrated an inability to relax in workers with pain. In general, there was a linear relationship between the workers' self-reported levels of pain and disability and the movement and muscle changes. These results are consistent with those found in other cervical musculoskeletal disorders and may represent an altered muscle recruitment strategy to stabilize the head and neck. An exercise program including motor reeducation may assist in the management of neck pain in office workers.

The effects of stretching on the flexibility, muscle performance and functionality of institutionalized older women

Directory of Open Access Journals (Sweden)

D. Gallon

2011-03-01

Full Text Available Stretching has been widely used to increase the range of motion. We assessed the effects of a stretching program on muscle-tendon length, flexibility, torque, and activities of daily living of institutionalized older women. Inclusion/exclusion criteria were according to Mini-Mental State Examination (MMSE (>13, Barthel Index (>13 and Lysholm Scoring Scale (>84. Seventeen 67 ± 9 year-old elderly women from a nursing home were divided into 2 groups at random: the control group (CG, N = 9 participated in enjoyable cultural activities; the stretching group (SG, N = 8 performed active stretching of hamstrings, 4 bouts of 1 min each. Both groups were supervised three times per week over a period of 8 weeks. Peak torque was assessed by an isokinetic method. Both groups were evaluated by a photogrammetric method to assess muscle-tendon length of uni- and biarticular hip flexors and hamstring flexibility. All measurements were analyzed before and after 8 weeks by two-way ANOVA with the level of significance set at 5%. Hamstring flexibility increased by 30% in the SG group compared to pre-training (76.5 ± 13.0° vs 59.5 ± 9.0°, P = 0.0002 and by 9.2% compared to the CG group (76.5 ± 13.0° vs 64.0 ± 12.0°, P = 0.0018. Muscle-tendon lengths of hip biarticular flexor muscles (124 ± 6.8° vs 118.3 ± 7.6°, 5.0 ± 7.0%, P = 0.031 and eccentric knee extensor peak torque were decreased in the CG group compared to pre-test values (-49.4 ± 16.8 vs -60.5 ± 18.9 Nm, -15.7 ± 20%, P = 0.048. The stretching program was sufficient to increase hamstring flexibility and a lack of stretching can cause reduction of muscle performance.

Isometric muscle strength and mobility capacity in children with cerebral palsy.

Science.gov (United States)

Dallmeijer, Annet J; Rameckers, Eugene A; Houdijk, Han; de Groot, Sonja; Scholtes, Vanessa A; Becher, Jules G

2017-01-01

To determine the relationship between isometric leg muscle strength and mobility capacity in children with cerebral palsy (CP) compared to typically developing (TD) peers. Participants were 62 children with CP (6-13 years), able to walk with (n = 10) or without (n = 52) walking aids, and 47 TD children. Isometric muscle strength of five muscle groups of the leg was measured using hand-held dynamometry. Mobility capacity was assessed with the 1-min walk, the 10-m walk, sit-to-stand, lateral-step-up and timed-stair tests. Isometric strength of children with CP was reduced to 36-82% of TD. When adjusted for age and height, the percentage of variance in mobility capacity that was explained by isometric strength of the leg muscles was 21-24% (walking speed), 25% (sit-to-stand), 28% (lateral-step-up) and 35% (timed-stair) in children with CP. Hip abductors and knee flexors had the largest contribution to the explained variance, while knee extensors showed the weakest correlation. Weak or no associations were found between strength and mobility capacity in TD children. Isometric strength, especially hip abductor and knee flexor strength, is moderately related to mobility capacity in children with CP, but not in TD children. To what extent training of these muscle groups will lead to better mobility capacity needs further study. Implications for Rehabilitation Strength training in children with cerebral palsy (CP) may be targeted more specifically at hip abductors and knee flexors. The moderate associations imply that large improvements in mobility capacity may not be expected when strength increases.

Comparison of the effect of selected muscle groups fatigue on ...

African Journals Online (AJOL)

During each session, postural control was assessed during two 30-s trials of bipedal stance with eyes close before and after the fatigue protocol. Fatigue protocols were performed by 60% of their unfatigued Maximum Voluntary Contraction of unilateral ankle plantar flexors, bilateral lumbar extensors and bilateral neck ...

Multiple regeneration from axolotl limb stumps bearing cross-transplanted minced muscle regenerates : brief note

NARCIS (Netherlands)

Carlson, Bruce M.

Flexor and extensor muscles in the upper arms of axolotls were minced and cross-transplanted. The limbs were amputated 5 and 30 days after mincing. In each experiment a high percentage of the regenerates consisted of multiple limbs. This demonstrates that the morphogenetic information which produces

Comparison of physical fitness between rice farmers with and without chronic low back pain: a cross-sectional study.

Science.gov (United States)

Taechasubamorn, Panada; Nopkesorn, Tawesak; Pannarunothai, Supasit

2010-12-01

To compare physical fitness between rice farmers with chronic low back pain (CLBP) and a healthy control group. Sixty-eight rice farmers with CLBP were matched according to age and sex with healthy farmers. All subjects underwent nine physical fitness tests for body composition, lifting capacity, static back extensor endurance, leg strength, static abdominal endurance, handgrip strength, hamstring flexibility, posterior leg and back muscles flexibility and abdominal flexibility. There was no significant difference between CLBP and healthy groups for all tests, except the static back extensor endurance. The back extensor endurance times of the CLBP group was significantly lower than that of the control group (p = 0.002). Static back extensor endurance is the deficient physical fitness in CLBP rice farmers. Back extensor endurance training should be emphasized in both prevention and rehabilitation programs.

Cervico-mandibular muscle activity in females with chronic cervical pain

OpenAIRE

T. Lang; R. Parker; T. Burgess

2013-01-01

Pathophysiological mechanisms behind pain in chroniccervical musculoskeletal conditions (MSC) in office workers remainunclear. Chronic cervical pain has established links with temporomandibular(TM) disorders. Yet there is no current published evidence to reportwhether individuals with cervical dysfunction exhibit altered masseterand cervical extensor (CE) muscle activity. Objective: To explore CE andmasseter surface electromyographic (sEMG) activity and teeth clenchinghabits in females with c...

Individual and combined influence of ACE and ACTN3 genes on muscle phenotypes in Polish athletes.

Science.gov (United States)

Orysiak, Joanna; Mazur-Różycka, Joanna; Busko, Krzysztof; Gajewski, Jan; Szczepanska, Beata; Malczewska-Lenczowska, Jadwiga

2017-02-08

The aim of this study was to examine the association between ACE and ACTN3 genes, independently or in combination, and muscle strength and power in male and female athletes. The study involved 398 young male (n=266) and female (n=132) athletes representing various sport disciplines (ice hockey, canoeing, swimming, volleyball). All were Caucasians. The following measurements were taken: height of jump and mechanical power in countermovement jump (CMJ) and spike jump (SPJ), and muscle strength of 10 muscle groups (flexors and extensors of the elbow, shoulder, hip, knee and trunk). The ID polymorphism of ACE and the R577X polymorphism of ACTN3 were typed using PCR (polymerase chain reaction) and PCR-RFLP (polymerase chain reaction - restriction fragment length polymorphism), respectively. The genotype distribution of the ACE and ACTN3 genes did not differ significantly between groups of athletes for either sex. There was no association between ACE and ACTN3 genotypes (alone or in combination) and sum of muscle strength, height of jump or mechanical power in both jump tests (CMJ and SPJ) for male and female athletes. These findings do not support an influential role of the ACE and ACTN3 genes in determining power/strength performance of elite athletes.

Anatomic relationship of the proximal nail matrix to the extensor hallucis longus tendon insertion.

Science.gov (United States)

Palomo López, P; Becerro de Bengoa Vallejo, R; López López, D; Prados Frutos, J C; Alfonso Murillo González, J; Losa Iglesias, M E

2015-10-01

The purpose of this study was to delineate the relationship of the terminal extensor hallucis longus tendon insertion to the proximal limit of the nail matrix of the great toe. Fifty fresh-frozen human cadaver great toes with no evidence of trauma (average age, 62.5 years; 29 males and 21 females) were used for this study. Under 25X magnification, the proximal limit of the nail matrix and the terminal bony insertion of the extensor hallucis longus tendons were identified. The distance from the terminal tendon insertion to the nail matrix was ascertained using precision calipers, an optical microscope, and autocad(®) software for windows. Twenty-five great toes were placed in a neutral formalin solution and further analysed by histological longitudinal-sections. The specimens were stained with haematoxylin and eosin and examined microscopically to determine the presence of the extensor hallucis longus tendon along the dorsal aspect of the distal phalanx of each great toe. The main result we found in great toes was that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx in all, 100%, specimens. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of the distal phalanx as is the case for fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone. We have found that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of distal phalanx as is the case in fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone. Our anatomic study demonstrates that the proximal limit of the matrix and nail bed of the human great toe are dorsal and

Body Composition, Neuromuscular Performance, and Mobility: Comparison Between Regularly Exercising and Inactive Older Women.

Science.gov (United States)

Rava, Anni; Pihlak, Anu; Ereline, Jaan; Gapeyeva, Helena; Kums, Tatjana; Purge, Priit; Jürimäe, Jaak; Pääsuke, Mati

2017-01-01

The purpose of this study was to evaluate the differences in body composition, neuromuscular performance, and mobility in healthy, regularly exercising and inactive older women, and examine the relationship between skeletal muscle indices and mobility. Overall, 32 healthy older women participated. They were divided into groups according to their physical activity history as regularly exercising (n = 22) and inactive (n = 10) women. Body composition, hand grip strength, leg extensor muscle strength, rapid force development, power output, and mobility indices were assessed. Regularly exercising women had lower fat mass and higher values for leg extensor muscle strength and muscle quality, and also for mobility. Leg extensor muscle strength and power output during vertical jumping and appendicular lean mass per unit of body mass were associated with mobility in healthy older women. It was concluded that long-term regular exercising may have beneficial effects on body composition and physical function in older women.

Rate of Torque Development and Feedforward Control of the Hip and Knee Extensors: Gender Differences.

Science.gov (United States)

Stearns-Reider, Kristen M; Powers, Christopher M

2017-10-06

The purpose of this study was to determine whether women demonstrate decreased rate of torque development (RTD) of the hip and knee extensors and altered onset timing of the vastus lateralis and gluteus maximus during a drop-jump task when compared with men. On average, women demonstrated significantly lower normalized RTD of the hip extensors (women: 11.6 ± 1.3 MVT.s -1 , men: 13.1 ± 0.9 MVT.s -1 ; p ≤ .01); however, there was no significant difference in knee extensor RTD. Women also demonstrated significantly earlier activation of their vastus lateralis (women: 206.0 ± 130.6 ms, men: 80.9 ± 69.6 ms; p ≤ .01) and gluteus maximus (women: 85.7 ± 58.6 ms, men: 54.5 ± 35.4 ms; p = .02). In both men and women, there was a significant negative correlation between the hip extensor RTD and the vastus lateralis electromyographic onset time (men: r = -.386, p = .046; women: r = -.531, p = .008). The study findings suggest that women may utilize a feedforward control strategy in which they activate their knee extensors earlier than men to compensate for deficits in hip extensor RTD. The impaired capacity to rapidly stabilize the hip and knee joints during dynamic maneuvers may contribute to the increased risk of anterior cruciate ligament injury observed in women.

Nonparetic Knee Extensor Strength Is the Determinant of Exercise Capacity of Community-Dwelling Stroke Survivors

Directory of Open Access Journals (Sweden)

Wei-Te Wang

2014-01-01

Full Text Available Objective. To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. Design. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects’ exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. Results. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO2 peak was 1.21±0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Conclusions. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living.

Nonparetic knee extensor strength is the determinant of exercise capacity of community-dwelling stroke survivors.

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Wang, Wei-Te; Huang, Ling-Tzu; Chou, Ya-Hui; Wei, Ta-Sen; Lin, Chung-Che

2014-01-01

To investigate the relationship among walking speed, exercise capacity, and leg strength in community dwelling stroke subjects and to evaluate which one was the leading determinant factor of them. This is a descriptive, cross-sectional study. Thirty-five chronic stroke patients who were able to walk independently in their community were enrolled. Walking speed was evaluated by using the 12-meter walking test. A maximal exercise test was used to determine the stroke subjects' exercise capacity. Knee extensor strength, measured as isokinetic torque, was assessed by isokinetic dynamometer. The main walking speed of our subjects was 0.52 m/s. Peak oxygen uptake (VO₂ peak) was 1.21 ± 0.43 L/min. Knee extensor strength, no matter whether paretic or nonparetic side, was significantly correlated to 12-meter walking speed and exercise capacity. Linear regression also showed the strength of the affected knee extensor was the determinant of walking speed and that of the nonparetic knee extensor was the determinant of exercise capacity in community dwelling stroke subjects. Walking speed and peak oxygen uptake were markedly decreased after stroke. Knee extensor strength of nonparetic leg was the most important determinant of exercise capacity of the community-dwelling stroke subjects. Knee extensor strengthening should be emphasized to help stroke patient to achieve optimal community living.

Associations of knee extensor strength and standing balance with physical function in knee osteoarthritis.

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Pua, Yong-Hao; Liang, Zhiqi; Ong, Peck-Hoon; Bryant, Adam L; Lo, Ngai-Nung; Clark, Ross A

2011-12-01

Knee extensor strength is an important correlate of physical function in patients with knee osteoarthritis; however, it remains unclear whether standing balance is also a correlate. The purpose of this study was to evaluate the cross-sectional associations of knee extensor strength, standing balance, and their interaction with physical function. One hundred four older adults with end-stage knee osteoarthritis awaiting a total knee replacement (mean ± SD age 67 ± 8 years) participated. Isometric knee extensor strength was measured using an isokinetic dynamometer. Standing balance performance was measured by the center of pressure displacement during quiet standing on a balance board. Physical function was measured by the self-report Short Form 36 (SF-36) questionnaire and by the 10-meter fast-pace gait speed test. After adjustment for demographic and knee pain variables, we detected significant knee strength by standing balance interaction terms for both SF-36 physical function and fast-pace gait speed. Interrogation of the interaction revealed that standing balance in the anteroposterior plane was positively related to physical function among patients with lower knee extensor strength. Conversely, among patients with higher knee extensor strength, the standing balance-physical function associations were, or tended to be, negative. These findings suggest that although standing balance was related to physical function in patients with knee osteoarthritis, this relationship was complex and dependent on knee extensor strength level. These results are of importance in developing intervention strategies and refining theoretical models, but they call for further study. Copyright © 2011 by the American College of Rheumatology.

Group Ia afferents likely contribute to short-latency interlimb reflexes in the human biceps femoris muscle

DEFF Research Database (Denmark)

Stevenson, Andrew James Thomas; Kamavuako, Ernest Nlandu; Geertsen, Svend Sparre

2017-01-01

amplitudes (4 vs. 8°) at the same 150°/s velocity (p’s > 0.08). Conclusion: Because fast conducting group Ia muscle spindle afferents are sensitive to changes in muscle stretch velocity, while group II spindle afferents are sensitive to changes in amplitude (Grey et al., JPhysiol., 2001; Matthews, Trends...... Neurosci., 1991), group Ia velocity sensitive muscle spindle afferents likely contribute to the short-latency crossed spinal reflexes in the cBF muscle following iKnee joint rotations. This supports the findings for the short-latency crossed responses in the human soleus muscle (Stubbs & Mrachacz...... neurons in humans, with primary contributions from group Ia muscle spindle afferents....

Multi-slice MRI reveals heterogeneity in disease distribution along the length of muscle in Duchenne muscular dystrophy.

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Chrzanowski, Stephen M; Baligand, Celine; Willcocks, Rebecca J; Deol, Jasjit; Schmalfuss, Ilona; Lott, Donovan J; Daniels, Michael J; Senesac, Claudia; Walter, Glenn A; Vandenborne, Krista

2017-09-01

Duchenne muscular dystrophy (DMD) causes progressive pathologic changes to muscle secondary to a cascade of inflammation, lipid deposition, and fibrosis. Clinically, this manifests as progressive weakness, functional loss, and premature mortality. Though insult to whole muscle groups is well established, less is known about the relationship between intramuscular pathology and function. Differences of intramuscular heterogeneity across muscle length were assessed using an ordinal MRI grading scale in lower leg muscles of boys with DMD and correlated to patient's functional status. Cross sectional T 1 weighted MRI images with fat suppression were obtained from ambulatory boys with DMD. Six muscles (tibialis anterior, extensor digitorum longus, peroneus, soleus, medial and lateral gastrocnemii) were graded using an ordinal grading scale over 5 slice sections along the lower leg length. The scores from each slice were combined and results were compared to global motor function and age. Statistically greater differences of involvement were observed at the proximal ends of muscle compared to the midbellies. Multi-slice assessment correlated significantly to age and the Vignos functional scale, whereas single-slice assessment correlated to the Vignos functional scale only. Lastly, differential disease involvement of whole muscle groups and intramuscular heterogeneity were observed amongst similar age subjects. A multi-slice ordinal MRI grading scale revealed that muscles are not uniformly affected, with more advanced disease visible near the tendons in a primarily ambulatory population with DMD. A geographically comprehensive evaluation of the heterogeneously affected muscle in boys with DMD may more accurately assess disease involvement.

The relation between knee muscle strength and performance tests in orienteering athletes.

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Çinar-Medeni, Özge; Colakoglu, Fatma F; Yüce, Koray; Ipekoğlu, Gökhan; Baltaci, Gul

2016-11-01

The aim of this study was to analyze the effect of knee muscle strength on performance tests in orienteers. Thirty-seven orienteers were voluntarily included in this study. Isokinetic knee flexor and extensor muscles' strength was assessed at 120°/s velocity for both "dominant leg" (DL) and "non-dominant leg" (NDL). "Single-legged hop test" (SLHT), "flamingo balance test" (FBT), "star excursion balance test" (SEBT), vertical jump-and-reach test (for anaerobic power), T-drill test and 20-meter shuttle run test (for aerobic power) were carried out. Correlation and regression analyses were performed on the data. VO2max levels showed moderate correlations with DL's "flexor peak torque" (FPT) and NDL's "extensor peak torque" (EPT) and FPT values respectively (r=0.49, r=0.38, r=0.58). FPT of NDL was a predictor of VO2max level (R2=0.33). Anaerobic power has a relationship with EPT of NDL (r=0.43) and T-drill test with EPT and FPT values of both DL and NDL respectively (r=-0.35, r=-0.63, r=-0.53, r=-0.58). EPT of NDL was a predictor for anaerobic power (R2=0.19) and FPT of DL for agility (R2=0.40). Nonparametric linear regression results showed that EPT is a predictor in DL (median slope=-0.71, P=0.01), and FPT in NDL (median slope=-0.90, P=0.006) for FBT. FPT was a predictor of SEBT scores for both legs (0.13extensor muscle strength are of importance to improve orienteering performance.

Effects of Quadriceps Muscle Fatigue on Stiff-Knee Gait in Patients with Hemiparesis

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Boudarham, Julien; Roche, Nicolas; Pradon, Didier; Delouf, Eric; Bensmail, Djamel; Zory, Raphael

2014-01-01

The relationship between neuromuscular fatigue and locomotion has never been investigated in hemiparetic patients despite the fact that, in the clinical context, patients report to be more spastic or stiffer after walking a long distance or after a rehabilitation session. The aim of this study was to evaluate the effects of quadriceps muscle fatigue on the biomechanical gait parameters of patients with a stiff-knee gait (SKG). Thirteen patients and eleven healthy controls performed one gait analysis before a protocol of isokinetic quadriceps fatigue and two after (immediately after and after 10 minutes of rest). Spatiotemporal parameters, sagittal knee and hip kinematics, rectus femoris (RF) and vastus lateralis (VL) kinematics and electromyographic (EMG) activity were analyzed. The results showed that quadriceps muscle weakness, produced by repetitive concentric contractions of the knee extensors, induced an improvement of spatiotemporal parameters for patients and healthy subjects. For the patient group, the increase in gait velocity and step length was associated with i) an increase of sagittal hip and knee flexion during the swing phase, ii) an increase of the maximal normalized length of the RF and VL and of the maximal VL lengthening velocity during the pre-swing and swing phases, and iii) a decrease in EMG activity of the RF muscle during the initial pre-swing phase and during the latter 2/3 of the initial swing phase. These results suggest that quadriceps fatigue did not alter the gait of patients with hemiparesis walking with a SKG and that neuromuscular fatigue may play the same functional role as an anti-spastic treatment such as botulinum toxin-A injection. Strength training of knee extensors, although commonly performed in rehabilitation, does not seem to be a priority to improve gait of these patients. PMID:24718087

Strengths of lower extremity and lower trunk muscles in females with patellofemoral pain syndrome

Directory of Open Access Journals (Sweden)

Fateme Bokaee

2010-09-01

Full Text Available Introduction: Patellofemoral pain syndrome (PFPS is one of the most common orthopaedic problemsof the knee joint. Muscular weakness considered as a risk factor of this syndrome. Muscular weaknesscan alter lower extremity kinematics and lead to this syndrome. Also according to the kinetic chain,weakness in one motor segment can influence other motor segments. So the aim of this study was todetermine the association between muscular strengths of both lower extremity and trunks muscles andPFPS.Materials and Methods: 40 women participated in this study (20 subjects with PFPS and 20 ascontrols. In both groups isometric strengths of the lower extremity and lower trunk muscles wereevaluated with Nicholas hand-held dynamometer and then compared with each other.Results: There was a significant decrease in strength of the hip abductors, adductors, external rotators,flexors and extensors, quadriceps, ankle plantarflexors, dorsiflexors, flexor and lateral flexors of the trunkin patients with PFPS.Conclusion: Our results indicate that decrease in strength of the hip and trunk muscles is associatedwith the knee injury. It seems strengthening of muscles of these areas to be effective in preventing theinjury, reducing the risk of more injury and treatment of patients with this syndrome.

Wearing an active spinal orthosis improves back extensor strength in women with osteoporotic vertebral fractures

DEFF Research Database (Denmark)

Valentin, Gitte Hoff; Pedersen, Louise Nymann; Maribo, Thomas

2014-01-01

.Study design:Experimental follow-up.Methods:The women used the active spinal orthosis for 3 months. Outcomes were changes in isometric back extensor strength, changes in back pain and changes in physical functioning.Results:A total of 13 women were included in the trial. Wearing the orthosis during a 3-month......Background:Vertebral fractures are the most common clinical manifestations of osteoporosis. Vertebral fractures and reduced back extensor strength can result in hyperkyphosis. Hyperkyphosis is associated with diminished daily functioning and an increased risk of falling. Improvements in back...... extensor strength can result in decreased kyphosis and thus a decreased risk of falls and fractures.Objectives:The aim was to examine the effects of an active spinal orthosis - Spinomed III - on back extensor strength, back pain and physical functioning in women with osteoporotic vertebral fractures...

Is the relationship between increased knee muscle strength and improved physical function following exercise dependent on baseline physical function status?

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Hall, Michelle; Hinman, Rana S; van der Esch, Martin; van der Leeden, Marike; Kasza, Jessica; Wrigley, Tim V; Metcalf, Ben R; Dobson, Fiona; Bennell, Kim L

2017-12-08

Clinical guidelines recommend knee muscle strengthening exercises to improve physical function. However, the amount of knee muscle strength increase needed for clinically relevant improvements in physical function is unclear. Understanding how much increase in knee muscle strength is associated with improved physical function could assist clinicians in providing appropriate strength gain targets for their patients in order to optimise outcomes from exercise. The aim of this study was to investigate whether an increase in knee muscle strength is associated with improved self-reported physical function following exercise; and whether the relationship differs according to physical function status at baseline. Data from 100 participants with medial knee osteoarthritis enrolled in a 12-week randomised controlled trial comparing neuromuscular exercise to quadriceps strengthening exercise were pooled. Participants were categorised as having mild, moderate or severe physical dysfunction at baseline using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Associations between 12-week changes in physical function (dependent variable) and peak isometric knee extensor and flexor strength (independent variables) were evaluated with and without accounting for baseline physical function status and covariates using linear regression models. In covariate-adjusted models without accounting for baseline physical function, every 1-unit (Nm/kg) increase in knee extensor strength was associated with physical function improvement of 17 WOMAC units (95% confidence interval (CI) -29 to -5). When accounting for baseline severity of physical function, every 1-unit increase in knee extensor strength was associated with physical function improvement of 24 WOMAC units (95% CI -42 to -7) in participants with severe physical dysfunction. There were no associations between change in strength and change in physical function in participants with mild or moderate physical

Calprotectin is released from human skeletal muscle tissue during exercise

DEFF Research Database (Denmark)

Mortensen, Ole Hartvig; Andersen, Kasper; Fischer, Christian

2008-01-01

Skeletal muscle has been identified as a secretory organ. We hypothesized that IL-6, a cytokine secreted from skeletal muscle during exercise, could induce production of other secreted factors in skeletal muscle. IL-6 was infused for 3 h into healthy young males (n = 7) and muscle biopsies obtained...... in skeletal muscle following IL-6 infusion compared to controls. Furthermore, S100A8 and S100A9 mRNA levels were up-regulated 5-fold in human skeletal muscle following cycle ergometer exercise for 3 h at approximately 60% of in young healthy males (n = 8). S100A8 and S100A9 form calprotectin, which is known...... as an acute phase reactant. Plasma calprotectin increased 5-fold following acute cycle ergometer exercise in humans, but not following IL-6 infusion. To identify the source of calprotectin, healthy males (n = 7) performed two-legged dynamic knee extensor exercise for 3 h with a work load of approximately 50...

Comparison of isometric cervical flexor and isometric cervical extensor system exercises on patients with neuromuscular imbalance and cervical crossed syndrome associated forward head posture.

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Lee, Jaejin; Kim, Dohyeon; Yu, Kyunghoon; Cho, Youngki; You, Joshua H

2018-01-01

Isometric cervical flexor system exercise (ICF) and isometric cervical extensor system exercise (ICE) are cervical stabilization techniques that have been used to restore cervical crossed syndrome (CCS)-associated forward head posture. However, the therapeutic effects and underlying motor control mechanisms remain elusive. The purpose of present study was investigating the concurrent therapeutic effects of ICF and ICE on muscle size, muscle imbalance ratio, and muscle recruitment sequence using ultrasound imaging and electromyography. A total of 18 participants (7 females; age=24±4.0 years) with CCS associated with forward head posture underwent ICF and ICE. Paired t-test analysis was used for statistical analysis. Paired t-test analysis showed that sternocleidomastoid thickness was greater during ICF than ICE. Similarly, cross-sectional area and horizontal thickness of the longus colli were greater during ICE than ICF. The upper trapezius/lower trapezius muscle imbalance ratio and the pectoralis major/lower trapezius muscle imbalance ratio were significantly decreased during the application of ICE compared to ICF. These results provide compelling, mechanistic evidence as to how ICE is more beneficial for the restoration of neuromuscular imbalance than ICF in individuals with CCS.

Neck and shoulder muscle strength in patients with tension-type headache

DEFF Research Database (Denmark)

Madsen, Bjarne K; Søgaard, Karen; Andersen, Lars L.

2016-01-01

in TTH patients and healthy controls by examining maximal voluntary isometric contraction (MVC) during shoulder abduction, neck flexion and extension as well as the extension/flexion strength ratio of the neck. METHODS: Sixty TTH patients and 30 sex- and age-matched healthy controls were included......INTRODUCTION: Tension-type headache (TTH) is highly prevalent in the general population, and it is characterized by increased muscle tenderness with increasing headache frequency and intensity. AIM: The aim of this case-control study was to compare muscle strength in neck and shoulder muscles....... Patients were included if they had TTH ≥8 days per month. The MVC neck extensor and flexor muscles were tested with the participant seated upright. MVC shoulder abduction was tested with the individual lying supine. RESULTS: Compared to controls TTH patients had significantly weaker muscle strength in neck...

Hip and trunk muscles activity during nordic hamstring exercise

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Narouei, Shideh; Imai, Atsushi; Akuzawa, Hiroshi; Hasebe, Kiyotaka; Kaneoka, Koji

2018-01-01

The nordic hamstring exercise (NHE) is a dynamic lengthening hamstring exercise that requires trunk and hip muscles activation. Thigh muscles activation, specifically hamstring/quadriceps contractions has been previously examined during NHE. Trunk and hip muscles activity have not been enough studied. The aim of this study was to analyze of hip and trunk muscles activity during NHE. Surface electromyography (EMG) and kinematic data were collected during NHE. Ten healthy men with the age range of 21–36 years performed two sets of two repetitions with downward and upward motions each of NHE. EMG activity of fifteen trunk and hip muscles and knee kinematic data were collected. Muscle activity levels were calculated through repeated measure analysis of variance in downward and upward motions, through Paired t-test between downward and upward motions and gluteus maximus to erector spine activity ratio (Gmax/ES ratio) using Pearson correlation analyses were evaluated. Semitendinosus and biceps femoris muscles activity levels were the greatest in both motions and back extensors and internal oblique muscles activity were greater than other muscles (Phamstrings contractions. It could be important for early assessment of subjects with hamstring injury risk. PMID:29740557

Hip and trunk muscles activity during nordic hamstring exercise.

Science.gov (United States)

Narouei, Shideh; Imai, Atsushi; Akuzawa, Hiroshi; Hasebe, Kiyotaka; Kaneoka, Koji

2018-04-01

The nordic hamstring exercise (NHE) is a dynamic lengthening hamstring exercise that requires trunk and hip muscles activation. Thigh muscles activation, specifically hamstring/quadriceps contractions has been previously examined during NHE. Trunk and hip muscles activity have not been enough studied. The aim of this study was to analyze of hip and trunk muscles activity during NHE. Surface electromyography (EMG) and kinematic data were collected during NHE. Ten healthy men with the age range of 21-36 years performed two sets of two repetitions with downward and upward motions each of NHE. EMG activity of fifteen trunk and hip muscles and knee kinematic data were collected. Muscle activity levels were calculated through repeated measure analysis of variance in downward and upward motions, through Paired t -test between downward and upward motions and gluteus maximus to erector spine activity ratio (Gmax/ES ratio) using Pearson correlation analyses were evaluated. Semitendinosus and biceps femoris muscles activity levels were the greatest in both motions and back extensors and internal oblique muscles activity were greater than other muscles ( P hamstrings contractions. It could be important for early assessment of subjects with hamstring injury risk.

Speed-related spinal excitation from ankle dorsiflexors to knee extensors during human walking

DEFF Research Database (Denmark)

Iglesias, Caroline; Nielsen, Jens Bo; Marchand-Pauvert, Véronique

2008-01-01

Automatic adjustments of muscle activity throughout the body are required for the maintenance of balance during human walking. One mechanism that is likely to contribute to this control is the heteronymous spinal excitation between human ankle dorsiflexors and knee extensors (CPQ-reflex). Here, we...... investigated the CPQ-reflex at different walking speeds (1-6 km/h) and stride frequencies (0.6-1.3 Hz) in healthy human subjects to provide further evidence of its modulation, and its role in ensuring postural stability during walking. The CPQ-reflex was small or absent at walking speeds below 2-3 km....../h, then increased with walking speeds about 3-4 km/h, and reached a plateau without any further change at walking speeds from 4 to 6 km/h. The reflex showed no modulation when the stride cycle was varied at constant speed (4 km/h; short steps versus long steps). These changes were unlikely to be only caused...

Anatomy and histochemistry of spread-wing posture in birds. 3. Immunohistochemistry of flight muscles and the "shoulder lock" in albatrosses.

Science.gov (United States)

Meyers, Ron A; Stakebake, Eric F

2005-01-01

As a postural behavior, gliding and soaring flight in birds requires less energy than flapping flight. Slow tonic and slow twitch muscle fibers are specialized for sustained contraction with high fatigue resistance and are typically found in muscles associated with posture. Albatrosses are the elite of avian gliders; as such, we wanted to learn how their musculoskeletal system enables them to maintain spread-wing posture for prolonged gliding bouts. We used dissection and immunohistochemistry to evaluate muscle function for gliding flight in Laysan and Black-footed albatrosses. Albatrosses possess a locking mechanism at the shoulder composed of a tendinous sheet that extends from origin to insertion throughout the length of the deep layer of the pectoralis muscle. This fascial "strut" passively maintains horizontal wing orientation during gliding and soaring flight. A number of muscles, which likely facilitate gliding posture, are composed exclusively of slow fibers. These include Mm. coracobrachialis cranialis, extensor metacarpi radialis dorsalis, and deep pectoralis. In addition, a number of other muscles, including triceps scapularis, triceps humeralis, supracoracoideus, and extensor metacarpi radialis ventralis, were found to have populations of slow fibers. We believe that this extensive suite of uniformly slow muscles is associated with sustained gliding and is unique to birds that glide and soar for extended periods. These findings suggest that albatrosses utilize a combination of slow muscle fibers and a rigid limiting tendon for maintaining a prolonged, gliding posture.

Neuromuscular adaptations to long-term progressive resistance training translates to improved functional capacity for people with multiple sclerosis and is maintained at follow-up

DEFF Research Database (Denmark)

Kjolhede, T.; Vissing, K.; de Place, L.

2015-01-01

BACKGROUND: Progressive resistance training (PRT) is acknowledged to effectively improve muscle strength for people with multiple sclerosis (PwMS), but diverging results exist regarding whether such improvements translates to improved functional capacity, possibly relating to insufficient duration......: This study was a randomised controlled trial, with a training group and a waitlist group undergoing supervised PRT for 24 weeks initially or after 24 weeks of habitual lifestyle, respectively. Functional capacity, isometric muscle strength of knee extensors and flexors, neural drive and thigh muscle cross......-sectional area was measured at baseline, after 24 and 48 weeks. RESULTS: The training group significantly improved neuromuscular function of the knee extensors and flexors, which translated to improvements in functional capacity. Furthermore, the improved functional capacity was maintained after 24 weeks of self...

Relationship between Muscle Function, Muscle Typology and Postural Performance According to Different Postural Conditions in Young and Older Adults.

Science.gov (United States)

Paillard, Thierry

2017-01-01

Although motor output of the postural function clearly influences postural performance in young and older subjects, no relationship has been formally established between them. However, the relationship between lower-extremity muscle strength/power and postural performance is often pointed out, especially in older subjects. In fact, the influence of motor output may vary according to the postural condition considered (e.g., static, dynamic, challenging, disturbing). In static postural condition, there may be a relationship between lower-extremity muscle strength and postural performance when the value of muscle strength is below a certain threshold in older subjects. Above this threshold of muscle strength, this relationship may disappear. In dynamic postural condition, lower-extremity muscle power could facilitate compensatory postural actions, limiting induced body imbalance likely to generate falls in older subjects. In young subjects, there could be a relationship between very early rapid torque of the leg extensor muscles and postural performance. In the case of postural reaction to (external) perturbations, a high percentage of type II muscle fibers could be associated with the ability to react quickly to postural perturbations in young subjects, while it may enable a reduction in the risk of falls in older subjects. In practice, in older subjects, muscle strength and/or power training contributes to reducing the risk of falls, as well as slowing down the involution of muscle typology regarding type II muscle fibers.