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Sample records for quadriceps muscle group

  1. Quadriceps muscle use in the flywheel and barbell squat.

    Science.gov (United States)

    Norrbrand, Lena; Tous-Fajardo, Julio; Vargas, Roberto; Tesch, Per A

    2011-01-01

    Resistance exercise has been proposed as an aid to counteract quadriceps muscle atrophy in astronauts during extended missions in orbit. While space authorities have advocated the squat exercise should be prescribed, no exercise system suitable for in-flight use has been validated with regard to quadriceps muscle use. We compared muscle involvement in the terrestrial "gold standard" squat using free weights and a nongravity dependent flywheel resistance exercise device designed for use in space. The subjects were 10 strength-trained men who performed 5 sets of 10 repetitions using the barbell squat (BS; 10 repetition maximum) or flywheel squat (FS; each repetition maximal), respectively. Functional magnetic resonance imaging (MRI) and surface electromyography (EMG) techniques assessed quadriceps muscle use. Exercise-induced contrast shift of MR images was measured by means of transverse relaxation time (T2). EMG root mean square (RMS) was measured during concentric (CON) and eccentric (ECC) actions and normalized to EMG RMS determined during maximal voluntary contraction. The quadriceps muscle group showed greater exercise-induced T2 increase following FS compared with BS. Among individual muscles, the rectus femoris displayed greater T2 increase with FS (+24 +/- 14%) than BS (+8 +/- 4%). Normalized quadriceps EMG showed no difference across exercise modes. Collectively, the results of this study suggest that quadriceps muscle use in the squat is comparable, if not greater, with flywheel compared with free weight resistance exercise. Data appear to provide support for use of flywheel squat resistance exercise as a countermeasures adjunct during spaceflight.

  2. Different Muscle Action Training Protocols on Quadriceps-Hamstrings Neuromuscular Adaptations.

    Science.gov (United States)

    Ruas, Cassio V; Brown, Lee E; Lima, Camila D; Gregory Haff, G; Pinto, Ronei S

    2018-05-01

    The aim of this study was to compare three specific concentric and eccentric muscle action training protocols on quadriceps-hamstrings neuromuscular adaptations. Forty male volunteers performed 6 weeks of training (two sessions/week) of their dominant and non-dominant legs on an isokinetic dynamometer. They were randomly assigned to one of four groups; concentric quadriceps and concentric hamstrings (CON/CON, n=10), eccentric quadriceps and eccentric hamstrings (ECC/ECC, n=10), concentric quadriceps and eccentric hamstrings (CON/ECC, n=10), or no training (CTRL, n=10). Intensity of training was increased every week by decreasing the angular velocity for concentric and increasing it for eccentric groups in 30°/s increments. Volume of training was increased by adding one set every week. Dominant leg quadriceps and hamstrings muscle thickness, muscle quality, muscle activation, muscle coactivation, and electromechanical delay were tested before and after training. Results revealed that all training groups similarly increased MT of quadriceps and hamstrings compared to control (p0.05). These findings suggest that different short-term muscle action isokinetic training protocols elicit similar muscle size increases in hamstrings and quadriceps, but not for other neuromuscular variables. Nevertheless, effect sizes indicate that CON/ECC and ECC/ECC may elicit the greatest magnitude of change in muscle hypertrophy. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Isokinetic hamstring and quadriceps muscle strength profiles of elite ...

    African Journals Online (AJOL)

    Football players are at risk of lower limb injuries, specifically hamstring muscle strains and ACL injuries due to muscle imbalances. This was a descriptive study assessing the isokinetic hamstring and quadriceps muscle strength and endurance in 28 elite, male, South African football players. Muscle strength was tested at 60 ...

  4. DEVELOPMENTS IN THE USE OF THE HAMSTRING/QUADRICEPS RATIO FOR THE ASSESSMENT OF MUSCLE BALANCE

    Directory of Open Access Journals (Sweden)

    Gerard Garbutt

    2002-09-01

    Full Text Available Isokinetic moment ratios of the hamstrings (H and quadriceps (Q muscle groups, and their implication in muscle imbalance, have been investigated for more than three decades. The conventional concentric H/Q ratio with its normative value of 0.6 has been at the forefront of the discussion. This does not account for the joint angle at which moment occurs and the type of muscle action involved. Advances towards more functional analyses have occurred such that previous protocols are being re-examined raising questions about their ability to demonstrate a relationship between thigh muscle imbalance and increased incidence or risk of knee injury. This article addresses the function of the hamstring-quadriceps ratio in the interpretation of this relationship using the ratios Hecc/Qcon (ratio of eccentric hamstring strength to concentric quadriceps strength, representative of isolated knee extension and Hcon/Qecc (ratio of concentric hamstring strength to eccentric quadriceps strength, representative of isolated knee flexion.

  5. Partial rupture of the quadriceps muscle in a child

    Directory of Open Access Journals (Sweden)

    Aydemir Gokhan

    2010-09-01

    Full Text Available Abstract Background The quadriceps femoris muscle ruptures usually occur in the middle-aged population. We present a 4-year-old patient with partial rupture of the quadriceps femoris muscle. To our knowledge, this is the youngest patient reported with a quadriceps femoris muscle rupture. Case Presentation A 4-year-old girl admitted to our clinic with left knee pain and limitation in knee movements. Her father reported that she felt pain while jumping on sofa. There was no direct trauma to thigh or knee. We located a palpable soft tissue swelling at distal anterolateral side of thigh. The history revealed that 10 days ago the patient was treated for upper tract respiratory infection with intramuscular Clindamycin for 7 days. When we consulted the patient with her previous doctor and nurse, we learnt that multiple daily injections might be injected to same side of left thigh. MRI showed a partial tear of vastus lateralis muscle matching with the injection sites. The patient treated with long leg half-casting for three weeks. Clinical examination and knee flexion had good results with conservative treatment. Conclusions Multiple intramuscular injections may contribute to damage muscles and make prone to tears with muscle contractions. Doctors and nurses must be cautious to inject from different parts of both thighs.

  6. Reliability of the Q Force; a mobile instrument for measuring isometric quadriceps muscle strength

    NARCIS (Netherlands)

    Douma, K W; Regterschot, G R H; Krijnen, W P; Slager, G E C; van der Schans, C P; Zijlstra, W

    2016-01-01

    BACKGROUND: The ability to generate muscle strength is a pre-requisite for all human movement. Decreased quadriceps muscle strength is frequently observed in older adults and is associated with a decreased performance and activity limitations. To quantify the quadriceps muscle strength and to

  7. Reliability of the Q Force; a mobile instrument for measuring isometric quadriceps muscle strength

    NARCIS (Netherlands)

    Douma, Rob; Regterschot, G.R.H.; Krijnen, Wim; Slager, Geranda; van der Schans, Cees; Zijlstra, W.

    2016-01-01

    Background: The ability to generate muscle strength is a pre-requisite for all human movement. Decreased quadriceps muscle strength is frequently observed in older adults and is associated with a decreased performance and activity limitations. To quantify the quadriceps muscle strength and to

  8. A stepwise procedure to test contractility and susceptibility to injury for the rodent quadriceps muscle

    Directory of Open Access Journals (Sweden)

    Stephen J.P. Pratt

    2014-07-01

    Full Text Available In patients with muscle injury or muscle disease, assessment of muscle damage is typically limited to clinical signs, such as tenderness, strength, range of motion, and more recently, imaging studies.  Biological markers can also be used in measuring muscle injury, such as increased creatine kinase levels in the blood, but these are not always correlated with loss in muscle function (i.e. loss of force production.  This is even true of histological findings from animals, which provide a “direct measure” of damage, but do not account for loss of function.  The most comprehensive measure of the overall health of the muscle is contractile force.  To date, animal models testing contractile force have been limited to the muscle groups moving the ankle.  Here we describe an in vivo animal model for the quadriceps, with abilities to measure torque, produce a reliable muscle injury, and follow muscle recovery within the same animal over time.  We also describe a second model used for direct measurement of force from an isolated quadriceps muscle in situ. 

  9. Effect of quadriceps and hamstrings muscle cooling on standing balance in healthy young men.

    Science.gov (United States)

    Alghadir, A H; Anwer, S; Zafar, H; Al-Eisa, E S

    2017-09-01

    The present study compared the effect of quadriceps and hamstring muscle cooling on standing balance in healthy young men. Thirty healthy young men (18-30 years) participated in the study. The participants were randomly assigned to three groups (n=10 each): quadriceps cooling (QC), hamstring cooling (HC), or control group (no cooling). Participants in the QC and HC groups received 20 minutes of cooling using a cold pack (gel pack), placed on the anterior thigh (from the apex of the patella to the mid-thigh) and the posterior thigh (from the base of the popliteal fossa to the mid-thigh), respectively. Balance score including unilateral stance was measured at baseline and immediately after the application of the cold pack. No significant difference in the balance score was noted in any group after the application of the cold pack (p⟩0.05). Similarly, no significant differences in post-test balance score were noted among the three groups (p⟩0.05). Cooling of the quadriceps and hamstring muscles has no immediate effect on standing balance in healthy young men. However, longitudinal studies are warranted to investigate the long-term effects of cooling these muscles on standing balance.

  10. Effect of isometric quadriceps exercise on muscle strength, pain, and function in patients with knee osteoarthritis: a randomized controlled study.

    Science.gov (United States)

    Anwer, Shahnawaz; Alghadir, Ahmad

    2014-05-01

    [Purpose] The aim of present study was to investigate the effects of isometric quadriceps exercise on muscle strength, pain, and function in knee osteoarthritis. [Subjects and Methods] Outpatients (N=42, 21 per group; age range 40-65 years; 13 men and 29 women) with osteoarthritis of the knee participated in the study. The experimental group performed isometric exercises including isometric quadriceps, straight leg raising, and isometric hip adduction exercise 5 days a week for 5 weeks, whereas the control group did not performed any exercise program. The outcome measures or dependent variables selected for this study were pain intensity, isometric quadriceps strength, and knee function. These variables were measured using the Numerical Rating Scale (NRS), strength gauge device, and reduced WOMAC index, respectively. All the measurements were taken at baseline (week 0) and at the end of the trial at week 5. [Results] In between-group comparisons, the maximum isometric quadriceps strength, reduction in pain intensity, and improvement in function in the isometric exercise group at the end of the 5th week were significantly greater than those of the control group (pisometric quadriceps exercise program showed beneficial effects on quadriceps muscle strength, pain, and functional disability in patients with osteoarthritis of the knee.

  11. Femoral quadriceps muscle injury: ultrasonography and magnetic resonance

    International Nuclear Information System (INIS)

    Rodriguez, P.; Manjon, P.; Revilla, Y.; Ciudad, E.; Buj, M.J.

    1998-01-01

    Femoral quadriceps muscle (FQM) injury is a common lesion amongathletes, especially soccer players. It is important to determine the extension of the lesion and whether or not here is accompanying hematoma. Ultrasound and magnetic resonance (MR) are excellent methods for studying these lesions. To assess the ultrasonographic and MR findings associated with FQM injury to aid in its diagnosis and the determination of its extension. We review the ultrasonographic studies in 9 patients with FQM injury and the corresponding MR studies in five of these patients. Ultrasound and MR reveal the rupture of the muscle fibers, the mass effect produced by the hematoma between the ruptured fiber and the changes in echogenicity and typical signal changes in the hematoma. Chronic cases presented fibrous scar tissue and intermittent mass effects mimicking those of tumors. Ultrasound and MR demonstrate that these masses correspond to normal contractions of the muscle fibers among the fibrous scar tissue, ruling our their tumor-related etiology. Although both ultrasound and MR are excellent methods and of similar value in the study of muscle injury, we consider the former to be more readily available and inexpensive. Moreover, the ultrasonographic study is more suitable for the study of the intermittent mass effect produced by abnormal contraction of chronically injured muscles. (Author) 5 refs

  12. Reliability of the Q Force; a mobile instrument for measuring isometric quadriceps muscle strength

    OpenAIRE

    Schans, van der, C.P.; Zijlstra, W.; Regterschot, G.R.H.; Krijnen, W.P.; Douma, K.W.; Slager, G.E.C.

    2016-01-01

    BACKGROUND: The ability to generate muscle strength is a pre-requisite for all human movement. Decreased quadriceps muscle strength is frequently observed in older adults and is associated with a decreased performance and activity limitations. To quantify the quadriceps muscle strength and to monitor changes over time, instruments and procedures with a sufficient reliability are needed. The Q Force is an innovative mobile muscle strength measurement instrument suitable to measure in various d...

  13. Effects of Quadriceps Muscle Fatigue on Stiff-Knee Gait in Patients with Hemiparesis

    Science.gov (United States)

    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

  14. Serial Changes of Quadriceps and Hamstring Muscle Strength Following Total Knee Arthroplasty: A Meta-Analysis

    Science.gov (United States)

    Ahn, Hyeong-Sik; Lee, Dae-Hee

    2016-01-01

    This meta-analysis was performed to analyze serial changes in thigh muscles, including quadriceps and hamstring muscles, from before to one year after total knee arthroplasty (TKA). All studies sequentially comparing isokinetic quadriceps and hamstring muscle strengths between the TKA side and the contralateral uninjured limb were included in this meta-analysis. Five studies with 7 cohorts were included in this meta-analysis. The mean differences in the strengths of quadriceps and hamstring muscles between the TKA and uninjured sides were greatest three months after surgery (26.8 N∙m, 12.8 N∙m, Phamstring strengths relative to preoperative levels were 9.2 N∙m and 4.9 N∙m, respectively, three months postoperatively (P = 0.041), but were no longer significant after six months and one year. During the year after TKA, quadriceps and hamstring muscle strengths were lowest after 3 months, recovering to preoperative level after six months, but not reaching the muscle strength on the contralateral side. Relative to preoperative levels, the difference in muscle strength between the TKA and contralateral knees was only significant at three months. Because decrease of strength of the quadriceps was significantly greater than decrease in hamstring muscle strength at postoperative three months, early rehabilitation after TKA should focus on recovery of quadriceps muscle strength. PMID:26849808

  15. The twitch interpolation technique for study of fatigue of human quadriceps muscle

    DEFF Research Database (Denmark)

    Bülow, P M; Nørregaard, J; Mehlsen, J

    1995-01-01

    The aim of the study was to examine if the twitch interpolation technique could be used to objectively measure fatigue in the quadriceps muscle in subjects performing submaximally. The 'true' maximum isometric quadriceps torque was determined in 21 healthy subject using the twitch interpolation...... technique. Then an endurance test was performed in which the subjects made repeated isometric contractions at 50% of the 'true' maximum torque for 4 s, separated by 6 s rest periods. During the test, the force response to single electrical stimulation (twitch amplitude) was measured at 50% and 25......). In conclusion, the twitch technique can be used for objectively measuring fatigue of the quadriceps muscle....

  16. Influence of Isometric Exercise Training on Quadriceps Muscle Architecture and Strength in Obese Subjects with Knee Osteoarthritis

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    Waleed S Mahmoud

    2017-03-01

    Full Text Available Obese individuals have reduced quadriceps muscle strength relative to body mass that may increase the rate of progression of knee osteoarthritis (OA. The purpose of this study was to evaluate the effects of isometric exercise training on quadriceps muscle architecture and strength in obese subjects with knee osteoarthritis. Methods: Fortyfour obese male subjects aged 40–65 years diagnosed with knee osteoarthritis were randomly assigned into group A (n=32 and group B (n=12. Group A subjects performed a 12-week isometric exercise program. Group B subjects did not participate in any exercise program and maintained their ordinary activities for the same period. Both groups received the same conventional physical therapy program including hot packs and therapeutic ultrasonic. Muscle thickness, pennation angles and fascicle length of the vastus lateralis (VL muscle of the affected knee were measured at rest by B-mode ultrasonography. Maximal voluntary isometric knee extension torque (MVIC of the affected knee was measured using an isokinetic dynamometer. Knee pain and function were evaluated using visual analogue pain scale (VAS and Western Ontario and McMaster Universities Arthritis Index (WOMAC. All variables were evaluated before and the end of the intervention period for both groups. Results: at the end of the program, group A subjects showed significant improvements compared with group B subjects regarding MVIC and muscle architecture parameters (p<0.05. Also, there was significant improvement in post-test VAS and WOMAC scores in group A subjects compared to group B subjects (p<0.05. Conclusion: A 12-week quadriceps isometric training program improves knee pain and quadriceps muscle strength and architecture in obese subjects with knee OA. These results indicate that isometric training should be regarded as a proper exercise intervention for obese patients with knee OA.

  17. 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.

  18. Fatigue-related changes in motor-unit synchronization of quadriceps muscles within and across legs

    NARCIS (Netherlands)

    Boonstra, T.W.; Daffertshofer, A.; van Ditshuizen, J.C.; van den Heuvel, M.R.C.; Hofman, C.; Willigenburg, N.W.; Beek, P.J.

    2008-01-01

    Two experiments were conducted to examine effects of muscle fatigue on motor-unit synchronization of quadriceps muscles (rectus femoris, vastus medialis, vastus lateralis) within and between legs. We expected muscle fatigue to result in an increased common drive to different motor units of

  19. Quadriceps Strength and Endurance After Posterior Cruciate Ligament Tears Versus Matched Group With Anterior Cruciate Ligament Tears.

    Science.gov (United States)

    Lee, Dae-Hee; Han, Seung-Beom; Lee, Jin-Hyuck; Lee, Seok-Joo; Suh, Dong-Won; Jeong, Hye-Jin

    2015-06-01

    This study was designed to compare the preoperative strengths and endurances of the quadriceps and hamstring muscles in patients with anterior cruciate ligament (ACL) versus posterior cruciate ligament (PCL) tears. Quadriceps and hamstring muscle strength and endurance were compared between 20 prospectively enrolled patients with isolated PCL tears and a retrospective, matched control group of 20 patients with isolated ACL tears. The maximal torque (60°/s) and total work (180°/s) of the quadriceps and hamstring were evaluated with an isokinetic testing device. Total work (1,094.4 ± 505.8 J v 797.5 ± 332.7 J, P = .035) and peak torque (129.9 ± 56.2 N ∙ m v 98.2 ± 37.4 N ∙ m, P = .046) of the quadriceps muscle on the involved side were higher in the PCL tear group than in the ACL tear group. However, there were no significant differences between the PCL tear group and ACL tear group in hamstring muscle strength (45.8 ± 42.3 N ∙ m and 46.0 ± 24.4 N ∙ m, respectively; P = .940) and endurance (429.3 ± 238.9 J and 382.4 ± 256.1 J, respectively; P = .574) on the involved side. The strength and endurance of the quadriceps muscle of the injured limb were greater after PCL tears than after ACL tears. However, there were no significant between-group differences in hamstring muscle strength and endurance on the involved side. Level III, retrospective comparative study. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  20. Influence of Anterior Cruciate Ligament Tear on Thigh Muscle Strength and Hamstring-to-Quadriceps Ratio: A Meta-Analysis

    Science.gov (United States)

    Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

    2016-01-01

    Theoretical compensation after anterior cruciate ligament (ACL) tear could cause quadriceps weakness and hamstring activation, preventing anterior tibial subluxation and affecting the expected hamstring-to-quadriceps ratio. Although quadriceps weakness often occurs after ACL tears, it remains unclear whether hamstring strength and hamstring-to-quadriceps ratio increase in ACL deficient knees. This meta-analysis compared the isokinetic muscle strength of quadriceps and hamstring muscles, and the hamstring-to-quadriceps ratio, of the injured and injured limbs of patients with ACL tears. This meta-analysis included all studies comparing isokinetic thigh muscle strengths and hamstring-to-quadriceps ratio in the injured and uninjured legs of patients with ACL tear, without or before surgery. Thirteen studies were included in the meta-analysis. Quadriceps and hamstring strengths were 22.3 N∙m (95% CI: 15.2 to 29.3 N∙m; Phamstring-to-quadriceps ratio was 4% greater in ACL deficient than in uninjured limbs (95% CI: 1.7% to 6.3%; Phamstring muscles of patients with ACL tear, with the decrease in quadriceps strength being 3-fold greater. These uneven reductions slightly increase the hamstring-to-quadriceps ratio in ACL deficient knees. PMID:26745808

  1. Sports Mass Age Therapy on the Reduction of Delayed Onset Muscle Soreness of the Quadriceps Femoris

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    Boguszewski Dariusz

    2014-12-01

    Full Text Available Purpose. Massage therapy is one of most commonly applied treatments during athletic training. The aim of this study was to assess the effectiveness of sports massage therapy on reducing post-exercise quadriceps muscle soreness. Methods. A sample of 29 women aged 24-26 years was divided into an experimental group (n = 15 receiving classic sports massage therapy and a control group (n = 14 given no treatment. An exercise session consisting of five sets of deep squat jumps was administered after which lower limb power as assessed via the vertical jump test. Muscle soreness was assessed using the visual analogue scale (VAS and exercise intensity with the Borg Rating of Perceived Exertion Scale. Subsequent measurements of lower limb power and muscle soreness were performed 24, 48, 72 and 96 h after the exercise session. Differences between the measurements were assessed by the Friedman and least significant difference tests while between-group comparisons involved the Mann-Whitney U test. Results. The largest decrease in lower limb power was observed between the first measurement after the exercise session and 24 h later (p < 0.01. The smallest decrease in power was observed in the massage group. The highest levels of muscle soreness were noted 24 h post-exercise in the massage group and 48 h post-exercise in the control group. The experimental group showed a decrease in muscle soreness in each subsequent measurement, with the results close to zero on the VAS 96 h postexercise. Conclusions. Massage therapy quickened recovery and improved muscle efficiency post-exercise and may serve as an effective treatment of muscle soreness. The analgesic effect of massage suggests it should be widely applied in sport, physical therapy and rehabilitation.

  2. Quadriceps muscle strength and voluntary activation after polio

    NARCIS (Netherlands)

    Beelen, Anita; Nollet, Frans; de Visser, Marianne; de Jong, Bareld A.; Lankhorst, Gustaaf J.; Sargeant, Anthony J.

    2003-01-01

    Quadriceps strength, maximal anatomical cross-sectional area (CSA), maximal voluntary activation (MVA), and maximal relaxation rate (MRR) were studied in 48 subjects with a past history of polio, 26 with and 22 without postpoliomyelitis syndrome (PPS), and in 13 control subjects. It was also

  3. Quadriceps muscle function after rehabilitation with cryotherapy in patients with anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Hart, Joseph M; Kuenze, Christopher M; Diduch, David R; Ingersoll, Christopher D

    2014-01-01

    Persistent muscle weakness after anterior cruciate ligament (ACL) reconstruction may be due to underlying activation failure and arthrogenic muscle inhibition (AMI). Knee-joint cryotherapy has been shown to improve quadriceps function transiently in those with AMI, thereby providing an opportunity to improve quadriceps muscle activation and strength in patients with a reconstructed ACL. To compare quadriceps muscle function in patients with a reconstructed ACL who completed a 2-week intervention including daily cryotherapy (ice bag), daily exercises, or both. Cross-sectional study. Laboratory. A total of 30 patients with reconstructed ACLs who were at least 6 months post-index surgery and had measurable quadriceps AMI. The patients attended 4 supervised visits over a 2-week period. They were randomly assigned to receive 20 minutes of knee-joint cryotherapy, 1 hour of therapeutic rehabilitation exercises, or cryotherapy followed by exercises. We measured quadriceps Hoffmann reflex, normalized maximal voluntary isometric contraction torque, central activation ratio using the superimposed-burst technique, and patient-reported outcomes before and after the intervention period. After the 2-week intervention period, patients who performed rehabilitation exercises immediately after cryotherapy had higher normalized maximal voluntary isometric contraction torques (P = .002, Cohen d effect size = 1.4) compared with those who received cryotherapy alone (P = .16, d = 0.58) or performed exercise alone (P = .16, d = 0.30). After ACL reconstruction, patients with AMI who performed rehabilitation exercises immediately after cryotherapy experienced greater strength gains than those who performed cryotherapy or exercises alone.

  4. Duration Dependent Effect of Static Stretching on Quadriceps and Hamstring Muscle Force

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    Leyla Alizadeh Ebadi

    2018-03-01

    Full Text Available The aim of this study was to determine the acute effect of static stretching on hamstring and quadriceps muscles’ isokinetic strength when applied for various durations to elite athletes, to investigate the effect of different static stretching durations on isokinetic strength, and finally to determine the optimal stretching duration. Fifteen elite male athletes from two different sport branches (10 football and five basketball participated in this study. Experimental protocol was designed as 17 repetitive static stretching exercises for hamstring and quadriceps muscle groups according to the indicated experimental protocols; ((A 5 min jogging; (B 5 min jogging followed by 15 s static stretching; (C 5 min jogging followed by 30 s static stretching; (D 5 min jogging, followed by static stretching for 45 s. Immediately after each protocol, an isokinetic strength test consisting of five repetitions at 60°/s speed and 20 repetitions at 180°/s speed was recorded for the right leg by the Isomed 2000 device. Friedman variance analysis test was employed for data analysis. According to the analyzes, it was observed that 5 min jogging and 15 s stretching exercises increased the isokinetic strength, whereas 30 and 45 s stretching exercises caused a decrease.

  5. Exercise-induced quadriceps muscle fatigue in men and women: effects of arterial oxygen content and respiratory muscle work.

    Science.gov (United States)

    Dominelli, Paolo B; Molgat-Seon, Yannick; Griesdale, Donald E G; Peters, Carli M; Blouin, Jean-Sébastien; Sekhon, Mypinder; Dominelli, Giulio S; Henderson, William R; Foster, Glen E; Romer, Lee M; Koehle, Michael S; Sheel, A William

    2017-08-01

    High work of breathing and exercise-induced arterial hypoxaemia (EIAH) can decrease O 2 delivery and exacerbate exercise-induced quadriceps fatigue in healthy men. Women have a higher work of breathing during exercise, dedicate a greater fraction of whole-body V̇O2 towards their respiratory muscles and develop EIAH. Despite a greater reduction in men's work of breathing, the attenuation of quadriceps fatigue was similar between the sexes. The degree of EIAH was similar between sexes, and regardless of sex, those who developed the greatest hypoxaemia during exercise demonstrated the most attenuation of quadriceps fatigue. Based on our previous finding that women have a greater relative oxygen cost of breathing, women appear to be especially susceptible to work of breathing-related changes in quadriceps muscle fatigue. Reducing the work of breathing or eliminating exercise-induced arterial hypoxaemia (EIAH) during exercise decreases the severity of quadriceps fatigue in men. Women have a greater work of breathing during exercise, dedicate a greater fraction of whole-body V̇O2 towards their respiratory muscles, and demonstrate EIAH, suggesting women may be especially susceptible to quadriceps fatigue. Healthy subjects (8 male, 8 female) completed three constant load exercise tests over 4 days. During the first (control) test, subjects exercised at ∼85% of maximum while arterial blood gases and work of breathing were assessed. Subsequent constant load exercise tests were iso-time and iso-work rate, but with EIAH prevented by inspiring hyperoxic gas or work of breathing reduced via a proportional assist ventilator (PAV). Quadriceps fatigue was assessed by measuring force in response to femoral nerve stimulation. For both sexes, quadriceps force was equally reduced after the control trial (-27 ± 2% baseline) and was attenuated with hyperoxia and PAV (-18 ± 1 and -17 ± 2% baseline, P Physiology © 2017 The Physiological Society.

  6. A novel noninvasive method for measuring fatigability of the quadriceps muscle in noncooperating healthy subjects

    DEFF Research Database (Denmark)

    Poulsen, Jesper Brøndum; Rose, Martin Høyer; Møller, Kirsten

    2015-01-01

    days, nonvoluntary isometric contractions (twitch and tetanic) of the quadriceps femoris muscle evoked by transcutaneous electrical muscle stimulation were recorded in twelve healthy adults. For tetanic contractions, the Fatigue Index (ratio of peak torque values) and the slope of the regression line...... of peak torque values were primary outcome measures. For twitch contractions, maximum peak torque and rise time were calculated. Relative (intraclass correlation, ICC3.1) and absolute (standard error of measurement, SEM) reliability were assessed and minimum detectable change was calculated using a 95...... fatigability of the quadriceps muscle produces reliable results in healthy subjects and may provide valuable data on quantitative changes in muscle working capacity and treatment effects in patients who are incapable of producing voluntary muscle contractions....

  7. Influence of Anterior Cruciate Ligament Tear on Thigh Muscle Strength and Hamstring-to-Quadriceps Ratio: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Hyun-Jung Kim

    Full Text Available Theoretical compensation after anterior cruciate ligament (ACL tear could cause quadriceps weakness and hamstring activation, preventing anterior tibial subluxation and affecting the expected hamstring-to-quadriceps ratio. Although quadriceps weakness often occurs after ACL tears, it remains unclear whether hamstring strength and hamstring-to-quadriceps ratio increase in ACL deficient knees. This meta-analysis compared the isokinetic muscle strength of quadriceps and hamstring muscles, and the hamstring-to-quadriceps ratio, of the injured and injured limbs of patients with ACL tears. This meta-analysis included all studies comparing isokinetic thigh muscle strengths and hamstring-to-quadriceps ratio in the injured and uninjured legs of patients with ACL tear, without or before surgery. Thirteen studies were included in the meta-analysis. Quadriceps and hamstring strengths were 22.3 N∙m (95% CI: 15.2 to 29.3 N∙m; P<0.001 and 7.4 N∙m (95% CI: 4.3 to 10.5 N∙m; P<0.001 lower, respectively, on the injured than on the uninjured side. The mean hamstring-to-quadriceps ratio was 4% greater in ACL deficient than in uninjured limbs (95% CI: 1.7% to 6.3%; P<0.001. Conclusively, Decreases were observed in both the quadriceps and hamstring muscles of patients with ACL tear, with the decrease in quadriceps strength being 3-fold greater. These uneven reductions slightly increase the hamstring-to-quadriceps ratio in ACL deficient knees.

  8. RAPID KNEE-EXTENSIONS TO INCREASE QUADRICEPS MUSCLE ACTIVITY IN PATIENTS WITH TOTAL KNEE ARTHROPLASTY

    DEFF Research Database (Denmark)

    Husted, Rasmus Skov; Wilquin, Lousia; Jakobsen, Thomas Linding

    2017-01-01

    rapid knee-extensions were associated with greater voluntary quadriceps muscle activity during an experimental strength training session, compared to that elicited using slow knee-extensions. STUDY DESIGN: A randomized cross-over study. METHODS: Twenty-four patients (age 66.5) 4-8 weeks post total knee...... agonist muscle activity, especially if the exercise is conducted using rapid muscle contractions. PURPOSE: The purpose of this study was to examine if patients with total knee arthroplasty could perform rapid knee-extensions using a 10 RM load four to eight weeks after surgery, and the degree to which...... arthroplasty randomly performed one set of five rapid, and one set of five slow knee-extensions with the operated leg, using a load of their 10 repetition maximum, while surface electromyography recordings were obtained from the vastus medialis and lateralis of the quadriceps muscle. RESULTS: Data from 23...

  9. Rapid knee-extensions to increase quadriceps muscle activity in patients with total knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Rasmus Skov; Wilquin, Lousia; Jakobsen, Thomas Linding

    2017-01-01

    rapid knee-extensions were associated with greater voluntary quadriceps muscle activity during an experimental strength training session, compared to that elicited using slow knee-extensions. STUDY DESIGN: A randomized cross-over study. METHODS: Twenty-four patients (age 66.5) 4-8 weeks post total knee...... agonist muscle activity, especially if the exercise is conducted using rapid muscle contractions. PURPOSE: The purpose of this study was to examine if patients with total knee arthroplasty could perform rapid knee-extensions using a 10 RM load four to eight weeks after surgery, and the degree to which...... arthroplasty randomly performed one set of five rapid, and one set of five slow knee-extensions with the operated leg, using a load of their 10 repetition maximum, while surface electromyography recordings were obtained from the vastus medialis and lateralis of the quadriceps muscle. RESULTS: Data from 23...

  10. The comparison of quadriceps muscle strength between sprint runner and normal un-trained individuals (Determined by Kin-Com

    Directory of Open Access Journals (Sweden)

    Talebian Moghaddam S "

    2002-08-01

    Full Text Available Introduction: It is suggested that quadriceps muscle has an important role in stability & mobility of Knee joint in athletics and normal individuals; therefore, the purpose of this study was evaluation of the strength in Power Athletics (PA and Normal Un-trained Individuals (NUI groups. Methods and Materials: 31 Females (20 NUI & 11 PA participated in this study. For measuring the strength, each individual performed 5 continuous concentric-eccentric maximal contraction at angular velocities of 90°/s, 135°/s. Twenty five percent of each individual (Maximum Voluntary Isometric Contraction MVIC was determined and used as Pre-load force. Results: Averages concentric & eccentric torques were greater in PA group in comparison with NUI group. The significant difference (P<0.02 existed between PA and NUI groups. Average concentric torques of quadriceps muscle decreased (with increasing of speed from 90°/s to 135°/s and average eccentric torques increased. Average eccentric torques were greater (P<0.01 in PA & NUI groups in comparison with average concentric torques. Conclusion: PA group strength was greater in comparison with NUI group. This is possibly due to the type of muscle fibers in this group have (greater type II fibers. Accordingly, it is critical to consider the role of eccentric exercise in PA group for preventing sport injury.

  11. Effect of whole body vibration training on quadriceps muscle strength in individuals with knee osteoarthritis: a systematic review and meta-analysis.

    Science.gov (United States)

    Anwer, Shahnawaz; Alghadir, Ahmad; Zafar, Hamayun; Al-Eisa, Einas

    2016-06-01

    Several studies have reported the effects of whole body vibration (WBV) training on muscle strength. This systematic review investigates the current evidence regarding the effects of WBV training on quadriceps muscle strength in individuals with knee osteoarthritis (OA). We searched PubMed, CINAHL, Embase, Scopus, PEDro, and Science citation index for research articles published prior to March 2015 using the keywords whole body vibration, vibration training, strength and vibratory exercise in combination with the Medical Subject Heading 'Osteoarthritis knee'. This meta-analysis was limited to randomized controlled trials published in the English language. The quality of the selected studies was assessed by two independent evaluators using the PEDro scale and criteria given by the International Society of Musculoskeletal and Neuronal Interactions (ISMNI) for reporting WBV intervention studies. The risk of bias was assessed using the Cochrane collaboration's tool for domain-based evaluation. Isokinetic quadriceps muscle strength was calculated for each intervention. Eighteen studies were identified in the search. Of these, four studies met the inclusion criteria. Three of these four studies reached high methodological quality on the PEDro scale. Out of the four studies, only one study found significantly greater quadriceps muscle strength gains following WBV compared to the control group. In three of the four studies that compared a control group performing the same exercise as the WBV groups, no additional effect of WBV on quadriceps muscle strength in individuals with knee OA was indicated. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  12. Focal vibration of quadriceps muscle enhances leg power and decreases knee joint laxity in female volleyball players.

    Science.gov (United States)

    Brunetti, O; Botti, F M; Roscini, M; Brunetti, A; Panichi, R; Filippi, G M; Biscarini, A; Pettorossi, V E

    2012-12-01

    This double-blind randomized controlled study aims at determining the effect of repeated muscle vibration (rMV) on explosive and reactive leg power and on knee laxity of female volleyball players. Eighteen voluntary volleyball athletes, belonging to the same senior regional level team (age=22.7 ± 3 years, height=180.3 ± 5 cm, mass= 64 ± 4 kg) were assigned to three groups (N.=6) for vibration on contracted quadriceps (VC), vibration on relaxed muscle (VR), and sham vibration (NV), respectively. Intervention consisted in 3 rMV sessions performed in 3 consecutive days. In each session, 100 Hz, 300-500 μm amplitude vibratory stimuli were bilaterally delivered to the quadriceps in three consecutive 10-minutes applications. Explosive and reactive leg power and knee joint laxity were evaluated 1 day before, and 1, 30, and 240 days after intervention. In VC group, explosive and reactive leg power increased respectively by ~16% and ~9% at 1 day, by ~19% and ~11% at 30 days and by ~26% and ~13% at 240 days, concomitantly knee laxity decreased by ~6%, ~15% and ~18% at the same times. These changes were significantly larger than in the other groups, in which leg power increment and knee joint laxity reduction remained close to ~3%, ~5% and ~10% at 1, 30 and 240 days, respectively. Combined bilateral voluntary contraction and rMV of the quadriceps muscles is a short-lasting, non-invasive technique that can significantly and persistently improve muscle performance and knee laxity in volleyball women players.

  13. Normative Quadriceps and Hamstring Muscle Strength Values for Female, Healthy, Elite Handball and Football Players.

    Science.gov (United States)

    Risberg, May A; Steffen, Kathrin; Nilstad, Agnethe; Myklebust, Grethe; Kristianslund, Eirik; Moltubakk, Marie M; Krosshaug, Tron

    2018-05-23

    Risberg, MA, Steffen, K, Nilstad, A, Myklebust, G, Kristianslund, E, Moltubakk, MM, and Krosshaug, T. Normative quadriceps and hamstring muscle strength values for female, healthy, elite handball and football players. J Strength Cond Res XX(X): 000-000, 2018-This study presents normative values for isokinetic knee extension and flexion muscle strength tests in 350 elite, female, handball (n = 150) and football (n = 200) players. Isokinetic concentric muscle strength tests at 60°·sec were recorded bilaterally using a dynamometer. Peak torque (in Newton meter [N·m]), body mass normalized peak torque (N·m·kg), and hamstring to quadriceps ratio (H:Q ratio) for dominant and nondominant legs were recorded. The female elite players were 20.9 ± 4.0 years, started playing at the elite level at the age of 18.2 ± 2.7 years, with a mean of 9.7 ± 2.2 hours of weekly in-season training. Handball players demonstrated greater quadriceps muscle strength compared with football players (11.0%) (p handball players only (p = 0.012).The H:Q ratio was significantly lower for handball players (0.58) compared with football players (0.60) (p handball and football players can be used to set rehabilitation goals for muscle strength after injury and enable comparison with uninjured legs. Significantly greater quadriceps muscle strength was found for handball players compared with football players, also when normalized to body mass.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  14. Stiffness of individual quadriceps muscle assessed using ultrasound shear wave elastography during passive stretching

    Directory of Open Access Journals (Sweden)

    Jingfei Xu

    2018-04-01

    Full Text Available Background: Until recently it has not been possible to isolate the mechanical behavior of individual muscles during passive stretching. Muscle shear modulus (an index of muscle stiffness measured using ultrasound shear wave elastography can be used to estimate changes in stiffness of an individual muscle. The aims of the present study were (1 to determine the shear modulus–knee angle relationship and the slack angle of the vastus medialis oblique (VMO, rectus femoris (RF, and vastus lateralis (VL muscles; (2 to determine whether this differs between the muscles. Methods: Nine male rowers took part in the study. The shear modulus of VMO, RF, and VL muscles was measured while the quadriceps was passively stretched at 3°/s. The relationship between the muscle shear modulus and knee angle was plotted as shear modulus–knee angle curve through which the slack angle of each muscle was determined. Results: The shear modulus of RF was higher than that of VMO and VL when the muscles were stretched over 54° (all p  0.05. The slack angle was similar among the muscles: 41.3° ± 10.6°, 44.3° ± 9.1°, and 44.3° ± 5.6° of knee flexion for VMO, RF, and VL, respectively (p = 0.626. Conclusion: This is the first study to experimentally determine the muscle mechanical behavior of individual heads of the quadriceps during passive stretching. Different pattern of passive tension was observed between mono- and bi-articular muscles. Further research is needed to determine whether changes in muscle stiffness are muscle-specific in pathological conditions or after interventions such as stretching protocols. Keywords: Muscle tension, Optimal length, Shear modulus, Slack angle, Stretch, Ultrasonography, Vastus lateralis, Vastus medialis

  15. Influence of Anterior Cruciate Ligament Tear on Thigh Muscle Strength and Hamstring-to-Quadriceps Ratio: A Meta-Analysis.

    Science.gov (United States)

    Kim, Hyun-Jung; Lee, Jin-Hyuck; Ahn, Sung-Eun; Park, Min-Ji; Lee, Dae-Hee

    2016-01-01

    Theoretical compensation after anterior cruciate ligament (ACL) tear could cause quadriceps weakness and hamstring activation, preventing anterior tibial subluxation and affecting the expected hamstring-to-quadriceps ratio. Although quadriceps weakness often occurs after ACL tears, it remains unclear whether hamstring strength and hamstring-to-quadriceps ratio increase in ACL deficient knees. This meta-analysis compared the isokinetic muscle strength of quadriceps and hamstring muscles, and the hamstring-to-quadriceps ratio, of the injured and injured limbs of patients with ACL tears. This meta-analysis included all studies comparing isokinetic thigh muscle strengths and hamstring-to-quadriceps ratio in the injured and uninjured legs of patients with ACL tear, without or before surgery. Thirteen studies were included in the meta-analysis. Quadriceps and hamstring strengths were 22.3 N∙m (95% CI: 15.2 to 29.3 N∙m; Pratio was 4% greater in ACL deficient than in uninjured limbs (95% CI: 1.7% to 6.3%; Pratio in ACL deficient knees.

  16. 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...

  17. Muscle metabolism during graded quadriceps exercise in man

    DEFF Research Database (Denmark)

    Helge, Jørn W; Stallknecht, Bente; Galbo, Henrik

    2007-01-01

    , oxidation of plasma free fatty acids increases and accordingly oxidation of other fat sources decreases. These findings are in contrast to whole body measurements performed during graded exercise involving a large muscle mass during which fat oxidation peaks at around 60% of .......The aim of the study was to examine local muscle metabolism in response to graded exercise when the involved muscle mass is too small to elicit marked hormonal changes and local blood flow restriction. Nine healthy overnight fasted male subjects performed knee extension exercise with both thighs...... intensity. In conclusion, in the presence of a high blood flow and oxygen supply and only small hormonal changes, total fat oxidation in muscle increases from rest to light exercise, but then remains constant with exercise intensity up to heavy exercise. However, with increasing exercise intensity...

  18. THE MID - TERM EFFECT OF KINESIO TAPING ON PEAK POWER OF QUADRICEPS AND HAMSTRING MUSCLES AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Amel Khabazan Mahdi

    2017-01-01

    Full Text Available Purpose: The aim of this study was to assess mid- term effect of Kinesio tape on peak power of quadriceps and hamstrings muscles after ACL reconstruction 24 hours after taping. Material: Thirty six men who had undergone ACL reconstruction and completed physiotherapy periods (6 months were assigned to no taping, placebo and taping groups. Peak power was tested before and 24 hours after taping by Isokinetic dynamometry. Data was analyzed by SPSS software 19. ANOVA and post hoc test (LSD were used for interpretive analysis. Results: The results showed that the effect of Kinesio tape on peak power of quadriceps muscles at velocities of 180°/s and 300°/s was significant. In the hamstring muscles, significant effects were obtained at velocities of 60°/s, 180°/s & 300°/s. Conclusion: Positive impacts of Kinesio tape on muscular peak power among athletes who had ACL reconstruction were observed. Regardless of psychological effect and reducing re - injury fear, Kinesio - tape causes to stabilize and increase effective range of motion of the knee, so it is recommended that in the explosive training, athletes who have ACL reconstruction should use tape to reduce the probability of re-injury and increase muscle power.

  19. CHANGES IN QUADRICEPS MUSCLE ACTIVITY DURING SUSTAINED RECREATIONAL ALPINE SKIING

    Directory of Open Access Journals (Sweden)

    Josef Kröll

    2011-03-01

    Full Text Available During a day of skiing thousands of repeated contractions take place. Previous research on prolonged recreational alpine skiing show that physiological changes occur and hence some level of fatigue is inevitable. In the present paper the effect of prolonged skiing on the recruitment and coordination of the muscle activity was investigated. Six subjects performed 24 standardized runs. Muscle activity during the first two (PREskiing and the last two (POSTskiing runs was measured from the vastus lateralis (VL and rectus femoris (RF using EMG and quantified using wavelet and principal component analysis. The frequency content of the EMG signal shifted in seven out of eight cases significantly towards lower frequencies with highest effects observed for RF on outside leg. A significant pronounced outside leg loading occurred during POSTskiing and the timing of muscle activity peaks occurred more towards turn completion. Specific EMG frequency changes were observed at certain time points throughout the time windows and not over the whole double turn. It is suggested that general muscular fatigue, where additional specific muscle fibers have to be recruited due to the reduced power output of other fibers did not occur. The EMG frequency decrease and intensity changes for RF and VL are caused by altered timing (coordination within the turn towards a most likely more uncontrolled skiing technique. Hence, these data provide evidence to suggest recreational skiers alter their skiing technique before a potential change in muscle fiber recruitment occurs

  20. [Simultaneous Traumatic Rupture of Patellar Ligament and Contralateral Rupture of Quadriceps Femoris Muscle].

    Science.gov (United States)

    Hladký, V; Havlas, V

    2017-01-01

    Our paper presents a unique case of a 64-year-old patient after a fall, treated with oral antidiabetic drugs for type II diabetes mellitus. Following a series of examinations, a bilateral injury was diagnosed - patellar ligament tear on the right side and rupture of quadriceps femoris muscle on the left side. It is a rare injury, complicated by simultaneous involvement of both knee joints. The used therapy consisted of a bilateral surgery followed by gradual verticalisation, first with the support of a walking frame and later with the use of forearm crutches. During the final examination, the patient demonstrated full flexion at both knees, while an extension deficit of approx. 5 degrees was still present on the left side. The right knee X-ray showed a proper position of the patella after the removal of temporary tension band wire. Although the clinical results of operative treatment of both the patellar ligament rupture and rupture of quadriceps femoris muscle are in most cases good, early operative treatment, proper technique and post-operative rehabilitation are a prerequisite for success. Key words: knee injuries, patellar ligament, quadriceps muscle, rupture.

  1. Changes in Quadriceps Muscle Activity During Sustained Recreational Alpine Skiing

    Science.gov (United States)

    Kröll, Josef; Müller, Erich; Seifert, John G.; Wakeling, James M.

    2011-01-01

    During a day of skiing thousands of repeated contractions take place. Previous research on prolonged recreational alpine skiing show that physiological changes occur and hence some level of fatigue is inevitable. In the present paper the effect of prolonged skiing on the recruitment and coordination of the muscle activity was investigated. Six subjects performed 24 standardized runs. Muscle activity during the first two (PREskiing) and the last two (POSTskiing) runs was measured from the vastus lateralis (VL) and rectus femoris (RF) using EMG and quantified using wavelet and principal component analysis. The frequency content of the EMG signal shifted in seven out of eight cases significantly towards lower frequencies with highest effects observed for RF on outside leg. A significant pronounced outside leg loading occurred during POSTskiing and the timing of muscle activity peaks occurred more towards turn completion. Specific EMG frequency changes were observed at certain time points throughout the time windows and not over the whole double turn. It is suggested that general muscular fatigue, where additional specific muscle fibers have to be recruited due to the reduced power output of other fibers did not occur. The EMG frequency decrease and intensity changes for RF and VL are caused by altered timing (coordination) within the turn towards a most likely more uncontrolled skiing technique. Hence, these data provide evidence to suggest recreational skiers alter their skiing technique before a potential change in muscle fiber recruitment occurs. Key points The frequency content of the EMG signal shifted in seven out of eight cases significantly towards lower frequencies with highest effects observed for RF. General muscular fatigue, where additional specific fibers have to be recruited due to the reduced power output of other fibers, did not occur. A modified skiing style towards a less functional and hence more uncontrolled skiing technique seems to be a key

  2. Altered mitochondrial regulation in quadriceps muscles of patients with COPD

    DEFF Research Database (Denmark)

    Naimi, Ashley I; Bourbeau, Jean; Perrault, Helene

    2011-01-01

    Evidence exists for locomotor muscle impairment in patients with chronic obstructive pulmonary disease (COPD), including fiber type alterations and reduced mitochondrial oxidative capacity. In this study high-resolution respirometry was used to quantify oxygen flux in permeabilized fibres from bi...

  3. The associations between quadriceps muscle strength, power, and knee joint mechanics in knee osteoarthritis: A cross-sectional study.

    Science.gov (United States)

    Murray, Amanda M; Thomas, Abbey C; Armstrong, Charles W; Pietrosimone, Brian G; Tevald, Michael A

    2015-12-01

    Abnormal knee joint mechanics have been implicated in the pathogenesis and progression of knee osteoarthritis. Deficits in muscle function (i.e., strength and power) may contribute to abnormal knee joint loading. The associations between quadriceps strength, power and knee joint mechanics remain unclear in knee osteoarthritis. Three-dimensional motion analysis was used to collect peak knee joint angles and moments during the first 50% of stance phase of gait in 33 participants with knee osteoarthritis. Quadriceps strength and power were assessed using a knee extension machine. Strength was quantified as the one repetition maximum. Power was quantified as the peak power produced at 40-90% of the one repetition maximum. Quadriceps strength accounted for 15% of the variance in peak knee flexion angle (P=0.016). Quadriceps power accounted for 20-29% of the variance in peak knee flexion angle (Pknee adduction moment (P=0.05). These data suggest that quadriceps power explains more variance in knee flexion angle and knee adduction moment during gait in knee osteoarthritis than quadriceps strength. Additionally, quadriceps power at multiple loads is associated with knee joint mechanics and therefore should be assessed at a variety of loads. Taken together, these results indicate that quadriceps power may be a potential target for interventions aimed at changing knee joint mechanics in knee osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Exposure to microgravity for 30 days onboard Bion M1 caused muscle atrophy and impaired regeneration in murine femoral Quadriceps

    Science.gov (United States)

    Radugina, E. A.; Almeida, E. A. C.; Blaber, E.; Poplinskaya, V. A.; Markitantova, Y. V.; Grigoryan, E. N.

    2018-02-01

    Mechanical unloading in microgravity during spaceflight is known to cause muscular atrophy, changes in muscle fiber composition, gene expression, and reduction in regenerative muscle growth. Although some limited data exists for long-term effects of microgravity in human muscle, these processes have mostly been studied in rodents for short periods of time. Here we report on how long-term (30-day long) mechanical unloading in microgravity affects murine muscles of the femoral Quadriceps group. To conduct these studies we used muscle tissue from 6 microgravity mice, in comparison to habitat (7), and vivarium (14) ground control mice from the NASA Biospecimen Sharing Program conducted in collaboration with the Institute for Biomedical Problems of the Russian Academy of Sciences, during the Russian Bion M1 biosatellite mission in 2013. Muscle histomorphology from microgravity specimens showed signs of extensive atrophy and regenerative hypoplasia relative to ground controls. Specifically, we observed a two-fold decrease in the number of myonuclei, compared to vivarium and ground controls, and central location of myonuclei, low density of myofibers in the tissue, and of myofibrils within a fiber, as well as fragmentation and swelling of myofibers. Despite obvious atrophy, muscle regeneration nevertheless appeared to have continued after 30 days in microgravity as evidenced by thin and short newly formed myofibers. Many of them, however, showed evidence of apoptotic cells and myofibril degradation, suggesting that long-term unloading in microgravity may affect late stages of myofiber differentiation. Ground asynchronous and vivarium control animals demonstrated normal, well-developed tissue structure with sufficient blood and nerve supply and evidence of regenerative formation of new myofibers free of apoptotic nuclei. Regenerative activity of satellite cells in muscles was observed both in microgravity and ground control groups, using Pax7 and Myogenin

  5. Reliability of the Q Force; a mobile instrument for measuring isometric quadriceps muscle strength.

    Science.gov (United States)

    Douma, K W; Regterschot, G R H; Krijnen, W P; Slager, G E C; van der Schans, C P; Zijlstra, W

    2016-01-01

    The ability to generate muscle strength is a pre-requisite for all human movement. Decreased quadriceps muscle strength is frequently observed in older adults and is associated with a decreased performance and activity limitations. To quantify the quadriceps muscle strength and to monitor changes over time, instruments and procedures with a sufficient reliability are needed. The Q Force is an innovative mobile muscle strength measurement instrument suitable to measure in various degrees of extension. Measurements between 110 and 130° extension present the highest values and the most significant increase after training. The objective of this study is to determine the test-retest reliability of muscle strength measurements by the Q Force in older adults in 110° extension. Forty-one healthy older adults, 13 males and 28 females were included in the study. Mean (SD) age was 81.9 (4.89) years. Isometric muscle strength of the Quadriceps muscle was assessed with the Q Force at 110° of knee extension. Participants were measured at two sessions with a three to eight day interval between sessions. To determine relative reliability, the intraclass correlation coefficient (ICC) was calculated. To determine absolute reliability, Bland and Altman Limits of Agreement (LOA) were calculated and t-tests were performed. Relative reliability of the Q Force is good to excellent as all ICC coefficients are higher than 0.75. Generally a large 95 % LOA, reflecting only moderate absolute reliability, is found as exemplified for the peak torque left leg of -18.6 N to 33.8 N and the right leg of -9.2 N to 26.4 N was between 15.7 and 23.6 Newton representing 25.2 % to 39.9 % of the size of the mean. Small systematic differences in mean were found between measurement session 1 and 2. The present study shows that the Q Force has excellent relative test-retest reliability, but limited absolute test-retest reliability. Since the Q Force is relatively cheap and mobile it is suitable for

  6. Neuromuscular function of the quadriceps muscle during isometric maximal, submaximal and submaximal fatiguing voluntary contractions in knee osteoarthrosis patients.

    Directory of Open Access Journals (Sweden)

    Anett Mau-Moeller

    Full Text Available Knee osteoarthrosis (KOA is commonly associated with a dysfunction of the quadriceps muscle which contributes to alterations in motor performance. The underlying neuromuscular mechanisms of muscle dysfunction are not fully understood. The main objective of this study was to analyze how KOA affects neuromuscular function of the quadriceps muscle during different contraction intensities.The following parameters were assessed in 20 patients and 20 healthy controls: (i joint position sense, i.e. position control (mean absolute error, MAE at 30° and 50° of knee flexion, (ii simple reaction time task performance, (iii isometric maximal voluntary torque (IMVT and root mean square of the EMG signal (RMS-EMG, (iv torque control, i.e. accuracy (MAE, absolute fluctuation (standard deviation, SD, relative fluctuation (coefficient of variation, CV and periodicity (mean frequency, MNF of the torque signal at 20%, 40% and 60% IMVT, (v EMG-torque relationship at 20%, 40% and 60% IMVT and (vi performance fatigability, i.e. time to task failure (TTF at 40% IMVT.Compared to the control group, the KOA group displayed: (i significantly higher MAE of the angle signal at 30° (99.3%; P = 0.027 and 50° (147.9%; P < 0.001, (ii no significant differences in reaction time, (iii significantly lower IMVT (-41.6%; P = 0.001 and tendentially lower RMS-EMG of the rectus femoris (-33.7%; P = 0.054, (iv tendentially higher MAE of the torque signal at 20% IMVT (65.9%; P = 0.068, significantly lower SD of the torque signal at all three torque levels and greater MNF at 60% IMVT (44.8%; P = 0.018, (v significantly increased RMS-EMG of the vastus lateralis at 20% (70.8%; P = 0.003 and 40% IMVT (33.3%; P = 0.034, significantly lower RMS-EMG of the biceps femoris at 20% (-63.6%; P = 0.044 and 40% IMVT (-41.3%; P = 0.028 and tendentially lower at 60% IMVT (-24.3%; P = 0.075 and (vi significantly shorter TTF (-51.1%; P = 0.049.KOA is not only associated with a deterioration of IMVT

  7. Coordinated collagen and muscle protein synthesis in human patella tendon and quadriceps muscle after exercise

    DEFF Research Database (Denmark)

    Miller, Benjamin F; Olesen, Jens L; Hansen, Mette

    2005-01-01

    We hypothesized that an acute bout of strenuous, non-damaging exercise would increase rates of protein synthesis of collagen in tendon and skeletal muscle but these would be less than those of muscle myofibrillar and sarcoplasmic proteins. Two groups (n = 8 and 6) of healthy young men were studied...... collagen (0.077% h(-1)), muscle collagen (0.054% h(-1)), myofibrillar protein (0.121% h(-1)), and sarcoplasmic protein (0.134% h(-1))). The rates decreased toward basal values by 72 h although rates of tendon collagen and myofibrillar protein synthesis remained elevated. There was no tissue damage...... of muscle visible on histological evaluation. Neither tissue microdialysate nor serum concentrations of IGF-I and IGF binding proteins (IGFBP-3 and IGFBP-4) or procollagen type I N-terminal propeptide changed from resting values. Thus, there is a rapid increase in collagen synthesis after strenuous exercise...

  8. Differential glucose uptake in quadriceps and other leg muscles during one-legged dynamic submaximal knee-extension exercise

    DEFF Research Database (Denmark)

    Kalliokoski, Kari K; Boushel, Robert; Langberg, Henning

    2011-01-01

    One-legged dynamic knee-extension exercise (DKE) is a widely used model to study the local cardiovascular and metabolic responses to exercise of the quadriceps muscles. In this study, we explored the extent to which different muscles of the quadriceps are activated during exercise using positron...... emission tomography (PET) determined uptake of [18F]-fluoro-deoxy-glucose (GU) during DKE. Five healthy male subjects performed DKE at 25 W for 35 min and both the contracting and contralateral resting leg were scanned with PET from mid-thigh and distally. On average, exercise GU was the highest...

  9. Impact of pain reported during isometric quadriceps muscle strength testing in people with knee pain: data from the osteoarthritis initiative.

    Science.gov (United States)

    Riddle, Daniel L; Stratford, Paul W

    2011-10-01

    Muscle force testing is one of the more common categories of diagnostic tests used in clinical practice. Clinicians have little evidence to guide interpretations of muscle force tests when pain is elicited during testing. The purpose of this study was to examine the construct validity of isometric quadriceps muscle strength tests by determining whether the relationship between maximal isometric quadriceps muscle strength and functional status was influenced by pain during isometric testing. A cross-sectional design was used. Data from the Osteoarthritis Initiative were used to identify 1,344 people with unilateral knee pain and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale scores of 1 or higher on the involved side. Measurements of maximal isometric quadriceps strength and ratings of pain during isometric testing were collected. Outcome variables were WOMAC physical function subscale, 20-m walk test, 400-m walk test, and a repeated chair stand test. Multiple regression models were used to determine whether pain during testing modified or confounded the relationship between strength and functional status. Pearson r correlations among the isometric quadriceps strength measures and the 4 outcome measures ranged from -.36 (95% confidence interval=-.41, -.31) for repeated chair stands to .36 (95% confidence interval=.31, .41) for the 20-m walk test. In the final analyses, neither effect modification nor confounding was found for the repeated chair stand test, the 20-m walk test, the 400-m walk test, or the WOMAC physical function subscale. Moderate or severe pain during testing was weakly associated with reduced strength, but mild pain was not. The disease spectrum was skewed toward mild or moderate symptoms, and the pain measurement scale used during muscle force testing was not ideal. Given that the spectrum of the sample was skewed toward mild or moderate symptoms and disease, the data suggest that isometric quadriceps muscle

  10. Asymmetry of quadriceps muscle oxygenation during elite short-track speed skating.

    Science.gov (United States)

    Hesford, Catherine Mary; Laing, Stewart J; Cardinale, Marco; Cooper, Chris E

    2012-03-01

    It has been suggested that, because of the low sitting position in short-track speed skating, muscle blood flow is restricted, leading to decreases in tissue oxygenation. Therefore, wearable wireless-enabled near-infrared spectroscopy (NIRS) technology was used to monitor changes in quadriceps muscle blood volume and oxygenation during a 500-m race simulation in short-track speed skaters. Six elite skaters, all of Olympic standard (age = 23 ± 1.8 yr, height = 1.8 ± 0.1 m, mass = 80.1 ± 5.7 kg, midthigh skinfold thickness = 7 ± 2 mm), were studied. Subjects completed a 500-m race simulation time trial (TT). Whole-body oxygen consumption was simultaneously measured with muscle oxygenation in right and left vastus lateralis as measured by NIRS. Mean time for race completion was 44.8 ± 0.4 s. VO2 peaked 20 s into the race. In contrast, muscle tissue oxygen saturation (TSI%) decreased and plateaued after 8 s. Linear regression analysis showed that right leg TSI% remained constant throughout the rest of the TT (slope value = 0.01), whereas left leg TSI% increased steadily (slope value = 0.16), leading to a significant asymmetry (P skating has implications for training and performance.

  11. Aerobic metabolism of human quadriceps muscle: in vivo data parallel measurements on isolated mitochondria

    DEFF Research Database (Denmark)

    Rasmussen, U.F.; Rasmussen, H.N.; Krustrup, Peter

    2001-01-01

    The aim of the present study was to examine whether parameters of isolated mitochondria could account for the in vivo maximum oxygen uptake ( O2 max) of human skeletal muscle. O2 max and work performance of the quadriceps muscle of six volunteers were measured in the knee extensor model (range 10......-18 mmol O2 · min 1 · kg 1 at work rates of 22-32 W/kg). Mitochondria were isolated from the same muscle at rest. Strong correlations were obtained between O2 max and a number of mitochondrial parameters (mitochondrial protein, cytochrome aa3, citrate synthase, and respiratory activities). The activities...... of citrate synthase, succinate dehydrogenase, and pyruvate dehydrogenase, measured in isolated mitochondria, corresponded to, respectively, 15, 3, and 1.1 times the rates calculated from O2 max. The respiratory chain activity also appeared sufficient. Fully coupled in vitro respiration, which is limited...

  12. The influence of isometric exercises of the quadriceps muscle on young female patients with anterior knee pain

    Directory of Open Access Journals (Sweden)

    Jacek Wilczyński

    2015-10-01

    Full Text Available Introduction: Anterior knee pain is a disease associated with abnormalities in the patellofemoral joint. It is a common reason for seeking advice from an orthopaedist. This problem is characterised by chronic pain in the anterior part of one or both knees. This issue often affects women, especially at a young age. The effect of this ailment is deterioration of the quality of life. This dysfunction significantly reduces abilities, and often prevents the performance of daily activities. Pain usually occurs during physical activity, but may also be accompanied by prolonged immobilisation of the knee joint. In defining the type of patellofemoral instability, orthopaedists use magnetic resonance imaging, arthroscopy, ultrasonography, and X-ray examination. A relatively effective method of treatment of pain in the patellofemoral joint is through isometric exercises of the quadriceps. They increase the strength of the quadriceps femoris muscle and reduce instability in the patellofemoral joint. Aim of the research: To evaluate the effectiveness of isometric exercises of the quadriceps muscle on young female patients with anterior knee pain. Material and methods : The study involved 30 women aged 13–44 years (mean age: 26.8 years, who had been diagnosed with pain in the front of the knee. Results and conclusions: Isometric exercises of the quadriceps muscle are an effective method of reducing anterior knee pain. Isometric exercises have a beneficial influence on improving physical activity, including performing basic activities of daily living. Student’s t distribution showed, that isometric exercises of the quadriceps muscle reduce pain at the front of the knee. Kruskal-Wallis test confirmed a significant reduction of anterior knee pain.

  13. Effect of Electromyographic Biofeedback Training on Pain, Quadriceps Muscle Strength, and Functional Ability in Juvenile Rheumatoid Arthritis.

    Science.gov (United States)

    Eid, Mohamed Ahmed Mahmoud; Aly, Sobhy M; El-Shamy, Shamekh M

    2016-12-01

    To investigate the effects of electromyographic (EMG) biofeedback training on pain, quadriceps strength, and functional ability in juvenile rheumatoid arthritis (JRA). This is a randomized controlled study; 36 children (11 boys and 25 girls) with polyarticular JRA, with ages ranging from 8 to 13 years, were selected and assigned randomly, using computer-generated random numbers, into 2 groups. The control group (n = 18) received the conventional physical therapy program, whereas the study group (n = 18) received the same program as the control group in addition to EMG biofeedback-guided isometric exercises for 3 days a week for 12 weeks. Pain, peak torque of quadriceps strength, and functional ability were evaluated before, after 6 weeks, and at the end of 12 weeks of the treatment program. By 6 weeks, significant differences were observed in the study group (P biofeedback may be a useful intervention modality to reduce pain, improve quadriceps strength, and functional performance in JRA.

  14. 99mTc-sestamibi muscle scintigraphy to assess the response to neuromuscular electrical stimulation of normal quadriceps femoris muscle

    International Nuclear Information System (INIS)

    Pekindil, Y.; Sarikaya, A.; Birtane, M.; Pekindil, G.; Salan, A.

    2001-01-01

    Neuromuscular electrical stimulation (NMES) is widely used for improving muscle strength by simultaneous contraction in the prevention of muscle atrophy. Although there exist many clinical methods for evaluating the therapeutic response of muscles, 99m Tc-sestamibi which is a skeletal muscle perfusion and metabolism agent has not previously been used for this purpose. The aim of our work was to ascertain whether 99m Tc-sestamibi muscle scintigraphy is useful in the monitoring of therapeutic response to NMES in healthy women. The study included 16 women aged between 21 and 45, with a mean age of 32.7±6.4. Both quadriceps femoris muscles (QFM) of each patient were studied. After randomization to remove the effect of the dominant side, one QFM of each patient was subjected to the NMES procedure for a period of 20 days. NMES was performed with an alternating biphasic rectangular current, from a computed electrical stimulator daily for 23 minutes. After measurement of skinfold thickness over the thigh, pre- and post-NMES girth measurements were assessed in centimeters. Sixty minutes after injections of 555 MBq 99m Tc-sestamibi, static images of the thigh were obtained for 5 minutes. The thigh-to-knee uptake ratio was calculated by semiquantitative analysis and normalized to body surface area (NUR=normalized uptake ratio). The difference between the pre and post NMES NUR values was significant (1.76±0.31 versus 2.25±0.38, p=0.0000). The percentage (%) increase in NUR values also well correlated with the % increase in thigh girth measurements (r=0.89, p=0.0000). These results indicated that 99m Tc-sestamibi muscle scintigraphy as a new tool may be useful in evaluating therapeutic response to NMES. (author)

  15. Volume measurements of individual muscles in human quadriceps femoris using atlas-based segmentation approaches.

    Science.gov (United States)

    Le Troter, Arnaud; Fouré, Alexandre; Guye, Maxime; Confort-Gouny, Sylviane; Mattei, Jean-Pierre; Gondin, Julien; Salort-Campana, Emmanuelle; Bendahan, David

    2016-04-01

    Atlas-based segmentation is a powerful method for automatic structural segmentation of several sub-structures in many organs. However, such an approach has been very scarcely used in the context of muscle segmentation, and so far no study has assessed such a method for the automatic delineation of individual muscles of the quadriceps femoris (QF). In the present study, we have evaluated a fully automated multi-atlas method and a semi-automated single-atlas method for the segmentation and volume quantification of the four muscles of the QF and for the QF as a whole. The study was conducted in 32 young healthy males, using high-resolution magnetic resonance images (MRI) of the thigh. The multi-atlas-based segmentation method was conducted in 25 subjects. Different non-linear registration approaches based on free-form deformable (FFD) and symmetric diffeomorphic normalization algorithms (SyN) were assessed. Optimal parameters of two fusion methods, i.e., STAPLE and STEPS, were determined on the basis of the highest Dice similarity index (DSI) considering manual segmentation (MSeg) as the ground truth. Validation and reproducibility of this pipeline were determined using another MRI dataset recorded in seven healthy male subjects on the basis of additional metrics such as the muscle volume similarity values, intraclass coefficient, and coefficient of variation. Both non-linear registration methods (FFD and SyN) were also evaluated as part of a single-atlas strategy in order to assess longitudinal muscle volume measurements. The multi- and the single-atlas approaches were compared for the segmentation and the volume quantification of the four muscles of the QF and for the QF as a whole. Considering each muscle of the QF, the DSI of the multi-atlas-based approach was high 0.87 ± 0.11 and the best results were obtained with the combination of two deformation fields resulting from the SyN registration method and the STEPS fusion algorithm. The optimal variables for FFD

  16. The Influence of External Load on Quadriceps Muscle and Tendon Dynamics during Jumping.

    Science.gov (United States)

    Earp, Jacob E; Newton, Robert U; Cormie, Prue; Blazevich, Anthony J

    2017-11-01

    Tendons possess both viscous (rate-dependent) and elastic (rate-independent) properties that determine tendon function. During high-speed movements external loading increases both the magnitude (FT) and rate (RFDT) of tendon loading. The influence of external loading on muscle and tendon dynamics during maximal vertical jumping was explored. Ten resistance-trained men performed parallel-depth, countermovement vertical jumps with and without additional load (0%, 30%, 60%, and 90% of maximum squat lift strength), while joint kinetics and kinematics, quadriceps tendon length (LT) and patellar tendon FT and RFDT were estimated using integrated ultrasound, motion analysis and force platform data and muscle tendon modelling. Estimated FT and RFDT, but not peak LT, increased with external loading. Temporal comparisons between 0% and 90% loads revealed that FT was greater with 90% loading throughout the majority of the movement (11%-81% and 87%-95% movement duration). However, RFDT was greater with 90% load only during the early movement initiation phase (8%-15% movement duration) but was greater in the 0% load condition later in the eccentric phase (27%-38% movement duration). LT was longer during the early movement (12%-23% movement duration) but shorter in the late eccentric and early concentric phases (48%-55% movement duration) with 90% load. External loading positively influenced peak FT and RFDT but tendon strain appeared unaffected, suggesting no additive effect of external loading on patellar tendon lengthening during human jumping. Temporal analysis revealed that external loading resulted in a large initial RFDT that may have caused dynamic stiffening of the tendon and attenuated tendon strain throughout the movement. These results suggest that external loading influences tendon lengthening in both a load- and movement-dependent manner.

  17. Effect of retro and forward walking on quadriceps muscle strength, pain, function, and mobility in patients with knee osteoarthritis: a protocol for a randomized controlled trial.

    Science.gov (United States)

    Alghadir, Ahmad; Anwer, Shahnawaz

    2016-04-12

    Walking, a closed kinetic chain (CKC) activity, is widely used in knee rehabilitation as it allows early weight bearing and movement. It has been suggested that retro-walking may provide additional benefits beyond those experienced by forward-walking. The present study will investigate the effect of retro- and forward-walking on quadriceps muscle strength, pain, function, balance and mobility in knee Osteoarthritis (OA) subjects. Sixty-nine participants with knee OA will be recruited from the outpatient department in this randomized controlled trial. The participants will be randomly assigned to one of three groups; retro walking, forward walking or control group. The training program will be 3 days/week for 6 weeks. In addition, all the participants will receive a standard physiotherapy training program. An independent assessor blinded to group assignment will measure quadriceps muscle strength, knee pain intensity, functional disability, and mobility at baseline and 6 weeks after training. The results of this study will enhance our understanding on the therapeutic effects of walking (retro- or forward-walking) in knee OA. The findings from this study will help determine whether retro- or forward-walking or both are effective in the rehabilitation of subjects with knee OA. Controlled Trials ISRCTN12850845, Registered 26 January 2015.

  18. Immediate effects of kinesiotaping on quadriceps muscle strength: a single-blind, placebo-controlled crossover trial.

    Science.gov (United States)

    Vercelli, Stefano; Sartorio, Francesco; Foti, Calogero; Colletto, Lorenzo; Virton, Domenico; Ronconi, Gianpaolo; Ferriero, Giorgio

    2012-07-01

    To investigate the immediate effects on maximal muscle strength of kinesiotaping (KT) applied to the dominant quadriceps of healthy subjects. Single-blind, placebo-controlled crossover trial. "Salvatore Maugeri" Foundation. With ethical approval and informed consent, a convenience sample of 36 healthy volunteers were recruited. Two subjects did not complete the sessions and were excluded from the analysis. Subjects were tested across 3 different sessions, randomly receiving 2 experimental KT conditions applied with the aim of enhancing and inhibiting muscle strength and a sham KT application. Quadriceps muscle strength was measured by means of an isokinetic maximal test performed at 60 and 180 degrees per second. Two secondary outcome measures were performed: the single-leg triple hop for distance to measure limb performance and the Global Rating of Change Scale (GRCS) to calculate agreement between KT application and subjective perception of strength. Compared with baseline, none of the 3 taping conditions showed a significant change in muscle strength and performance (all P > 0.05). Effect size was very low under all conditions (≤0.08). Very few subjects showed an individual change greater than the minimal detectable change. Global Rating of Change Scale scores demonstrated low to moderate agreement with the type of KT applied, but some placebo effects were reported independently of condition. Our findings indicated no significant effect in the maximal quadriceps strength immediately after the application of inhibition, facilitation, or sham KT. These results do not support the use of KT applied in this way to change maximal muscle strength in healthy people.

  19. Effect of eccentric exercise with reduced muscle glycogen on plasma interleukin-6 and neuromuscular responses of musculus quadriceps femoris.

    Science.gov (United States)

    Gavin, James P; Myers, Stephen D; Willems, Mark E T

    2016-07-01

    Eccentric exercise can result in muscle damage and interleukin-6 (IL-6) secretion. Glycogen availability is a potent stimulator of IL-6 secretion. We examined effects of eccentric exercise in a low-glycogen state on neuromuscular function and plasma IL-6 secretion. Twelve active men (23 ± 4 yr, 179 ± 5 cm, 77 ± 10 kg, means ± SD) completed two downhill treadmill runs (gradient, -12%, 5 × 8 min; speed, 12.1 ± 1.1 km/h) with normal (NG) and reduced muscle glycogen (RG) in randomized order and at least 6 wk apart. Muscle glycogen was reduced using an established cycling protocol until exhaustion and dietary manipulation the evening before the morning run. Physiological responses were measured up to 48 h after the downhill runs. During recovery, force deficits of musculus quadriceps femoris by maximal isometric contractions were similar. Changes in low-frequency fatigue were larger with RG. Voluntary activation and plasma IL-6 levels were similar in recovery between conditions. It is concluded that unaccustomed, damaging eccentric exercise with low muscle glycogen of the m. quadriceps femoris 1) exacerbated low-frequency fatigue but 2) had no additional effect on IL-6 secretion. Neuromuscular impairment after eccentric exercise with low muscle glycogen appears to have a greater peripheral component in early recovery. Copyright © 2016 the American Physiological Society.

  20. The effect of anterior cruciate ligament reconstruction on hamstring and quadriceps muscle function outcome ratios in male athletes

    Directory of Open Access Journals (Sweden)

    Kadija Marko

    2016-01-01

    Full Text Available Introduction. Maximal strength ratios such as the limb symmetry index (LSI and hamstring-to-quadriceps ratio (HQ may be considered the main outcome measures in the monitoring of recovery after anterior cruciate ligament (ACL reconstruction. Although explosive strength is much more important than maximal strength, it is generally disregarded in the follow-up of muscle function recovery. Objective. The purpose of this study was to compare ratios between maximal (Fmax and explosive strength (rate of force development - RFD in individuals with ACL reconstruction. Methods. Fifteen male athletes were enrolled and had maximum voluntary isometric quadriceps and hamstring contractions tested (4.0 ± 0.1 months post reconstruction. In addition to Fmax, RFD was estimated (RFDmax, as well as RFD at 50, 100, and 200 ms from onset of contraction and LSI and HQ ratios were calculated. Results. The involved leg demonstrated significant hamstring and quadriceps deficits compared to uninvolved leg (p < 0.01. Deficits were particularly significant in the involved quadriceps, causing higher HQ ratios (average 0.63, compared to the uninvolved leg (0.44. LSI was significantly lower for RFD variables (average 55% than for Fmax (66%. Conclusion. The assessment of RFD may be considered an objective recovery parameter for one’s readiness to return to sports and should be an integral part of standard follow-up protocol for athletes after ACL reconstruction. Moreover, the combination of indices derived from maximal and explosive strength may provide better insight in muscle strength balance, as well as a clear picture of functional implications. [Projekat Ministarstva nauke Republike Srbije, br. 175012 i br. 175037

  1. Effect of endurance versus resistance training on quadriceps muscle dysfunction in COPD

    DEFF Research Database (Denmark)

    Iepsen, Ulrik Winning; Munch, Gregers Druedal Wibe; Rugbjerg, Mette

    2016-01-01

    INTRODUCTION: Exercise is an important countermeasure to limb muscle dysfunction in COPD. The two major training modalities in COPD rehabilitation, endurance training (ET) and resistance training (RT), may both be efficient in improving muscle strength, exercise capacity, and health-related quality...... and after the training intervention to assess muscle morphology and metabolic and angiogenic factors. Symptom burden, exercise capacity (6-minute walking and cycle ergometer tests), and vascular function were also assessed. RESULTS: Both training modalities improved symptom burden and exercise capacity...... with no difference between the two groups. The mean (SD) proportion of glycolytic type IIa muscle fibers was reduced after ET (from 48% [SD 11] to 42% [SD 10], Ptraining modality on muscle...

  2. Torque decrease during submaximal evoked contractions of the quadriceps muscle is linked not only to muscle fatigue.

    Science.gov (United States)

    Matkowski, Boris; Lepers, Romuald; Martin, Alain

    2015-05-01

    The aim of this study was to analyze the neuromuscular mechanisms involved in the torque decrease induced by submaximal electromyostimulation (EMS) of the quadriceps muscle. It was hypothesized that torque decrease after EMS would reflect the fatigability of the activated motor units (MUs), but also a reduction in the number of MUs recruited as a result of changes in axonal excitability threshold. Two experiments were performed on 20 men to analyze 1) the supramaximal twitch superimposed and evoked at rest during EMS (Experiment 1, n = 9) and 2) the twitch response and torque-frequency relation of the MUs activated by EMS (Experiment 2, n = 11). Torque loss was assessed by 15 EMS-evoked contractions (50 Hz; 6 s on/6 s off), elicited at a constant intensity that evoked 20% of the maximal voluntary contraction (MVC) torque. The same stimulation intensity delivered over the muscles was used to induce the torque-frequency relation and the single electrical pulse evoked after each EMS contraction (Experiment 2). In Experiment 1, supramaximal twitch was induced by femoral nerve stimulation. Torque decreased by ~60% during EMS-evoked contractions and by only ~18% during MVCs. This was accompanied by a rightward shift of the torque-frequency relation of MUs activated and an increase of the ratio between the superimposed and posttetanic maximal twitch evoked during EMS contraction. These findings suggest that the torque decrease observed during submaximal EMS-evoked contractions involved muscular mechanisms but also a reduction in the number of MUs recruited due to changes in axonal excitability. Copyright © 2015 the American Physiological Society.

  3. Dynamic 31P-MR-spectroscopy of the quadriceps muscle. Influence of sex and age on spectroscopic results

    International Nuclear Information System (INIS)

    Schunk, K.; Romaneehsen, B.; Kessler, S.; Schadmand-Fischer, S.; Thelen, M.

    1999-01-01

    Purpose: 31 P-MRS is used to assess the influence of sex and age on quadriceps muscle metabolism before and after exercise. Materials and Methods: 32 healthy volunteers (15 women, 17 men; mean age: 38±17 yrs.) were examined by dynamic phosphorus-31 ( 31 P) magnetic resonance spectroscopy (MRS). In the magnet, the quadriceps muscle was stressed by an isometric and an isotonic form of exercise until exhaustion, respectively. Results: Resting conditions: With increasing subjects' age, the ratio β-adenosine triphosphate/total phosphate decreased (r=-0.37; p=0.02). With increasing subjects' age, the ratios inorganic phosphate/phosphocreatine (r=0.79; p=5x10 -8 ), phosphomonoester/β-adenosine triphosphate (r=0.74; p=10 -6 ) and phosphodiester/β-adenosine triphosphate (r=0.62; p=10 -4 ) increased. The pH was the only one of the evaluated spectroscopic parameters which showed a sex-dependence: Female subjects had a significantly lower pH (7.03±0.02) than male subjects (7.05±0.03; p=0,01). Exercise: With increasing age, the maxima of inorganic phosphate/phosphocreatine were less extreme during both of the exercises (r=-0.42; p=0.0005). Likewise, the exercise-induced acidosis was less severe with increasing age (r=0.53; p=6x10 -6 ). After the end of the exercise, the times of half recovery of inorganic phosphate/phosphocreatine and the pH correlated neither with the subjects' age nor with sex or cross-sectional area of the quadriceps muscle. Conclusion: Sex and age of volunteers affect spectroscopic results. This influence has to be considered in the interpretation of spectroscopic studies. (orig.) [de

  4. 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...

  5. Gender differences in tibio-femoral kinematics and quadriceps muscle force during weight-bearing knee flexion in vitro.

    Science.gov (United States)

    Wünschel, Markus; Wülker, Nikolaus; Müller, Otto

    2013-11-01

    Females have a higher risk in terms of anterior cruciate ligament injuries during sports than males. Reasons for this fact may be different anatomy and muscle recruitment patterns leading to less protection for the cruciate- and collateral-ligaments. This in vitro study aims to evaluate gender differences in knee joint kinematics and muscle force during weight-bearing knee flexions. Thirty-four human knee specimens (17 females/17 males) were mounted on a dynamic knee simulator. Weight-bearing single-leg knee flexions were performed with different amounts of simulated body weight (BW). Gender-specific kinematics was measured with an ultrasonic motion capture system and different loading conditions were examined. Knee joint kinematics did not show significant differences regarding anteroposterior and medial-lateral movement as well as tibial varus-valgus and internal-external rotation. This applied to all simulated amounts of BW. Simulating 100 N BW in contrast to AF50 led to a significant higher quadriceps overall force in female knees from 45° to 85° of flexion in contrast to BW 50 N. In these female specimens, the quadriceps overall force was about 20 % higher than in male knees being constant in higher flexion angles. It is indicated by our results that in a squatting movement females compared with males produce higher muscle forces, suggesting an increased demand for muscular stabilization, whereas tibio-femoral kinematics was similar for both genders.

  6. The effect of dynamic knee-extension exercise on patellar tendon and quadriceps femoris muscle glucose uptake in humans studied by positron emission tomography

    DEFF Research Database (Denmark)

    Kalliokoski, Kari K; Langberg, Henning; Ryberg, Ann Kathrine

    2005-01-01

    Both tendon and peritendinous tissue show evidence of metabolic activity, but the effect of acute exercise on substrate turnover is unknown. We therefore examined the influence of acute exercise on glucose uptake in the patellar and quadriceps tendons during dynamic exercise in humans. Glucose...... that tendon glucose uptake is increased during exercise. However, the increase in tendon glucose uptake is less pronounced than in muscle and the increases are uncorrelated. Thus tendon glucose uptake is likely to be regulated by mechanisms independently of those regulating skeletal muscle glucose uptake....... uptake was measured in five healthy men in the patellar and quadriceps tendons and the quadriceps femoris muscle at rest and during dynamic knee-extension exercise (25 W) using positron emission tomography and [18F]-2-fluoro-2-deoxy-D-glucose ([18F]FDG). Glucose uptake index was calculated by dividing...

  7. Femoral nerve compression syndrome with paresis of the quadriceps muscle caused by radiotherapy of malignant tumours. A report of four cases

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, L E [Orthopaedic Hospital of the Invalid Foundation, Helsinki, Finland

    1975-01-01

    Four patients showed signs of femoral nerve compression with subsequent paresis of the quadriceps muscle, after radiation therapy of malignant tumours. The compression was caused by scar tissue due to radiation treatment of the inguinal region. The first symptom was radiating pain in the front of the thigh and lower leg which appeared 12-16 months after X-ray treatment. A decrease in the strength of quadriceps muscle occurred some months later. In one case the femoral nerve was decompressed, another patient was treated by an intradural phenolglycerin injection and one patient was treated with cortisone and oxiphenbutanzone. In these cases the pain decreased considerably, but in one case only the paresis of the quadriceps muscle improved after treatment.

  8. Cross-sectional area measurements versus volumetric assessment of the quadriceps femoris muscle in patients with anterior cruciate ligament reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Marcon, Magda [University Hospital Zurich, Department of Radiology, Zurich (Switzerland); University Hospital Udine, Department of Radiology, Udine (Italy); Ciritsis, Bernhard; Laux, Christoph [University Hospital Zurich, Department of Traumatology, Zurich (Switzerland); Nanz, Daniel; Nguyen-Kim, Thi Dan Linh; Fischer, Michael A.; Andreisek, Gustav; Ulbrich, Erika J. [University Hospital Zurich, Department of Radiology, Zurich (Switzerland)

    2014-10-31

    Our aim was to validate the use of cross-sectional area (CSA) measurements at multiple quadriceps muscle levels for estimating the total muscle volume (TMV), and to define the best correlating measurement level. Prospective institutional review board (IRB)-approved study with written informed patient consent. Thighs of thirty-four consecutive patients with ACL-reconstructions (men, 22; women, 12) were imaged at 1.5-T using three-dimensional (3D) spoiled dual gradient-echo sequences. CSA was measured at three levels: 15, 20, and 25 cm above the knee joint line. TMV was determined using dedicated volumetry software with semiautomatic segmentation. Pearson's correlation and regression analysis (including standard error of the estimate, SEE) was used to compare CSA and TMV. The mean ± standard deviation (SD) for the CSA was 60.6 ± 12.8 cm{sup 2} (range, 35.6-93.4 cm{sup 2}), 71.1 ± 15.1 cm{sup 2} (range, 42.5-108.9 cm{sup 2}) and 74.2 ± 17.1 cm{sup 2} (range, 40.9-115.9 cm{sup 2}) for CSA-15, CSA-20 and CSA-25, respectively. The mean ± SD quadriceps' TMV was 1949 ± 533.7 cm{sup 3} (range, 964.0-3283.0 cm{sup 3}). Pearson correlation coefficient was r = 0.835 (p < 0.01), r = 0.906 (p < 0.01), and r = 0.956 (p < 0.01) for CSA-15, CSA-20 and CSA-25, respectively. Corresponding SEE, expressed as percentage of the TMV, were 15.2 %, 11.6 % and 8.1 %, respectively. The best correlation coefficient between quadriceps CSA and TMV was found for CSA-25, but its clinical application to estimate the TMV is limited by a relatively large SEE. (orig.)

  9. The Isolated Effect of Adductor Canal Block on Quadriceps Femoris Muscle Strength After Total Knee Arthroplasty

    DEFF Research Database (Denmark)

    Sørensen, Johan Kløvgaard; Jæger, Pia; Dahl, Jørgen Berg

    2016-01-01

    TKA. METHODS: We included 64 patients on the first postoperative day. Group A received an ACB with 30 mL ropivacaine 0.75% at t0 and with 30 mL saline 60 minutes later (t60). Group B received the treatment in the opposite order. The primary end point was the difference between groups in MVIC at t60......, expressed as a percentage of postoperative preblock values. In this manner, the effect of the ACB could be isolated from the detrimental effect on muscle strength caused by the surgery. Secondary end points were differences between groups in mobility and pain scores. We planned a subgroup analysis dividing...

  10. Electrically induced contraction levels of the quadriceps femoris muscles in healthy men: the effects of three patterns of burst-modulated alternating current and volitional muscle fatigue.

    Science.gov (United States)

    Parker, Michael G; Broughton, Alex J; Larsen, Ben R; Dinius, Josh W; Cimbura, Mac J; Davis, Matthew

    2011-12-01

    The purpose of this study was to compare electrically induced contraction levels produced by three patterns of alternating current in fatigued and nonfatigued skeletal muscles. Eighteen male volunteers without health conditions, with a mean (SD) age of 24.9 (3.4) yrs were randomly exposed to a fatiguing volitional isometric quadriceps contraction and one of three patterns of 2.5-KHz alternating current; two were modulated at 50 bursts per second (10% burst duty cycle with five cycles per burst and 90% burst duty cycle with 45 cycles per burst), and one pattern was modulated at 100 bursts per second (10% burst duty cycle with 2.5 cycles per burst). The electrically induced contraction levels produced by the three patterns of electrical stimulation were compared before and after the fatiguing contraction. The 10% burst duty cycles produced 42.9% (95% confidence interval, 29.1%-56.7%) and 32.1% (95% confidence interval, 18.2%-45.9%) more muscle force (P stronger muscle contractions. Furthermore, the stimulation patterns had no influence on the difference in muscle force before and after the fatiguing quadriceps contraction. Consequently, for clinical applications in which high forces are desired, the patterns using the 10% burst duty cycle may be helpful.

  11. Contribution of hamstring fatigue to quadriceps inhibition following lumbar extension exercise.

    Science.gov (United States)

    Hart, Joseph M; Kerrigan, D Casey; Fritz, Julie M; Saliba, Ethan N; Gansneder, Bruce; Ingersoll, Christopher D

    2006-01-01

    The purpose of this study was to determine the contribution of hamstrings and quadriceps fatigue to quadriceps inhibition following lumbar extension exercise. Regression models were calculated consisting of the outcome variable: quadriceps inhibition and predictor variables: change in EMG median frequency in the quadriceps and hamstrings during lumbar fatiguing exercise. Twenty-five subjects with a history of low back pain were matched by gender, height and mass to 25 healthy controls. Subjects performed two sets of fatiguing isometric lumbar extension exercise until mild (set 1) and moderate (set 2) fatigue of the lumbar paraspinals. Quadriceps and hamstring EMG median frequency were measured while subjects performed fatiguing exercise. A burst of electrical stimuli was superimposed while subjects performed an isometric maximal quadriceps contraction to estimate quadriceps inhibition after each exercise set. Results indicate the change in hamstring median frequency explained variance in quadriceps inhibition following the exercise sets in the history of low back pain group only. Change in quadriceps median frequency explained variance in quadriceps inhibition following the first exercise set in the control group only. In conclusion, persons with a history of low back pain whose quadriceps become inhibited following lumbar paraspinal exercise may be adapting to the fatigue by using their hamstring muscles more than controls. Key PointsA neuromuscular relationship between the lumbar paraspinals and quadriceps while performing lumbar extension exercise may be influenced by hamstring muscle fatigue.QI following lumbar extension exercise in persons with a history of LBP group may involve significant contribution from the hamstring muscle group.More hamstring muscle contribution may be a necessary adaptation in the history of LBP group due to weaker and more fatigable lumbar extensors.

  12. Dynamic 31phosphorus magnetic resonance spectroscopy of the quadriceps muscle: Metabolic changes resulting from two different forms of exercise

    International Nuclear Information System (INIS)

    Schunk, K.; Kersjes, W.; Schadmand-Fischer, S.; Thelen, M.

    1997-01-01

    Purpose: The aim of the present investigation was to examine the metabolism of the quadriceps muscles of normal young individuals using dynamic 31 phosphorus magnetic resonance spectroscopy. Methods: 22 normal individuals were examined in a 1.5 T-MRT using a 6 cm surface coil. The metabolic changes in the quadriceps muscle as shown by the phosphorus spectrum were evaluated during rest, exercise (isometric and isotonic exercise) and during a 36-second period of recovery. Results: The P i /PCr quotient rose from its resting value of 0.11±0.02 following exercise to a maximum of 0.83±0.47 (isometric) or 1.40±0.59 (isotonic) (difference p=0.0001). Half-time recovery of P i /PCr was 35±11 s or 31±10 s, respectively (p=0.13). During the recovery phase P i /PCr fell briefly but significantly below its rest value. Following an initial rise in pH, there was a continual fall. Minimum pH (6.68±0.21 and 6.53±0.27 respectively; p=0.01) occurred in the early recovery phase. The recovery process of pH values lasted longer following isotonic than after isometric exercise (half-value recovery time 229±72 s and 146±55 s, respectively; p=0.001). Conlcusion: Compared with isometric exercise, isotonic stress is more expensive in terms of metabolism. Dynamic 31 phosphorus MRT spectroscopy can differentiate changes in muscle metabolism during different forms of exercise. (orig.) [de

  13. CONTRIBUTION OF HAMSTRING FATIGUE TO QUADRICEPS INHIBITION FOLLOWING LUMBAR EXTENSION EXERCISE

    Directory of Open Access Journals (Sweden)

    Joseph M. Hart

    2006-03-01

    Full Text Available The purpose of this study was to determine the contribution of hamstrings and quadriceps fatigue to quadriceps inhibition following lumbar extension exercise. Regression models were calculated consisting of the outcome variable: quadriceps inhibition and predictor variables: change in EMG median frequency in the quadriceps and hamstrings during lumbar fatiguing exercise. Twenty-five subjects with a history of low back pain were matched by gender, height and mass to 25 healthy controls. Subjects performed two sets of fatiguing isometric lumbar extension exercise until mild (set 1 and moderate (set 2 fatigue of the lumbar paraspinals. Quadriceps and hamstring EMG median frequency were measured while subjects performed fatiguing exercise. A burst of electrical stimuli was superimposed while subjects performed an isometric maximal quadriceps contraction to estimate quadriceps inhibition after each exercise set. Results indicate the change in hamstring median frequency explained variance in quadriceps inhibition following the exercise sets in the history of low back pain group only. Change in quadriceps median frequency explained variance in quadriceps inhibition following the first exercise set in the control group only. In conclusion, persons with a history of low back pain whose quadriceps become inhibited following lumbar paraspinal exercise may be adapting to the fatigue by using their hamstring muscles more than controls

  14. Comparison of the large muscle group widths of the pelvic limb in seven breeds of dogs.

    Science.gov (United States)

    Sabanci, Seyyid Said; Ocal, Mehmet Kamil

    2018-05-14

    Orthopaedic diseases are common in the pelvic limbs of dogs, and reference values for large muscle groups of the pelvic limb may aid in diagnosis such diseases. As such, the objective of this study was to compare the large muscle groups of the pelvic limb in seven breeds of dogs. A total of 126 dogs from different breeds were included, and the widths of the quadriceps, hamstring and gastrocnemius muscles were measured from images of the lateral radiographies. The width of the quadriceps was not different between the breeds, but the widths of the hamstring and gastrocnemius muscles were significantly different between the breeds. The widest hamstring and gastrocnemius muscles were seen in the Rottweilers and the Boxers, respectively. The narrowest hamstring and gastrocnemius muscles were seen in the Belgian Malinois and the Golden retrievers, respectively. All ratios between the measured muscles differed significantly between the breeds. Doberman pinschers and Belgian Malinois had the highest ratio of gastrocnemius width:hamstring width. Doberman pinschers had also the highest ratio of quadriceps width:hamstring width. German shepherds had the highest ratio of gastrocnemius width:quadriceps width. The lowest ratios of quadriceps width:hamstring width were determined in the German shepherds. The ratios of the muscle widths may be used as reference values to assess muscular atrophy or hypertrophy in cases of bilateral or unilateral orthopaedic diseases of the pelvic limbs. Further studies are required to determine the widths and ratios of the large muscle groups of the pelvic limbs in other dog breeds. © 2018 Blackwell Verlag GmbH.

  15. Morphological and qualitative characteristics of the quadriceps muscle of community-dwelling older adults based on ultrasound imaging: classification using latent class analysis.

    Science.gov (United States)

    Kawai, Hisashi; Kera, Takeshi; Hirayama, Ryo; Hirano, Hirohiko; Fujiwara, Yoshinori; Ihara, Kazushige; Kojima, Motonaga; Obuchi, Shuichi

    2018-04-01

    Muscle thickness and echo intensity measured using ultrasound imaging represent both increased muscle volume and connective tissue accumulation. In combination, these ultrasound measurements can be utilized for assessing sarcopenia in community-dwelling older adults. This study aimed to determine whether morphological and qualitative characteristics classified by quadriceps muscle thickness and echo intensity measured using ultrasound are associated with muscle strength, physical function, and sarcopenia in community-dwelling older adults. Quadriceps muscle thickness and echo intensity were measured using ultrasound imaging in 1239 community-dwelling older adults. Latent class analyses were conducted to classify participants based on similarity in the subcutaneous fat thickness (FT), quadriceps muscle thickness (MT), subcutaneous fat echo intensity (FEI), and muscle echo intensity (MEI), which were assessed using ultrasound imaging. Morphological and qualitative characteristics were classified into four types as follows: (A) normal, (B) sarcopenic obesity, (C) obesity, and (D) sarcopenia type. Knee extension strength was significantly greater in A than in B and D. FT and percent body fat were greater in C than in the other types. The correlation between the ultrasound measures and knee extension strength differed among the classification types. The classification types were significantly associated with sarcopenia prevalence. Classification of the morphological and qualitative characteristics obtained from ultrasound imaging may be useful for assessing sarcopenia in community-dwelling older adults.

  16. Validity and reliability of isometric, isokinetic and isoinertial modalities for the assessment of quadriceps muscle strength in patients with total knee arthroplasty.

    Science.gov (United States)

    Lienhard, K; Lauermann, S P; Schneider, D; Item-Glatthorn, J F; Casartelli, N C; Maffiuletti, N A

    2013-12-01

    Reliability of isometric, isokinetic and isoinertial modalities for quadriceps strength evaluation, and the relation between quadriceps strength and physical function was investigated in 29 total knee arthroplasty (TKA) patients, with an average age of 63 years. Isometric maximal voluntary contraction torque, isokinetic peak torque, and isoinertial one-repetition maximum load of the involved and uninvolved quadriceps were evaluated as well as objective (walking parameters) and subjective physical function (WOMAC). Reliability was good and comparable for the isometric, isokinetic, and isoinertial strength outcomes on both sides (intraclass correlation coefficient range: 0.947-0.966; standard error of measurement range: 5.1-9.3%). Involved quadriceps strength was significantly correlated to walking speed (r range: 0.641-0.710), step length (r range: 0.685-0.820) and WOMAC function (r range: 0.575-0.663), independent from the modality (P strength was also significantly correlated to walking speed (r range: 0.413-0.539), step length (r range: 0.514-0.608) and WOMAC function (r range: 0.374-0.554) (P 0.05). In conclusion, isometric, isokinetic, and isoinertial modalities ensure valid and reliable assessment of quadriceps muscle strength in TKA patients. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Effect of time-dependent cryotherapy on redox balance of quadriceps injuries.

    Science.gov (United States)

    Silva, Marco Aurélio dos Santos; Carvalho, Taiara Ramos de; Cruz, Amanda Cristina Marques Barros da; Jesus, Lennon Rafael Guedine de; Silva Neto, Larissa Alexsandra da; Trajano, Eduardo Tavares Lima; Bezerra, Frank Silva

    2016-02-01

    Muscle trauma represents a high number of injuries in professional sport and recreation and may occur through several mechanisms. This study aims at analyzing time-dependent effects of cryotherapy on the redox balance in lesioned quadriceps muscles in F1 mice. Twenty male F1 mice were divided into five groups: (a) animals were not subjected to muscle lesioning or treatment (CTR); (b) quadriceps muscle was lesioned without treatment (L); (c) quadriceps muscle was lesioned and treated with cryotherapy for 5 min (LC5); (d) quadriceps muscle was lesioned and treated with cryotherapy for 20 min (LC20); and quadriceps muscle was lesioned and treated with cryotherapy for 40 min (LC40). The mice were euthanized; the quadriceps muscles were collected and subjected to analyses for levels of protein, hydroperoxides, nitrite, catalase (CAT) activity, oxidized glutathione (GSSG) and reduced glutathione (GSH). Protein levels were reduced in L (-39%; p cryotherapy does not improve the oxidative stress in lesioned muscles. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Association between leg strength and muscle cross-sectional area of the quadriceps femoris with the physical activity level in octogenarians.

    Science.gov (United States)

    Latorre-Román, Pedro Á; Arévalo-Arévalo, Juan Manuel; García-Pinillos, Felipe

    2016-06-03

    Aging is a complex physiological process whose main feature is the progressive loss of functionality, which may be delayed or attenuated by improving physical fitness.  To determine the association between leg strength and the muscle cross-sectional area of the quadriceps femoris in relation to physical activity level in the elderly.  Thirty-two functionally autonomous people over 80 years (men: 82.80±2.09 years; women: 83.77±4.09 years) participated in this study. The Barthel Index, the Yale Physical Activity Survey and the Chair Stand Test were the instruments used.  There were significant differences between sexes in muscle area (pmen. The muscle area and the Chair Stand Test correlated significantly with the walk index (r=0.445, pactivity index (r=0.430, pactivity index, muscle area and the Chair Stand Test, only the latter behaved as a predictor variable.  Muscle strength and muscle mass of quadriceps showed a significant association with the physical activity level in older people. Leg muscle strength was useful to reveal muscle mass and physical activity level in older people, which is relevant as a clinical practice indicator.

  19. {sup 99m}Tc-sestamibi muscle scintigraphy to assess the response to neuromuscular electrical stimulation of normal quadriceps femoris muscle

    Energy Technology Data Exchange (ETDEWEB)

    Pekindil, Y.; Sarikaya, A.; Birtane, M.; Pekindil, G.; Salan, A. [Trakya Univ., Edirne (Turkey). Hospital

    2001-08-01

    Neuromuscular electrical stimulation (NMES) is widely used for improving muscle strength by simultaneous contraction in the prevention of muscle atrophy. Although there exist many clinical methods for evaluating the therapeutic response of muscles, {sup 99m}Tc-sestamibi which is a skeletal muscle perfusion and metabolism agent has not previously been used for this purpose. The aim of our work was to ascertain whether {sup 99m}Tc-sestamibi muscle scintigraphy is useful in the monitoring of therapeutic response to NMES in healthy women. The study included 16 women aged between 21 and 45, with a mean age of 32.7{+-}6.4. Both quadriceps femoris muscles (QFM) of each patient were studied. After randomization to remove the effect of the dominant side, one QFM of each patient was subjected to the NMES procedure for a period of 20 days. NMES was performed with an alternating biphasic rectangular current, from a computed electrical stimulator daily for 23 minutes. After measurement of skinfold thickness over the thigh, pre- and post-NMES girth measurements were assessed in centimeters. Sixty minutes after injections of 555 MBq {sup 99m}Tc-sestamibi, static images of the thigh were obtained for 5 minutes. The thigh-to-knee uptake ratio was calculated by semiquantitative analysis and normalized to body surface area (NUR=normalized uptake ratio). The difference between the pre and post NMES NUR values was significant (1.76{+-}0.31 versus 2.25{+-}0.38, p=0.0000). The percentage (%) increase in NUR values also well correlated with the % increase in thigh girth measurements (r=0.89, p=0.0000). These results indicated that {sup 99m}Tc-sestamibi muscle scintigraphy as a new tool may be useful in evaluating therapeutic response to NMES. (author)

  20. Caffeine-induced increase in voluntary activation and strength of the quadriceps muscle during isometric, concentric and eccentric contractions.

    Science.gov (United States)

    Behrens, Martin; Mau-Moeller, Anett; Weippert, Matthias; Fuhrmann, Josefin; Wegner, Katharina; Skripitz, Ralf; Bader, Rainer; Bruhn, Sven

    2015-05-13

    This study investigated effects of caffeine ingestion (8 mg/kg) on maximum voluntary torque (MVT) and voluntary activation of the quadriceps during isometric, concentric and eccentric contractions. Fourteen subjects ingested caffeine and placebo in a randomized, controlled, counterbalanced, double-blind crossover design. Neuromuscular tests were performed before and 1 h after oral caffeine and placebo intake. MVTs were measured and the interpolated twitch technique was applied during isometric, concentric and eccentric contractions to assess voluntary activation. Furthermore, normalized root mean square of the EMG signal was calculated and evoked spinal reflex responses (H-reflex evoked at rest and during weak isometric voluntary contraction) as well as twitch torques were analyzed. Caffeine increased MVT by 26.4 N m (95%CI: 9.3-43.5 N m, P = 0.004), 22.5 N m (95%CI: 3.1-42.0 N m, P = 0.025) and 22.5 N m (95%CI: 2.2-42.7 N m, P = 0.032) for isometric, concentric and eccentric contractions. Strength enhancements were associated with increases in voluntary activation. Explosive voluntary strength and voluntary activation at the onset of contraction were significantly increased following caffeine ingestion. Changes in spinal reflex responses and at the muscle level were not observed. Data suggest that caffeine ingestion induced an acute increase in voluntary activation that was responsible for the increased strength regardless of the contraction mode.

  1. Spatial distribution of motor units recruited during electrical stimulation of the quadriceps muscle versus the femoral nerve.

    Science.gov (United States)

    Rodriguez-Falces, Javier; Maffiuletti, Nicola A; Place, Nicolas

    2013-11-01

    In this study we investigated differences in the spatial recruitment of motor units (MUs) in the quadriceps when electrical stimulation is applied over the quadriceps belly versus the femoral nerve. M-waves and mechanical twitches were evoked using over-the-quadriceps and femoral nerve stimulation of gradually increasing intensity from 22 young, healthy subjects. Spatial recruitment was investigated using recruitment curves of M-waves recorded from the vastus medialis (VM) and vastus lateralis (VL) and of twitches recorded from the quadriceps. At maximal stimulation intensity (Imax), no differences were found between nerve and over-the-quadriceps stimulation. At submaximal intensities, VL M-wave amplitude was higher for over-the-quadriceps stimulation at 40% Imax, and peak twitch force was greater for nerve stimulation at 60% and 80% Imax. For the VM, MU spatial recruitment during nerve and over-the-quadriceps stimulation of increasing intensity occurred in a similar manner, whereas significant differences were observed for the VL. Copyright © 2013 Wiley Periodicals, Inc.

  2. Dynamic {sup 31}P-MR-spectroscopy of the quadriceps muscle. Influence of sex and age on spectroscopic results; Die dynamische 31-Phosphor-Magnetresonanz-Spektroskopie des M. quadriceps. Einfluss von Geschlecht und Alter auf spektroskopische Parameter

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, K.; Romaneehsen, B.; Kessler, S.; Schadmand-Fischer, S.; Thelen, M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie

    1999-05-01

    Purpose: {sup 31}P-MRS is used to assess the influence of sex and age on quadriceps muscle metabolism before and after exercise. Materials and Methods: 32 healthy volunteers (15 women, 17 men; mean age: 38{+-}17 yrs.) were examined by dynamic phosphorus-31 ({sup 31}P) magnetic resonance spectroscopy (MRS). In the magnet, the quadriceps muscle was stressed by an isometric and an isotonic form of exercise until exhaustion, respectively. Results: Resting conditions: With increasing subjects` age, the ratio {beta}-adenosine triphosphate/total phosphate decreased (r=-0.37; p=0.02). With increasing subjects` age, the ratios inorganic phosphate/phosphocreatine (r=0.79; p=5x10{sup -8}), phosphomonoester/{beta}-adenosine triphosphate (r=0.74; p=10{sup -6}) and phosphodiester/{beta}-adenosine triphosphate (r=0.62; p=10{sup -4}) increased. The pH was the only one of the evaluated spectroscopic parameters which showed a sex-dependence: Female subjects had a significantly lower pH (7.03{+-}0.02) than male subjects (7.05{+-}0.03; p=0,01). Exercise: With increasing age, the maxima of inorganic phosphate/phosphocreatine were less extreme during both of the exercises (r=-0.42; p=0.0005). Likewise, the exercise-induced acidosis was less severe with increasing age (r=0.53; p=6x10{sup -6}). After the end of the exercise, the times of half recovery of inorganic phosphate/phosphocreatine and the pH correlated neither with the subjects` age nor with sex or cross-sectional area of the quadriceps muscle. Conclusion: Sex and age of volunteers affect spectroscopic results. This influence has to be considered in the interpretation of spectroscopic studies. (orig.) [Deutsch] Ziel: Die Ueberpruefung des Einflusses von Geschlecht und Alter gesunder Probanden auf phosphorspektroskopische Ergebnisse. Material und Methodik: 32 gesunde Probanden (15 Frauen, 17 Maenner) mit einem Durchschnittsalter von 38{+-}17 Jahren wurden mit der dynamischen 31-Phosphor-Magnetresonanz-Spektroskopie (MRS

  3. Inter- and intramuscular differences in training-induced hypertrophy of the quadriceps femoris: association with muscle activation during the first training session.

    Science.gov (United States)

    Wakahara, Taku; Ema, Ryoichi; Miyamoto, Naokazu; Kawakami, Yasuo

    2017-07-01

    The purpose of this study was to examine whether inter- and intramuscular differences in hypertrophy induced by resistance training correspond to differences in muscle activation during the first training session. Eleven young men completed 12 weeks of training intervention for knee extension. Before and after the intervention, T1-weighted magnetic resonance (MR) images were recorded to determine the volume and anatomical cross-sectional area (CSA) along the length of the individual muscles of the quadriceps femoris. The T2-weighted MR images were also acquired before and immediately after the first training session. The T2 was calculated for each pixel within the quadriceps femoris, from which the muscle activation was evaluated as %activated volume and area. The results showed that the %activated volume after the first training session was significantly higher in the vastus intermedius than the vastus medialis. However, the relative change in muscle volume after the training intervention was significantly greater in the rectus femoris than the vasti muscles (vastus lateralis, intermedius and medialis). Within the rectus femoris, both the %activated area and relative increase in CSA were significantly greater in the distal region than the proximal region. In contrast, the %activated area and relative increase in CSA of the vasti were nearly uniform along each muscle. These results suggest that the muscle activation during the first training session is associated with the intramuscular difference in hypertrophy induced by training intervention, but not with the intermuscular difference. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  4. EFFECT OF ISOMETRIC QUADRICEPS STRENGTHENING EXERCISE AT MULTIPLE ANGLES IN KNEE JOINT AMONG NORMAL ADULTS

    Directory of Open Access Journals (Sweden)

    JibiPaul

    2014-04-01

    Full Text Available Introduction: Strengthening exercises have been routinely used in persons with orthopaedic problems and athletes to increase force production or minimize muscle imbalance and joint injuries.Many studies have reported that isometric contractions can rapidly increases strength in quadriceps muscle. Objective: Objective of the study was to find out the effect of isometric strengthening exercise on strength of quadriceps at 45 and 90 degree of knee joint and also to compare the effect of strengthening exercise on strength of quadriceps at multiple angles of knee joint among control and experimental group. Methodology: This was a ccomparative experimental study with forty female healthy subjects from physiotherapy department of KPJ Healthcare University College, Malaysia. Convenient sampling method used to select the samples. The subjects were selected by inclusion criteria and randomly divided equally in to two with 20 subjects in each group. Isometric strengthening exercise and squatting exercise were given as intervention program for eight weeks respectively for experimental and control group. Pre and post data of quadriceps muscle strength measured were collected separately at 45 and 90 degree of knee joint using goniometry during resisted extension of knee in multi gym. Result: In experimental group Pre –Post statistical analysis found significant effect in increase of quadriceps strength at 45 and 90 degree with P<0.0001.****In control group quadriceps pre-post statistical analysis found no significant effect in increase of quadriceps strength at 45 and 90 degree with P<0.083NS and P<0.055 NS respectively. Comparative study between experimental and control groups for quadriceps strength at 90 degree of knee joint found significant effect in increase of quadriceps strength with P< 0.001.*** Comparative study between experimental and control groups for quadriceps strength at 45 degree of knee joint found significant effect in increase of

  5. A new approach to assess the spasticity in hamstrings muscles using mechanomyography antagonist muscular group.

    Science.gov (United States)

    Krueger, Eddy; Scheeren, Eduardo M; Nogueira-Neto, Guilherme N; Button, Vera Lúcia da S N; Nohama, Percy

    2012-01-01

    Several pathologies can cause muscle spasticity. Modified Ashworth scale (MAS) can rank spasticity, however its results depend on the physician subjective evaluation. This study aims to show a new approach to spasticity assessment by means of MMG analysis of hamstrings antagonist muscle group (quadriceps muscle). Four subjects participated in the study, divided into two groups regarding MAS (MAS0 and MAS1). MMG sensors were positioned over the muscle belly of rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) muscles. The range of movement was acquired with an electrogoniometer placed laterally to the knee. The system was based on a LabVIEW acquisition program and the MMG sensors were built with triaxial accelerometers. The subjects were submitted to stretching reflexes and the integral of the MMG (MMG(INT)) signal was calculated to analysis. The results showed that the MMG(INT) was greater to MAS1 than to MAS0 [muscle RF (p = 0.004), VL (p = 0.001) and VM (p = 0.007)]. The results showed that MMG was viable to detect a muscular tonus increase in antagonist muscular group (quadriceps femoris) of spinal cord injured volunteers.

  6. Haptic control of a pneumatic muscle actuator to provide resistance for simulated isokinetic exercise: Part I--dynamic test station and human quadriceps dynamic simulator.

    Science.gov (United States)

    Hall, Kara L; Phillips, Chandler A; Reynolds, David B; Mohler, Stanley R; Rogers, Dana B; Neidhard-Doll, Amy T

    2014-01-01

    Pneumatic muscle actuators (PMAs) have a high power to weight ratio and possess unique characteristics which make them ideal actuators for applications involving human interaction. PMAs are difficult to control due to nonlinear dynamics, presenting challenges in system implementation. Despite these challenges, PMAs have great potential as a source of resistance for strength training and rehabilitation. The objective of this work was to control a PMA for use in isokinetic exercise, potentially benefiting anyone in need of optimal strength training through a joint's range of motion. A human quadriceps dynamic simulator (HQDS) was developed so that control effectiveness and accommodation could be tested prior to human implementation. The experimental set-up and HQDS are discussed in Part I of this work. The development of a PMA haptic controller and its interaction with the HQDS are discussed in Part II.

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

    Science.gov (United States)

    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

  8. Recruitment order of quadriceps motor units: femoral nerve vs. direct quadriceps stimulation.

    Science.gov (United States)

    Rodriguez-Falces, Javier; Place, Nicolas

    2013-12-01

    To investigate potential differences in the recruitment order of motor units (MUs) in the quadriceps femoris when electrical stimulation is applied over the quadriceps belly versus the femoral nerve. M-waves and mechanical twitches were evoked using femoral nerve stimulation and direct quadriceps stimulation of gradually increasing intensity from 20 young, healthy subjects. Recruitment order was investigated by analysing the time-to-peak twitch and the time interval from the stimulus artefact to the M-wave positive peak (M-wave latency) for the vastus medialis (VM) and vastus lateralis (VL) muscles. During femoral nerve stimulation, time-to-peak twitch and M-wave latency decreased consistently (P  0.05). For the VM muscle, M-wave latency decreased with increasing stimulation level for both femoral nerve and direct quadriceps stimulation, whereas, for the VL muscle, the variation of M-wave latency with stimulus intensity was different for the two stimulation geometries (P recruitment order during direct quadriceps stimulation was more complex, depending ultimately on the architecture of the peripheral nerve and its terminal branches below the stimulating electrodes for each muscle. For the VM, MUs were orderly recruited for both stimulation geometries, whereas, for the VL muscle, MUs were orderly recruited for femoral nerve stimulation, but followed no particular order for direct quadriceps stimulation.

  9. Influence of patterned electrical neuromuscular stimulation on quadriceps activation in individuals with knee joint injury.

    Science.gov (United States)

    Glaviano, Neal R; Langston, William T; Hart, Joseph M; Saliba, Susan

    2014-12-01

    Neuromuscular Electrical Stimulation is a common intervention to address muscle weakness, however presents with many limitations such as fatigue, muscle damage, and patient discomfort that may influence its effectiveness. One novel form of electrical stimulation purported to improve neuromuscular re-education is Patterned Electrical Neuromuscular Stimulation (PENS), which is proposed to mimic muscle-firing patterns of healthy individuals. PENS provides patterned stimulating to the agonist muscle, antagonist muscle and then agonist muscle again in an effort to replicate firing patterns. The purpose of this study was to determine the effect of a single PENS treatment on knee extension torque and quadriceps activation in individuals with quadriceps inhibition. 18 subjects (10 males and 8 females: 24.2±3.4 years, 175.3±11.8cm, 81.8±12.4kg) with a history of knee injury/pain participated in this double-blinded randomized controlled laboratory trial. Participants demonstrated quadriceps inhibition with a central activation ratio of ≤90%. Maximal voluntary isometric contraction of the quadriceps and central activation ratio were measured before and after treatment. The treatment intervention was a 15-minute patterned electrical stimulation applied to the quadriceps and hamstring muscles with a strong motor contraction or a sham group, who received an identical set up as the PENS group, but received a 1mA subsensory stimulation. A 2×2 (group × time) ANCOVA was used to determine differences in maximal voluntary isometric contraction and central activation ratio between groups. The maximal voluntary isometric contraction was selected as a covariate due to baseline differences. There were no differences in change scores between pre- and post-intervention for maximal voluntary isometric contraction: (PENS: 0.09±0.32Nm/kg and Sham 0.15±0.18Nm/kg, p=0.713), or central activation ratio:(PENS: -1.22±6.06 and Sham: 1.48±3.7, p=0.270). A single Patterned Electrical

  10. Exercise training induces similar elevations in the activity of oxoglutarate dehydrogenase and peak oxygen uptake in the human quadriceps muscle

    DEFF Research Database (Denmark)

    Blomstrand, Eva; Krustrup, Peter; Søndergaard, Hans

    2011-01-01

    During exercise involving a small muscle mass, peak oxygen uptake is thought to be limited by peripheral factors, such as the degree of oxygen extraction from the blood and/or mitochondrial oxidative capacity. Previously, the maximal activity of the Krebs cycle enzyme oxoglutarate dehydrogenase has...

  11. Comparison of quadriceps-sparing minimally invasive and medial parapatellar total knee arthroplasty: A 2-year follow-up study

    Directory of Open Access Journals (Sweden)

    Hongsen Chiang

    2012-12-01

    Conclusions: Patients undergoing quadriceps-sparing and standard medial parapatellar TKA had comparable outcomes for quadriceps muscle strength, hamstring–quadriceps balance, and knee function; however, the quadriceps-sparing TKA was more time consuming surgically and resulted in a less accurate prosthesis position.

  12. Effects of contraction duration on low-frequency fatigue in voluntary and electrically induced exercise of quadriceps muscle in humans.

    Science.gov (United States)

    Ratkevicius, A; Skurvydas, A; Povilonis, E; Quistorff, B; Lexell, J

    1998-04-01

    The aims of this study were to investigate if low-frequency fatigue (LFF) dependent on the duration of repeated muscle contractions and to compare LFF in voluntary and electrically induced exercise. Male subjects performed three 9-min periods of repeated isometric knee extensions at 40% maximal voluntary contraction with contraction plus relaxation periods of 30 plus 60 s, 15 plus 30 s and 5 plus 10 s in protocols 1, 2 and 3, respectively. The same exercise protocols were repeated using feedback-controlled electrical stimulation at 40% maximal tetanic torque. Before and 15 min after each exercise period, knee extension torque at 1, 7, 10, 15, 20, 50 and 100 Hz was assessed. During voluntary exercise, electromyogram root mean square (EMGrms) of the vastus lateralis muscle was evaluated. The 20-Hz torque:100-Hz torque (20:100 Hz torque) ratio was reduced more after electrically induced than after voluntary exercise (P exercise, the decrease in 20:100 Hz torque ratio was gradually (P exercise, the decrease in 20:100 Hz torque ratio and the increase in EMGrms were greater in protocol 1 (P exercise and that the electrically induced exercise produced a more pronounced LFF compared to voluntary exercise of submaximal intensity. It is suggested that compensatory recruitment of faster-contracting motor units is an additional factor affecting the severity of LFF during voluntary exercise.

  13. Changes in calsequestrin, TNF-α, TGF-β and MyoD levels during the progression of skeletal muscle dystrophy in mdx mice: a comparative analysis of the quadriceps, diaphragm and intrinsic laryngeal muscles.

    Science.gov (United States)

    Barros Maranhão, Juliana; de Oliveira Moreira, Drielen; Maurício, Adriana Fogagnolo; de Carvalho, Samara Camaçari; Ferretti, Renato; Pereira, Juliano Alves; Santo Neto, Humberto; Marques, Maria Julia

    2015-10-01

    In Duchenne muscular dystrophy (DMD), the search for new biomarkers to follow the evolution of the disease is of fundamental importance in the light of the evolving gene and pharmacological therapies. In addition to the lack of dystrophin, secondary events including changes in calcium levels, inflammation and fibrosis greatly contribute to DMD progression and the molecules involved in these events may represent potential biomarkers. In this study, we performed a comparative evaluation of the progression of dystrophy within muscles that are differently affected by dystrophy (diaphragm; DIA and quadriceps; QDR) or spared (intrinsic laryngeal muscles) using the mdx mice model of DMD. We assessed muscle levels of calsequestrin (calcium-related protein), tumour necrosis factor (TNF-α; pro-inflammatory cytokine), tumour growth factor (TGF-β; pro-fibrotic factor) and MyoD (muscle proliferation) vs. histopathology at early (1 and 4 months of age) and late (9 months of age) stages of dystrophy. Fibrosis was the primary feature in the DIA of mdx mice (9 months: 32% fibrosis), which was greater than in the QDR (9 months: 0.6% fibrosis). Muscle regeneration was the primary feature in the QDR (9 months: 90% of centrally nucleated fibres areas vs. 33% in the DIA). The QDR expressed higher levels of calsequestrin than the DIA. Laryngeal muscles showed normal levels of TNF-α, TGF-β and MyoD. A positive correlation between histopathology and cytokine levels was observed only in the diaphragm, suggesting that TNF-α and TGF-β serve as markers of dystrophy primarily for the diaphragm. © 2015 The Authors. International Journal of Experimental Pathology © 2015 International Journal of Experimental Pathology.

  14. The importance of dynamic radiography with quadriceps contraction ...

    African Journals Online (AJOL)

    ... and concluded that the Xray of the knee with and without quadriceps contraction is a reliable and reproducible technique to objectify and quantify the degree of the anterior translation in ACL tears. Keywords: Knee, ACL (Anterior cruciate ligament), Magnetic resonance imaging, Quadriceps muscle, dynamicradiography.

  15. Acute effects of static stretching on peak and end-range hamstring-to-quadriceps functional ratios

    Science.gov (United States)

    Sekir, Ufuk; Arabaci, Ramiz; Akova, Bedrettin

    2015-01-01

    AIM: To evaluate if static stretching influences peak and end-range functional hamstring-to-quadriceps (H/Q) strength ratios in elite women athletes. METHODS: Eleven healthy female athletes in an elite competitive level participated to the study. All the participants fulfilled the static stretching or non-stretching (control) intervention protocol in a randomized design on different days. Two static unassisted stretching exercises, one in standing and one in sitting position, were used to stretch both the hamstring and quadriceps muscles during these protocols. The total time for the static stretching was 6 ± 1 min. The isokinetic peak torque measurements for the hamstring and quadriceps muscles in eccentric and concentric modes and the calculations for the functional H/Q strength ratios at angular velocities of 60°/s and 180°/s were made before (pre) and after (post) the control or stretching intervention. The strength measurements and functional strength ratio calculations were based during the entire- and end-range of knee extension. RESULTS: The pre-test scores for quadriceps and hamstring peak torque and end range values were not significantly different between the groups (P > 0.05). Subsequently, although the control group did not exhibit significant changes in quadriceps and hamstring muscle strength (P > 0.05), static stretching decreased eccentric and concentric quadriceps muscle strength at both the 60°/s and 180°/s test speeds (P hamstring muscle strength at both the 60°/s and 180°/s test speeds (P 0.05). Furthermore, the functional H/Q strength ratios exhibited no significant alterations during the entire and end ranges of knee extension both in the static stretching or the control intervention (P > 0.05). CONCLUSION: According to our results, static stretching routine does not influence functional H/Q ratio. Athletes can confidently perform static stretching during their warm-up routines. PMID:26495249

  16. Multi-parametric MR imaging of quadriceps musculature in the setting of clinical frailty syndrome

    International Nuclear Information System (INIS)

    Melville, David M.; Sharma, Puneet; Taljanovic, Mihra S.; Mohler, Jane; Fain, Mindy; Muchna, Amy E.; Krupinski, Elizabeth

    2016-01-01

    Frailty is a common geriatric syndrome associated with loss of skeletal muscle mass (sarcopenia) conferring an increased risk of rapid decline in health and function with increased vulnerability to adverse outcomes. The purpose of this study was to investigate the correlation between diffusion tensor, T2 and intramuscular fat content values of the quadriceps muscle group and clinical frailty status using diffusion tensor MR imaging. Subjects were recruited from the Arizona Frailty cohort composed of all females with frailty status based on the Fried criteria, including 6 non-frail and 10 pre-frail/frail adults, as well as a community sample of 11 young, healthy controls. Axial images of both thighs were obtained on a 3-T magnet with T1, T2 and diffusion tensor imaging as well as intramuscular fat analysis. Diffusion tensor and T2 values were determined by region-of-interest measurements at the proximal, mid and distal thirds of both thighs. Data were evaluated to determine differences between measured values and frailty status. The mean fractional anisotropy (FA) values in the bilateral quadriceps muscles demonstrated significant differences (F = 7.558, p = 0.0030) between the control and pre-frail/frail and non-frail and pre-frail/frail groups. There was a significant difference in mean T2 (F = 21.675, p < 0.0001) and lipid content (F = 19.266, p < 0.0001) among all three groups in the total quadriceps muscle group. The quadriceps musculature of pre-frail/frail adults demonstrated increased FA compared to young controls and non-frail adults with increasing T2 and intramuscular fat among the control, non-frail and pre-frail/frail categories. (orig.)

  17. Multi-parametric MR imaging of quadriceps musculature in the setting of clinical frailty syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Melville, David M.; Sharma, Puneet; Taljanovic, Mihra S. [University of Arizona College of Medicine, Department of Medical Imaging, 1501 N. Campbell Ave., P.O. Box 245067, Tucson, AZ (United States); Mohler, Jane; Fain, Mindy; Muchna, Amy E. [University of Arizona College of Medicine, Arizona Center on Aging, Tucson, AZ (United States); Krupinski, Elizabeth [University of Arizona College of Medicine, Department of Medical Imaging, 1501 N. Campbell Ave., P.O. Box 245067, Tucson, AZ (United States); Emory University, Department of Radiology and Imaging Services, Atlanta, GA (United States)

    2016-05-15

    Frailty is a common geriatric syndrome associated with loss of skeletal muscle mass (sarcopenia) conferring an increased risk of rapid decline in health and function with increased vulnerability to adverse outcomes. The purpose of this study was to investigate the correlation between diffusion tensor, T2 and intramuscular fat content values of the quadriceps muscle group and clinical frailty status using diffusion tensor MR imaging. Subjects were recruited from the Arizona Frailty cohort composed of all females with frailty status based on the Fried criteria, including 6 non-frail and 10 pre-frail/frail adults, as well as a community sample of 11 young, healthy controls. Axial images of both thighs were obtained on a 3-T magnet with T1, T2 and diffusion tensor imaging as well as intramuscular fat analysis. Diffusion tensor and T2 values were determined by region-of-interest measurements at the proximal, mid and distal thirds of both thighs. Data were evaluated to determine differences between measured values and frailty status. The mean fractional anisotropy (FA) values in the bilateral quadriceps muscles demonstrated significant differences (F = 7.558, p = 0.0030) between the control and pre-frail/frail and non-frail and pre-frail/frail groups. There was a significant difference in mean T2 (F = 21.675, p < 0.0001) and lipid content (F = 19.266, p < 0.0001) among all three groups in the total quadriceps muscle group. The quadriceps musculature of pre-frail/frail adults demonstrated increased FA compared to young controls and non-frail adults with increasing T2 and intramuscular fat among the control, non-frail and pre-frail/frail categories. (orig.)

  18. Partial tear of the quadriceps tendon in a child

    International Nuclear Information System (INIS)

    Khanna, Geetika; El-Khoury, George

    2008-01-01

    We present a case of partial rupture of the quadriceps tendon in an 8-year-old girl. This is one of the youngest patients reported with a quadriceps tendon rupture, an entity seen predominantly in middle-aged people. The strength of the muscle tendon unit in a child makes tendon injuries extremely unusual as compared to apophyseal avulsions. The MR imaging findings of this unusual pediatric injury are illustrated. (orig.)

  19. Static stretching vs. dynamic warm-ups: a comparison of their effects on torque and electromyography output of the quadriceps and hamstring muscles.

    Science.gov (United States)

    Williams, N; Coburn, J; Gillum, T

    2015-11-01

    The aim of this paper was to determine if two different warm-up protocols differently affect torque of the quadriceps and hamstrings, and electromyography (EMG) output of the rectus femoris (RF) and vastus lateralis (VL) when completing 30 maximal leg extensions and curls. Twenty-one healthy male (N.=8) and female (N.=13) subjects volunteered to participate in a familiarization session and three testing sessions. The three testing sessions control, dynamic, and static were completed in a counterbalanced order on non-consecutive days. First, subjects warmed-up on a treadmill for five minutes before completing six dynamic movements, six static-stretches, or no stretches. They then rested for five minutes before completing 30 maximal leg extensions and curls at a speed of 60 s-1. A significant decrease in quadriceps torque output over time was determined for the dynamic protocol when compared to the control (Phamstring torque or EMG output of the RF and VL. Short duration static-stretching has the ability to increase peak and average torque of the leg extensors, while some types of anaerobic exercise involving maximal contractions to fatigue may be hindered by performing dynamic movements as part of the warm-up.

  20. Intrarater Reliability of Muscle Strength and Hamstring to Quadriceps Strength Imbalance Ratios During Concentric, Isometric, and Eccentric Maximal Voluntary Contractions Using the Isoforce Dynamometer.

    Science.gov (United States)

    Mau-Moeller, Anett; Gube, Martin; Felser, Sabine; Feldhege, Frank; Weippert, Matthias; Husmann, Florian; Tischer, Thomas; Bader, Rainer; Bruhn, Sven; Behrens, Martin

    2017-08-17

    To determine intrasession and intersession reliability of strength measurements and hamstrings to quadriceps strength imbalance ratios (H/Q ratios) using the new isoforce dynamometer. Repeated measures. Exercise science laboratory. Thirty healthy subjects (15 females, 15 males, 27.8 years). Coefficient of variation (CV) and intraclass correlation coefficients (ICC) were calculated for (1) strength parameters, that is peak torque, mean work, and mean power for concentric and eccentric maximal voluntary contractions; isometric maximal voluntary torque (IMVT); rate of torque development (RTD), and (2) H/Q ratios, that is conventional concentric, eccentric, and isometric H/Q ratios (Hcon/Qcon at 60 deg/s, 120 deg/s, and 180 deg/s, Hecc/Qecc at -60 deg/s and Hiso/Qiso) and functional eccentric antagonist to concentric agonist H/Q ratios (Hecc/Qcon and Hcon/Qecc). High reliability: CV 0.90; moderate reliability: CV between 10% and 20%, ICC between 0.80 and 0.90; low reliability: CV >20%, ICC Strength parameters: (a) high intrasession reliability for concentric, eccentric, and isometric measurements, (b) moderate-to-high intersession reliability for concentric and eccentric measurements and IMVT, and (c) moderate-to-high intrasession reliability but low intersession reliability for RTD. (2) H/Q ratios: (a) moderate-to-high intrasession reliability for conventional ratios, (b) high intrasession reliability for functional ratios, (c) higher intersession reliability for Hcon/Qcon and Hiso/Qiso (moderate to high) than Hecc/Qecc (low to moderate), and (d) higher intersession reliability for conventional H/Q ratios (low to high) than functional H/Q ratios (low to moderate). The results have confirmed the reliability of strength parameters and the most frequently used H/Q ratios.

  1. Measurement of quadriceps endurance by fNIRS

    Science.gov (United States)

    Erdem, Devrim; Şayli, Ömer; Karahan, Mustafa; Akin, A.

    2006-02-01

    In this paper, the changes in muscle deoxygenation trends during a sustained isometric quadriceps (chair squat/half squat) endurance exercise were evaluated among twelve male subjects and the relationship between muscle oxygenation and endurance times was investigated by means of functional near-infrared spectroscopy (fNIRS). Neuromuscular activation and predictions of muscle performance decrements during extended fatiguing task was investigated by means of surface electromyography (sEMG). The results of the study showed that in the subjects who maintained exercise longer than five minutes (group 1), mean Hb recovery time (33 [sec.]) was 37.4% less than the others (group 2, 52.7 [sec.]). Also mean HbO II decline amplitude (2.53 [a.u.] in group 1 and 2.07 [a.u.] in group 2) and oxy decline amplitude (8.4 [a.u.] in group 1 and 3.04 [a.u.] in group 2) in the beginning of squat exercise are found to be 22.6% and 176.9% bigger in these group. For the EMG parameters, mean slope of MNF and MDF decline are found to be 57.5% and 42.2% bigger in magnitude in group 2 which indicates higher degree of decrement in mean and median frequencies although their mean squat duration time is less. This indicates higher index of fatigue for this group. It is concluded that training leads to altered oxygenation and oxygen extraction capability in the exercising muscle and investigated fNIRS parameters could be used for endurance evaluation.

  2. 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

  3. Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: a randomized controlled trial.

    Science.gov (United States)

    Sørensen, T J; Langberg, H; Hodges, P W; Bliddal, H; Henriksen, M

    2012-01-01

    Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology. Copyright © 2012 by the American College of Rheumatology.

  4. Knee flexion with quadriceps cocontraction: A new therapeutic exercise for the early stage of ACL rehabilitation.

    Science.gov (United States)

    Biscarini, Andrea; Contemori, Samuele; Busti, Daniele; Botti, Fabio M; Pettorossi, Vito E

    2016-12-08

    Quadriceps strengthening exercises designed for the early phase of anterior cruciate ligament (ACL) rehabilitation should limit the anterior tibial translation developed by quadriceps contraction near full knee extension, in order to avoid excessive strain on the healing tissue. We hypothesize that knee-flexion exercises with simultaneous voluntary contraction of quadriceps (voluntary quadriceps cocontraction) can yield considerable levels of quadriceps activation while preventing the tibia from translating forward relative to the femur. Electromyographic activity in quadriceps and hamstring muscles was measured in 20 healthy males during isometric knee-flexion exercises executed near full knee extension with maximal voluntary effort of quadriceps cocontraction and external resistance (R) ranging from 0% to 60% of the 1-repetition maximum (1RM). Biomechanical modeling was applied to derive the shear (anterior/posterior) tibiofemoral force developed in each exercise condition. Isometric knee-flexion exercises with small external resistance (R=10% 1RM) and maximal voluntary effort of quadriceps cocontraction yielded a net posterior (ACL-unloading) tibial pull (P=0.005) and levels of activation of 32%, 50%, and 45% of maximum voluntary isometric contraction, for the rectus femoris, vastus medialis, and vastus lateralis, respectively. This exercise might potentially rank as one of the most appropriate quadriceps strengthening interventions in the early phase of ACL rehabilitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Quadriceps force and anterior tibial force occur obviously later than vertical ground reaction force: a simulation study

    OpenAIRE

    Ueno, Ryo; Ishida, Tomoya; Yamanaka, Masanori; Taniguchi, Shohei; Ikuta, Ryohei; Samukawa, Mina; Saito, Hiroshi; Tohyama, Harukazu

    2017-01-01

    Background: Although it is well known that quadriceps force generates anterior tibial force, it has been unclear whether quadriceps force causes great anterior tibial force during the early phase of a landing task. The purpose of the present study was to examine whether the quadriceps force induced great anterior tibial force during the early phase of a landing task. Methods: Fourteen young, healthy, female subjects performed a single-leg landing task. Muscle force and anterior tibial force w...

  6. Muscle cramps

    Science.gov (United States)

    ... the lower leg/calf Back of the thigh (hamstrings) Front of the thigh (quadriceps) Cramps in the ... Names Cramps - muscle Images Chest stretch Groin stretch Hamstring stretch Hip stretch Thigh stretch Triceps stretch References ...

  7. Flexibility of Knee Joint Muscles in Women with Knee Osteoarthritis and Healthy Controls

    Directory of Open Access Journals (Sweden)

    Sara Abolahrari Shirazi

    2015-09-01

    Full Text Available Background: Osteoarthritis is one of the most common diseases in synovial joints. Due to high loading forces during weight-bearing activities, the knee joint is prone to degenerative processes. This study aimed to compare the flexibility of muscles around the knee joint in patients with knee osteoarthritis with those of healthy individuals. Methods: Twenty-three women with bilateral knee osteoarthritis and 23 healthy women matched with the patient group for age, height and weight participated in this study. Flexibility of the quadriceps, hamstring, iliotibial band, adductor and gastrocnemius muscles was evaluated with a goniometric device. Pain intensity was assessed with a visual analogue scale. The data were analyzed with independent t-tests to compare the two groups, and Pearson correlation coefficient was calculated to correlate muscle flexibility and pain intensity. Results: significant lower flexibility of the bilateral quadriceps muscles was found in patients compared to healthy women (P<0.05. No significant differences were detected between groups regarding other muscles. Quadriceps flexibility correlated significantly with pain intensity in patients (P<0.001. Conclusion: In patients with osteoarthritis, quadriceps flexibility may be decreased although other muscles may remain unaffected. Quadriceps stretching is thus a potentially important component of treatment, which may influence pain reduction in these patients.

  8. Delayed presentation of compartment syndrome of the thigh secondary to quadriceps trauma and vascular injury in a soccer athlete

    Directory of Open Access Journals (Sweden)

    Moo Ing How

    2015-01-01

    Conclusion: A high index of suspicion for compartment syndrome is needed in all severe quadriceps contusion. Vascular injury can cause thigh compartment syndrome in sports trauma. MRI findings of deep thigh muscle swelling and “blow-out” tear of the vastus lateralis are strongly suggestive of severe quadriceps injury, and may be a harbinger of delayed thigh compartment syndrome.

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

    Science.gov (United States)

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

    2017-12-01

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

  10. Isokinetic and isometric muscle strength combined with transcutaneous electrical muscle stimulation in primary fibromyalgia syndrome

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Wildschiødtz, Gordon; Danneskiold-Samsøe, B

    1991-01-01

    Twenty women with primary fibromyalgia syndrome and 20 age matched healthy women were investigated. The subjects performed maximum voluntary isokinetic contractions of the right quadriceps in an isokinetic dynamometer. Maximum voluntary isometric contractions of the right quadriceps were performed...... of superimposed twitches was 65% in the patient group and 15% in the control group (p = 0.003). Patients with primary fibromyalgia have a lower maximum voluntary muscle strength than expected. The increased presence of superimposed electrically elicited twitches during maximum voluntary contraction indicates...... submaximal force application in primary fibromyalgia syndrome....

  11. VARIATIONS IN NEUROMUSCULAR ACTIVITY OF THIGH MUSCLES DURING WHOLE-BODY VIBRATION IN CONSIDERATION OF DIFFERENT BIOMECHANICAL VARIABLES

    Directory of Open Access Journals (Sweden)

    Dennis Perchthaler

    2013-09-01

    Full Text Available The intention of this study was to systematically analyze the impact of biomechanical variables in terms of different vibration frequencies, amplitudes and knee angles on quadriceps femoris and hamstring activity during exposure to whole-body vibration (WBV. 51 healthy men and women (age 55 ± 8 years voluntary participated in the study and were randomly allocated to five different vibration-frequency groups. Each subject performed 9 static squat positions (3 amplitudes x 3 knee angles on a side alternating vibration platform. Surface electromyography (EMG was used to record the neuromuscular activity of the quadriceps femoris and hamstring muscles. Maximal voluntary contractions (MVCs were performed prior to the measurements to normalize the EMG signals. A three-way mixed ANOVA was performed to analyze the different effects of the biomechanical variables on muscle activity. Depending on the biomechanical variables, EMG muscle activity ranged between 18.2 and 74.1 % MVC in the quadriceps femoris and between 5.2 and 27. 3 % MVC in the hamstrings during WBV. The highest levels of muscle activation were found at high frequencies and large amplitudes. Especially in the quadriceps femoris muscle, a WBV frequency of 30 Hz led to a significant increase in muscle activity compared to the other tested frequencies. However, it seems that knee angle is only relevant for the quadriceps femoris muscle. The results of this study should give more information for developing individual training protocols for WBV treatment in different practical applications

  12. Handgrip strength, quadriceps muscle power, and optimal shortening velocity roles in maintaining functional abilities in older adults living in a long-term care home: a 1-year follow-up study

    Directory of Open Access Journals (Sweden)

    Kozicka I

    2016-05-01

    Full Text Available Izabela Kozicka, Tomasz Kostka Department of Geriatrics, Medical University of Lodz, Lodz, Poland Purpose: To assess the relative role of handgrip strength (HGS, quadriceps muscle power (Pmax, and optimal shortening velocity (υopt in maintaining functional abilities (FAs in older adults living in a long-term care home over a 1-year follow-up. Subjects and methods: Forty-one inactive older institutionalized adults aged 69.8±9.0 years participated in this study. HGS, Pmax, υopt, cognitive function using the Mini-Mental State Examination, depressive symptoms using the Geriatric Depression Scale, nutritional status using the Mini Nutritional Assessment (MNA, and physical activity (PA using the Seven-Day Physical Activity Recall Questionnaire were assessed at baseline and at 1-year follow-up. FAs were assessed with activities of daily living (ADL, instrumental ADL, and Timed Up & Go test. Results: Both at baseline and at follow-up, FAs were related to age, HGS, Pmax/kg, υopt, MNA, and PA. These associations were generally similar in both sexes. As revealed in multiple regression analysis, υopt was the strongest predictor of FA, followed by Pmax/kg, PA, and MNA. FA deteriorated after 1 year as measured by ADL and Timed Up & Go test. Pmax and υopt, but not HGS, also decreased significantly after 1 year. Nevertheless, 1-year changes in FAs were not related to changes in HGS, Pmax, υopt, or PA. Conclusion: The 1-year period of physical inactivity among older institutionalized adults was found to have a negative effect on their FAs, Pmax, and υopt. The present study demonstrates that Pmax and, especially, υopt correlated with FAs of older adults more than HGS, both at baseline and at follow-up. Despite this, 1-year natural fluctuations of PA, Pmax, and υopt are not significant enough to influence FAs in inactive institutionalized older adults. Keywords: aging, handgrip strength, institutionalization, functional status, physical activity

  13. Comparative analysis of quadriceps and hamstrings strength in knee osteoarthritis before and after total knee arthroplasty: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Naasson Trindade Cavanellas

    Full Text Available ABSTRACT Objective: Compare the maximal isokinetic muscle strength of knee extensor and flexor muscles between patients with knee osteoarthritis and patients submitted to total knee arthroplasty. Methods: Volunteers were divided into five groups (n = 20: Control; Ahlbäck I and II; Ahlbäck IV; six months after total knee arthroplasty; 12 months after total knee arthroplasty. An isokinetic knee strength evaluation was conducted for the quadriceps and hamstrings at 60°/s. Results: Significant differences in the peak torque of the quadriceps and hamstrings were found among the groups (p < 0.001. The Ahlbäck IV, six-month, and 12-month postoperative groups demonstrated lower values when compared to the Control and Ahlbäck I and II groups. When percentage values were compared to the Control group, mean differences ranged from 7% to 41%. Conclusion: Patients with healthy knees or early stage osteoarthritis have higher quadriceps and hamstrings strengths than those with a more advanced stage of the disease, even after knee replacement. These findings suggest that the traditional rehabilitation programs do not recover strength to levels observed in individuals without knee osteoarthritis.

  14. Experimental evidence against the mitochondrial theory of aging. A study of isolated human skeletal muscle mitochondria

    DEFF Research Database (Denmark)

    Rasmussen, Ulla F.; Krustrup, Peter; Kjær, Michael

    2003-01-01

    age effects, ATP formation, BSA effects, collagen content, low temperature spectroscopy, oxygen uptakes, quadriceps muscle, respiration, specific enzyme activities......age effects, ATP formation, BSA effects, collagen content, low temperature spectroscopy, oxygen uptakes, quadriceps muscle, respiration, specific enzyme activities...

  15. Quadriceps bulk and strength and effect of its training in patients with moderate to severe chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Nasr Affara

    2013-01-01

    Conclusion: We have collected evidence indicating that both bulk and strength of quadriceps muscles in particular were reduced in patients with COPD compared with normal controls and these changes can be improved with progressive training without change in pulmonary functions.

  16. ACL deficient potential copers and non-copers reveal different isokinetic quadriceps strength profiles in the early stage after injury

    Science.gov (United States)

    Eitzen, I; Eitzen, TJ; Holm, I; Snyder-Mackler, L; Risberg, MA

    2011-01-01

    Background Isokinetic muscle strength tests using the peak torque value is the most frequently included quadriceps muscle strength measurement for anterior cruciate ligament (ACL) injured subjects. Aims The purpose of this study was to investigate quadriceps muscle performance during the whole isokinetic curve in ACL deficient subjects classified as potential copers or non-copers, and investigate whether these curve profiles were associated with single-leg hop performance. We hypothesized that quadriceps muscle torque at other knee flexion angles than peak torque would give more information about quadriceps muscle strength deficits. Furthermore, we hypothesized that there would be significant torque differences between potential copers and non-copers, and a significant relationship between angle specific torque values and single-leg hop performance. Study Design Cross-sectional study; Level of evidence, 2 Methods Seventy-six individuals with a complete unilateral ACL rupture within the last 3 months were included. The subjects were classified into potential copers and non-copers according to the criteria from Fitzgerald et al12. Isokinetic quadriceps muscle tests were performed at 60°/sec (Biodex 6000). Mean torque values were calculated for peak torque as well as for specific knee flexion angles. The one-leg hop and the 6 meter timed hop tests were included and symmetry indices were used. Results The peak torque value did not identify the largest quadriceps muscle strength deficit. Rather, these were established at knee flexion angles of less than 40°. There were significant differences in angle specific torque values between potential copers and non-copers (p<0.05). Moderate to strong associations were disclosed between angle specific torque values and single-leg hop performance, but only for non-copers (r≥0.32– 0.58). Conclusions Angle specific quadriceps muscle torque values of less than 40° of knee flexion provide more information on the quadriceps

  17. Muscle sonography in six patients with hereditary inclusion body myopathy

    International Nuclear Information System (INIS)

    Adler, Ronald S.; Garolfalo, Giovanna; Paget, Stephen; Kagen, Lawrence

    2008-01-01

    To evaluate the morphological changes of muscle with sonography in six patients affected by hereditary inclusion body myopathy (HIBM). We studied a group of six Persian Jews diagnosed with HIBM. All were homozygous for the GNE mutation M712T. Ultrasonographic examinations of the quadriceps femoris and hamstring muscle groups were performed. A follow-up ultrasound examination was performed, after an interval of 3 years, in four of these patients. Muscles were assessed subjectively as to echogenicity, determined by gray-scale assessment, and loss of normal muscle morphology. Power Doppler sonography (PDS) was used to assess vascularity. A sonographic finding of central atrophy and peripheral sparing resulting in a target-like appearance was noted in the hamstring compartment of all six patients. The quadriceps compartment also showed involvement of the rectus femoris of all patients, which, in some cases, was the only muscle involved in the quadriceps. Vascularity was markedly reduced in the affected areas, with blood flow demonstrated in the peripherally spared areas. The severity of atrophy increased with disease duration. In this case series, we describe a new sonographic finding as well as document progression of HIBM disease, which has generally been described as quadriceps sparing. The myopathic target lesion, as well as isolated rectus femoris atrophy, may provide a useful adjunct to disease diagnosis. (orig.)

  18. Quadriceps strength, inter-extremity difference (IED) and joint status in adult persons with severe haemophilia in different age stages.

    Science.gov (United States)

    Brunner, A; Stäuber, F; Göhler, S; Czepa, D; Krüger, S; Wendel, M; Seuser, A; Hilberg, T

    2013-03-01

    Quadriceps weakness seems to be a hallmark in adult persons with severe haemophilia (PWH). The purpose of this study was to compare PWH and non-haemophilic controls in different age stages with reference to joint status and quadriceps strength. Further aims were to examine the extent of strength-specific inter-extremity-difference (IED) and the prevalence of abnormal IED (AIED). A total of 106 adults with severe haemophilia (H) and 80 controls (C) had undergone an orthopaedic examination for classification of knee and ankle status using the WFH score. Quadriceps strength was evaluated unilaterally as well as bilaterally with a knee extensor device. Each group was divided into four age-related subgroups (HA/CA: 18-29, HB/CB: 30-39, HC/CC: 40-49, HD/CD: 50-70; in years). H presented a worse knee and ankle status than C indicated by higher WFH scores (P age-matched subgroups only HB showed higher knee scores than CB (P age-matched controls (P age in H. We discovered an AIED in 35% of H. These findings highlight the importance for the early implementation of preventive and rehabilitative muscle training programmes in the comprehensive treatment of PWH. © 2012 Blackwell Publishing Ltd.

  19. KOMBINASI LATIHAN EKSENTRIK M.GASTROCNEMIUS DAN LATIHAN PLYOMETRIC LEBIH BAIK DARI PADA LATIHAN EKSENTRIK M.QUADRICEPS DAN LATIHAN PLYOMETRIC TERHADAP PENINGKATAN AGILITY PADA MAHASISWA DI UNIVERSITAS ESA UNGGUL

    Directory of Open Access Journals (Sweden)

    Miranti Yolanda Anggita

    2015-08-01

    Full Text Available Increase agility for students is determined by muscular strength, speed, and flexibility. The ability of muscles to contract quickly will increase the speed of muscle in motion. Increase in speed, strength and flexibility of muscles due to stretch muscle-tendinous unit. The mechanism become the basis for moving in the shortest possible time. Agility on student issues has not received much attention, the attention of the agility found better in many athletes. This research is an experimental study to analysis at the difference between the intervention of with gastrocmineus muscle eccentric exercises and plyometric exercises with eccentric exercise quadriceps muscle and plyometric to increase agility on students at the University of Esa Unggul. A total of 40 students aged 18-21 years old who meet the criteria inclusion were randomly divided into 2 treatment groups. The old treatment group I was given quadriceps muscle eccentric and plyometric treatment group II eccentric exercise gastrocmineus muscle and plyometric exercises. Both exercise was done 3 times was given per week for 6 weeks. Agility is measured by Right-Boomerang Run Test. The results of the hypothesis testing using t-test related and different mean values obtained agility treatment group I (16,43±0.89secon and a second treatment group (16,01± 1,04seconwith p?0.05. Conclusion of the study is a combination of eccentric exercise m.gastrocnemius with plyometric exercise no better than the m.quadriceps eceentric exercises with plyometric exercises to increase agility on student at Esa Unggul University.

  20. Neuromuscular electrical stimulation of the quadriceps in patients with non-small cell lung cancer receiving palliative chemotherapy: a randomized phase II study.

    Directory of Open Access Journals (Sweden)

    Matthew Maddocks

    Full Text Available A reduced exercise capacity is associated with increased morbidity and mortality in patients with advanced non-small cell lung cancer (NSCLC. Therapeutic exercise can be beneficial and neuromuscular electrical stimulation (NMES of the quadriceps muscles may represent a practical approach. The primary aim of this study was to determine the acceptability of NMES of the quadriceps to patients with NSCLC used alongside palliative chemotherapy. Secondary aims explored aspects of safety and efficacy of NMES in this setting.Patients with advanced NSCLC due to receive first-line palliative chemotherapy were randomized to usual care with or without NMES. They were asked to undertake 30 minute sessions of NMES, ideally daily, but as a minimum, three times weekly. For NMES to be considered acceptable, it was predetermined that ≥80% of patients should achieve this minimum level of adherence. Qualitative interviews were held with a subset of patients to explore factors influencing adherence. Safety was assessed according to the Common Terminology Criteria for Adverse Events. Quadriceps muscle strength, thigh lean mass, and physical activity level were assessed at baseline and after three cycles of chemotherapy.49 patients (28 male, median (IQR age 69 (64-75 years participated. Of 30 randomized to NMES, 18 were eligible for the primary endpoint, of whom 9 (50% [90% CI, 29 to 71] met the minimum level of adherence. Adherence was enhanced by incorporating sessions into a daily routine and hindered by undesirable effects of chemotherapy. There were no serious adverse events related to NMES, nor significant differences in quadriceps muscle strength, thigh lean mass or physical activity level between groups.NMES is not acceptable in this setting, nor was there a suggestion of benefit. The need remains to explore NMES in patients with cancer in other settings.Current Controlled Trials ISRCTN 42944026 www.controlled-trials.com/ISRCTN42944026.

  1. Performance on a Clinical Quadriceps Activation Battery Is Related to a Laboratory Measure of Activation and Recovery After Total Knee Arthroplasty.

    Science.gov (United States)

    Bade, Michael; Struessel, Tamara; Paxton, Roger; Winters, Joshua; Baym, Carol; Stevens-Lapsley, Jennifer

    2018-01-01

    To determine the relation between performance on a clinical quadriceps activation battery with (1) activation measured by doublet interpolation and (2) recovery of quadriceps strength and functional performance after total knee arthroplasty (TKA). Planned secondary analysis of a randomized controlled trial. University research laboratory. Patients (N=162; mean age, 63±7y; 89 women) undergoing TKA. Patients were classified as high (quadriceps activation battery ≥4/6) or low (quadriceps activation battery ≤3/6) based on performance on the quadriceps activation battery measured 4 days after TKA. Differences between groups in activation and recovery at 1, 2, 3, 6, and 12 months after TKA were compared using a repeated-measures maximum likelihood model. The low quadriceps activation battery group demonstrated poorer quadriceps activation via doublet interpolation (P=.01), greater quadriceps strength loss (P=.01), and greater functional performance decline (all Pbattery group. Differences between low and high quadriceps activation battery groups on all measures did not persist at 3 and 12 months (all P>.05). Poor performance on the quadriceps activation battery early after TKA is related to poor quadriceps activation and poor recovery in the early postoperative period. Patients in the low quadriceps activation battery group took 3 months to recover to the same level as the high quadriceps activation battery group. The quadriceps activation battery may be useful in identifying individuals who need specific interventions to target activation deficits or different care pathways in the early postoperative period to speed recovery after TKA. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  2. Effect of transcutaneous electrical muscle stimulation on muscle volume in patients with septic shock

    DEFF Research Database (Denmark)

    Poulsen, Jesper Brøndum; Møller, Kirsten; Jensen, Claus V

    2011-01-01

    Objective: Intensive care unit admission is associated with muscle wasting and impaired physical function. We investigated the effect of early transcutaneous electrical muscle stimulation on quadriceps muscle volume in patients with septic shock. Design: Randomized interventional study using...

  3. The effect of local skin cooling before a sustained, submaximal isometric contraction on fatigue and isometric quadriceps femoris performance: A randomized controlled trial.

    Science.gov (United States)

    Hohenauer, Erich; Cescon, Corrado; Deliens, Tom; Clarys, Peter; Clijsen, Ron

    2017-04-01

    The central- and peripheral mechanisms by which heat strain limits physical performance are not fully elucidated. Nevertheless, pre-cooling is often used in an attempt to improve subsequent performance. This study compared the effects of pre-cooling vs. a pre-thermoneutral application on central- and peripheral fatigue during 60% of isometric maximum voluntary contraction (MVC) of the right quadriceps femoris muscle. Furthermore, the effects between a pre-cooling and a pre-thermoneutral application on isometric MVC of the right quadriceps femoris muscle and subjective ratings of perceived exertion (RPE) were investigated. In this randomized controlled trial, 18 healthy adults voluntarily participated. The participants received either a cold (experimental) application (+8°C) or a thermoneutral (control) application (+32°C) for 20min on their right thigh (one cuff). After the application, central (fractal dimension - FD) and peripheral (muscle fiber conduction velocity - CV) fatigue was estimated using sEMG parameters during 60% of isometric MVC. Surface EMG signals were detected from the vastus medialis and lateralis using bidimensional arrays. Immediately after the submaximal contraction, isometric MVC and RPE were assessed. Participants receiving the cold application were able to maintain a 60% isometric MVC significantly longer when compared to the thermoneutral group (mean time: 78 vs. 46s; p=0.04). The thermoneutral application had no significant impact on central fatigue (p>0.05) compared to the cold application (p=0.03). However, signs of peripheral fatigue were significantly higher in the cold group compared to the thermoneutral group (p=0.008). Pre-cooling had no effect on isometric MVC of the right quadriceps muscle and ratings of perceived exertion. Pre-cooling attenuated central fatigue and led to significantly longer submaximal contraction times compared to the pre-thermoneutral application. These findings support the use of pre-cooling procedures

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

    Directory of Open Access Journals (Sweden)

    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

  5. Chronic exercise preserves lean muscle mass in masters athletes.

    Science.gov (United States)

    Wroblewski, Andrew P; Amati, Francesca; Smiley, Mark A; Goodpaster, Bret; Wright, Vonda

    2011-09-01

    Aging is commonly associated with a loss of muscle mass and strength, resulting in falls, functional decline, and the subjective feeling of weakness. Exercise modulates the morbidities of muscle aging. Most studies, however, have examined muscle-loss changes in sedentary aging adults. This leaves the question of whether the changes that are commonly associated with muscle aging reflect the true physiology of muscle aging or whether they reflect disuse atrophy. This study evaluated whether high levels of chronic exercise prevents the loss of lean muscle mass and strength experienced in sedentary aging adults. A cross-section of 40 high-level recreational athletes ("masters athletes") who were aged 40 to 81 years and trained 4 to 5 times per week underwent tests of health/activity, body composition, quadriceps peak torque (PT), and magnetic resonance imaging of bilateral quadriceps. Mid-thigh muscle area, quadriceps area (QA), subcutaneous adipose tissue, and intramuscular adipose tissue were quantified in magnetic resonance imaging using medical image processing, analysis, and visualization software. One-way analysis of variance was used to examine age group differences. Relationships were evaluated using Spearman correlations. Mid-thigh muscle area (P = 0.31) and lean mass (P = 0.15) did not increase with age and were significantly related to retention of mid-thigh muscle area (P lean mass (P = 0.4) and PT. This study contradicts the common observation that muscle mass and strength decline as a function of aging alone. Instead, these declines may signal the effect of chronic disuse rather than muscle aging. Evaluation of masters athletes removes disuse as a confounding variable in the study of lower-extremity function and loss of lean muscle mass. This maintenance of muscle mass and strength may decrease or eliminate the falls, functional decline, and loss of independence that are commonly seen in aging adults.

  6. Improvement of stance control and muscle performance induced by focal muscle vibration in young-elderly women: a randomized controlled trial.

    Science.gov (United States)

    Filippi, Guido M; Brunetti, Orazio; Botti, Fabio M; Panichi, Roberto; Roscini, Mauro; Camerota, Filippo; Cesari, Matteo; Pettorossi, Vito E

    2009-12-01

    Filippi GM, Brunetti O, Botti FM, Panichi R, Roscini M, Camerota F, Cesari M, Pettorossi VE. Improvement of stance control and muscle performance induced by focal muscle vibration in young-elderly women: a randomized controlled trial. To determine the effect of a particular protocol of mechanical vibration, applied focally and repeatedly (repeated muscle vibration [rMV]) on the quadriceps muscles, on stance and lower-extremity muscle power of young-elderly women. Double-blind randomized controlled trial; 3-month follow-up after intervention. Human Physiology Laboratories, University of Perugia, Italy. Sedentary women volunteers (N=60), randomized in 3 groups (mean age +/- SD, 65.3+/-4.2y; range, 60-72). rMV (100Hz, 300-500microm, in three 10-minute sessions a day for 3 consecutive days) was applied to voluntary contracted quadriceps (vibrated and contracted group) and relaxed quadriceps (vibrated and relaxed group). A third group received placebo stimulation (nonvibrated group). Area of sway of the center of pressure, vertical jump height, and leg power. Twenty-four hours after the end of the complete series of applications, the area of sway of the center of pressure decreased significantly by approximately 20%, vertical jump increased by approximately 55%, and leg power increased by approximately 35%. These effects were maintained for at least 90 days after treatment. rMV is a short-lasting and noninvasive protocol that can significantly and persistently improve muscle performance in sedentary young-elderly women.

  7. Effects of preoperative neuromuscular electrical stimulation on quadriceps strength and functional recovery in total knee arthroplasty. A pilot study.

    LENUS (Irish Health Repository)

    Walls, Raymond J

    2010-01-01

    Supervised preoperative muscle strengthening programmes (prehabilitation) can improve recovery after total joint arthroplasty but are considered resource intensive. Neuromuscular electrical stimulation (NMES) has been shown to improve quadriceps femoris muscle (QFM) strength and clinical function in subjects with knee osteoarthritis (OA) however it has not been previously investigated as a prehabilitation modality.

  8. Effect of Adductor Canal Block Versus Femoral Nerve Block on Quadriceps Strength, Mobilization, and Pain After Total Knee Arthroplasty

    DEFF Research Database (Denmark)

    Grevstad, Jens Ulrik; Mathiesen, Ole; Valentiner, Laura Risted Staun

    2015-01-01

    strength. METHODS: We included 50 TKA patients with severe movement-related pain; defined as having visual analog scale pain score of greater than 60 mm during active flexion of the knee. The ACB group received an ACB with ropivacaine 0.2% 30 mL and a femoral nerve block (FNB) with 30 mL saline. The FNB...... group received an ACB with 30 mL saline and an FNB with ropivacaine 0.2% 30 mL. We compared the effect of the ACB versus FNB on maximum voluntary isometric contraction of the quadriceps muscle relative to a postoperative baseline value. Secondary end points were differences between groups in ability...

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

    Science.gov (United States)

    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.

  10. Gear Shifting of Quadriceps during Isometric Knee Extension Disclosed Using Ultrasonography.

    Science.gov (United States)

    Zhang, Shu; Huang, Weijian; Zeng, Yu; Shi, Wenxiu; Diao, Xianfen; Wei, Xiguang; Ling, Shan

    2018-01-01

    Ultrasonography has been widely employed to estimate the morphological changes of muscle during contraction. To further investigate the motion pattern of quadriceps during isometric knee extensions, we studied the relative motion pattern between femur and quadriceps under ultrasonography. An interesting observation is that although the force of isometric knee extension can be controlled to change almost linearly, femur in the simultaneously captured ultrasound video sequences has several different piecewise moving patterns. This phenomenon is like quadriceps having several forward gear ratios like a car starting from rest towards maximal voluntary contraction (MVC) and then returning to rest. Therefore, to verify this assumption, we captured several ultrasound video sequences of isometric knee extension and collected the torque/force signal simultaneously. Then we extract the shapes of femur from these ultrasound video sequences using video processing techniques and study the motion pattern both qualitatively and quantitatively. The phenomenon can be seen easier via a comparison between the torque signal and relative spatial distance between femur and quadriceps. Furthermore, we use cluster analysis techniques to study the process and the clustering results also provided preliminary support to the conclusion that, during both ramp increasing and decreasing phases, quadriceps contraction may have several forward gear ratios relative to femur.

  11. Quantitative MRI and strength measurements in the assessment of muscle quality in Duchenne muscular dystrophy.

    Science.gov (United States)

    Wokke, B H; van den Bergen, J C; Versluis, M J; Niks, E H; Milles, J; Webb, A G; van Zwet, E W; Aartsma-Rus, A; Verschuuren, J J; Kan, H E

    2014-05-01

    The purpose of this study was to assess leg muscle quality and give a detailed description of leg muscle involvement in a series of Duchenne muscular dystrophy patients using quantitative MRI and strength measurements. Fatty infiltration, as well as total and contractile (not fatty infiltrated) cross sectional areas of various leg muscles were determined in 16 Duchenne patients and 11 controls (aged 8-15). To determine specific muscle strength, four leg muscle groups (quadriceps femoris, hamstrings, anterior tibialis and triceps surae) were measured and related to the amount of contractile tissue. In patients, the quadriceps femoris showed decreased total and contractile cross sectional area, attributable to muscle atrophy. The total, but not the contractile, cross sectional area of the triceps surae was increased in patients, corresponding to hypertrophy. Specific strength decreased in all four muscle groups of Duchenne patients, indicating reduced muscle quality. This suggests that muscle hypertrophy and fatty infiltration are two distinct pathological processes, differing between muscle groups. Additionally, the quality of remaining muscle fibers is severely reduced in the legs of Duchenne patients. The combination of quantitative MRI and quantitative muscle testing could be a valuable outcome parameter in longitudinal studies and in the follow-up of therapeutic effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Quadriceps strength, quadriceps power, and gait speed in older U.S. adults with diabetes mellitus: results from the National Health and Nutrition Examination Survey, 1999-2002.

    Science.gov (United States)

    Kalyani, Rita Rastogi; Tra, Yolande; Yeh, Hsin-Chieh; Egan, Josephine M; Ferrucci, Luigi; Brancati, Frederick L

    2013-05-01

    To examine the independent association between diabetes mellitus (and its duration and severity) and quadriceps strength, quadriceps power, and gait speed in a national population of older adults. Cross-sectional nationally representative survey. United States. Two thousand five hundred seventy-three adults aged 50 and older in the National Health and Nutrition Examination Survey 1999-2002 who had assessment of quadriceps strength. Diabetes mellitus was ascertained according to questionnaire. Measurement of isokinetic knee extensor (quadriceps) strength was performed at 60º/s. Gait speed was assessed using a 20-foot walk test. Multiple linear regression analyses were used to assess the association between diabetes mellitus status and outcomes, adjusting for potential confounders or mediators. Older U.S. adults with diabetes mellitus had significantly slower gait speed (0.96 ± 0.02 m/s) than those without (1.08 ± 0.01 m/s; P diabetes mellitus was also associated with significantly lower quadriceps strength (-4.6 ± 1.9 Nm; P = .02) and power (-4.9 ± 2.0 W; P = .02) and slower gait speed (-0.05 ± 0.02 m/s; P = .002). Associations remained significant after adjusting for physical activity and C-reactive protein. After accounting for comorbidities (cardiovascular disease, peripheral neuropathy, amputation, cancer, arthritis, fracture, chronic obstructive pulmonary disease), diabetes mellitus was independently associated only with gait speed (-0.04 ± 0.02 m/s; P = .02). Diabetes mellitus duration in men and women was negatively associated with age-adjusted quadriceps strength (-5.7 and -3.5 Nm/decade of diabetes mellitus, respectively) and power (-6.1 and -3.8 W/decade of diabetes mellitus, respectively) (all P ≤ .001, no significant interactions according to sex). Glycosylated hemoglobin was not associated with outcomes after accounting for body weight. Older U.S. adults with diabetes mellitus have lower quadriceps strength and quadriceps power that is related

  13. Modulation of Isometric Quadriceps Strength in Soccer Players With Transcranial Direct Current Stimulation: A Crossover Study.

    Science.gov (United States)

    Vargas, Valentine Z; Baptista, Abrahão F; Pereira, Guilherme O C; Pochini, Alberto C; Ejnisman, Benno; Santos, Marcelo B; João, Silvia M A; Hazime, Fuad A

    2018-05-01

    Vargas, VZ, Baptista, AF, Pereira, GOC, Pochini, AC, Ejnisman, B, Santos, MB, João, SMA, and Hazime, FA. Modulation of isometric quadriceps strength in soccer players with transcranial direct current stimulation: a crossover study. J Strength Cond Res 32(5): 1336-1341, 2018-The aim of this study was to evaluate the effect of transcranial direct current stimulation (tDCS) on the maximum isometric muscle contraction (MVIC) of the knee extensors in soccer players at the preprofessional level. Twenty female soccer players aged 15-17 years (mean = 16.1; SD = 0.9) with 5.2 ± 2.6 years of training were randomly divided into 2 groups to receive either active or sham tDCS in a single session (2 mA; 0.057 mA·cm). The MVIC of the knee extensors was evaluated in both lower limbs by manual dynamometry in 5 sets of contractions divided into 4 blocks: (a) prestimulation, (b) during tDCS, (c) 30 minutes after tDCS, and (d) 60 minutes after tDCS. After an interval of 7 days, the groups were evaluated again, and the type of initial stimulation was inverted between participants. The MVIC of the knee extensors increased significantly during active tDCS (dominant limb (DL) = 0.4; IC = 0.1-0.8 N·Kg), 30 minutes after active tDCS (DL = 0.9; IC 0.4-1.4 N·Kg), and 60 minutes after active tDCS (DL = 1.0; IC 0.3-1.6 N·Kg) but not for sham tDCS. Our conclusion was that tDCS temporarily increases isometric quadriceps strength in adolescent female soccer players, which may be useful for both strength training and rehabilitation.

  14. Functional and morphological changes in the quadriceps muscle induced by eccentric training after ACL reconstruction Alterações funcionais e morfológicas do quadríceps induzidas pelo treinamento excêntrico após reconstrução do LCA

    Directory of Open Access Journals (Sweden)

    Jamilson S. Brasileiro

    2011-08-01

    Full Text Available OBJECTIVES: The purpose of this study was to investigate the contributions of functional and morphological factors in the recovery of the quadriceps muscle after anterior cruciate ligament (ACL reconstruction. METHODS: Nine subjects (31.3±5.8 years underwent eccentric exercise sessions twice a week for 12 weeks. Quadriceps muscle function was evaluated using an isokinetic dynamometer (isometric and eccentric peak torque and electromyography (RMS. Morphological changes were measured using magnetic resonance imaging. RESULTS: The initial evaluation showed a significant deficit in knee extensor torque in the involved limb and significant muscle atrophy along the length of the quadriceps. EMG activity was lower in all tested situations. Eccentric training significantly increased isokinetic torque (from 199±51 to 240±63, pOBJETIVOS: O propósito deste estudo foi avaliar as contribuições dos fatores funcionais e morfológicos na recuperação da força muscular do quadríceps femoral após reconstrução do Ligamento Cruzado Anterior (LCA. MÉTODOS: Nove indivíduos (31,3±5,8 anos foram treinados por meio de contrações excêntricas máximas, duas vezes por semana, durante 12 semanas. A função do quadríceps foi avaliada pela dinamometria isocinética (pico de torque isométrico e excêntrico e pela eletromiografia (EMG. As alterações morfológicas foram mensuradas por meio de ressonância magnética (RNM. Na avaliação inicial, observou-se significativo déficit no torque extensor do joelho do membro acometido, com hipotrofia muscular de todo o quadríceps e redução na atividade EMG, quando comparado ao membro não-acometido. RESULTADOS: O treinamento excêntrico produziu aumento no torque excêntrico a 30º/s (de 199±51 Nm para 240±63 Nm, p<0,05 e no volume muscular, sendo que maiores hipertrofias ocorreram na região proximal da coxa (de 169±27 para 189±25,8 cm², p<0,01. A atividade EMG do Vasto Medial (VM aumentou nas primeiras

  15. The alterations in adenosine nucleotides and lactic acid in striated muscles of rats during Rigor mortis following death with drowning or cervical dislocation.

    Science.gov (United States)

    Pençe, Halime Hanim; Pençe, Sadrettin; Kurtul, Naciye; Yilmaz, Necat; Kocoglu, Hasan; Bakan, Ebubekir

    2003-01-01

    In this study, adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP) and lactic acid in the muscles of masseter, triceps, and quadriceps obtained from right and left sides of Spraque-Dawley rats following death were investigated. The samples were taken immediately and 120 minutes after death occurred. The rats were killed either by cervical dislocation or drowning. ATP concentrations in the muscles of masseter, triceps, and quadriceps were lower in samples obtained 120 minutes after death than in those obtained immediately after death. ADP, AMP, and lactic acid concentrations in these muscles were higher in samples obtained 120 minutes after death than those obtained immediately after death. A positive linear correlation was determined between ATP and ADP concentrations in quadriceps muscles of the rats killed with cervical dislocation and in triceps muscles of the rats killed with drowning. When rats killed with cervical dislocation and with drowning were compared, ADP, AMP, and lactic acid concentrations were lower in the former than in the latter for both times (immediately and 120 minutes after death occurred). In the case of drowning, ATP is consumed faster because of hard exercise or severe physical activity, resulting in a faster rigor mortis. Higher lactic acid levels were determined in muscles of the rats killed with drowning than the other group. In the control and electric shock rats, ATP decreased in different levels in the three different muscle types mentioned above in control group, being much decline in masseter and then in quadriceps. This may be caused by lower mass and less glycogen storage of masseter. No different ATP levels were measured in drowning group with respect to the muscle type possibly because of the severe activity of triceps and quadriceps and because of smaller mass of masseter. One can conclude that the occurrence of rigor mortis is closely related to the mode of death.

  16. Quadriceps Tendon Autograft Medial Patellofemoral Ligament Reconstruction.

    Science.gov (United States)

    Fink, Christian; Steensen, Robert; Gföller, Peter; Lawton, Robert

    2018-06-01

    Critically evaluate the published literature related to quadriceps tendon (QT) medial patellofemoral ligament (MPFL) reconstruction. Hamstring tendon (HT) MPFL reconstruction techniques have been shown to successfully restore patella stability, but complications including patella fracture are reported. Quadriceps tendon (QT) reconstruction techniques with an intact graft pedicle on the patella side have the advantage that patella bone tunnel drilling and fixation are no longer needed, reducing risk of patella fracture. Several QT MPFL reconstruction techniques, including minimally invasive surgical (MIS) approaches, have been published with promising clinical results and fewer complications than with HT techniques. Parallel laboratory studies have shown macroscopic anatomy and biomechanical properties of QT are more similar to native MPFL than hamstring (HS) HT, suggesting QT may more accurately restore native joint kinematics. Quadriceps tendon MPFL reconstruction, via both open and MIS techniques, have promising clinical results and offer valuable alternatives to HS grafts for primary and revision MPFL reconstruction in both children and adults.

  17. CT findings of leg muscles in the hemiplegics due to cerebrovascular accidents. Correlation to disuse atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Odajima, Natsu; Ishiai, Sumio; Okiyama, Ryouichi; Furukawa, Tetsuo; Tsukagoshi, Hiroshi

    1987-09-01

    Muscle wastings in hemiplegics due to cerebrovascular accidents were studied with CT scanning in the mid-portion of the thigh and largest-diameter section of the calf bilaterally. Muscle size and average CT density of muscle were measured. The 80 patients were classified into one of the following three stages of disability, i.e. stage 1, severely disabled (wheel-chair-bound but capable of self care (20 patients)); stage 2, moderately disabled (poorly ambulatory (41 patients)); and stage 3, mildly disabled (well ambulatory (19 patients)). Muscle cross-sectional area and CT density in both legs of non-ambulatory patients were smaller and lower than those of other groups. The atrophic change was marked in the affected side, but it was also noticeable in the non-affected side. Gracilis muscle was relatively well spared in all 3 stages. These CT findings of hemiplegics were similar to those of disuse atropy in patients with knee or hip joint lesions. Atrophy was seen first in the quadriceps in thigh and flexor muscle group in calf. These findings were similar to the systemic myogenic or neurogenic atrophies. Although gracilis and sartorius muscles were spared in these systemic deseases, only gracilis muscle was spared in hemiplegics and in patients with disuse atrophy. The ratios of the size of quadriceps, adductor group and sartorius muscle of thigh in affected side to that of non-affected side were smaller in more severely disabled group. Those of the other muscles showed no differences among each stages. In stage 3, there was significant negative correlation between the ratio of quadriceps muscle and periods from the attack. There was no relationship between the severity of the muscle atrophy and parietal lobe lesion. The atrophy is considered to be the result of disuse from immobilization.

  18. CT findings of leg muscles in the hemiplegics due to cerebrovascular accidents

    International Nuclear Information System (INIS)

    Odajima, Natsu; Ishiai, Sumio; Okiyama, Ryouichi; Furukawa, Tetsuo; Tsukagoshi, Hiroshi.

    1987-01-01

    Muscle wastings in hemiplegics due to cerebrovascular accidents were studied with CT scanning in the mid-portion of the thigh and largest-diameter section of the calf bilaterally. Muscle size and average CT density of muscle were measured. The 80 patients were classified into one of the following three stages of disability, i.e. stage 1, severely disabled (wheel-chair-bound but capable of self care [20 patients]); stage 2, moderately disabled (poorly ambulatory [41 patients]); and stage 3, mildly disabled (well ambulatory [19 patients]). Muscle cross-sectional area and CT density in both legs of non-ambulatory patients were smaller and lower than those of other groups. The atrophic change was marked in the affected side, but it was also noticeable in the non-affected side. Gracilis muscle was relatively well spared in all 3 stages. These CT findings of hemiplegics were similar to those of disuse atropy in patients with knee or hip joint lesions. Atrophy was seen first in the quadriceps in thigh and flexor muscle group in calf. These findings were similar to the systemic myogenic or neurogenic atrophies. Although gracilis and sartorius muscles were spared in these systemic deseases, only gracilis muscle was spared in hemiplegics and in patients with disuse atrophy. The ratios of the size of quadriceps, adductor group and sartorius muscle of thigh in affected side to that of non-affected side were smaller in more severely disabled group. Those of the other muscles showed no differences among each stages. In stage 3, there was significant negative correlation between the ratio of quadriceps muscle and periods from the attack. There was no relationship between the severity of the muscle atrophy and parietal lobe lesion. The atrophy is considered to be the result of disuse from immobilization. (author)

  19. Knee and Hip Joint Kinematics Predict Quadriceps and Hamstrings Neuromuscular Activation Patterns in Drop Jump Landings.

    Science.gov (United States)

    Malfait, Bart; Dingenen, Bart; Smeets, Annemie; Staes, Filip; Pataky, Todd; Robinson, Mark A; Vanrenterghem, Jos; Verschueren, Sabine

    2016-01-01

    The purpose was to assess if variation in sagittal plane landing kinematics is associated with variation in neuromuscular activation patterns of the quadriceps-hamstrings muscle groups during drop vertical jumps (DVJ). Fifty female athletes performed three DVJ. The relationship between peak knee and hip flexion angles and the amplitude of four EMG vectors was investigated with trajectory-level canonical correlation analyses over the entire time period of the landing phase. EMG vectors consisted of the {vastus medialis(VM),vastus lateralis(VL)}, {vastus medialis(VM),hamstring medialis(HM)}, {hamstring medialis(HM),hamstring lateralis(HL)} and the {vastus lateralis(VL),hamstring lateralis(HL)}. To estimate the contribution of each individual muscle, linear regressions were also conducted using one-dimensional statistical parametric mapping. The peak knee flexion angle was significantly positively associated with the amplitudes of the {VM,HM} and {HM,HL} during the preparatory and initial contact phase and with the {VL,HL} vector during the peak loading phase (phamstrings medialis activity) during the preparatory and initial contact phase and an increased lateral neuromuscular activation (dominant vastus lateralis activity) during the peak loading phase.

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

    Science.gov (United States)

    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.

  1. Isokinetic Hamstrings: Quadriceps Ratios in Intercollegiate Athletes.

    Science.gov (United States)

    Rosene, John M.; Fogarty, Tracey D.; Mahaffey, Brian L.

    2001-01-01

    Compared the differences in the concentric hamstrings to quadriceps (H:Q) ratio among athletes in different sports at three velocities. Measurement of H:Q ratio of both knees among male and female college athletes indicated that the H:Q ratio increased as velocity increased. No differences existed for the H:Q ratio for sport or side of body. (SM)

  2. Bilateral synchronous rupture of the quadriceps tendon.

    LENUS (Irish Health Repository)

    Ellanti, P

    2012-09-01

    Bilateral simultaneous rupture of the quadriceps tendon is a rare entity. They are often associated with degenerative changes of the tendons and predisposing conditions such as diabetes or excessive steroid use. They most commonly tend to occur in patients of 40 years of age or older.

  3. Dorsiflexor muscle-group thickness in children with cerebral palsy: Relation to cross-sectional area

    DEFF Research Database (Denmark)

    Bandholm, Thomas; Magnusson, Peter; Jensen, Bente Rona

    2009-01-01

    If the thickness and cross-sectional area of the dorsiflexor muscle group are related in children with cerebral palsy, measurements of muscle thickness may be used to monitor changes in muscle size due to training or immobilisation in these patients. We assessed the validity and reliability.......001), and the reliability of the muscle-thickness measurements was high in the healthy subjects (ICC_{2.1} = 0.94, standard error of measurement = 0.04 cm). The dorsiflexor muscle-thickness was 22% less in the affected compared to the non-affected leg in children with hemiplegic cerebral palsy (P ..., the dorsiflexor cross-sectional area was 32% less in the affected compared to the non-affected leg (P = 0.002). Measurements of dorsiflexor muscle-thickness can be reliably obtained, and they reflect dorsiflexor cross-sectional area in children with cerebral palsy....

  4. Investigation and clinical applications of muscle strength change in cerebrospinal fluid tap test in cases of idiopathic normal pressure hydrocephalus: A retrospective study.

    Science.gov (United States)

    Matsuoka, Tsuyoshi; Iida, Jun-Ichi; Kawahara, Makoto; Uchiyama, Yoshitomo

    2016-12-15

    The cerebrospinal fluid tap test (CSFTT) is widely used to diagnose idiopathic normal pressure hydrocephalus (iNPH) and predict the therapeutic effectiveness of shunting. However, the ability to walk cannot be quantified for patients who are unable to walk. Therefore, we examined whether the iNPH diagnostic aid is possible using dynamometry, even for patients who are unable to walk. In this study, 45 patients underwent grip strength assessment, quadriceps strength assessment, 10-m walk test, and 3-m Timed Up and Go test before and after CSFTT. Our investigation of physical functions indicated that the CSFTT-positive group demonstrated significant improvements in grip and bilateral quadriceps muscle strength. The results of the receiver operating characteristic analysis indicated that leg muscle strength measurement reliability was high and that the area under the curve was 0.754-0.811. Our investigation of the clinically effective cutoff point for the rate of change indicated that it was 13.6% for right quadriceps muscle strength and 15.3% for left quadriceps muscle strength. Comparing CSFTT results in cases of iNPH with the observed rate of change in muscle strength can aid in the diagnosis of iNPH. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Efeitos na medida do ângulo Q com a contração isométrica voluntária máxima do músculo quadricipital Efectos en la medida del ángulo Q con la contracción isométrica voluntária máxima del musculo cuadricipital Effects in the Q angle measurement with maximal voluntary isometric contraction of the quadriceps muscle

    Directory of Open Access Journals (Sweden)

    A.C.G. Belchior

    2006-02-01

    examination situations, having the quadriceps relaxed and in a maximal voluntary isometric contraction (MVIC through radiographic measurement, aiming to contribute to the assessment and treatment of patients with patelofemoral disorder (PFD. Through the standard radiological method twenty 21 years old mean women (40 knees were assessed. All individuals were positioned supine using a U-podalic stabilizer, having their lower limbs relaxed, using a plumb film on the anterior tuberosity of the tibia. For the statistical analysis, the averages for the asymptomatic and symptomatic groups in a relaxed and MVIC status, as well as the Student's t-test with p < 0.05 significance level were used. The mean values to the Q angle compared to the asymptomatic group were 17.15º on relaxation, and 14.5º on MVIC, while the asymptomatic group presented 21.45º, and 15.8º, respectively. The results in the equality analysis between the symptomatic and asymptomatic groups on the relaxed status attained a p = 0.004, and to the maximal voluntary isometric contraction, p = 0.29. Considering the data attained in the present study, it can be verified that in a relaxing status, there is a difference between the value of the Q angle among symptomatic and asymptomatic individuals, being found a higher value in the FPD bearers, while in a maximal isometric contraction of the quadriceps muscle no statistical difference was found in the present study, with a reduction in the angle in both groups.

  6. Experimental knee joint pain during strength training and muscle strength gain in healthy subjects

    DEFF Research Database (Denmark)

    Sørensen, T J; Langberg, Henning; Hodges, P W

    2012-01-01

    Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function...... and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals....

  7. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    Science.gov (United States)

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  8. Efficacy of kinesio taping on isokinetic quadriceps torque in knee osteoarthritis: a double blinded randomized controlled study.

    Science.gov (United States)

    Anandkumar, Sudarshan; Sudarshan, Shobhalakshmi; Nagpal, Pratima

    2014-08-01

    Double blind pre-test post-test control group design. To compare the isokinetic quadriceps torque, standardized stair-climbing task (SSCT) and pain during SSCT between subjects diagnosed with knee osteoarthritis pre and post kinesio tape (KT) application with and without tension. Strength of the quadriceps and torque producing capability is frequently found to be compromised in knee osteoarthritis. The efficacy of KT in improving isokinetic quadriceps torque in knee osteoarthritis is unknown, forming the basis for this study. Forty subjects were randomly allocated to either the experimental (therapeutic KT with tension) or control group (sham KT without tension) with the allocation being concealed. Pre and post test measurements of isokinetic quadriceps torque, SSCT and pain during SSCT were carried out by a blinded assessor. A large effect size with significant improvements in the peak quadriceps torque (concentric and eccentric at angular velocities of 90° per second and 120° per second), SSCT and pain were obtained in the experimental group when compared to the control group. Application of therapeutic KT is effective in improving isokinetic quadriceps torque, SSCT and reducing pain in knee osteoarthritis.

  9. EFFECTS OF KINESIOTAPING ALONG WITH QUADRICEPS STRENGTHENING EXERCISES ON PAIN, JOINT RANGE OF MOTION AND FUNCTIONAL ACTIVITIES OF KNEE IN SUBJECTS WITH PATELLOFEMORAL OSTEOARTHRITIS

    Directory of Open Access Journals (Sweden)

    M. Harshitha

    2014-08-01

    Full Text Available Background: Patello femoral Osteoarthritis is the most common degenerative disease in older age group, causing pain, physical disability, and decreased quality of life.As many treatment options available, kinesiotaping is an efficacious treatment for management of pain & disability in patellofemoral joint osteoarthritis. Previous studies have shown that kinesiotaping as well as quadriceps strengthening significantly yields functional benefits. But there is lack of evidence revealing combined effectiveness & effects of kinesiotaping along with quadriceps strengthening in subjects with patellofemoral joint osteoarthritis. Methods: 30 subjects with symptoms of patellofemoral osteoarthritis fulfilled the inclusion criteria were randomly assigned into 2 groups of 15 in each group. Taping along with quadriceps strengthening program is compared to the quadriceps strengthening program alone. Pain were measured by Visual Analogue Scale (VAS, knee ROM were measured by Goniometer, Functional status were measured by Western Ontario McMaster Universities index (WOMAC, score. Measurements were taken pre & post intervention. Results: The results indicated that kinesiotaping along with quadriceps strengthening exercises showed there was statistically significant improvement in pain (<0.05, knee ROM (<0.05 and functional activities (<0.05 after 6 weeks compared to quadriceps strengthening alone. Conclusion: Subjects with kinesiotaping along with quadriceps strengthening showed significant improvement in reducing pain, in improving ROM & functional activities at the end of 6th week treatment when compared to subjects with patellofemoral osteoarthritis underwent quadriceps strengthening exercises alone.

  10. Changes in contractile properties of muscles receiving repeat injections of botulinum toxin (Botox).

    Science.gov (United States)

    Fortuna, Rafael; Vaz, Marco Aurélio; Youssef, Aliaa Rehan; Longino, David; Herzog, Walter

    2011-01-04

    Botulinum toxin type A (BTX-A) is a frequently used therapeutic tool to denervate muscles in the treatment of neuromuscular disorders. Although considered safe by the US Food and Drug Administration, BTX-A can produce adverse effects in target and non-target muscles. With an increased use of BTX-A for neuromuscular disorders, the effects of repeat injections of BTX-A on strength, muscle mass and structure need to be known. Therefore, the purpose of this study was to investigate the changes in strength, muscle mass and contractile material in New Zealand White (NZW) rabbits. Twenty NZW rabbits were divided into 4 groups: control and 1, 3 and 6 months of unilateral, repeat injections of BTX-A into the quadriceps femoris. Outcome measures included knee extensor torque, muscle mass and the percentage of contractile material in the quadriceps muscles of the target and non-injected contralateral hindlimbs. Strength in the injected muscles was reduced by 88%, 89% and 95% in the 1, 3 and 6 months BTX-A injected hindlimbs compared to controls. Muscle mass was reduced by 50%, 42% and 31% for the vastus lateralis (VL), rectus femoris (RF) and vastus medialis (VM), respectively, at 1 month, by 68%, 51% and 50% at 3 months and by 76%, 44% and 13% at 6 months. The percentage of contractile material was reduced for the 3 and 6 months animals to 80-64%, respectively, and was replaced primarily by fat. Similar, but less pronounced results were also observed for the quadriceps muscles of the contralateral hindlimbs, suggesting that repeat BTX-A injections cause muscle atrophy and loss of contractile tissue in target muscles and also in non-target muscles that are far removed from the injection site. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Relation between body mass index percentile and muscle strength and endurance

    Directory of Open Access Journals (Sweden)

    Noha Abdel Kader Abdel Kader Hasan

    2016-10-01

    Conclusion: The study shows that the BMI of children had a positive correlation with the muscle strength of quadriceps, triceps, and abdominal muscles while a negative correlation with the endurance time of these muscles.

  12. Anthropometric and quantitative EMG status of femoral quadriceps before and after conventional kinesitherapy with and without magnetotherapy.

    Science.gov (United States)

    Graberski Matasović, M; Matasović, T; Markovac, Z

    1997-06-01

    The frequency of femoral quadriceps muscle hypotrophy has become a significant therapeutic problem. Efforts are being made to improve the standard scheme of kinesitherapeutic treatment by using additional more effective therapeutic methods. Beside kinesitherapy, the authors have used magnetotherapy in 30 of the 60 patients. The total of 60 patients, both sexes, similar age groups and intensity of hypotrophy, were included in the study. They were divided into groups A and B, the experimental and the control one (30 patients each). The treatment was scheduled for the usual 5-6 weeks. Electromyographic quantitative analysis was used to check-up the treatment results achieved after 5 and 6 weeks of treatment period. Analysis of results has confirmed the assumption that magnetotherapy may yield better and faster treatment results, disappearance of pain and decreased risk of complications. The same results were obtained in the experimental group, only one week earlier than in the control group. The EMG quantitative analysis has not proved sufficiently reliable and objective method in the assessment of real condition of the muscle and effects of treatment.

  13. The Artificial Gravity Bed Rest Pilot Project: Effects on Knee Extensor and Plantar Flexor Muscle Groups

    Science.gov (United States)

    Caiozzo, V. J.; Haddad, F.; Lee, S.; Baker, M.; Baldwin, K. M.

    2007-01-01

    The goal of this project was to examine the effects of artificial gravity (2.5 g) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) control (C) group (N=7); and 2) an AG group (N=8), which was exposed to 21 days of bed-rest plus daily 1 hr exposures to AG (2.5 g). This particular experiment was part of an integrated AG Pilot Project sponsored by NASA/Johnson Space Center. The in vivo torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre and post treatment. Also, pre- and post treatment biopsy samples were obtained from both the vastus lateralis and soleus muscles and were used, in part, for a series of analyses on gene expression (mRNA abundance) of key factors implicated in the anabolic versus catabolic state of the muscle. Post/Pre toque-velocity determinations revealed greater decrements in knee extensor performance in the C versus AG group (P less than 0.04). The plantar flexor muscle group of the AG subjects actually demonstrated a net gain in torque-velocity relationship; whereas, in the C group the overall post/pre responses declined (AG vs C; P less than 0.001). Measurements of muscle fiber cross-sectional area (for both muscles) demonstrated a loss of approx. 20% in the C group while no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity (IGF-1, IGF-1 BP4, mechano growth factor, total RNA, and pro-collagen 3a) were higher in the AG group, whereas catabolic markers (myostatin and atrogen) were elevated in the C group. Importantly, these patterns were seen in both muscles. Based on these observations we conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading states. These findings also

  14. Pain level after ACL reconstruction: A comparative study between free quadriceps tendon and hamstring tendons autografts.

    Science.gov (United States)

    Buescu, Cristian Tudor; Onutu, Adela Hilda; Lucaciu, Dan Osvald; Todor, Adrian

    2017-03-01

    The objective of this study was to compare the pain levels and analgesic consumption after single bundle ACL reconstruction with free quadriceps tendon autograft versus hamstring tendon autograft. A total of 48 patients scheduled for anatomic single-bundle ACL reconstruction were randomized into two groups: the free quadriceps tendon autograft group (24 patients) and the hamstring tendons autograft group (24 patients). A basic multimodal analgesic postoperative program was used for all patients and rescue analgesia was provided with tramadol, at pain scores over 30 on the Visual Analog Scale. The time to the first rescue analgesic, the number of doses of tramadol and pain scores were recorded. The results within the same group were compared with the Wilcoxon signed test. Supplementary analgesic drug administration proved significantly higher in the group of subjects with hamstring grafts, with a median (interquartile range) of 1 (1.3) dose, compared to the group of subjects treated with a quadriceps graft, median = 0.5 (0.1.25) (p = 0.009). A significantly higher number of subjects with a quadriceps graft did not require any supplementary analgesic drug (50%) as compared with subjects with hamstring graft (13%; Z-statistics = 3.01, p = 0.002). The percentage of subjects who required a supplementary analgesic drug was 38% higher in the HT group compared with the FQT group. The use of the free quadriceps tendon autograft for ACL reconstruction leads to less pain and analgesic consumption in the immediate postoperative period compared with the use of hamstrings autograft. Level I Therapeutic study. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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.

  16. Bedside Ultrasound of Quadriceps to Predict Rehospitalization and Functional Decline in Hospitalized Elders

    Directory of Open Access Journals (Sweden)

    Ana Clara Guerreiro

    2017-07-01

    Full Text Available ObjectiveTo evaluate the capacity of total anterior thigh thickness, quadriceps muscle thickness, and quadriceps contractile index, all measured by bedside ultrasound, to predict rehospitalization, functional decline, and death in elderly patients 3 months after hospital discharge. To evaluate intra and interobserver reproducibility of the dominant thigh evaluation method by point of care ultrasound.MethodsCohort study of patients aged 65 years or more admitted to a medium complexity unit in a teaching hospital in southern Brazil. Comprehensive geriatric assessment and ultrasound evaluation of the dominant thigh of each participant were performed. After 3 months of hospital discharge, telephone contact was made to evaluate the outcomes of rehospitalization or death and functional decline—assessed by the 100 points Barthel scale and defined as a decrease of five or more points.Results100 participants were included. There was no statistically significant difference between intraobserver measurements in the GEE method analysis (p > 0.05, and the mean bias obtained in Bland–Altman plots was close to zero in all four analyses performed, suggesting good intra and interobserver agreement. There was a significant correlation between the echographic measurements (quadriceps thickness and contractile index and gait speed, timed up and go, and handgrip tests. There was a significant association between contractile index (quadriceps thickness over total anterior thigh thickness multiplied by 100 lower than 60% and functional decline (relative risk 1.35; CI 95% 1.10–1.65; p = 0.003 as well as between the thickness of the quadriceps and rehospitalization or death, in both individuals with preserved walking capacity and in bedridden elders (relative risk 1.34; CI 95% 1.02–1.75; p = 0.04.ConclusionThe ultrasonographic method to evaluate thigh thickness was easily applicable and reproducible. The thickness of the quadriceps could

  17. [Association between carbonyl proteins and tumor necrosis factor alpha with muscle strength in young and older women: exploratory study].

    Science.gov (United States)

    Martínez Huenchullán, Sergio Francisco; Mancilla Solorza, Eladio Bernabé

    2015-01-01

    It has recently been proposed that there is a close relationship between oxidative stress and low-grade chronic inflammation. Both processes have been related separately to muscle function in older adults (OA). Nevertheless, it still has not been determined if this relationship is present particularly in OA. The objective of this study was to determine the relationship between the plasma levels of TNF-α and carbonyl proteins (CP) and muscle strength in a group of young and older women. An exploratory study was conducted on 13 older and 8 young women, in whom the plasma levels of CP and TNF-α were measured. Muscle strength was measured by handgrip test, quadriceps voluntary maximal isometric strength, arm curl, and the 30 second sit to stand test. There were no differences in the plasma levels of CP and TNF-α between the groups, but there was relationship between the biomarkers only in the OA group. A non-linear relationship was observed between CP and quadriceps voluntary maximal isometric strength only in the OA group (R(2)=36.2; P=.038). For TNF-α there were no significant association with any of the applied tests. There is an association between CP and quadriceps voluntary maximal isometric strength only in the OA group, which could indicate a deleterious action of oxidative stress on muscle function, particularly in aging. Copyright © 2015 SEGG. Published by Elsevier Espana. All rights reserved.

  18. Mechanisms of cisplatin-induced muscle atrophy

    International Nuclear Information System (INIS)

    Sakai, Hiroyasu; Sagara, Atsunobu; Arakawa, Kazuhiko; Sugiyama, Ryoto; Hirosaki, Akiko; Takase, Kazuhide; Jo, Ara; Sato, Ken; Chiba, Yoshihiko; Yamazaki, Mitsuaki; Matoba, Motohiro; Narita, Minoru

    2014-01-01

    Fatigue is the most common side effect of chemotherapy. However, the mechanisms of “muscle fatigue” induced by anti-cancer drugs are not fully understood. We therefore investigated the muscle-atrophic effect of cisplatin, a platinum-based anti-cancer drug, in mice. C57BL/6J mice were treated with cisplatin (3 mg/kg, i.p.) or saline for 4 consecutive days. On Day 5, hindlimb and quadriceps muscles were isolated from mice. The loss of body weight and food intake under the administration of cisplatin was the same as those in a dietary restriction (DR) group. Under the present conditions, the administration of cisplatin significantly decreased not only the muscle mass of the hindlimb and quadriceps but also the myofiber diameter, compared to those in the DR group. The mRNA expression levels of muscle atrophy F-box (MAFbx), muscle RING finger-1 (MuRF1) and forkhead box O3 (FOXO3) were significantly and further increased by cisplatin treated group, compared to DR. Furthermore, the mRNA levels of myostatin and p21 were significantly upregulated by the administration of cisplatin, compared to DR. On the other hand, the phosphorylation of Akt and FOXO3a, which leads to the blockade of the upregulation of MuRF1 and MAFbx, was significantly and dramatically decreased by cisplatin. These findings suggest that the administration of cisplatin increases atrophic gene expression, and may lead to an imbalance between protein synthesis and protein degradation pathways, which would lead to muscle atrophy. This phenomenon could, at least in part, explain the mechanism of cisplatin-induced muscle fatigue. - Highlights: • Cisplatin decreased mass and myofiber diameter in quadriceps muscle. • The mRNA of MAFbx, MuRF1 and FOXO3 were increased by the cisplatin. • The mRNA of myostatin and p21 were upregulated by cisplatin. • The phosphorylation of Akt and FOXO3a was decreased by cisplatin

  19. Mechanisms of cisplatin-induced muscle atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Hiroyasu, E-mail: sakai@hoshi.ac.jp [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Division of Pharmacy Professional Development and Research, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Sagara, Atsunobu; Arakawa, Kazuhiko; Sugiyama, Ryoto; Hirosaki, Akiko; Takase, Kazuhide; Jo, Ara [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Sato, Ken [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Division of Pharmacy Professional Development and Research, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Chiba, Yoshihiko [Department of Biology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan); Yamazaki, Mitsuaki [Department of Anesthesiology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, 2630 Sugitani, Toyama-shi, Toyama 9300194 (Japan); Matoba, Motohiro [Department of Palliative Medicine and Psychooncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 1040045 (Japan); Narita, Minoru, E-mail: narita@hoshi.ac.jp [Department of Pharmacology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 1428501 (Japan)

    2014-07-15

    Fatigue is the most common side effect of chemotherapy. However, the mechanisms of “muscle fatigue” induced by anti-cancer drugs are not fully understood. We therefore investigated the muscle-atrophic effect of cisplatin, a platinum-based anti-cancer drug, in mice. C57BL/6J mice were treated with cisplatin (3 mg/kg, i.p.) or saline for 4 consecutive days. On Day 5, hindlimb and quadriceps muscles were isolated from mice. The loss of body weight and food intake under the administration of cisplatin was the same as those in a dietary restriction (DR) group. Under the present conditions, the administration of cisplatin significantly decreased not only the muscle mass of the hindlimb and quadriceps but also the myofiber diameter, compared to those in the DR group. The mRNA expression levels of muscle atrophy F-box (MAFbx), muscle RING finger-1 (MuRF1) and forkhead box O3 (FOXO3) were significantly and further increased by cisplatin treated group, compared to DR. Furthermore, the mRNA levels of myostatin and p21 were significantly upregulated by the administration of cisplatin, compared to DR. On the other hand, the phosphorylation of Akt and FOXO3a, which leads to the blockade of the upregulation of MuRF1 and MAFbx, was significantly and dramatically decreased by cisplatin. These findings suggest that the administration of cisplatin increases atrophic gene expression, and may lead to an imbalance between protein synthesis and protein degradation pathways, which would lead to muscle atrophy. This phenomenon could, at least in part, explain the mechanism of cisplatin-induced muscle fatigue. - Highlights: • Cisplatin decreased mass and myofiber diameter in quadriceps muscle. • The mRNA of MAFbx, MuRF1 and FOXO3 were increased by the cisplatin. • The mRNA of myostatin and p21 were upregulated by cisplatin. • The phosphorylation of Akt and FOXO3a was decreased by cisplatin.

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

    Science.gov (United States)

    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.

  1. Effects of knee and ankle muscle fatigue on postural control in the unipedal stance.

    Science.gov (United States)

    Bizid, Riadh; Margnes, Eric; François, Yrieix; Jully, Jean Louis; Gonzalez, Gerard; Dupui, Philippe; Paillard, Thierry

    2009-06-01

    The aim of this study was to compare the effects of acute muscle fatigue of the ankle and knee musculature on postural control by immediate measures after performing fatiguing tasks (POST condition). One group of subjects (n = 8) performed a fatiguing task by voluntary contractions of the triceps surae (group TRI) and the other (n = 9) performed a fatiguing task by voluntary contractions of the quadriceps femoris (group QUA). Each muscle group was exercised until the loss of maximal voluntary contraction torque reached 50% (isokinetic dynamometer). Posture was assessed by measuring the centre of foot pressure (COP) with a force platform during a test of unipedal quiet standing posture with eyes closed. Initially (in PRE condition), the mean COP velocity was not significantly different between group TRI and group QUA. In POST condition, the mean COP velocity increased more in group QUA than in group TRI. The postural control was more impaired by knee muscle fatigue than by ankle muscle fatigue.

  2. Assessment of muscle function using hybrid PET/MRI

    DEFF Research Database (Denmark)

    Haddock, Bryan; Holm, Søren; Poulsen, Jákup M.

    2017-01-01

    -FDG while activating the quadriceps of one leg with repeated knee extension exercises followed by hand-grip exercises for one arm. Immediately following the exercises, the subjects were scanned simultaneously with 18F-FDG PET/MRI and muscle groups were evaluated for increases in 18F-FDG uptake and MRI T2......Purpose: The aim of this study was to determine the relationship between relative glucose uptake and MRI T2 changes in skeletal muscles following resistance exercise using simultaneous PET/MRI scans. Methods: Ten young healthy recreationally active men (age 21 – 28 years) were injected with 18F...... values. Results: A significant linear correlation between 18F-FDG uptake and changes in muscle T2 (R2 = 0.71) was found. for both small and large muscles and in voxel to voxel comparisons. Despite large intersubject differences in muscle recruitment, the linear correlation between 18F-FDG uptake...

  3. Fatigue Responses in Various Muscle Groups in Well-Trained Competitive Male Players after a Simulated Soccer Game

    DEFF Research Database (Denmark)

    Fransson, Dan; Vigh-Larsen, Jeppe Foged; Fatouros, Ioannis G

    2018-01-01

    soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement (p ≤ 0.05) at 0 h post-match with knee flexors (14 ± 3%) and hip...... decrement still persistent (4 ± 1%, p ≤ 0.05) for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin) and 24 h into recovery...... (creatine kinase), respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02). In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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).

  6. Compensatory strategies during manual wheelchair propulsion in response to weakness in individual muscle groups: A simulation study.

    Science.gov (United States)

    Slowik, Jonathan S; McNitt-Gray, Jill L; Requejo, Philip S; Mulroy, Sara J; Neptune, Richard R

    2016-03-01

    The considerable physical demand placed on the upper extremity during manual wheelchair propulsion is distributed among individual muscles. The strategy used to distribute the workload is likely influenced by the relative force-generating capacities of individual muscles, and some strategies may be associated with a higher injury risk than others. The objective of this study was to use forward dynamics simulations of manual wheelchair propulsion to identify compensatory strategies that can be used to overcome weakness in individual muscle groups and identify specific strategies that may increase injury risk. Identifying these strategies can provide rationale for the design of targeted rehabilitation programs aimed at preventing the development of pain and injury in manual wheelchair users. Muscle-actuated forward dynamics simulations of manual wheelchair propulsion were analyzed to identify compensatory strategies in response to individual muscle group weakness using individual muscle mechanical power and stress as measures of upper extremity demand. The simulation analyses found the upper extremity to be robust to weakness in any single muscle group as the remaining groups were able to compensate and restore normal propulsion mechanics. The rotator cuff muscles experienced relatively high muscle stress levels and exhibited compensatory relationships with the deltoid muscles. These results underline the importance of strengthening the rotator cuff muscles and supporting muscles whose contributions do not increase the potential for impingement (i.e., the thoracohumeral depressors) and minimize the risk of upper extremity injury in manual wheelchair users. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Quadriceps Strength and Executive Functions in Older Women

    NARCIS (Netherlands)

    Scherder, E. J. A.; Eggermont, L. H. P.; Geuze, R. H.; Vis, J.; Verkerke, G. J.

    Objective: The aim of this study is to answer the question whether the strength of the knee extensor musculus quadriceps (m. quadriceps), in particular, is related to specific executive functions and whether this relationship is independent of aerobic fitness. The clinical relevance of this question

  8. Motor units in the human medial gastrocnemius muscle are not spatially localized or functionally grouped.

    Science.gov (United States)

    Héroux, Martin E; Brown, Harrison J; Inglis, J Timothy; Siegmund, Gunter P; Blouin, Jean-Sébastien

    2015-08-15

    Human medial gastrocnemius (MG) motor units (MUs) are thought to occupy small muscle territories or regions, with low-threshold units preferentially located distally. We used intramuscular recordings to measure the territory of muscle fibres from MG MUs and determine whether these MUs are grouped by recruitment threshold or joint action (ankle plantar flexion and knee flexion). The territory of MUs from the MG muscle varied from somewhat localized to highly distributed, with approximately half the MUs spanning at least half the length and width of the muscle. There was also no evidence of regional muscle activity based on MU recruitment thresholds or joint action. The CNS does not have the means to selectively activate regions of the MG muscle based on task requirements. Human medial gastrocnemius (MG) motor units (MUs) are thought to occupy small muscle territories, with low-threshold units preferentially located distally. In this study, subjects (n = 8) performed ramped and sustained isometric contractions (ankle plantar flexion and knee flexion; range: ∼1-40% maximal voluntary contraction) and we measured MU territory size with spike-triggered averages from fine-wire electrodes inserted along the length (seven electrodes) or across the width (five electrodes) of the MG muscle. Of 69 MUs identified along the length of the muscle, 32 spanned at least half the muscle length (≥ 6.9 cm), 11 of which spanned all recording sites (13.6-17.9 cm). Distal fibres had smaller pennation angles (P recruitment threshold or contraction type, nor was there a relationship between MU territory size and recruitment threshold (Spearman's rho = -0.20 and 0.13, P > 0.18). MUs in the human MG have larger territories than previously reported and are not localized based on recruitment threshold or joint action. This indicates that the CNS does not have the means to selectively activate regions of the MG muscle based on task requirements. © 2015 The Authors. The Journal of

  9. Subjective evaluation of physical and mental workload interactions across different muscle groups.

    Science.gov (United States)

    Mehta, Ranjana K; Agnew, Michael J

    2015-01-01

    Both physical and mental demands, and their interactions, have been shown to increase biomechanical loading and physiological reactivity as well as impair task performance. Because these interactions have shown to be muscle-dependent, the aim of this study was to determine the sensitivity of the NASA Task Load Index (NASA TLX) and Ratings of Perceived Exertion (RPE) to evaluate physical and mental workload during muscle-specific tasks. Twenty-four participants performed upper extremity and low back exertions at three physical workload levels in the absence and presence of a mental stressor. Outcome measures included RPE and NASA TLX (six sub-scales) ratings. The findings indicate that while both RPEs and NASA TLX ratings were sensitive to muscle-specific changes in physical demand, only an additional mental stressor and its interaction with either physical demand or muscle groups influenced the effort sub-scale and overall workload scores of the NASA TLX. While additional investigations in actual work settings are warranted, the NASA TLX shows promise in evaluating perceived workload that is sensitive not only to physical and mental demands but also sensitive in determining workload for tasks that employ different muscle groups.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Fatigue Responses in Various Muscle Groups in Well-Trained Competitive Male Players after a Simulated Soccer Game.

    Science.gov (United States)

    Fransson, Dan; Vigh-Larsen, Jeppe Foged; Fatouros, Ioannis G; Krustrup, Peter; Mohr, Magni

    2018-03-01

    We examined the degree of post-game fatigue and the recovery pattern in various leg and upper-body muscle groups after a simulated soccer game. Well-trained competitive male soccer players (n = 12) participated in the study. The players completed the Copenhagen Soccer Test, a 2 x 45 min simulated soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement ( p ≤ 0.05) at 0 h post-match with knee flexors (14 ± 3%) and hip abductors (6 ± 1%) demonstrating the largest and smallest impairment. However, 24 h into recovery all individual muscles had recovered. When pooled in specific muscle groups, the trunk muscles and knee joint muscles presented the largest decline 0 h post-match, 11 ± 2% for both, with the performance decrement still persistent (4 ± 1%, p ≤ 0.05) for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin) and 24 h into recovery (creatine kinase), respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02). In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing the greatest performance decrement. Fatigue and recovery patterns vary markedly between muscle groups and players, yet trunk muscles display the slowest recovery.

  12. Fatigue Responses in Various Muscle Groups in Well-Trained Competitive Male Players after a Simulated Soccer Game

    Directory of Open Access Journals (Sweden)

    Fransson Dan

    2018-03-01

    Full Text Available We examined the degree of post-game fatigue and the recovery pattern in various leg and upper-body muscle groups after a simulated soccer game. Well-trained competitive male soccer players (n = 12 participated in the study. The players completed the Copenhagen Soccer Test, a 2 x 45 min simulated soccer protocol, following baseline measures of maximal voluntary contractions of multiple muscle groups and systemic markers of muscle damage and inflammation at 0, 24 and 48 h into recovery. All muscle groups had a strength decrement (p ≤ 0.05 at 0 h post-match with knee flexors (14 ± 3% and hip abductors (6 ± 1% demonstrating the largest and smallest impairment. However, 24 h into recovery all individual muscles had recovered. When pooled in specific muscle groups, the trunk muscles and knee joint muscles presented the largest decline 0 h post-match, 11 ± 2% for both, with the performance decrement still persistent (4 ± 1%, p ≤ 0.05 for trunk muscles 24 h into recovery. Large inter-player variations were observed in game-induced fatigue and recovery patterns in the various muscle groups. Markers of muscle damage and inflammation peaked 0 h post-match (myoglobin and 24 h into recovery (creatine kinase, respectively, but thereafter returned to baseline. Intermittent test performance correlated with creatine kinase activity 24 h after the Copenhagen Soccer Test (r = -0.70; p = 0.02. In conclusion, post-game fatigue is evident in multiple muscle groups with knee flexors showing the greatest performance decrement. Fatigue and recovery patterns vary markedly between muscle groups and players, yet trunk muscles display the slowest recovery.

  13. Isometric quadriceps strength determines sailing performance and neuromuscular fatigue during an upwind sailing emulation.

    Science.gov (United States)

    Bourgois, Jan G; Callewaert, Margot; Celie, Bert; De Clercq, Dirk; Boone, Jan

    2016-01-01

    This study investigates the physiological responses to upwind sailing on a laser emulation ergometer and analyses the components of the physical profile that determine the physiological responses related to sailing level. Ten male high-level laser sailors performed an upwind sailing test, incremental cycling test and quadriceps strength test. During the upwind sailing test, heart rate (HR), oxygen uptake, ventilation, respiratory exchange ratio, rating of perceived exertion (RPE) and lactate concentration were measured, combined with near-infrared spectroscopy (NIRS) and electromyography (EMG) registration of the M. Vastus lateralis. Repeated measures ANOVA showed for the cardio-respiratory, metabolic and muscles responses (mean power frequency [MPF], root mean square [RMS], deoxy[Hb+Mb]) during the upwind sailing test an initial significant increase followed by a stabilisation, despite a constant increase in RPE. Stepwise regression analysis showed that better sailing level was for 46.5% predicted by lower MPF decrease. Lower MPF decrease was for 57.8% predicted by a higher maximal isometric quadriceps strength. In conclusion, this study indicates that higher sailing level was mainly determined by a lower rate of neuromuscular fatigue during the upwind sailing test (as indicated by MPF decrease). Additionally, the level of neuromuscular fatigue was mainly determined by higher maximal isometric quadriceps strength stressing the importance of resistance training in the planning of training.

  14. Fatigue affects peak joint torque angle in hamstrings but not in quadriceps.

    Science.gov (United States)

    Coratella, Giuseppe; Bellin, Giuseppe; Beato, Marco; Schena, Federico

    2015-01-01

    Primary aim of this study was to investigate peak joint torque angle (i.e. the angle of peak torque) changes recorded during an isokinetic test before and after a fatiguing soccer match simulation. Secondarily we want to investigate functional Hecc:Qconc and conventional Hconc:Qconc ratio changes due to fatigue. Before and after a standardised soccer match simulation, twenty-two healthy male amateur soccer players performed maximal isokinetic strength tests both for hamstrings and for quadriceps muscles at 1.05 rad · s(‒1), 3.14 rad · s(‒1) and 5.24 rad · s(‒1). Peak joint torque angle, peak torque and both functional Hecc:Qconc and conventional Hconc:Qconc ratios were examined. Both dominant and non-dominant limbs were tested. Peak joint torque angle significantly increased only in knee flexors. Both eccentric and concentric contractions resulted in such increment, which occurred in both limbs. No changes were found in quadriceps peak joint torque angle. Participants experienced a significant decrease in torque both in hamstrings and in quadriceps. Functional Hecc:Qconc ratio was lower only in dominant limb at higher velocities, while Hconc:Qconc did not change. This study showed after specific fatiguing task changes in hamstrings only torque/angle relationship. Hamstrings injury risk could depend on altered torque when knee is close to extension, coupled with a greater peak torque decrement compared to quadriceps. These results suggest the use eccentric based training to prevent hamstrings shift towards shorter length.

  15. RELIABILITY OF THE ONE-REPETITION MAXIMUM TEST BASED ON MUSCLE GROUP AND GENDER

    Directory of Open Access Journals (Sweden)

    Dong-il Seo

    2012-06-01

    Full Text Available The purpose of the present study was to examine the influence of muscle group location and gender on the reliability of assessing the one-repetition maximum (1RM test. Thirty healthy males (n = 15 and females (n = 15 who experienced at least 3 months of continuous resistance training during the last 2 years aged 18-35 years volunteered to participate in the study. The 1RM for the biceps curl, lat pull down, bench press, leg curl, hip flexion, triceps extension, shoulder press, low row, leg extension, hip extension, leg press and squat were measured twice by a trained professional using a standard published protocol. Biceps curl, lat pull down, bench press, leg curl, hip flexion, and squat 1RM's were measured on the first visit, then 48 hours later, subjects returned for their second visit. During their second visit, 1RM of triceps extension, shoulder press, low row, leg extension, hip extension, and leg press were measured. One week from the second visit, participants completed the 1 RM testing as previously done during the first and second visits. The third and fourth visits were separated by 48 hours as well. All four visits to the laboratory were at the same time of day. A high intraclass correlation coefficient (ICC > 0.91 was found for all exercises, independent of gender and muscle group size or location, however there was a significant interaction for muscle group location (upper body vs. lower body in females (p < 0.027. In conclusion, a standardized 1RM testing protocol with a short warm-up and familiarization period is a reliable measurement to assess muscle strength changes regardless of muscle group location or gender

  16. 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....

  17. Phototherapy during treadmill training improves quadriceps performance in postmenopausal women.

    Science.gov (United States)

    Paolillo, F R; Corazza, A V; Paolillo, A R; Borghi-Silva, A; Arena, R; Kurachi, C; Bagnato, V S

    2014-06-01

    To evaluate the effects of infrared-light-emitting diode (LED) during treadmill training on functional performance. Thirty postmenopausal women aged 50-60 years were randomly assigned to one of three groups and successfully completed the full study. The three groups were: (1) the LED group, which performed treadmill training associated with phototherapy (n = 10); (2) the exercise group, which carried out treadmill training only (n = 10); and (3) the sedentary group, which neither performed physical training nor underwent phototherapy (n = 10). Training was performed over a period of 6 months, twice a week for 45 min per session at 85-90% of maximal heart rate, which was obtained during progressive exercise testing. The irradiation parameters were 100 mW, 39 mW/cm(2) and 108 J/cm(2) for 45 min. Quadriceps performance was measured during isokinetic exercise testing at 60°/s and 300°/s. Peak torque did not differ amongst the groups. However, the results showed significantly higher values of power and total work for the LED group (∆ = 21 ± 6 W and ∆ = 634 ± 156 J, p women.

  18. The effects of joint aspiration and intra-articular corticosteroid injection on flexion reflex excitability, quadriceps strength and pain in individuals with knee synovitis: a prospective observational study.

    Science.gov (United States)

    Rice, David Andrew; McNair, Peter John; Lewis, Gwyn Nancy; Dalbeth, Nicola

    2015-07-28

    Substantial weakness of the quadriceps muscles is typically observed in patients with arthritis. This is partly due to ongoing neural inhibition that prevents the quadriceps from being fully activated. Evidence from animal studies suggests enhanced flexion reflex excitability may contribute to this weakness. This prospective observational study examined the effects of joint aspiration and intra-articular corticosteroid injection on flexion reflex excitability, quadriceps muscle strength and knee pain in individuals with knee synovitis. Sixteen patients with chronic arthritis and clinically active synovitis of the knee participated in this study. Knee pain flexion reflex threshold, and quadriceps peak torque were measured at baseline, immediately after knee joint aspiration alone and 5 ± 2 and 15 ± 2 days after knee joint aspiration and the injection of 40 mg of methylprednisolone acetate. Compared to baseline, knee pain was significantly reduced 5 (p = 0.001) and 15 days (p = 0.009) post intervention. Flexion reflex threshold increased immediately after joint aspiration (p = 0.009) and 5 (p = 0.01) and 15 days (p = 0.002) post intervention. Quadriceps peak torque increased immediately after joint aspiration (p = 0.004) and 5 (p = 0.001) and 15 days (p knee synovitis.

  19. Effect of knee joint angle on neuromuscular activation of the vastus intermedius muscle during isometric contraction.

    Science.gov (United States)

    Watanabe, K; Akima, H

    2011-12-01

    The purpose of this study was to compare the relationship between surface electromyography (EMG) and knee joint angle of the vastus intermedius muscle (VI) with the synergistic muscles in the quadriceps femoris (QF) muscle group. Fourteen healthy men performed maximal voluntary contractions during isometric knee extension at four knee joint angles from 90°, 115°, 140°, and 165° (180° being full extension). During the contractions, surface EMG was recorded at four muscle components of the QF muscle group: the VI, vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) muscles. The root mean square of the surface EMG at each knee joint angle was calculated and normalized by that at a knee joint angle of 90° for individual muscles. The normalized RMS of the VI muscle was significantly lower than those of the VL and RF muscles at the knee joint angles of 115° and 165° and those of the VL, VM, and RF muscles at the knee joint angle of 140° (Pneuromuscular activation of the VI muscle is regulated in a manner different from the alteration of the knee joint angle compared with other muscle components of the QF muscle group. © 2011 John Wiley & Sons A/S.

  20. Estimation of thigh muscle mass with magnetic resonance imaging in older adults and people with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Mathur, Sunita; Takai, Karen Pr; Macintyre, Donna L; Reid, Darlene

    2008-02-01

    Quantifying muscle mass is an essential part of physical therapy assessment, particularly in older adults and in people with chronic conditions associated with muscle atrophy. The purposes of this study were to examine the relationship between muscle cross-sectional area (CSA) and volume by use of magnetic resonance imaging (MRI) and to compare anthropometric estimations of midthigh CSA with measurements obtained from MRI. Twenty older adults who were healthy and 20 people with chronic obstructive pulmonary disease (COPD), matched for age, sex, and body mass index, underwent MRI to obtain measurements of thigh muscle CSA and volume. Anthropometric measurements (skinfold thickness and thigh circumference) were used to estimate midthigh CSA. Muscle volumes were significantly lower in the people with COPD than in the older adults who were healthy. Moderate to high correlations were found between midthigh CSA and volume in both groups (r=.61-.94). Anthropometric measurements tended to overestimate midthigh CSA in both the people with COPD (estimated CSA=64.9+/-17.8; actual CSA=48.3+/-10.2 cm(2)) and the older adults who were healthy (estimated quadriceps femoris muscle CSA=65.0+/-14.0; actual CSA=56.8+/-13.5 cm(2)). Furthermore, the estimated quadriceps femoris muscle CSAs were not sensitive enough to detect a difference in muscle size between people with COPD and controls. Thigh circumference alone was not different between groups and showed only low to moderate correlations with muscle volume (r=.19-.47). Muscle CSA measured from a single slice provides a good indication of volume, but the most representative slice should be chosen on the basis of the muscle group of interest. Thigh circumference is not correlated with muscle volume and, therefore, should not be used as an indicator of muscle size. The development of population-specific reference equations for estimating muscle CSA from anthropometric measurements is warranted.

  1. Relationship between quadriceps strength and patellofemoral joint chondral lesions after anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Wang, Hai-Jun; Ao, Ying-Fang; Jiang, Dong; Gong, Xi; Wang, Yong-Jian; Wang, Jian; Yu, Jia-Kuo

    2015-09-01

    The incidence of the patellofemoral joint chondral lesions after anterior cruciate ligament reconstruction (ACLR) is disturbingly high. Few studies have assessed the factors affecting patellofemoral joint chondral lesions postoperatively. The recovery of quadriceps strength after ACLR could be associated with patellofemoral joint cartilage damage. Cohort study; Level of evidence, 3. A total of 88 patients who underwent arthroscopic anatomic double-bundle ACLR with hamstring autografts received second-look arthroscopy at the time of metal staple removal at an average of 24.1 months (range, 12-51 months) postoperatively. All patients underwent standardized isokinetic strength testing for bilateral quadriceps and hamstrings 1 to 2 days before second-look arthroscopy. The patients were divided into 2 groups: Patients in group 1 had a ≥20% deficit on the peak torque measures for quadriceps compared with that of the contralateral knee, whereas those in group 2 had a patellofemoral joint and tibiofemoral joint were evaluated by second-look arthroscopy and the Outerbridge classification. Other assessments included the International Knee Documentation Committee (IKDC) score, Tegner and Lysholm scores, side-to-side difference on KT-2000 arthrometer, and range of motion. There were 42 patients included in group 1 and 46 patients in group 2. The mean postoperative quadriceps peak torque of the involved knee compared with the contralateral knee was 70% (range, 57%-80%) in group 1 and 95% (range, 81%-116%) in group 2. For all patients, a significant worsening was seen in the patellar and trochlear cartilage (P = .030 and <.001, respectively) but not at the medial or lateral tibiofemoral joint after ACLR. A significant worsening in the status of both patellar and trochlear cartilage was seen after ACLR in group 1 (P = .013 and =.011, respectively) and of trochlear cartilage in group 2 (P = .006). Significantly fewer severe chondral lesions of the patella were found in group 2

  2. Acetyl group availability influences phosphocreatine degradation even during intense muscle contraction.

    Science.gov (United States)

    Timmons, James A; Constantin-Teodosiu, Dumitru; Poucher, Simon M; Greenhaff, Paul L

    2004-12-15

    We previously established that activation of the pyruvate dehydrogenase complex (PDC) using dichloroacetate (DCA) reduced the reliance on substrate-level phosphorylation (SLP) at the onset of exercise, with normal and reduced blood flow. PDC activation also reduced fatigue development during contraction with reduced blood flow. Since these observations, several studies have re-evaluated our observations. One study demonstrated a performance benefit without a reduction in SLP, raising a question mark over PDC's role in the regulation of ATP regeneration and our interpretation of fatigue mechanisms. Using a model of muscle contraction similar to the conflicting study (i.e. tetanic rather than twitch stimulation), we re-examined this question. Using canine skeletal muscle, one group was infused with saline while the other was pretreated with 300 mg (kg body mass)(-1) DCA. Muscle biopsies were taken at rest, peak tension (1 min) and after 6 min of tetanic electrical stimulation (75 ms on-925 ms off per second) and blood flow was limited to 25% of normal values observed during contraction. DCA reduced phosphocreatine (PCr) degradation by 40% during the first minute of contraction, but did not prevent the almost complete depletion of PCr stores at 6 min, while muscle fatigue did not differ between the two groups. During intermittent tetanic stimulation PCr degradation was 75% greater than with our previous 3 Hz twitch contraction protocol, despite a similar rate of oxygen consumption at 6 min. Thus, in the present study enhanced acetyl group availability altered the time course of PCr utilization but did not prevent the decline towards depletion. Consistent with our earlier conclusions, DCA pretreatment reduces muscle fatigue only when SLP is attenuated. The present study and our met-analysis indicates that enhanced acetyl group availability results in a readily measurable reduction in SLP when the initial rate of PCr utilization is approximately 1 mmol (kg dry mass)(-1

  3. Direct measurement of skeletal muscle fatigue in patients with chronic heart failure.

    OpenAIRE

    Buller, N P; Jones, D; Poole-Wilson, P A

    1991-01-01

    Skeletal muscle function was measured as force production and fatigue in both the quadriceps (a large locomotive muscle) and adductor pollicis (a small intrinsic hand muscle) in five healthy volunteers, five patients with mild chronic heart failure, and five patients with severe chronic heart failure. The quadriceps of patients with chronic heart failure had a reduced muscle cross sectional area, a reduced maximum isometric force production, and an increased tendency to fatigue. Isometric for...

  4. Efficacy of pre-exercise low-level laser therapy on isokinetic muscle performance in individuals with type 2 diabetes mellitus: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Gomes, Cid André Fidelis de Paula; Leal-Junior, Ernesto Cesar Pinto; Biasotto-Gonzalez, Daniela Aparecida; El-Hage, Yasmin; Politti, Fabiano; Gonzalez, Tabajara de Oliveira; Dibai-Filho, Almir Vieira; de Oliveira, Adriano Rodrigues; Frigero, Marcelo; Antonialli, Fernanda Colella; Vanin, Adriane Aver; de Tarso Camillo de Carvalho, Paulo

    2014-04-09

    Type 2 diabetes, also known non-insulin-dependent diabetes, is the most prevalent type of the disease and involves defects in the secretion and action of insulin. The aim of the proposed study is to evaluate the efficacy of pre-exercise low-level laser therapy (LLLT) on muscle performance of the quadriceps femoris in individuals with type 2 diabetes. A double-blind, randomized, controlled clinical trial will be carried out in two treatment phases. In the first phase, quadriceps muscle performance will be evaluated using an isokinetic dynamometer and the levels of creatine kinase and lactate dehydrogenase (biochemical markers of muscle damage) will be determined. The participants will then be allocated to four LLLT groups through a randomization process using opaque envelopes: Group A (4 Joules), Group B (6 Joules), Group C (8 Joules) and Group D (0 Joules; placebo). Following the administration of LLLT, the participants will be submitted to an isokinetic eccentric muscle fatigue protocol involving the quadriceps muscle bilaterally. Muscle performance and biochemical markers of muscle damage will be evaluated again immediately after as well as 24 and 48 hours after the experimental protocol. One week after the last evaluation the second phase will begin, during which Groups A, B and C will receive the LLLT protocol that achieved the best muscle performance in phase 1 for a period of 4 weeks. At the end of this period, muscle performance will be evaluated again. The protocol for this study is registered with the World Health Organization under Universal Trial Number U1111-1146-7109. The purpose of this randomized clinical trial is to evaluate the efficacy of pre-exercise LLLT on the performance of the quadriceps muscle (peak torque, total muscle work, maximum power and fatigue index - normalized by body mass) in individuals with DM-2. The study will support the practice of evidence-based to the use of LLLT in improving muscle performance in Individuals with DM-2

  5. Magnetic resonance imaging with k-means clustering objectively measures whole muscle volume compartments in sarcopenia/cancer cachexia.

    Science.gov (United States)

    Gray, Calum; MacGillivray, Thomas J; Eeley, Clare; Stephens, Nathan A; Beggs, Ian; Fearon, Kenneth C; Greig, Carolyn A

    2011-02-01

    Sarcopenia and cachexia are characterized by infiltration of non-contractile tissue within muscle which influences area and volume measurements. We applied a statistical clustering (k-means) technique to magnetic resonance (MR) images of the quadriceps of young and elderly healthy women and women with cancer to objectively separate the contractile and non-contractile tissue compartments. MR scans of the thigh were obtained for 34 women (n = 16 young, (median) age 26 y; n = 9 older, age 80 y; n = 9 upper gastrointestinal cancer patients, age 65 y). Segmented regions of consecutive axial images were used to calculate cross-sectional area and (gross) volume. The k-means unsupervised algorithm was subsequently applied to the MR binary mask image array data with resultant volumes compared between groups. Older women and women with cancer had 37% and 48% less quadriceps muscle respectively than young women (p k-means subtracted a significant 9%, 14% and 20% non-contractile tissue from the quadriceps of young, older and patient groups respectively (p K-means objectively separates contractile and non-contractile tissue components. Women with upper GI cancer have significant fatty infiltration throughout whole muscle groups which is maintained when controlling for age. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  6. Sociocultural influences on strategies to lose weight, gain weight, and increase muscles among ten cultural groups.

    Science.gov (United States)

    McCabe, Marita P; Busija, Lucy; Fuller-Tyszkiewicz, Matthew; Ricciardelli, Lina; Mellor, David; Mussap, Alexander

    2015-01-01

    This study determined how sociocultural messages to change one's body are perceived by adolescents from different cultural groups. In total, 4904 adolescents, including Australian, Chilean, Chinese, Indo-Fijian, Indigenous Fijian, Greek, Malaysian, Chinese Malaysian, Tongans in New Zealand, and Tongans in Tonga, were surveyed about messages from family, peers, and the media to lose weight, gain weight, and increase muscles. Groups were best differentiated by family pressure to gain weight. Girls were more likely to receive the messages from multiple sociocultural sources whereas boys were more likely to receive the messages from the family. Some participants in a cultural group indicated higher, and others lower, levels of these sociocultural messages. These findings highlight the differences in sociocultural messages across cultural groups, but also that adolescents receive contrasting messages within a cultural group. These results demonstrate the difficulty in representing a particular message as being characteristic of each cultural group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. EXERCISES THAT FACILITATE OPTIMAL HAMSTRING AND QUADRICEPS CO-ACTIVATION TO HELP DECREASE ACL INJURY RISK IN HEALTHY FEMALES: A SYSTEMATIC REVIEW OF THE LITERATURE.

    Science.gov (United States)

    Dedinsky, Rachel; Baker, Lindsey; Imbus, Samuel; Bowman, Melissa

    2017-01-01

    Background Anterior cruciate ligament (ACL) injury is common among females due to many anatomic, hormonal, and neuromuscular risk factors. One modifiable risk factor that places females at increased risk of ACL injury is a poor hamstrings: quadriceps (H:Q) co-activation ratio, which should be 0.6 or greater in order to decrease the stress placed on the ACL. Exercises that produce more quadriceps dominant muscle activation can add to the tension placed upon the ACL, potentially increasing the risk of ACL injury. Hypothesis/Purpose The purpose of this systematic review was to compare quadriceps and hamstring muscle activation during common closed kinetic chain therapeutic exercises in healthy female knees to determine what exercises are able to produce adequate H:Q co-activation ratios. Study Design Systematic Review Methods Multiple online databases were systematically searched and screened for inclusion. Eight articles were identified for inclusion. Data on mean electromyography (EMG) activation of both quadriceps and hamstring muscles, % maximal voluntary isometric contraction (MVIC), and H:Q co-activation ratios were extracted from the studies. Quality assessment was performed on all included studies. Results Exercises analyzed in the studies included variations of the double leg squat, variations of the single leg squat, lateral step-up, Fitter, Stairmaster® (Core Health and Fitness, Vancouver, WA), and slide board. All exercises, except the squat machine with posterior support at the level of the scapula and feet placed 50 cm in front of the hips, produced higher quadriceps muscle activation compared to hamstring muscle activation. Conclusion Overall, two leg squats demonstrate poor H:Q co-activation ratios. Single leg exercises, when performed between 30 and 90 degrees of knee flexion, produce adequate H:Q ratios, thereby potentially reducing the risk of tensile stress on the ACL and ACL injury. Level of Evidence 2a- Systematic Review of Cohort Studies PMID

  8. Knee joint laxity does not moderate the relationship between quadriceps strength and physical function in knee osteoarthritis patients: A cross-sectional study.

    Science.gov (United States)

    Altubasi, Ibrahim M

    2018-06-07

    Knee osteoarthritis is a common and a disabling musculoskeletal disorder. Patients with knee osteoarthritis have activity limitations which are linked to the strength of the quadriceps muscle. Previous research reported that the relationship between quadriceps muscle strength and physical function is moderated by the level of knee joint frontal plane laxity. The purpose of the current study is to reexamine the moderation effect of the knee joint laxity as measured by stress radiographs on the relationship between quadriceps muscle strength and physical function. One-hundred and sixty osteoarthritis patients participated in this cross-sectional study. Isometric quadriceps muscle strength was measured using an isokinetic dynamometer. Self-rated and performance-based physical function were measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function subscale and Get Up and Go test, respectively. Stress radiographs which were taken while applying varus and valgus loads to knee using the TELOS device. Knee joint laxity was determined by measuring the distance between joint surfaces on the medial and lateral sides. Hierarchical multiple regression models were constructed to study the moderation effect of laxity on the strength function relationship. Two regression models were constructed for self-rated and performance-based function. After controlling for demographics, strength contributed significantly in the models. The addition of laxity and laxity-strength interaction did not add significant contributions in the regression models. Frontal plane knee joint laxity measured by stress radiographs does not moderate the relationship between quadriceps muscle strength and physical function in patients with osteoarthritis. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Ultrasound Diagnosis of Bilateral Quadriceps Tendon Rupture After Statin Use

    Directory of Open Access Journals (Sweden)

    Nesselroade, Ryan D

    2010-09-01

    Full Text Available Simultaneous bilateral quadriceps tendon rupture is a rare injury. We report the case of bilateral quadriceps tendon rupture sustained with minimal force while refereeing a football game. The injury was suspected to be associated with statin use as the patient had no other identifiable risk factors.The diagnosis was confirmed using bedside ultrasound. [West J Emerg Med. 2010; 11(4:306-309.

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

    Science.gov (United States)

    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.

  11. Loads on small muscle groups as a risk of hypertensive conditions

    Directory of Open Access Journals (Sweden)

    Olga G. Kourova

    2017-12-01

    Full Text Available Background ― Hypertension is a widespread condition nowadays. Changes in physical activity patterns of the population, namely, sedentary lifestyle and increased loads on small muscle groups, are the key factors behind the development of hypertension. Although science has amassed sufficient amounts of facts about a hypertensive effect of local loads, the very mechanisms underlying adaptive reactions of the circulatory system have not received comprehensive study. Material and Methods ― We studied adaptive reactions to local muscle work in 108 adult subjects groups aged between 18 and 20, 30 and 35, and 60 and 74 respectively by means of a Mosso’s ergograph until the onset of fatigue with all the three age groups receiving medium loads. We have analyzed their work performance, including static and dynamic stamina. We took blood pressure measurements, electrocardiograms (ECGs and electroencephalograms (EEGs before and after the test. Results ― We discovered increased heartbeat rates, systolic blood pressure, and diastolic blood pressure in all of the subjects, as they were doing local load tests, while their ECGs showed shortened electric diastole time, which was indicative of heart functional tension, especially in the subjects aged between 18 and, and 60 and 74. Adverse heart reactions were more pronounced while the subjects were doing static tests rather than dynamic tests, and their EEGs showed increased slow-wave activity within alpha- and theta-ranges, with regularly recurrent alpha wave synchronizations. Conclusion ― Our research shows that central mechanisms underlie hypertensive reactions of the cardiovascular system to local loads with the participation of metabolic receptors of muscles. We have also justified the necessity of preventive campaigns against hypertensions in individuals receiving increased amounts of local muscle work in the motor mode.

  12. Quadriceps Function and Knee Joint Ultrasonography after ACL Reconstruction.

    Science.gov (United States)

    Pamukoff, Derek N; Montgomery, Melissa M; Moffit, Tyler J; Vakula, Michael N

    2018-02-01

    Individuals with anterior cruciate ligament reconstruction (ACLR) are at greater risk for knee osteoarthritis, partially because of chronic quadriceps dysfunction. Articular cartilage is commonly assessed using magnetic resonance imaging and radiography, but these methods are expensive and lack portability. Ultrasound imaging may provide a cost-effective and portable alternative for imaging the femoral cartilage. The purpose of this study was to compare ultrasonography of the femoral cartilage between the injured and uninjured limbs of individuals with unilateral ACLR, and to examine the association between quadriceps function and ultrasonographic measures of femoral cartilage. Bilateral femoral cartilage thickness and quadriceps function were assessed in 44 individuals with unilateral ACLR. Quadriceps function was assessed using peak isometric strength, and early (RTD100) and late (RTD200) rate of torque development. Cartilage thickness at the medial femoral condyle (P accounting for time since ACLR, quadriceps peak isometric strength was associated with cartilage thickness at the medial femoral condyle (r = 0.35, P = 0.02) and femoral cartilage cross-sectional area (r = 0.28, P = 0.04). RTD100 and RTD200 were not associated with femoral cartilage thickness or cross-sectional area. Individuals with ACLR have thinner cartilage in their injured limb compared with uninjured limb, and cartilage thickness is associated with quadriceps function. These results indicate that ultrasonography may be useful for monitoring cartilage health and osteoarthritis progression after ACLR.

  13. ACUTE EFFECTS OF DIFFERENT STATIC STRETCHING PROTOCOLS ON PEAK TORQUE, CONVENTIONAL AND FUNCTIONAL HAMSTRINGS-TO-QUADRICEPS RATIOS IN ACTIVE WOMEN

    Directory of Open Access Journals (Sweden)

    Ghada M. ALQaslah

    2016-10-01

    Full Text Available Background: This study might have been directed to some degree because of clashing results in the past studies regarding the impacts for different SS protocols on muscle strength and possibility for injury. The objective of the study was to investigate the acute effects of different static stretching (SS durations (20, 30, and 60s on isokinetic concentric quadriceps (Q and hamstrings (H peak torque (PT, eccentric H PT and conventional and functional H:Q ratios under different stretching conditions and angular velocities (60°and180°/s in active women. Methods: Isokinetic tests were performed on 108 active women. A HUMAC system was used to measure unilateral concentric Q and H PT, and eccentric H PT at 60 and 180º/s at baseline and after a bout of H-only, Q-only, and combined H and Q muscles SS. The data were statistically treated using five separate three-way (time x conditions x velocity ANOVA. Results: There were no significant differences among groups at baseline (P > 0.05. Significant reductions of all outcome measures have been shown to occur after 30 and 60s of SS (P 0.05. Conclusion: Short-lasting stretching can be done before exercises that require strength. However, since 30s or 60s stretching protocols adversely affect the muscle strength, performance and lower H:Q ratios they are not recommended prior to activities demanding the production of high forces.

  14. Atrophy of sacrospinal muscle groups in patients with chronic, diffusely radiating lumbar back pain

    Energy Technology Data Exchange (ETDEWEB)

    Laasonen, E.M.

    1984-01-01

    After surgery necessitated by lumbar back pain syndromes, radiolucency verified by CT may appear in the sacrospinal muscle group on the operate side. This radiolucency represents muscular atrophy and is in its most severe form a result of the replacement of muscle tissue with adipose tissue. Such muscular atrophy appeared in the present series in 31 out of all 156 patients (19.9%) and in 29 out of 94 patients operated on because of radiating lumbar back pain (30.9%). The radiological appearance, extent, and HU values of this muscular atrophy are presented in detail. Only weak correlations with the multitude of clinical symptoms and signs were found in this retrospective study. The effects of irreversible muscular atrophy on the indications for surgery and physiotherapy are discussed.

  15. Atrophy of sacrospinal muscle groups in patients with chronic, diffusely radiating lumbar back pain

    International Nuclear Information System (INIS)

    Laasonen, E.M.

    1984-01-01

    After surgery necessitated by lumbar back pain syndromes, radiolucency verified by CT may appear in the sacrospinal muscle group on the operate side. This radiolucency represents muscular atrophy and is in its most severe form a result of the replacement of muscle tissue with adipose tissue. Such muscular atrophy appeared in the present series in 31 out of all 156 patients (19.9%) and in 29 out of 94 patients operated on because of radiating lumbar back pain (30.9%). The radiological appearance, extent, and HU values of this muscular atrophy are presented in detail. Only weak correlations with the multitude of clinical symptoms and signs were found in this retrospective study. The effects of irreversible muscular atrophy on the indications for surgery and physiotherapy are discussed. (orig.)

  16. Noninvasive detection of change in skeletal muscle oxygenation during incremental exercise with near-infrared spectroscopy

    Science.gov (United States)

    Liu, Fang; Luo, Qingming; Xu, Guodong; Li, Pengcheng

    2003-12-01

    Near infrared spectroscopy (NIRS) has been developed as a non-invasive method to assess O2 delivery, O2 consumption and blood flow, in diverse local muscle groups at rest and during exercise. The aim of this study was to investigate local O2 consumption in exercising muscle by use of near-infrared spectroscopy (NIRS). Ten elite athletes of different sport items were tested in rest and during step incremental load exercise. Local variations of quadriceps muscles were investigated with our wireless NIRS blood oxygen monitor system. The results show that the changes of blood oxygen relate on the sport items, type of muscle, kinetic capacity et al. These results indicate that NIRS is a potential useful tool to detect local muscle oxygenation and blood flow profiles; therefore it might be easily applied for evaluating the effect of athletes training.

  17. Fatigue-induced changes in group IV muscle afferent activity: differences between high- and low-frequency electrically induced fatigues.

    Science.gov (United States)

    Darques, J L; Jammes, Y

    1997-03-07

    Recordings of group IV afferent activity of tibialis anterior muscle were performed in paralysed rabbits during runs of electrically induced fatigue produced by direct muscle stimulation at a high (100 Hz, high-frequency fatigue HFF) or a low rate (10 Hz, low-frequency fatigue LFF). In addition to analysis of afferent nerve action potentials, muscle force and compound muscle action potentials (M waves) elicited by direct muscle stimulation with single shocks were recorded. Changes in M wave configuration were used as an index of the altered propagation of membrane potentials and the associated efflux of potassium from muscle fibers. The data show that increased group IV afferent activity occurred during LFF as well as HFF trials and developed parallel with force failure. Enhanced afferent activity was significantly higher during LFF (maximal delta f(impulses) = 249 +/- 35%) than HFF (147 +/- 45%). No correlation was obtained between the responses of group IV afferents to LFF or to pressure exerted on tibialis anterior muscle. On the other hand, decreased M wave amplitude was minimal with LFF while it was pronounced with HFF. Close correlations were found between fatigue-induced activation of group IV afferents and decreases in force or M wave amplitude, but their strength was significantly higher with LFF compared to HFF. Thus, electrically induced fatigue activates group IV muscle afferents with a prominent effect of low-frequency stimulation. The mechanism of muscle afferent stimulation does not seem to be due to the sole increase in extracellular potassium concentration, but also by the efflux of muscle metabolites, present during fatiguing contractions at low rate of stimulation.

  18. Knee and Hip Joint Kinematics Predict Quadriceps and Hamstrings Neuromuscular Activation Patterns in Drop Jump Landings.

    Directory of Open Access Journals (Sweden)

    Bart Malfait

    Full Text Available The purpose was to assess if variation in sagittal plane landing kinematics is associated with variation in neuromuscular activation patterns of the quadriceps-hamstrings muscle groups during drop vertical jumps (DVJ.Fifty female athletes performed three DVJ. The relationship between peak knee and hip flexion angles and the amplitude of four EMG vectors was investigated with trajectory-level canonical correlation analyses over the entire time period of the landing phase. EMG vectors consisted of the {vastus medialis(VM,vastus lateralis(VL}, {vastus medialis(VM,hamstring medialis(HM}, {hamstring medialis(HM,hamstring lateralis(HL} and the {vastus lateralis(VL,hamstring lateralis(HL}. To estimate the contribution of each individual muscle, linear regressions were also conducted using one-dimensional statistical parametric mapping.The peak knee flexion angle was significantly positively associated with the amplitudes of the {VM,HM} and {HM,HL} during the preparatory and initial contact phase and with the {VL,HL} vector during the peak loading phase (p<0.05. Small peak knee flexion angles were significantly associated with higher HM amplitudes during the preparatory and initial contact phase (p<0.001. The amplitudes of the {VM,VL} and {VL,HL} were significantly positively associated with the peak hip flexion angle during the peak loading phase (p<0.05. Small peak hip flexion angles were significantly associated with higher VL amplitudes during the peak loading phase (p = 0.001. Higher external knee abduction and flexion moments were found in participants landing with less flexed knee and hip joints (p<0.001.This study demonstrated clear associations between neuromuscular activation patterns and landing kinematics in the sagittal plane during specific parts of the landing. These findings have indicated that an erect landing pattern, characterized by less hip and knee flexion, was significantly associated with an increased medial and posterior

  19. Comparison of skeletal muscle mass to fat-free mass ratios among different ethnic groups.

    Science.gov (United States)

    Abe, T; Bemben, M G; Kondo, M; Kawakami, Y; Fukunaga, T

    2012-01-01

    Asians seem to have less skeletal muscle mass (SMM) than other ethnic groups, but it is not clear whether relative SMM, i.e., SMM / height square or SMM to fat-free mass (FFM) ratio, differs among different ethnic groups at the same level of body mass index (BMI). To compare the SMM to fat-free mass (FFM) ratio as well as anthropometric variables and body composition among 3 ethnic groups. Three hundred thirty-nine Japanese, 343 Brazilian, and 183 German men and women were recruited for this cross-sectional study. Muscle thickness (MTH) and subcutaneous fat thickness (FTH) were measured by ultrasound at nine sites on the anterior and posterior aspects of the body. FTH was used to estimate the body density, from which fat mass and fat-free mass (FFM) was calculated by using Brozek equation. Total SMM was estimated from ultrasound-derived prediction equations. Percentage body fat was similar among the ethnic groups in men, while Brazilians were higher than Japanese in women. In German men and women, absolute SMM and FFM were higher than in their Japanese and Brazilians counterparts. SMM index and SMM:FFM ratios were similar among the ethnic groups in women, excluding SMM:FFM ratio in Brazilian. In men, however, these relative values (SMM index and SMM:FFM ratio) were still higher in Germans. After adjusting for age and BMI, the SMM index and SMM:FFM ratios were lower in Brazilian men and women compared with the other two ethnic groups, while the SMM index and SMM:FFM ratios were similar in Japanese and German men and women, excluding SMM:FFM ratio in women. Our results suggest that relative SMM is not lower in Asian populations compared with European populations after adjusted by age and BMI.

  20. Effect of transcutaneous electrical muscle stimulation on postoperative muscle mass and protein synthesis

    DEFF Research Database (Denmark)

    Vinge, O; Edvardsen, L; Jensen, F

    1996-01-01

    In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein ...... protein synthesis and muscle mass after abdominal surgery and should be evaluated in other catabolic states with muscle wasting.......In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein...... synthesis were assessed by computed tomography and ribosome analysis of percutaneous muscle biopsies before surgery and on the sixth postoperative day. The percentage of polyribosomes in the ribosome suspension decreased significantly (P

  1. The architectural design of the gluteal muscle group: implications for movement and rehabilitation.

    Science.gov (United States)

    Ward, Samuel R; Winters, Taylor M; Blemker, Silvia S

    2010-02-01

    The organization of fibers within a muscle (architecture) defines the performance capacity of that muscle. In the current commentary, basic architectural terms are reviewed in the context of the major hip muscles and then specific illustrative examples relevant to lower extremity rehabilitation are presented. These data demonstrate the architectural and functional specialization of the hip muscles, and highlight the importance of muscle physiology and joint mechanics when evaluating and treating musculoskeletal disorders.

  2. Localized bioimpedance to assess muscle injury

    International Nuclear Information System (INIS)

    Nescolarde, L; Rosell-Ferrer, J; Yanguas, J; Lukaski, H; Alomar, X; Rodas, G

    2013-01-01

    Injuries to lower limb muscles are common among football players. Localized bioimpedance analysis (BIA) utilizes electrical measurements to assess soft tissue hydration and cell membrane integrity non-invasively. This study reports the effects of the severity of muscle injury and recovery on BIA variables. We made serial tetra-polar, phase-sensitive 50 kHz localized BIA measurements of quadriceps, hamstring and calf muscles of three male football players before and after injury and during recovery until return-to-play, to determine changes in BIA variables (resistance (R), reactance (Xc) and phase angle (PA)) in different degrees of muscle injury. Compared to non-injury values, R, Xc and PA decreased with increasing muscle injury severity: grade III (23.1%, 45.1% and 27.6%), grade II (20.6%, 31.6% and 13.3%) and grade I (11.9%, 23.5% and 12.1%). These findings indicate that decreases in R reflect localized fluid accumulation, and reductions in Xc and PA highlight disruption of cellular membrane integrity and injury. Localized BIA measurements of muscle groups enable the practical detection of soft tissue injury and its severity. (paper)

  3. The Effect of Local Anesthetic Volume Within the Adductor Canal on Quadriceps Femoris Function Evaluated by Electromyography

    DEFF Research Database (Denmark)

    Grevstad, Ulrik; Jæger, Pia; Kløvgaard, Johan

    2016-01-01

    BACKGROUND: Single-injection adductor canal block (ACB) provides analgesia after knee surgery. Which nerves that are blocked by an ACB and what influence-if any-local anesthetic volume has on the effects remain undetermined. We hypothesized that effects on the nerve to the vastus medialis muscle......, they received a femoral nerve block and a placebo ACB. The effect on the vastus medialis (primary endpoint) and the vastus lateralis was evaluated using noninvasive electromyography (EMG). Quadriceps femoris muscle strength was evaluated using a dynamometer. RESULTS: There was a statistically significant......L was used (P = 0.0001). No statistically significant differences were found between volume and effect on the vastus lateralis (P = 0.81) or in muscle strength (P = 0.15). CONCLUSIONS: For ACB, there is a positive correlation between local anesthetic volume and effect on the vastus medialis muscle. Despite...

  4. Hamstring and Quadriceps Isokinetic Strength Deficits Are Weak Risk Factors for Hamstring Strain Injuries: A 4-Year Cohort Study.

    Science.gov (United States)

    van Dyk, Nicol; Bahr, Roald; Whiteley, Rodney; Tol, Johannes L; Kumar, Bhavesh D; Hamilton, Bruce; Farooq, Abdulaziz; Witvrouw, Erik

    2016-07-01

    A hamstring strain injury (HSI) has become the most common noncontact injury in soccer. Isokinetic muscle strength deficits are considered a risk factor for HSIs. However, underpowered studies with small sample sizes unable to determine small associations have led to inconclusive results regarding the role of isokinetic strength and strength testing in HSIs. To examine whether differences in isokinetic strength measures of knee flexion and extension represent risk factors for hamstring injuries in a large cohort of professional soccer players in an adequately powered study design. Cohort study; Level of evidence, 2. A total of 614 professional soccer players from 14 teams underwent isokinetic strength testing during preseason screening. Testing consisted of concentric knee flexion and extension at 60 deg/s and 300 deg/s and eccentric knee extension at 60 deg/s. A clustered multiple logistic regression analysis was used to identify variables associated with the risk of HSIs. Receiver operating characteristic (ROC) curves were calculated to determine sensitivity and specificity. Of the 614 players, 190 suffered an HSI during the 4 seasons. Quadriceps concentric strength at 60 deg/s (odds ratio [OR], 1.41; 95% CI, 1.03-1.92; P = .03) and hamstring eccentric strength at 60 deg/s (OR, 1.37; 95% CI, 1.01-1.85; P = .04) adjusted for bodyweight were independently associated with the risk of injuries. The absolute differences between the injured and uninjured players were 6.9 N·m and 9.1 N·m, with small effect sizes (d hamstring eccentric strength, respectively, indicating a failed combined sensitivity and specificity of the 2 strength variables identified in the logistic regression models. This study identified small absolute strength differences and a wide overlap of the absolute strength measurements at the group level. The small associations between lower hamstring eccentric strength and lower quadriceps concentric strength with HSIs can only be considered as weak

  5. Twitch interpolation technique in testing of maximal muscle strength

    DEFF Research Database (Denmark)

    Bülow, P M; Nørregaard, J; Danneskiold-Samsøe, B

    1993-01-01

    The aim was to study the methodological aspects of the muscle twitch interpolation technique in estimating the maximal force of contraction in the quadriceps muscle utilizing commercial muscle testing equipment. Six healthy subjects participated in seven sets of experiments testing the effects...

  6. Effects of the belt electrode skeletal muscle electrical stimulation system on lower extremity skeletal muscle activity: Evaluation using positron emission tomography.

    Science.gov (United States)

    Numata, Hitoaki; Nakase, Junsuke; Inaki, Anri; Mochizuki, Takafumi; Oshima, Takeshi; Takata, Yasushi; Kinuya, Seigo; Tsuchiya, Hiroyuki

    2016-01-01

    Lower-extremity muscle weakness in athletes after lower limb trauma or surgery can hinder their return to sports, and the associated muscle atrophy may lead to deterioration in performance after returning to sports. Recently, belt electrode skeletal muscle electrical stimulation (B-SES) which can contract all the lower limb skeletal muscles simultaneously was developed. However, no study has evaluated skeletal muscle activity with B-SES. Since only superficial muscles as well as a limited number of muscles can be investigated using electromyography, we investigated whether positron emission tomography (PET) can evaluate the activity of all the skeletal muscles in the body simultaneously. The purpose of this study was to evaluate the effectiveness of the B-SES system using PET. Twelve healthy males (mean age, 24.3 years) were divided into two groups. The subjects in the control group remained in a sitting position for 10 min, and [(18)F] fluorodeoxyglucose (FDG) was intravenously injected. In the exercise group, subjects exercised using the B-SES system for 20 min daily for three consecutive days as a pre-test exercise. On the measurement day, they exercised for 10 min, received an injection of FDG, and exercised for another 10 min. PET-computed tomography images were obtained in each group 60 min after the FDG injection. Regions of interest were drawn in each lower-extremity muscle. We compared each skeletal muscle metabolism using the standardized uptake value. In the exercise group, FDG accumulation in the gluteus maximus, gluteus medius, gluteus minimus, quadriceps femoris, sartorius, and hamstrings was significantly higher than the muscles in the control (P skeletal muscle activity of the gluteal muscles as well as the most lower-extremity muscles simultaneously. Copyright © 2015 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  7. Advanced age-related denervation and fiber-type grouping in skeletal muscle of SOD1 knockout mice.

    Science.gov (United States)

    Kostrominova, Tatiana Y

    2010-11-30

    In this study skeletal muscles from 1.5- and 10-month-old Cu/Zn superoxide dismutase (SOD1) homozygous knockout (JLSod1(-/-)) mice obtained from The Jackson Laboratory (C57Bl6/129SvEv background) were compared with muscles from age- and sex-matched heterozygous (JLSod1(+/-)) littermates. The results of this study were compared with previously published data on two different strains of Sod1(-/-) mice: one from Dr. Epstein's laboratory (ELSod1(-/-); C57Bl6 background) and the other from Cephalon, Inc. (CSod1(-/-); 129/CD-1 background). Grouping of succinate dehydrogenase-positive fibers characterized muscles of Sod1(-/-) mice from all three strains. The 10-month-old Sod1(-/-)C and JL mice displayed pronounced denervation of the gastrocnemius muscle, whereas the ELSod1(-/-) mice displayed a small degree of denervation at this age, but developed accelerated age-related denervation later on. Denervation markers were up-regulated in skeletal muscle of 10-month-old JLSod1(-/-) mice. This study is the first to show that metallothionein mRNA and protein expression was up-regulated in the skeletal muscle of 10-month-old JLSod1(-/-) mice and was mostly localized to the small atrophic muscle fibers. In conclusion, all three strains of Sod1(-/-) mice develop accelerated age-related muscle denervation, but the genetic background has significant influence on the progress of denervation. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Influência do alongamento dos músculos isquiostibial e retofemoral no pico de torque e potência máxima do joelho Influence of stretching hamstring and quadriceps femoral muscles on knee peak torque and maximum power

    Directory of Open Access Journals (Sweden)

    Gabriel Peixoto Leão Almeida

    2009-12-01

    Full Text Available O alongamento muscular é utilizado nas práticas desportivas para aumentar a flexibilidade muscular e amplitude articular, mas estudos mostram que pode produzir efeitos deletérios na produção de força muscular. A proposta deste estudo foi verificar a influência imediata e tardia do alongamento dos músculos isquiostibiais e retofemoral, por meio da facilitação neuromuscular proprioceptiva (FNP, no pico de torque e potência máxima do joelho. Quinze jovens sedentárias foram distribuídas em três grupos: GA, submetidas a 12 sessões de alongamento durante quatro semanas; GB, a apenas uma sessão de alongamento imediatamente antes da avaliação final; e GC, à mobilização articular passiva do joelho, de forma a não alongar. Todas as participantes foram avaliadas quanto à amplitude de movimento (ADM de flexão e extensão do joelho, e à dinamometria isocinética, antes e após a intervenção, mensurando-se ADM, pico de torque (PT e potência máxima (PM do joelho. Observou-se diferença entre as médias dos três grupos na ADM após a intervenção (p0,05. Os grupos GA e GB apresentaram melhoras na ADM e apenas o grupo GC apresentou melhora significativa em todas as variáveis isocinéticas (pMuscle stretching is often used in sports practice in order to increase muscle flexibility and joint range of motion. However, many studies have shown that muscle torque production may be reduced after stretching. The purpose of this work was to assess immediate and late effects of stretching, by proprioceptive neuromuscular facilitation (PNF techniques, on knee peak torque and maximum power. Fifteen young sedentary female subjects were evenly distributed into three groups: AG, submitted to 12 PNF stretching sessions along four weeks; BG, submitted to only one stretching session just before the final evaluation; and GC, submitted to passive knee mobilization so as not to produce muscle stretching. All of them were assessed, before and after

  9. Contribution of Hamstring Fatigue to Quadriceps Inhibition Following Lumbar Extension Exercise

    OpenAIRE

    Hart, Joseph M.; Kerrigan, D. Casey; Fritz, Julie M.; Saliba, Ethan N.; Gansneder, Bruce; Ingersoll, Christopher D.

    2006-01-01

    The purpose of this study was to determine the contribution of hamstrings and quadriceps fatigue to quadriceps inhibition following lumbar extension exercise. Regression models were calculated consisting of the outcome variable: quadriceps inhibition and predictor variables: change in EMG median frequency in the quadriceps and hamstrings during lumbar fatiguing exercise. Twenty-five subjects with a history of low back pain were matched by gender, height and mass to 25 healthy controls. Subjec...

  10. Quadriceps Strength in Patients With Isolated Cartilage Defects of the Knee: Results of Isokinetic Strength Measurements and Their Correlation With Clinical and Functional Results.

    Science.gov (United States)

    Hirschmüller, Anja; Andres, Tasja; Schoch, Wolfgang; Baur, Heiner; Konstantinidis, Lukas; Südkamp, Norbert P; Niemeyer, Philipp

    2017-05-01

    Recent studies have found a significant deficit of maximum quadriceps strength after autologous chondrocyte implantation (ACI) of the knee. However, it is unclear whether muscular strength deficits in patients with cartilage damage exist prior to operative treatment. To isokinetically test maximum quadriceps muscle strength and quantify the impact of possible strength deficits on functional and clinical test results. Cross-sectional study; Level of evidence, 3. To identify clinically relevant muscular strength deficits, 24 patients (5 females, 19 males; mean age, 34.5 years; body mass index, 25.9 kg/m 2 ) with isolated cartilage defects (mean onset, 5.05 years; SD, 7.8 years) in the knee joint underwent isokinetic strength measurements. Maximal quadriceps strength was recorded in 3 different testing modes: pure concentric contraction (flexors and extensors alternating work; con1), concentric-eccentric (only the extensors work concentrically and eccentrically; con2), and eccentric contraction in the alternating mode (ecc). Results were compared for functional performance (single-leg hop test), pain scales (visual analog scale [VAS], numeric rating scale [NRS]), self-reported questionnaires (International Knee Documentation Committee [IKDC], Knee Injury and Osteoarthritis Outcome Scale [KOOS]), and defect size (cm 2 ). Compared with the uninjured leg, significantly lower quadriceps strength was detected in the injured leg in all isokinetic working modes (con1 difference, 27.76 N·m [SD 17.47; P = .003]; con2 difference, 21.45 N·m [SD, 18.45; P =.025]; ecc difference, 29.48 N·m [SD, 21.51; P = .001]), with the largest deficits found for eccentric muscle performance. Moderate negative correlations were observed for the subjective pain scales NRS and VAS. The results of the IKDC and KOOS questionnaires showed low, nonsignificant correlations with findings in the isokinetic measurement. Moreover, defect sizes (mean, 3.13 cm 2 ) were of no importance regarding the

  11. Dexamethasone up-regulates skeletal muscle maximal Na+,K+ pump activity by muscle group specific mechanisms in humans

    DEFF Research Database (Denmark)

    Nordsborg, Nikolai; Goodmann, Craig; McKenna, Michael J.

    2005-01-01

    Dexamethasone, a widely clinically used glucocorticoid, increases human skeletal muscle Na+,K+ pump content, but the effects on maximal Na+,K+ pump activity and subunit specific mRNA are unknown. Ten healthy male subjects ingested dexamethasone for 5 days and the effects on Na+,K+ pump content......, maximal activity and subunit specific mRNA level (a1, a2, ß1, ß2, ß3) in deltoid and vastus lateralis muscle were investigated. Before treatment, maximal Na+,K+ pump activity, as well as a1, a2, ß1 and ß2 mRNA levels were higher (P ... increased Na+,K+ pump maximal activity in vastus lateralis and deltoid by 14 ± 7% (P Na+,K+ pump content by 18 ± 9% (P

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Adductor Canal Block versus Femoral Nerve Block and Quadriceps Strength

    DEFF Research Database (Denmark)

    Jæger, Pia Therese; Nielsen, Zbigniew Jerzy Koscielniak; Henningsen, Lene Marianne

    2013-01-01

    : The authors hypothesized that the adductor canal block (ACB), a predominant sensory blockade, reduces quadriceps strength compared with placebo (primary endpoint, area under the curve, 0.5-6 h), but less than the femoral nerve block (FNB; secondary endpoint). Other secondary endpoints were...

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

    Science.gov (United States)

    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.

  15. Comparison of isokinetic and isometric strength training effects on hamstring and quadriceps torques and physical function in knee pain

    International Nuclear Information System (INIS)

    Masood, T.; Khan, H.M.M.H.

    2017-01-01

    To compare the effects of isokinetic and isometric strength trainings on hamstring and quadriceps average-peak-torques, physical performance, and pain. Methodology: Twenty athletes with knee pain were randomly assigned to two equal groups: Isokinetic training and isometric training. Both groups were trained on Biodex System 3 Pro for 10 sessions. Isokinetic-group received isokinetic training on 5 different velocities while isometric-group performed isometric contractions at 3 knee joint angles. Results: Hamstring isokinetic average-peak-torque was significantly higher at all velocities without significant improvement in quadriceps average-peak-torque except for at the slowest velocity. Isometric training did not cause significant change in isometric average-peak-torque at any knee angle for either hamstring or quadriceps. Agility, elastic leg strength, and pain improved significantly in both groups with no significant between-group differences. No significant statistical correlation was observed between pain and any other parameter after either type of training. Conclusions: Athletes participating in sports requiring dynamic hamstring strength should prefer isokinetic strength training for physical rehabilitation of knee pain. However, physical performance and pain can be improved with both isometric and isokinetic strength training. (author)

  16. Effects of Eight Months of Whole-Body Vibration Training on the Muscle Mass and Functional Capacity of Elderly Women.

    Science.gov (United States)

    Santin-Medeiros, Fernanda; Rey-López, Juan P; Santos-Lozano, Alejandro; Cristi-Montero, Carlos S; Garatachea Vallejo, Nuria

    2015-07-01

    Few intervention studies have used whole-body vibration (WBV) training in the elderly, and there is inconclusive evidence about its health benefits. We examined the effect of 8 months of WBV training on muscle mass and functional capacity in elderly women. A total of 37 women (aged 82.4 ± 5.7 years) voluntarily participated in this study. Subjects were randomly assigned to a vibration group (n = 19) or a control group (n = 18). The vibration group trained on a vertical vibration platform twice a week. The control group was requested not to change their habitual lifestyle. The quadriceps femoris muscle cross-sectional area was determined by magnetic resonance imaging. All participants were evaluated by a battery of tests (Senior Fitness Test) to determine their functional capacity, as well as handgrip strength and balance/gait. General linear repeated-measure analysis of variance (group by time) was performed to examine the effect of the intervention on the outcomes variables. After 8 months, nonstatistically significant differences in the quadriceps CSA (pre-training: 8,516.16 ± 1,271.78 mm² and post-training: 8,671.63 ± 1,389.03 mm²) (p > 0.05) were found in the WBV group (Cohen's d: -0.12), whereas the CON group significantly decreased muscle mass (pre-training: 9,756.18 ± 1,420.07 mm² and post-training: 9,326.82 ± 1,577.53 mm²), with moderate effect size evident (Cohen's d: 0.29). In both groups, no changes were observed in the functional capacity, handgrip strength and balance/gait. The WBV training could prevent the loss of quadriceps CSA in elderly women.

  17. Impaired voluntary neuromuscular activation limits muscle power in mobility-limited older adults

    Science.gov (United States)

    Background. Age-related alterations of neuromuscular activation may contribute to deficits in muscle power and mobility function. This study assesses whether impaired activation of the agonist quadriceps and antagonist hamstrings, including amplitude- and velocity-dependent characteristics of activa...

  18. Increased skeletal muscle 11βHSD1 mRNA is associated with lower muscle strength in ageing.

    Directory of Open Access Journals (Sweden)

    Alixe H M Kilgour

    Full Text Available Sarcopenia, the loss of muscle mass and function with age, is associated with increased morbidity and mortality. Current understanding of the underlying mechanisms is limited. Glucocorticoids (GC in excess cause muscle weakness and atrophy. We hypothesized that GC may contribute to sarcopenia through elevated circulating levels or increased glucocorticoid receptor (GR signaling by increased expression of either GR or the GC-amplifying enzyme 11 beta-hydroxysteroid dehydrogenase type 1 (11βHSD1 in muscle.There were 82 participants; group 1 comprised 33 older men (mean age 70.2 years, SD 4.4 and 19 younger men (22.2 years, 1.7 and group 2 comprised 16 older men (79.1 years, 3.4 and 14 older women (80.1 years, 3.7. We measured muscle strength, mid-thigh cross-sectional area, fasting morning plasma cortisol, quadriceps muscle GR and 11βHSD1 mRNA, and urinary glucocorticoid metabolites. Data were analysed using multiple linear regression adjusting for age, gender and body size.Muscle strength and size were not associated with plasma cortisol, total urinary glucocorticoids or the ratio of urinary 5β-tetrahydrocortisol +5α-tetrahydrocortisol to tetrahydrocortisone (an index of systemic 11βHSD activity. Muscle strength was associated with 11βHSD1 mRNA levels (β -0.35, p = 0.04, but GR mRNA levels were not significantly associated with muscle strength or size.Although circulating levels of GC are not associated with muscle strength or size in either gender, increased cortisol generation within muscle by 11βHSD1 may contribute to loss of muscle strength with age, a key component of sarcopenia. Inhibition of 11βHSD1 may have therapeutic potential in sarcopenia.

  19. Kinesiotape and quadriceps strengthening with elastic band in women with knee osteoarthritis and overweight or obesity. A randomized clinical trial.

    Science.gov (United States)

    León-Ballesteros, Saúl; Espinosa-Morales, Rolando; Clark-Peralta, Patricia; Gómez-Pineda, Ascención Guadalupe; Guadarrama-Becerril, Jaime Horacio

    2018-04-07

    The beneficial effects of exercise in the treatment of Osteoarthritis (OA) of the knee have been verified in several studies. Kinesiotaping (KT) has been popularized due to its reducing local pressure and increasing circulation, resulting in decreased pain. Determine the clinical effectiveness of strengthening therapy with KT in women with knee OA for pain reduction. Thirty two women with knee OA, aged 50-70 years, with overweight or obesity grade I, who were randomized into two groups: one with exercise and KT, and the other, with exercise and placebo technique. Both groups performed stretching and quadriceps strengthening exercise with the elastic band 3 days weekly for 6 weeks. Measurement of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale was taken as primary outcome. Stiffness and functionality of the same index and the Visual Analog Scale (VAS) for pain intensity were measured. At the end of the study, there were no significant differences between the groups. Both groups had a difference of 2.7 points with respect to the baseline measurement, change percentage of 32.2% and 31.1% for placebo and experimental respectively (p=0.2). KT plus quadriceps strengthening exercise does not offer advantages for improvement of pain compared with quadriceps strengthening exercise alone in knee OA. Copyright © 2018 Sociedad Espaola de Reumatologa y Colegio Mexicano de Reumatologa. Publicado por Elsevier España, S.L.U. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Lech Grzegorz

    2015-03-01

    Full Text Available 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.

  1. Quadriceps tendon rupture: a biomechanical comparison of transosseous equivalent double-row suture anchor versus transosseous tunnel repair.

    Science.gov (United States)

    Hart, Nathan D; Wallace, Matthew K; Scovell, J Field; Krupp, Ryan J; Cook, Chad; Wyland, Douglas J

    2012-09-01

    Quadriceps rupture off the patella is traditionally repaired by a transosseous tunnel technique, although a single-row suture anchor repair has recently been described. This study biomechanically tested a new transosseous equivalent (TE) double-row suture anchor technique compared with the transosseous repair for quadriceps repair. After simulated quadriceps-patella avulsion in 10 matched cadaveric knees, repairs were completed by either a three tunnel transosseous (TT = 5) or a TE suture anchor (TE = 5) technique. Double-row repairs were done using two 5.5 Bio-Corkscrew FT (fully threaded) (Arthrex, Inc., Naples, FL, USA) and two 3.5 Bio-PushLock anchors (Arthrex, Inc., Naples, FL, USA) with all 10 repairs done with #2 FiberWire suture (Arthrex, Inc., Naples, FL). Cyclic testing from 50 to 250 N for 250 cycles and pull to failure load (1 mm/s) were undertaken. Gap formation and ultimate tensile load (N) were recorded and stiffness data (N/mm) were calculated. Statistical analysis was performed using a Mann-Whitney U test and survival characteristics examined with Kaplan-Meier test. No significant difference was found between the TE and TT groups in stiffness (TE = 134 +/- 15 N/mm, TT = 132 +/- 26 N/mm, p = 0.28). The TE group had significantly less ultimate tensile load (N) compared with the TT group (TE = 447 +/- 86 N, TT = 591 +/- 84 N, p = 0.04), with all failures occurring at the suture eyelets. Although both quadriceps repairs were sufficiently strong, the transosseous repairs were stronger than the TE suture anchor repairs. The repair stiffness and gap formation were similar between the groups.

  2. A parametric model of muscle moment arm as a function of joint angle: application to the dorsiflexor muscle group in mice.

    Science.gov (United States)

    Miller, S W; Dennis, R G

    1996-12-01

    A parametric model was developed to describe the relationship between muscle moment arm and joint angle. The model was applied to the dorsiflexor muscle group in mice, for which the moment arm was determined as a function of ankle angle. The moment arm was calculated from the torque measured about the ankle upon application of a known force along the line of action of the dorsiflexor muscle group. The dependence of the dorsiflexor moment arm on ankle angle was modeled as r = R sin(a + delta), where r is the moment arm calculated from the measured torque and a is the joint angle. A least-squares curve fit yielded values for R, the maximum moment arm, and delta, the angle at which the maximum moment arm occurs as offset from 90 degrees. Parametric models were developed for two strains of mice, and no differences were found between the moment arms determined for each strain. Values for the maximum moment arm, R, for the two different strains were 0.99 and 1.14 mm, in agreement with the limited data available from the literature. While in some cases moment arm data may be better fitted by a polynomial, use of the parametric model provides a moment arm relationship with meaningful anatomical constants, allowing for the direct comparison of moment arm characteristics between different strains and species.

  3. Fatigue Responses in Various Muscle Groups in Well-Trained Competitive Male Players after a Simulated Soccer Game

    DEFF Research Database (Denmark)

    Fransson, Dan; Vigh-Larsen, Jeppe Foged; Fatouros, Ioannis G

    2018-01-01

    We examined the degree of post-game fatigue and the recovery pattern in various leg and upper-body muscle groups after a simulated soccer game. Well-trained competitive male soccer players (n = 12) participated in the study. The players completed the Copenhagen Soccer Test, a 2 x 45 min simulated...

  4. Magnitude of physiological curvatures of the spine and the incidence of contractures of selected muscle groups in students

    Directory of Open Access Journals (Sweden)

    Olszewska Elżbieta

    2018-02-01

    Full Text Available Study aim: The aim of this study was to evaluate the incidence of contractures of selected muscle groups with respect to the magnitude of the physiological curvatures of the spine in young men with above-average levels of physical activity.

  5. Magnitude of physiological curvatures of the spine and the incidence of contractures of selected muscle groups in students

    OpenAIRE

    Olszewska Elżbieta; Tabor Piotr; Czarniecka Renata

    2018-01-01

    Study aim: The aim of this study was to evaluate the incidence of contractures of selected muscle groups with respect to the magnitude of the physiological curvatures of the spine in young men with above-average levels of physical activity.

  6. The functional significance of hamstrings composition: is it really a "fast" muscle group?

    Science.gov (United States)

    Evangelidis, Pavlos E; Massey, Garry J; Ferguson, Richard A; Wheeler, Patrick C; Pain, Matthew T G; Folland, Jonathan P

    2017-11-01

    Hamstrings muscle fiber composition may be predominantly fast-twitch and could explain the high incidence of hamstrings strain injuries. However, hamstrings muscle composition in vivo, and its influence on knee flexor muscle function, remains unknown. We investigated biceps femoris long head (BFlh) myosin heavy chain (MHC) composition from biopsy samples, and the association of hamstrings composition and hamstrings muscle volume (using MRI) with knee flexor maximal and explosive strength. Thirty-one young men performed maximal (concentric, eccentric, isometric) and explosive (isometric) contractions. BFlh exhibited a balanced MHC distribution [mean ± SD (min-max); 47.1 ± 9.1% (32.6-71.0%) MHC-I, 35.5 ± 8.5% (21.5-60.0%) MHC-IIA, 17.4 ± 9.1% (0.0-30.9%) MHC-IIX]. Muscle volume was correlated with knee flexor maximal strength at all velocities and contraction modes (r = 0.62-0.76, P hamstrings strain injury. Hamstrings muscle volume explained 38-58% of the inter-individual differences in knee flexor maximum strength at a range of velocities and contraction modes, while BFlh muscle composition was not associated with maximal or explosive strength. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. The Ash Content of the Main Muscle Groups and Edible Offal Collected From Hares (Lepus europaeus Pallas

    Directory of Open Access Journals (Sweden)

    Gabriela Tărnăuceanu Frunză

    2016-03-01

    Full Text Available Abstract. The availability of hares (Lepus europaeus Pallas, unlike that of domestic rabbits, is restricted by hunting seasons. Rabbit meat, according to research from Spain, is a rich source of K, P, Fe and Mg, but poor in Na, being recommended for people with hypertension. The largest quantity of macro minerals studied in rabbit meat was determined for K and P, and the most abundant micro minerals were Zn, Fe, Cu and Mn. In hare meat, ash content is not sufficiently studied. The current low level of knowledge motivated the present study. The aim of this study was to establish the ash content for major muscle groups and edible offal of hares. The biological material used was collected from 49 hares with an average weight of 5.6 kg, at the age of reproductive maturity (adults: 11-12 months. Different muscle groups (the muscles Cervicalis, Intercostalis, Longissimus Dorsi, Psoas major, Triceps Brachi, Biceps femoris, Semimembranosus and the main edible offal (heart, liver, kidney were sampled. The ash was determined by calcination (in Supertherm C311 oven calcination at 5500C. The results obtained were interpreted statistically (arithmetic mean (X, standard deviation (s, variance (s2 and coefficient of variation (V% and the statistical significance of differences was tested using the ANOVA Single Factor algorithm (p>0.05; p<0.01; p<0.001. Ash content for the main muscle groups analysed varied from the lowest average values of 1.095% for the Intercostalis muscles, to the highest average values of 1.256%, for Triceps brachii muscles.

  8. Gait analysis, bone and muscle density assessment for patients undergoing total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Benedikt Magnússon

    2012-12-01

    Full Text Available Total hip arthroplasty (THA is performed with or without the use of bone cement. Facing the lack of reliable clinical guidelines on decision making whether a patient should receive THA with or without bone cement, a joint clinical and engineering approach is proposed here with the objective to assess patient recovery developing monitoring techniques based on gait analysis, measurements of bone mineral density and structural and functional changes of quadriceps muscles. A clinical trial was conducted with 36 volunteer patients that were undergoing THA surgery for the first time: 18 receiving cemented implant and 18 receiving non-cemented implant. The patients are scanned with Computer Tomographic (CT modality prior-, immediately- and 12 months post-surgery. The CT data are further processed to segment muscles and bones for calculating bone mineral density (BMD. Quadriceps muscle density Hounsfield (HU based value is calculated from the segmented file on healthy and operated leg before and after THA surgery. Furthermore clinical assessment is performed using gait analysis technologies such as a sensing carpet, wireless electrodes and video. Patients undergo these measurements prior-, 6 weeks post - and 52 weeks post-surgery. The preliminary results indicate computational tools and methods that are able to quantitatively analyze patient’s condition pre and post-surgery: The spatial parameters such as step length and stride length increase 6 weeks post op in the patient group receiving cemented implant while the angle in the toe in/out parameter decrease in both patient groups.

  9. Quadriceps Activation Failure After Anterior Cruciate Ligament Rupture Is Not Mediated by Knee Joint Effusion

    Science.gov (United States)

    LYNCH, ANDREW D.; LOGERSTEDT, DAVID S.; AXE, MICHAEL J.; SNYDER-MACKLER, LYNN

    2013-01-01

    STUDY DESIGN Descriptive prospective cohort study. OBJECTIVES To investigate the relationships between knee joint effusion, quadriceps activation, and quadriceps strength. These relationships may help clinicians better identify impaired quadriceps activation. BACKGROUND After anterior cruciate ligament (ACL) injury, the involved quadriceps may demonstrate weakness. Experimental data have shown that quadriceps activation and strength may be directly mediated by intracapsular joint pressure created by saline injection. An inverse relationship between quadriceps activation and the amount of saline injected has been reported. This association has not been demonstrated for traumatic effusion. We hypothesized that traumatic joint effusion due to ACL rupture and postinjury quadriceps strength would correlate well with quadriceps activation, allowing clinicians to use effusion and strength measurement as a surrogate for electrophysiological assessment of quadriceps activation. METHODS Prospective data were collected on 188 patients within 100 days of ACL injury (average, 27 days) referred from a single surgeon. A complete clinical evaluation of the knee was performed, including ligamentous assessment and assessment of range of motion and effusion. Quadriceps function was electrophysiologically assessed using maximal volitional isometric contraction and burst superimposition techniques to quantify both strength and activation. RESULTS Effusion grade did not correlate with quadriceps central activation ratio (CAR) (zero effusion: mean ± SD CAR, 93.5% ± 5.8%; trace effusion: CAR, 93.8% ± 9.5%; 1+ effusion: CAR, 94.0% ± 7.5%; 2+/3+ effusion: CAR, 90.6% ± 11.1%). These values are lower than normative data from healthy subjects (CAR, 98% ± 3%). CONCLUSION Joint effusion after ACL injury does not directly mediate quadriceps activation failure seen after injury. Therefore, it should not be used as a clinical substitute for electrophysiological assessment of quadriceps

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

    Science.gov (United States)

    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.

  11. Ultrasound measurement of the size of the anterior tibial muscle group: the effect of exercise and leg dominance

    LENUS (Irish Health Repository)

    McCreesh, Karen

    2011-09-13

    Abstract Background Knowledge of normal muscle characteristics is crucial in planning rehabilitation programmes for injured athletes. There is a high incidence of ankle and anterior tibial symptoms in football players, however little is known about the effect of limb dominance on the anterior tibial muscle group (ATMG). The purpose of this study was to assess the effect of limb dominance and sports-specific activity on ATMG thickness in Gaelic footballers and non-football playing controls using ultrasound measurements, and to compare results from transverse and longitudinal scans. Methods Bilateral ultrasound scans were taken to assess the ATMG size in 10 Gaelic footballers and 10 sedentary controls (age range 18-25 yrs), using a previously published protocol. Both transverse and longitudinal images were taken. Muscle thickness measurements were carried out blind to group and side of dominance, using the Image-J programme. Results Muscle thickness on the dominant leg was significantly greater than the non-dominant leg in the footballers with a mean difference of 7.3%, while there was no significant dominance effect in the controls (p < 0.05). There was no significant difference between the measurements from transverse or longitudinal scans. Conclusions A significant dominance effect exists in ATMG size in this group of Gaelic footballers, likely attributable to the kicking action involved in the sport. This should be taken into account when rehabilitating footballers with anterior tibial pathology. Ultrasound is a reliable tool to measure ATMG thickness, and measurement may be taken in transverse or longitudinal section.

  12. [Relation between physical activity, muscle function and IGF-1, testosterone and DHEAS concentrations in the elderly].

    Science.gov (United States)

    Bonnefoy, M; Patricot, M C; Lacour, J R; Rahmani, A; Berthouze, S; Kostka, T

    2002-10-01

    Lower amounts of circulating anabolic hormones are thought to accelerate the age related decline in muscle mass and function. Replacement therapies are promising interventions but there are problems with these therapies. Thus alternative strategies should be developed. The age related changes in hormonal status may be probably influenced by exercise. The purpose of this study was: a) to confirm with other methods, more adapted for elderly people, the results of a previous study that has shown relationship between physical activity (PA) and quadriceps muscle function with dehydroepiandrosterone sulphate (DHEAS), insulin like growth factor-1 (IGF-1). Quadriceps muscle power (Pmax) is measured in this new work with a recently developed leg extensor machine and, b) to complete the results of the first study examining simultaneously the relationship between PA, Pmax and cardiorespiratory fitness (VO2max) with DHEAS, IGF-1 and testosterone in a group of healthy elderly people. Fifty independent, community dwelling elderly subjects (25 mens and 25 womens) aged from 66 to 84 volunteered to participate in the study. PA was evaluated by the questionnaire and expressed using two activity indices: mean habitual daily energy expenditure (MHDEE) and the daily energy expenditure corresponding to leisure time sports activities (Sports Activity). Pmax and optimal shortening velocity (vopt) were measured on a Ergopower dynamometer. The Pmax was expressed relative to body mass, Pmax/kg (W kg-1), and relative to the mass of the two quadriceps muscles, Pmax/Quadr (W.kgQuadr-1). VO2max has been measured during a maximal treadmill exercise. In women, IGF-1 correlated significantly with MHDEE (r = 0.54, P = 0.004), Pmax/kg (r = 0.54, P = 0.004) and Pmax/Quadr (r = 0.46, P = 0.02), whereas DHEAS with MHDEE (r = 0.54, P = 0.004), Sports Activity (r = 0.65, P < 0.001), VO2max (r = 0.46, P = 0.02), Pmax/kg (r = 0.46, P = 0.02) and Pmax/Quadr (r = 0.55, P = 0.004). No such correlation was

  13. Group-level variations in motor representation areas of thenar and anterior tibial muscles: Navigated Transcranial Magnetic Stimulation Study.

    Science.gov (United States)

    Niskanen, Eini; Julkunen, Petro; Säisänen, Laura; Vanninen, Ritva; Karjalainen, Pasi; Könönen, Mervi

    2010-08-01

    Navigated transcranial magnetic stimulation (TMS) can be used to stimulate functional cortical areas at precise anatomical location to induce measurable responses. The stimulation has commonly been focused on anatomically predefined motor areas: TMS of that area elicits a measurable muscle response, the motor evoked potential. In clinical pathologies, however, the well-known homunculus somatotopy theory may not be straightforward, and the representation area of the muscle is not fixed. Traditionally, the anatomical locations of TMS stimulations have not been reported at the group level in standard space. This study describes a methodology for group-level analysis by investigating the normal representation areas of thenar and anterior tibial muscle in the primary motor cortex. The optimal representation area for these muscles was mapped in 59 healthy right-handed subjects using navigated TMS. The coordinates of the optimal stimulation sites were then normalized into standard space to determine the representation areas of these muscles at the group-level in healthy subjects. Furthermore, 95% confidence interval ellipsoids were fitted into the optimal stimulation site clusters to define the variation between subjects in optimal stimulation sites. The variation was found to be highest in the anteroposterior direction along the superior margin of the precentral gyrus. These results provide important normative information for clinical studies assessing changes in the functional cortical areas because of plasticity of the brain. Furthermore, it is proposed that the presented methodology to study TMS locations at the group level on standard space will be a suitable tool for research purposes in population studies. 2010 Wiley-Liss, Inc.

  14. Pathology of skeletal muscle in fibromyalgia

    DEFF Research Database (Denmark)

    Drewes, A M; Andreasen, A; Schrøder, H D

    1993-01-01

    The value of muscle biopsy in fibromyalgia is still questioned. In this study we obtained 50 quadriceps biopsies from 20 patients and compared them blindly to 10 biopsies from five normal controls. Using light microscopy, histochemical and immunoenzymatic methods we found no definite evidence...

  15. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement.

    Directory of Open Access Journals (Sweden)

    Robert Rasnick

    Full Text Available Total knee replacement (TKR is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (p<0.05. No differences were observed for peak joint compressive forces between groups. Some muscle force compensatory strategies appear to be present in both the loading and push-off phases. Evidence from knee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups.

  16. Index of fatigue quadriceps in soccer athletes after anterior cruciate ligament reconstruction

    Directory of Open Access Journals (Sweden)

    Maria Luzete Costa Cavalcante

    Full Text Available ABSTRACT OBJECTIVE: The present study aimed to evaluate the muscle fatigue of the quadriceps muscle in high-performance soccer players undergoing (anterior cruciate ligament ACL reconstruction. METHODS: We evaluated 17 high-performance soccer players from three professional soccer teams of a state in Brazil from August 2011 to July 2012. All subjects were evaluated between 5.5 and 7 months after ACL reconstruction with a Biodex(r isokinetic dynamometer (System 4 Pro with test protocol CON/CON at 60°/s and 300°/s with 5 and 15 repetitions, respectively. In the calculation of local muscle fatigue, the fatigue index was used, which is calculated by dividing the labor done in the first one-third of the repetitions by that done at the final one-third of the repetitions, and multiplying by 100 to express a unit in percentage (i.e., as a discrete quantitative variable. RESULTS: All subjects were male, with a mean age of 21.3 ± 4.4 years and mean BMI 23.4 ± 1.53 cm; left dominance was observed in 47% (n = 8 of athletes, and right dominance, in 53% (n = 9 of athletes; and the limb involved in the lesion was the dominant in 29% (n = 5 and the non-dominant in 71% (n = 12. Fatigue rates were 19.6% in the involved limb and 29.0% in the non-involved limb. CONCLUSION: The results allow us to conclude that there was no significant difference between the limbs involved and not in ACL injuries regarding local muscle fatigue. No association was observed between the dominant side and the limb involved in the ACL injury.

  17. Acute hypoxia limits endurance but does not affect muscle contractile properties.

    NARCIS (Netherlands)

    Degens, H.; Sanchez Horneros, J.M.; Hopman, M.T.E.

    2006-01-01

    Acute hypoxia causes skeletal muscle dysfunction in vitro, but little is known about its effect on muscle function in vivo. In 10 healthy male subjects, isometric contractile properties and fatigue resistance of the quadriceps muscle were determined during normoxia and hypoxia using electrically

  18. Thigh muscle segmentation of chemical shift encoding-based water-fat magnetic resonance images: The reference database MyoSegmenTUM.

    Directory of Open Access Journals (Sweden)

    Sarah Schlaeger

    Full Text Available Magnetic resonance imaging (MRI can non-invasively assess muscle anatomy, exercise effects and pathologies with different underlying causes such as neuromuscular diseases (NMD. Quantitative MRI including fat fraction mapping using chemical shift encoding-based water-fat MRI has emerged for reliable determination of muscle volume and fat composition. The data analysis of water-fat images requires segmentation of the different muscles which has been mainly performed manually in the past and is a very time consuming process, currently limiting the clinical applicability. An automatization of the segmentation process would lead to a more time-efficient analysis. In the present work, the manually segmented thigh magnetic resonance imaging database MyoSegmenTUM is presented. It hosts water-fat MR images of both thighs of 15 healthy subjects and 4 patients with NMD with a voxel size of 3.2x2x4 mm3 with the corresponding segmentation masks for four functional muscle groups: quadriceps femoris, sartorius, gracilis, hamstrings. The database is freely accessible online at https://osf.io/svwa7/?view_only=c2c980c17b3a40fca35d088a3cdd83e2. The database is mainly meant as ground truth which can be used as training and test dataset for automatic muscle segmentation algorithms. The segmentation allows extraction of muscle cross sectional area (CSA and volume. Proton density fat fraction (PDFF of the defined muscle groups from the corresponding images and quadriceps muscle strength measurements/neurological muscle strength rating can be used for benchmarking purposes.

  19. Maternal and paternal genomes differentially affect myofibre characteristics and muscle weights of bovine fetuses at midgestation.

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    Ruidong Xiang

    Full Text Available Postnatal myofibre characteristics and muscle mass are largely determined during fetal development and may be significantly affected by epigenetic parent-of-origin effects. However, data on such effects in prenatal muscle development that could help understand unexplained variation in postnatal muscle traits are lacking. In a bovine model we studied effects of distinct maternal and paternal genomes, fetal sex, and non-genetic maternal effects on fetal myofibre characteristics and muscle mass. Data from 73 fetuses (Day153, 54% term of four genetic groups with purebred and reciprocal cross Angus and Brahman genetics were analyzed using general linear models. Parental genomes explained the greatest proportion of variation in myofibre size of Musculus semitendinosus (80-96% and in absolute and relative weights of M. supraspinatus, M. longissimus dorsi, M. quadriceps femoris and M. semimembranosus (82-89% and 56-93%, respectively. Paternal genome in interaction with maternal genome (P<0.05 explained most genetic variation in cross sectional area (CSA of fast myotubes (68%, while maternal genome alone explained most genetic variation in CSA of fast myofibres (93%, P<0.01. Furthermore, maternal genome independently (M. semimembranosus, 88%, P<0.0001 or in combination (M. supraspinatus, 82%; M. longissimus dorsi, 93%; M. quadriceps femoris, 86% with nested maternal weight effect (5-6%, P<0.05, was the predominant source of variation for absolute muscle weights. Effects of paternal genome on muscle mass decreased from thoracic to pelvic limb and accounted for all (M. supraspinatus, 97%, P<0.0001 or most (M. longissimus dorsi, 69%, P<0.0001; M. quadriceps femoris, 54%, P<0.001 genetic variation in relative weights. An interaction between maternal and paternal genomes (P<0.01 and effects of maternal weight (P<0.05 on expression of H19, a master regulator of an imprinted gene network, and negative correlations between H19 expression and fetal muscle mass (P

  20. A two-input sliding-mode controller for a planar arm actuated by four pneumatic muscle groups.

    Science.gov (United States)

    Lilly, John H; Quesada, Peter M

    2004-09-01

    Multiple-input sliding-mode techniques are applied to a planar arm actuated by four groups of pneumatic muscle (PM) actuators in opposing pair configuration. The control objective is end-effector tracking of a desired path in Cartesian space. The inputs to the system are commanded input pressure differentials for the two opposing PM groups. An existing model for the muscle is incorporated into the arm equations of motion to arrive at a two-input, two-output nonlinear model of the planar arm that is affine in the input and, therefore, suitable for sliding-mode techniques. Relationships between static input pressures are derived for suitable arm behavior in the absence of a control signal. Simulation studies are reported.

  1. Distal mdx muscle groups exhibiting up-regulation of utrophin and rescue of dystrophin-associated glycoproteins exemplify a protected phenotype in muscular dystrophy

    Science.gov (United States)

    Dowling, Paul; Culligan, Kevin; Ohlendieck, Kay

    2002-02-01

    Unique unaffected skeletal muscle fibres, unlike necrotic torso and limb muscles, may pave the way for a more detailed understanding of the molecular pathogenesis of inherited neuromuscular disorders and help to develop new treatment strategies for muscular dystrophies. The sparing of extraocular muscle in Duchenne muscular dystrophy is mostly attributed to the special protective properties of extremely fast-twitching small-diameter fibres, but here we show that distal muscles also represent a particular phenotype that is more resistant to necrosis. Immunoblot analysis of membranes isolated from the well established dystrophic animal model mdx shows that, in contrast to dystrophic limb muscles, the toe musculature exhibits an up-regulation of the autosomal dystrophin homologue utrophin and a concomitant rescue of dystrophin-associated glycoproteins. Thus distal mdx muscle groups provide a cellular system that naturally avoids myofibre degeneration which might be useful in the search for naturally occurring compensatory mechanisms in inherited skeletal muscle diseases.

  2. Comparison of Walking, Muscle Strength, Balance, and Fear of Falling Between Repeated Fall Group, One-time Fall Group, and Nonfall Group of the Elderly Receiving Home Care Service.

    Science.gov (United States)

    Jeon, MiYang; Gu, Mee Ock; Yim, JongEun

    2017-12-01

    The purpose of this study was to provide information to develop a program to prevent repeated falls by analyzing the difference in gait, muscle strength, balance, and fear of falling according to their fall experience. The study subjects were 110 elderly individuals aged over 60 years who agreed to their participation in this research. The study participants were categorized into a repeated fall group (n = 40), a one-time fall group (n = 15), and a nonfall group (n = 46) of the elderly. Measurements of gait, muscle strength, balance, and fear of falling were taken in each group. With regard to gait, there were significant differences among three groups in gait cycle (F = 3.50, p = .034), speed (F = 13.06, p balance, the nonfall group had significantly greater results than the one-time fall group and repeated fall group in dynamic balance (F = 10.80, p balance (F = 8.20, p = .001). In the case of the fear of falling, the repeated fall group had significantly higher score than other two groups (F = 20.62, p fall risk factors to enhance gait and balance and lower body muscle strength and reduce the fear of falling to prevent repeated incidences of falls in this population. Copyright © 2017. Published by Elsevier B.V.

  3. Supervised dance intervention based on video game choreography increases quadriceps cross sectional area and peak of torque in community dwelling older women

    Directory of Open Access Journals (Sweden)

    Elisângela Valevein Rodrigues

    2018-06-01

    Full Text Available Abstract AIMS the purpose of this study was to assess the effects of a supervised dance intervention based on video game choreography on isokinetic concentric and eccentric knee peak of torque (PT, quadriceps and hamstrings cross sectional area (CSA and functionality in community-dwelling older women. METHODS Forty-seven older women were allocated in Control Group (CG, n=25 and Intervention Group (IG, n=22. The IG performed dance based on video game choreography (Dance Central, XBOX 360®, Kinect, during 12 weeks, ~40 minutes, 3x/week, without foam (1-6week and with foam and visual disturbances (7-12 week. The pretest-training-posttest assessments included: isokinetic concentric and eccentric knee PT and CSA (Magnetic resonance imaging of quadriceps and hamstrings and functional tests. RESULTS The light-to-moderate-intensity 12-weeks training increased 8.5% the eccentric PT of quadriceps at 60°/s (p=0.04 and 1.3% quadriceps CSA (p=0.02. CONCLUSIONS These findings suggest that dance training based on video game choreography can enhance PT and induce hypertrophy in community-dwelling older women.

  4. Hamstring transfer for quadriceps paralysis in post polio residual paralysis

    Directory of Open Access Journals (Sweden)

    Jagadish J Patwa

    2012-01-01

    Conclusions: H to Q transfer in the presence of quadriceps paralysis with good power in hamstring is a better alternative than supracondylar osteotomy because it is a dynamic correction and it produces some degree of recurvatum with increasing stability of knee in extension while walking. While inserting hamstring over patella the periosteum is not cut in an I-shaped fashion to create a flap which gives additional strength to new insertion and also patella act as a fulcrum during the extension of knee by producing the bowstring effect.

  5. Bone mineral density, muscle strength and physical activity. A population-based study of 332 subjects aged 15-42 years.

    Science.gov (United States)

    Düppe, H; Gärdsell, P; Johnell, O; Nilsson, B E; Ringsberg, K

    1997-04-01

    The aim of this population-based study was to find out whether differences in levels of physical activity have an influence on bone mass quantity and whether quadriceps muscle strength is a reliable determinant of bone mass. Included were 175 men and 157 women, aged 15-42 years. Bone mineral density (BMD) was measured at various sites by dual X-ray absorptiometry (DXA) and single photon absorptiometry (SPA). Muscle strength was assessed using an isokinetic muscle force meter. A questionnaire was used to estimate the level of physical activity. We found a positive correlation between physical activity and BMD for boys at the distal forearm and for girls at the trochanter (age group 15-16 years). Active men (age group 21-42 years) had up to 9% higher BMD levels at the hip than those who were less active. Quadriceps muscle torque was not an independent predictor of BMD. Our data suggest that a higher level of physical activity-within the limits of a "normal life style"-may have a positive effect on BMD in the proximal femur of young adults, which in turn may lessen the subsequent risk of fracture.

  6. Use it or lose it: tonic activity of slow motoneurons promotes their survival and preferentially increases slow fiber-type groupings in muscles of old lifelong recreational sportsmen

    Directory of Open Access Journals (Sweden)

    Simone Mosole

    2016-11-01

    Full Text Available Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i denervation contributes to muscle atrophy, ii impaired mobility accelerates the process, and iii lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers; 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers; 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always

  7. Use it or Lose It: Tonic Activity of Slow Motoneurons Promotes Their Survival and Preferentially Increases Slow Fiber-Type Groupings in Muscles of Old Lifelong Recreational Sportsmen

    Science.gov (United States)

    Mosole, Simone; Carraro, Ugo; Kern, Helmut; Loefler, Stefan; Zampieri, Sandra

    2016-01-01

    Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i) denervation contributes to muscle atrophy, ii) impaired mobility accelerates the process, and iii) lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES) of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC) we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers); 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers); 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always more active

  8. Use it or Lose It: Tonic Activity of Slow Motoneurons Promotes Their Survival and Preferentially Increases Slow Fiber-Type Groupings in Muscles of Old Lifelong Recreational Sportsmen.

    Science.gov (United States)

    Mosole, Simone; Carraro, Ugo; Kern, Helmut; Loefler, Stefan; Zampieri, Sandra

    2016-09-15

    Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i) denervation contributes to muscle atrophy, ii) impaired mobility accelerates the process, and iii) lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES) of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC) we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers); 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers); 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always more active

  9. Comparison of neuromuscular and quadriceps strengthening exercise in the treatment of varus malaligned knees with medial knee osteoarthritis: a randomised controlled trial protocol

    Directory of Open Access Journals (Sweden)

    Bennell Kim L

    2011-12-01

    Full Text Available Abstract Background Osteoarthritis of the knee involving predominantly the medial tibiofemoral compartment is common in older people, giving rise to pain and loss of function. Many people experience progressive worsening of the disease over time, particularly those with varus malalignment and increased medial knee joint load. Therefore, interventions that can reduce excessive medial knee loading may be beneficial in reducing the risk of structural progression. Traditional quadriceps strengthening can improve pain and function in people with knee osteoarthritis but does not appear to reduce medial knee load. A neuromuscular exercise program, emphasising optimal alignment of the trunk and lower limb joints relative to one another, as well as quality of movement performance, while dynamically and functionally strengthening the lower limb muscles, may be able to reduce medial knee load. Such a program may also be superior to traditional quadriceps strengthening with respect to improved pain and physical function because of the functional and dynamic nature. This randomised controlled trial will investigate the effect of a neuromuscular exercise program on medial knee joint loading, pain and function in individuals with medial knee joint osteoarthritis. We hypothesise that the neuromuscular program will reduce medial knee load as well as pain and functional limitations to a greater extent than a traditional quadriceps strengthening program. Methods/Design 100 people with medial knee pain, radiographic medial compartment osteoarthritis and varus malalignment will be recruited and randomly allocated to one of two 12-week exercise programs: quadriceps strengthening or neuromuscular exercise. Each program will involve 14 supervised exercise sessions with a physiotherapist plus four unsupervised sessions per week at home. The primary outcomes are medial knee load during walking (the peak external knee adduction moment from 3D gait analysis, pain, and self

  10. Hamstring Activity in the Anterior Cruciate Ligament Injured Patient: Injury Implications and Comparison With Quadriceps Activity.

    Science.gov (United States)

    Frank, Rachel M; Lundberg, Hannah; Wimmer, Markus A; Forsythe, Brian; Bach, Bernard R; Verma, Nikhil N; Cole, Brian J

    2016-08-01

    To investigate the potential causes of diminished knee extension after acute anterior cruciate ligament (ACL) injury using both surface electromyography (sEMG) analysis of the quadriceps and hamstrings, and gait analysis to assess muscle action and tone. Consecutive patients with an acute ACL tear underwent sEMG and gait analysis within 2 weeks of injury, before ACL reconstruction. Standard motion analysis techniques were used and sEMG data were collected simultaneously with gait data. T-tests were used to determine differences between the ACL-deficient and control subjects in knee flexion angles, peak external knee joint moments, and total time that a muscle was activated ("on") during gait. External knee moments were expressed as a percentage of body weight times height. Ten patients (mean age 24 ± 4 years) were included at a mean 10.2 days between injury and analysis; 10 uninjured, matched control subjects were included for comparison. There were significant increases in minimum flexion angle at heel strike (5.92 ± 3.39 v -3.49 ± 4.55, P hamstring activity "on" time during gait (P > .05). In patients with acute ACL injury, the ACL-deficient limb does not reach as much extension as controls. Although the rectus femoris is "on" for shorter periods during the gait cycle, there is no difference in hamstring time on during gait. This information may help clinicians better understand muscle function and gait patterns in the acute time period after ACL injury. Level III, case control study. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  11. Bilateral simultaneous quadriceps tendon rupture in a patient with secondary hyperparathyroidism: a case report

    International Nuclear Information System (INIS)

    Lee, Yeon Soo; Son, Sang Beom; Han, Chang Whan; Kang, Si Won

    2001-01-01

    Simultaneous bilateral rupture of the quadriceps tendon without a significant history of trauma may occur in association with chronic metabolic disorders such as chronic renal failure and secondary hyperparathyroidism, though has rarely been reported. We describe a case of spontaneous bilateral quadriceps tendon rupture in a 36-year-old female patient with secondary hyperparathyroidism

  12. Whey protein hydrolysate augments tendon and muscle hypertrophy independent of resistance exercise contraction mode.

    Science.gov (United States)

    Farup, J; Rahbek, S K; Vendelbo, M H; Matzon, A; Hindhede, J; Bejder, A; Ringgard, S; Vissing, K

    2014-10-01

    In a comparative study, we investigated the effects of maximal eccentric or concentric resistance training combined with whey protein or placebo on muscle and tendon hypertrophy. 22 subjects were allocated into either a high-leucine whey protein hydrolysate + carbohydrate group (WHD) or a carbohydrate group (PLA). Subjects completed 12 weeks maximal knee extensor training with one leg using eccentric contractions and the other using concentric contractions. Before and after training cross-sectional area (CSA) of m. quadriceps and patellar tendon CSA was quantified with magnetic resonance imaging and a isometric strength test was used to assess maximal voluntary contraction (MVC) and rate of force development (RFD). Quadriceps CSA increased by 7.3 ± 1.0% (P tendon CSA increased by 14.9 ± 3.1% (P effect of contraction mode. MVC and RFD increased by 15.6 ± 3.5% (P effects. In conclusion, high-leucine whey protein hydrolysate augments muscle and tendon hypertrophy following 12 weeks of resistance training - irrespective of contraction mode. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. 31P MR spectroscopy and computational modeling identify a direct relation between Pi content of an alkaline compartment in resting muscle and phosphocreatine resynthesis kinetics in active muscle in humans.

    Directory of Open Access Journals (Sweden)

    Joep W M van Oorschot

    Full Text Available The assessment of mitochondrial properties in skeletal muscle is important in clinical research, for instance in the study of diabetes. The gold standard to measure mitochondrial capacity non-invasively is the phosphocreatine (PCr recovery rate after exercise, measured by (31P Magnetic Resonance spectroscopy ((31P MRS. Here, we sought to expand the evidence base for an alternative method to assess mitochondrial properties which uses (31P MRS measurement of the Pi content of an alkaline compartment attributed to mitochondria (Pi2; as opposed to cytosolic Pi (Pi1 in resting muscle at high magnetic field. Specifically, the PCr recovery rate in human quadriceps muscle was compared with the signal intensity of the Pi2 peak in subjects with varying mitochondrial content of the quadriceps muscle as a result of athletic training, and the results were entered into a mechanistic computational model of mitochondrial metabolism in muscle to test if the empirical relation between Pi2/Pi1 ratio and the PCr recovery was consistent with theory. Localized (31P spectra were obtained at 7T from resting vastus lateralis muscle to measure the intensity of the Pi2 peak. In the endurance trained athletes a Pi2/Pi1 ratio of 0.07 ± 0.01 was found, compared to a significantly lower (p<0.05 Pi2/Pi1 ratio of 0.03 ± 0.01 in the normally active group. Next, PCr recovery kinetics after in magnet bicycle exercise were measured at 1.5T. For the endurance trained athletes, a time constant τPCr 12 ± 3 s was found, compared to 24 ± 5s in normally active subjects. Without any parameter optimization the computational model prediction matched the experimental data well (r(2 of 0.75. Taken together, these results suggest that the Pi2 resonance in resting human skeletal muscle observed at 7T provides a quantitative MR-based functional measure of mitochondrial density.

  14. The neural response properties and cortical organization of a rapidly adapting muscle sensory group response that overlaps with the frequencies that elicit the kinesthetic illusion.

    Science.gov (United States)

    Marasco, Paul D; Bourbeau, Dennis J; Shell, Courtney E; Granja-Vazquez, Rafael; Ina, Jason G

    2017-01-01

    Kinesthesia is the sense of limb movement. It is fundamental to efficient motor control, yet its neurophysiological components remain poorly understood. The contributions of primary muscle spindles and cutaneous afferents to the kinesthetic sense have been well studied; however, potential contributions from muscle sensory group responses that are different than the muscle spindles have not been ruled out. Electrophysiological recordings in peripheral nerves and brains of male Sprague Dawley rats with a degloved forelimb preparation provide evidence of a rapidly adapting muscle sensory group response that overlaps with vibratory inputs known to generate illusionary perceptions of limb movement in humans (kinesthetic illusion). This group was characteristically distinct from type Ia muscle spindle fibers, the receptor historically attributed to limb movement sensation, suggesting that type Ia muscle spindle fibers may not be the sole carrier of kinesthetic information. The sensory-neural structure of muscles is complex and there are a number of possible sources for this response group; with Golgi tendon organs being the most likely candidate. The rapidly adapting muscle sensory group response projected to proprioceptive brain regions, the rodent homolog of cortical area 3a and the second somatosensory area (S2), with similar adaption and frequency response profiles between the brain and peripheral nerves. Their representational organization was muscle-specific (myocentric) and magnified for proximal and multi-articulate limb joints. Projection to proprioceptive brain areas, myocentric representational magnification of muscles prone to movement error, overlap with illusionary vibrational input, and resonant frequencies of volitional motor unit contraction suggest that this group response may be involved with limb movement processing.

  15. The neural response properties and cortical organization of a rapidly adapting muscle sensory group response that overlaps with the frequencies that elicit the kinesthetic illusion.

    Directory of Open Access Journals (Sweden)

    Paul D Marasco

    Full Text Available Kinesthesia is the sense of limb movement. It is fundamental to efficient motor control, yet its neurophysiological components remain poorly understood. The contributions of primary muscle spindles and cutaneous afferents to the kinesthetic sense have been well studied; however, potential contributions from muscle sensory group responses that are different than the muscle spindles have not been ruled out. Electrophysiological recordings in peripheral nerves and brains of male Sprague Dawley rats with a degloved forelimb preparation provide evidence of a rapidly adapting muscle sensory group response that overlaps with vibratory inputs known to generate illusionary perceptions of limb movement in humans (kinesthetic illusion. This group was characteristically distinct from type Ia muscle spindle fibers, the receptor historically attributed to limb movement sensation, suggesting that type Ia muscle spindle fibers may not be the sole carrier of kinesthetic information. The sensory-neural structure of muscles is complex and there are a number of possible sources for this response group; with Golgi tendon organs being the most likely candidate. The rapidly adapting muscle sensory group response projected to proprioceptive brain regions, the rodent homolog of cortical area 3a and the second somatosensory area (S2, with similar adaption and frequency response profiles between the brain and peripheral nerves. Their representational organization was muscle-specific (myocentric and magnified for proximal and multi-articulate limb joints. Projection to proprioceptive brain areas, myocentric representational magnification of muscles prone to movement error, overlap with illusionary vibrational input, and resonant frequencies of volitional motor unit contraction suggest that this group response may be involved with limb movement processing.

  16. Redox responses are preserved across muscle fibres with differential susceptibility to aging.

    Science.gov (United States)

    Smith, Neil T; Soriano-Arroquia, Ana; Goljanek-Whysall, Katarzyna; Jackson, Malcolm J; McDonagh, Brian

    2018-04-15

    Age-related loss of muscle mass and function is associated with increased frailty and loss of independence. The mechanisms underlying the susceptibility of different muscle types to age-related atrophy are not fully understood. Reactive oxygen species (ROS) are recognised as important signalling molecules in healthy muscle and redox sensitive proteins can respond to intracellular changes in ROS concentrations modifying reactive thiol groups on Cysteine (Cys) residues. Conserved Cys residues tend to occur in functionally important locations and can have a direct impact on protein function through modifications at the active site or determining protein conformation. The aim of this work was to determine age-related changes in the redox proteome of two metabolically distinct murine skeletal muscles, the quadriceps a predominantly glycolytic muscle and the soleus which contains a higher proportion of mitochondria. To examine the effects of aging on the global proteome and the oxidation state of individual redox sensitive Cys residues, we employed a label free proteomics approach including a differential labelling of reduced and reversibly oxidised Cys residues. Our results indicate the proteomic response to aging is dependent on muscle type but redox changes that occur primarily in metabolic and cytoskeletal proteins are generally preserved between metabolically distinct tissues. Skeletal muscle containing fast twitch glycolytic fibres are more susceptible to age related atrophy compared to muscles with higher proportions of oxidative slow twitch fibres. Contracting skeletal muscle generates reactive oxygen species that are required for correct signalling and adaptation to exercise and it is also known that the intracellular redox environment changes with age. To identify potential mechanisms for the distinct response to age, this article combines a global proteomic approach and a differential labelling of reduced and reversibly oxidised Cysteine residues in two

  17. Improved inflammatory balance of human skeletal muscle during exercise after supplementations of the ginseng-based steroid Rg1.

    Directory of Open Access Journals (Sweden)

    Chien-Wen Hou

    Full Text Available The purpose of the study was to determine the effect of ginseng-based steroid Rg1 on TNF-alpha and IL-10 gene expression in human skeletal muscle against exercise challenge, as well as on its ergogenic outcomes. Randomized double-blind placebo-controlled crossover trials were performed, separated by a 4-week washout. Healthy young men were randomized into two groups and received capsule containing either 5 mg of Rg1 or Placebo one night and one hour before exercise. Muscle biopsies were conducted at baseline, immediately and 3 h after a standardized 60-min cycle ergometer exercise. While treatment differences in glycogen depletion rate of biopsied quadriceps muscle during exercise did not reach statistical significance, Rg1 supplementations enhanced post-exercise glycogen replenishment and increased citrate synthase activity in the skeletal muscle 3 h after exercise, concurrent with improved meal tolerance during recovery (P<0.05. Rg1 suppressed the exercise-induced increases in thiobarbituric acids reactive substance (TBARS and reversed the increased TNF-alpha and decreased IL-10 mRNA of quadriceps muscle against the exercise challenge. PGC-1 alpha and GLUT4 mRNAs of exercised muscle were not affected by Rg1. Maximal aerobic capacity (VO2max was not changed by Rg1. However, cycling time to exhaustion at 80% VO2max increased significantly by ~20% (P<0.05.Our result suggests that Rg1 is an ergogenic component of ginseng, which can minimize unwanted lipid peroxidation of exercised human skeletal muscle, and attenuate pro-inflammatory shift under exercise challenge.

  18. Improved inflammatory balance of human skeletal muscle during exercise after supplementations of the ginseng-based steroid Rg1.

    Science.gov (United States)

    Hou, Chien-Wen; Lee, Shin-Da; Kao, Chung-Lan; Cheng, I-Shiung; Lin, Yu-Nan; Chuang, Sheng-Ju; Chen, Chung-Yu; Ivy, John L; Huang, Chih-Yang; Kuo, Chia-Hua

    2015-01-01

    The purpose of the study was to determine the effect of ginseng-based steroid Rg1 on TNF-alpha and IL-10 gene expression in human skeletal muscle against exercise challenge, as well as on its ergogenic outcomes. Randomized double-blind placebo-controlled crossover trials were performed, separated by a 4-week washout. Healthy young men were randomized into two groups and received capsule containing either 5 mg of Rg1 or Placebo one night and one hour before exercise. Muscle biopsies were conducted at baseline, immediately and 3 h after a standardized 60-min cycle ergometer exercise. While treatment differences in glycogen depletion rate of biopsied quadriceps muscle during exercise did not reach statistical significance, Rg1 supplementations enhanced post-exercise glycogen replenishment and increased citrate synthase activity in the skeletal muscle 3 h after exercise, concurrent with improved meal tolerance during recovery (P<0.05). Rg1 suppressed the exercise-induced increases in thiobarbituric acids reactive substance (TBARS) and reversed the increased TNF-alpha and decreased IL-10 mRNA of quadriceps muscle against the exercise challenge. PGC-1 alpha and GLUT4 mRNAs of exercised muscle were not affected by Rg1. Maximal aerobic capacity (VO2max) was not changed by Rg1. However, cycling time to exhaustion at 80% VO2max increased significantly by ~20% (P<0.05). Our result suggests that Rg1 is an ergogenic component of ginseng, which can minimize unwanted lipid peroxidation of exercised human skeletal muscle, and attenuate pro-inflammatory shift under exercise challenge.

  19. ELECTRICAL MUSCLE STIMULATION (EMS IMPLEMENTATION IN EXPLOSIVE STRENGTH DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Zoran Đokić

    2013-07-01

    Full Text Available Electrical muscle stimulation (EMS, is also known as neuromuscular electrical stimulation (NMES may be used for therapeutic purposes and training. EMS is causing muscle contractions via electrical impulses. The survey was conducted as a case study. The study was conducted on subject of 3 male of different ages. The study lasted 4 weeks, and the respondents have not used any type of training or activity, which would affect the development of explosive strength of the lower extremities. Electrical stimulation was performed in the evening, every other day, with COMPEX mi sport apparatus (Medical SA - All rights reserved - 07/06 - Art. 885,616 - V.2 model. In 4 week period, a total of 13 treatments were performed on selected muscle groups - quadriceps femoris and gastrocnemius. Program of plyometric training (Plyometric (28 min per treatment, for each muscle group were applied. The main objective of this study was to quantify and compare explosive leg strength, using different vertical jump protocols, before and after the EMS program. The initial and final testing was conducted in the laboratory of the Faculty of Sport and Tourism in Novi Sad, on the contact plate AXON JUMP (Bioingeniería Deportiva, VACUMED, 4538 Westinghouse Street Ventura, CA 93 003 under identical conditions. In all three of the respondents indicated an increase in vertical jump in all applied protocols.

  20. Differential Muscle Involvement in Mice and Humans Affected by McArdle Disease

    DEFF Research Database (Denmark)

    Krag, Thomas O; Pinós, Tomàs; Nielsen, Tue L

    2016-01-01

    McArdle disease (muscle glycogenosis type V) is caused by myophosphorylase deficiency, which leads to impaired glycogen breakdown. We investigated how myophosphorylase deficiency affects muscle physiology, morphology, and glucose metabolism in 20-week-old McArdle mice and compared the findings...... to those in McArdle disease patients. Muscle contractions in the McArdle mice were affected by structural degeneration due to glycogen accumulation, and glycolytic muscles fatigued prematurely, as occurs in the muscles of McArdle disease patients. Homozygous McArdle mice showed muscle fiber disarray...... no substitution for the missing muscle isoform. In the mice, the tibialis anterior (TA) muscles were invariably more damaged than the quadriceps muscles. This may relate to a 7-fold higher level of myophosphorylase in TA compared to quadriceps in wild-type mice and suggests higher glucose turnover in the TA. Thus...

  1. A pilot study using magnetic resonance imaging to determine the pattern of muscle group recruitment by rowers with different levels of experience

    International Nuclear Information System (INIS)

    Green, R.A.R.; Wilson, D.J.

    2000-01-01

    Objective. To determine whether it was possible using magnetic resonance imaging (MRI) to define the pattern of muscle recruitment in a specific sport (rowing) and to see whether there were differences in this pattern between athletes of different experience.Design and method. It has been shown that during vigorous exercise the water content of muscle increases transiently. This can be observed using MRI, where the prolonged T2 relaxation time of muscle can be demonstrated. In this study we have exploited the increase in signal seen in exercised muscle on short TI inversion recovery (STIR) sequences, to show how rowers of different experience use different muscle groups.Results. We have shown that trained athletes recruit selected muscle groups to carry out a given task, which they carry out more efficiently than untrained or less experienced athletes.Conclusion. We have provided the basis of potential research to refine training methods, in order to develop specific muscle groups in athletes, in the hope of achieving a higher level of performance at an earlier stage in their training. We have also defined a technique that may be of clinical value in cases of muscle dysfunction. (orig.)

  2. The effect of neuromuscular electrical stimulation on muscle strength, functional capacity and body composition in haemodialysis patients

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    Vicent Esteve

    2017-01-01

    Conclusions: (1 NMES improved muscle strength, functional capacity and quadriceps muscle composition in our patients. (2 Based on the results obtained, NMES could be a new therapeutic alternative to prevent muscle atrophy and progressive physical deterioration. (3 However, future studies are necessary to establish the potential beneficial effects of NMES in HD patients.

  3. Self-efficacy, pain, and quadriceps capacity at baseline predict changes in mobility performance over 2 years in women with knee osteoarthritis.

    Science.gov (United States)

    Brisson, Nicholas M; Gatti, Anthony A; Stratford, Paul W; Maly, Monica R

    2018-02-01

    This study examined the extent to which baseline measures of quadriceps strength, quadriceps power, knee pain and self-efficacy for functional tasks, and their interactions, predicted 2-year changes in mobility performance (walking, stair ascent, stair descent) in women with knee osteoarthritis. We hypothesized that lesser strength, power and self-efficacy, and higher pain at baseline would each be independently associated with reduced mobility over 2 years, and each of pain and self-efficacy would interact with strength and power in predicting 2-year change in stair-climbing performance. This was a longitudinal, observational study of women with clinical knee osteoarthritis. At baseline and follow-up, mobility was assessed with the Six-Minute Walk Test, and stair ascent and descent tasks. Quadriceps strength and power, knee pain, and self-efficacy for functional tasks were also collected at baseline. Multiple linear regression examined the extent to which 2-year changes in mobility performances were predicted by baseline strength, power, pain, and self-efficacy, after adjusting for covariates. Data were analyzed for 37 women with knee osteoarthritis over 2 years. Lower baseline self-efficacy predicted decreased walking (β = 1.783; p = 0.030) and stair ascent (β = -0.054; p baseline pain intensity/frequency predicted decreased walking performance (β = 1.526; p = 0.002). Lower quadriceps strength (β = 0.051; p = 0.015) and power (β = 0.022; p = 0.022) interacted with lesser self-efficacy to predict worsening stair ascent performance. Strategies to sustain or improve mobility in women with knee osteoarthritis must focus on controlling pain and boosting self-efficacy. In those with worse self-efficacy, developing knee muscle capacity is an important target.

  4. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement

    Science.gov (United States)

    Rasnick, Robert; Standifird, Tyler; Reinbolt, Jeffrey A.; Cates, Harold E.

    2016-01-01

    Total knee replacement (TKR) is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF) and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (pknee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups. PMID:27258086

  5. Evoked EMG versus Muscle Torque during Fatiguing Functional Electrical Stimulation-Evoked Muscle Contractions and Short-Term Recovery in Individuals with Spinal Cord Injury

    Science.gov (United States)

    Estigoni, Eduardo H.; Fornusek, Che; Hamzaid, Nur Azah; Hasnan, Nazirah; Smith, Richard M.; Davis, Glen M.

    2014-01-01

    This study investigated whether the relationship between muscle torque and m-waves remained constant after short recovery periods, between repeated intervals of isometric muscle contractions induced by functional electrical stimulation (FES). Eight subjects with spinal cord injury (SCI) were recruited for the study. All subjects had their quadriceps muscles group stimulated during three sessions of isometric contractions separated by 5 min of recovery. The evoked-electromyographic (eEMG) signals, as well as the produced torque, were synchronously acquired during the contractions and during short FES bursts applied during the recovery intervals. All analysed m-wave variables changed progressively throughout the three contractions, even though the same muscle torque was generated. The peak to peak amplitude (PtpA), and the m-wave area (Area) were significantly increased, while the time between the stimulus artefact and the positive peak (PosT) were substantially reduced when the muscles became fatigued. In addition, all m-wave variables recovered faster and to a greater extent than did torque after the recovery intervals. We concluded that rapid recovery intervals between FES-evoked exercise sessions can radically interfere in the use of m-waves as a proxy for torque estimation in individuals with SCI. This needs to be further investigated, in addition to seeking a better understanding of the mechanisms of muscle fatigue and recovery. PMID:25479324

  6. Comparison of Transcutaneous Electrical Nerve Stimulation and Cryotherapy for Increasing Quadriceps Activation in Patients With Knee Pathologies.

    Science.gov (United States)

    Gabler, Conrad M; Lepley, Adam S; Uhl, Tim L; Mattacola, Carl G

    2016-08-01

    Proper neuromuscular activation of the quadriceps muscle is essential for maintaining quadriceps (quad) strength and lower-extremity function. Quad activation (QA) failure is a common characteristic observed in patients with knee pathologies, defined as an inability to voluntarily activate the entire alpha-motor-neuron pool innervating the quad. One of the more popular techniques used to assess QA is the superimposed burst (SIB) technique, a force-based technique that uses a supramaximal, percutaneous electrical stimulation to activate all of the motor units in the quad during a maximal, voluntary isometric contraction. Central activation ratio (CAR) is the formula used to calculate QA level (CAR = voluntary force/SIB force) with the SIB technique. People who can voluntarily activate 95% or more (CAR = 0.95-1.0) of their motor units are defined as being fully activated. Therapeutic exercises aimed at improving quad strength in patients with knee pathologies are limited in their effectiveness due to a failure to fully activate the muscle. Within the past decade, several disinhibitory interventions have been introduced to treat QA failure in patients with knee pathologies. Transcutaneous electrical nerve stimulation (TENS) and cryotherapy are sensory-targeted modalities traditionally used to treat pain, but they have been shown to be 2 of the most successful treatments for increasing QA levels in patients with QA failure. Both modalities are hypothesized to positively affect voluntary QA by disinhibiting the motor-neuron pool of the quad. In essence, these modalities provide excitatory afferent stimuli to the spinal cord, which thereby overrides the inhibitory afferent signaling that arises from the involved joint. However, it remains unknown whether 1 is more effective than the other for restoring QA levels in patients with knee pathologies. By knowing the capabilities of each disinhibitory modality, clinicians can tailor treatments based on the rehabilitation goals

  7. Muscle Fiber Characteristics, Satellite Cells and Soccer Performance in Young Athletes

    Directory of Open Access Journals (Sweden)

    Thomas I. Metaxas, Athanasios Mandroukas, Efstratios Vamvakoudis, Kostas Kotoglou, Björn Ekblom, Konstantinos Mandroukas

    2014-09-01

    Full Text Available This study is aimed to examine the muscle fiber type, composition and satellite cells in young male soccer players and to correlate them to cardiorespiratory indices and muscle strength. The participants formed three Groups: Group A (n = 13, 11.2 ± 0.4yrs, Group B (n=10, 13.1 ± 0.5yrs and Group C (n = 9, 15.2 ± 0.6yrs. Muscle biopsies were obtained from the vastus lateralis. Peak torque values of the quadriceps and hamstrings were recorded and VO2max was measured on the treadmill. Group C had lower type I percentage distribution compared to A by 21.3% (p < 0.01, while the type IIA relative percentage was higher by 18.1% and 18.4% than in Groups A and B (p < 0.05. Groups B and C had higher cross-sectional area (CSA values in all fiber types than in Group A (0.05 < p < 0.001. The number of satellite cells did not differ between the groups. Groups B and C had higher peak torque at all angular velocities and absolute VO2max in terms of ml·min-1 than Group A (0.05 < p < 0.001. It is concluded that the increased percentage of type IIA muscle fibers noticed in Group C in comparison to the Groups A and B should be mainly attributed to the different workload exercise and training programs. The alteration of myosin heavy chain (MHC isoforms composition even in children is an important mechanism for skeletal muscle characteristics. Finally, CSA, isokinetic muscle strength and VO2max values seems to be expressed according to age.

  8. The influence of stimulus phase duration on discomfort and electrically induced torque of quadriceps femoris

    Directory of Open Access Journals (Sweden)

    Richard E. Liebano

    2013-10-01

    Full Text Available BACKGROUND: Although a number of studies have compared the influence of different electrical pulse parameters on maximum electrically induced torque (MEIT and discomfort, the role of phase duration has been poorly investigated. OBJECTIVE: To examine the variation in muscle torque and discomfort produced when electrically stimulating quadriceps femoris using pulsed current with three different phase durations in order to establish whether there are any advantages or disadvantages in varying the phase duration over the range examined. METHOD: This is a two repeated-measures, within-subject study conducted in a research laboratory. The study was divided into 2 parts with 19 healthy young adults in each part.In part 1, MEIT was determined for each phase duration (400, 700, and 1000 µs, using a biphasic pulsed current at a frequency of 50 Hz. In part 2, stimulus amplitude was increased until the contractions reached 40% of maximum voluntary isometric contraction (MVIC and the associated discomfort produced by each phase duration was measured. RESULTS: In part 1 of the study, we found that the average MEITs generated with each phase duration (400, 700, and 1000 µs were 55.0, 56.3, and 58.0% of MVIC respectively, but the differences were not statistically significant (p=.45. In part 2, we found a statistically significant increase in discomfort over the same range of phase durations. The results indicate that, for a given level of torque production, discomfort increases with increasing phase duration (p=.008. CONCLUSIONS: Greater muscle torque cannot be produced by increasing the stimulus phase duration over the range examined. Greater discomfort is produced by increasing the stimulus phase duration.

  9. Skeletal muscle expression of p43, a truncated thyroid hormone receptor α, affects lipid composition and metabolism.

    Science.gov (United States)

    Casas, François; Fouret, Gilles; Lecomte, Jérome; Cortade, Fabienne; Pessemesse, Laurence; Blanchet, Emilie; Wrutniak-Cabello, Chantal; Coudray, Charles; Feillet-Coudray, Christine

    2018-02-01

    Thyroid hormone is a major regulator of metabolism and mitochondrial function. Thyroid hormone also affects reactions in almost all pathways of lipids metabolism and as such is considered as the main hormonal regulator of lipid biogenesis. The aim of this study was to explore the possible involvement of p43, a 43 Kda truncated form of the nuclear thyroid hormone receptor TRα1 which stimulates mitochondrial activity. Therefore, using mouse models overexpressing p43 in skeletal muscle (p43-Tg) or lacking p43 (p43-/-), we have investigated the lipid composition in quadriceps muscle and in mitochondria. Here, we reported in the quadriceps muscle of p43-/- mice, a fall in triglycerides, an inhibition of monounsaturated fatty acids (MUFA) synthesis, an increase in elongase index and an decrease in desaturase index. However, in mitochondria from p43-/- mice, fatty acid profile was barely modified. In the quadriceps muscle of p43-Tg mice, MUFA content was decreased whereas the unsaturation index was increased. In addition, in quadriceps mitochondria of p43-Tg mice, we found an increase of linoleic acid level and unsaturation index. Last, we showed that cardiolipin content, a key phospholipid for mitochondrial function, remained unchanged both in quadriceps muscle and in its mitochondria whatever the mice genotype. In conclusion, this study shows that muscle lipid content and fatty acid profile are strongly affected in skeletal muscle by p43 levels. We also demonstrate that regulation of cardiolipin biosynthesis by the thyroid hormone does not imply p43.

  10. Anterior cruciate ligament tear induces a sustained loss of muscle fiber force production.

    Science.gov (United States)

    Gumucio, Jonathan P; Sugg, Kristoffer B; Enselman, Elizabeth R Sibilsky; Konja, Alexis C; Eckhardt, Logan R; Bedi, Asheesh; Mendias, Christopher L

    2018-01-18

    Patients with anterior cruciate ligament (ACL) tears have persistent quadriceps strength deficits that are thought to be due to altered neurophysiological function. Our goal was to determine the changes in muscle fiber contractility independent of the ability of motor neurons to activate fibers. We obtained quadriceps biopsies of patients undergoing ACL reconstruction, and additional biopsies 1, 2, and 6 months after surgery. Muscles fiber contractility was assessed in vitro, along with whole muscle strength testing. Compared with controls, patients had a 30% reduction in normalized muscle fiber force at the time of surgery. One month later, the force deficit was 41%, and at 6 months the deficit was 23%. Whole muscle strength testing demonstrated similar trends. While neurophysiological dysfunction contributes to whole muscle weakness, there is also a reduction in the force generating capacity of individual muscle cells independent of alpha motor neuron activation. Muscle Nerve, 2018. © 2018 Wiley Periodicals, Inc.

  11. Assessment of muscle function using hybrid PET/MRI: comparison of 18F-FDG PET and T2-weighted MRI for quantifying muscle activation in human subjects

    International Nuclear Information System (INIS)

    Haddock, Bryan; Holm, Soeren; Poulsen, Jakup M.; Enevoldsen, Lotte H.; Larsson, Henrik B.W.; Kjaer, Andreas; Suetta, Charlotte

    2017-01-01

    The aim of this study was to determine the relationship between relative glucose uptake and MRI T 2 changes in skeletal muscles following resistance exercise using simultaneous PET/MRI scans. Ten young healthy recreationally active men (age 21 - 28 years) were injected with 18 F-FDG while activating the quadriceps of one leg with repeated knee extension exercises followed by hand-grip exercises for one arm. Immediately following the exercises, the subjects were scanned simultaneously with 18 F-FDG PET/MRI and muscle groups were evaluated for increases in 18 F-FDG uptake and MRI T 2 values. A significant linear correlation between 18 F-FDG uptake and changes in muscle T 2 (R 2 = 0.71) was found. for both small and large muscles and in voxel to voxel comparisons. Despite large intersubject differences in muscle recruitment, the linear correlation between 18 F-FDG uptake and changes in muscle T 2 did not vary among subjects. This is the first assessment of skeletal muscle activation using hybrid PET/MRI and the first study to demonstrate a high correlation between 18 F-FDG uptake and changes in muscle T 2 with physical exercise. Accordingly, it seems that changes in muscle T 2 may be used as a surrogate marker for glucose uptake and lead to an improved insight into the metabolic changes that occur with muscle activation. Such knowledge may lead to improved treatment strategies in patients with neuromuscular pathologies such as stroke, spinal cord injuries and muscular dystrophies. (orig.)

  12. Expression of interleukin-15 in human skeletal muscle effect of exercise and muscle fibre type composition

    DEFF Research Database (Denmark)

    Nielsen, Anders Rinnov; Mounier, Remi; Plomgaard, Peter

    2007-01-01

    The cytokine interleukin-15 (IL-15) has been demonstrated to have anabolic effects in cell culture systems. We tested the hypothesis that IL-15 is predominantly expressed by type 2 skeletal muscle fibres, and that resistance exercise regulates IL-15 expression in muscle. Triceps brachii, vastus...... lateralis quadriceps and soleus muscle biopsies were obtained from normally physically active, healthy, young male volunteers (n = 14), because these muscles are characterized by having different fibre-type compositions. In addition, healthy, normally physically active male subjects (n = 8) not involved...

  13. 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...

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

    Science.gov (United States)

    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.

  15. Muscle ultrasound analysis : Normal values and differentiation between myopathies and neuropathies

    NARCIS (Netherlands)

    Maurits, NM; Bollen, AE; Windhausen, A; De Jager, AEJ; Van der Hoeven, JH

    In this study, 145 healthy adults (20 to 94 years old, 69 women) were examined using ultrasound (US) imaging to obtain reference values of muscle parameters that were previously not available. We measured biceps and quadriceps sizes and subcutaneous fat thickness. To quantify muscle aspect, we

  16. Absence of muscle regeneration after implantation of a collagen matrix seeded with myoblasts

    NARCIS (Netherlands)

    van Wachem, PB; Brouwer, LA; van Luyn, MJA

    Collagens are widely used as biomaterials for e.g. soft tissue reconstruction. The present study was aimed at reconstruction of abdominal wall muscle using processed dermal sheep collagen (DSC) and myoblast seeding. Myoblasts were harvested from foetal quadriceps muscle of an inbred rat strain,

  17. Exploring the Link between Serum Phosphate Levels and Low Muscle Strength, Dynapenia, and Sarcopenia.

    Science.gov (United States)

    Chen, Yuan-Yuei; Kao, Tung-Wei; Chou, Cheng-Wai; Wu, Chen-Jung; Yang, Hui-Fang; Lai, Ching-Huang; Wu, Li-Wei; Chen, Wei-Liang

    2018-02-23

    Emerging evidences addressed an association between phosphate and muscle function. Because little attention was focused on this issue, the objective of our study was to explore the relationship of phosphate with muscle strength, dynapenia, and sarcopenia. From the National Health and Nutrition Examination Survey, a total of 7421 participants aged 20 years or older were included in our study with comprehensive examinations included anthropometric parameters, strength of the quadriceps muscle, and appendicular lean masses. Within the normal range of serum phosphate, we used quartile-based analyses to determine the potential relationships of serum phosphate with dynapenia, and sarcopenia through multivariate regression models. After adjusting for the pertinent variables, an inverse association between the serum phosphate quartiles and muscle strength was observed and the linear association was stronger than other anthropometric parameters. Notably, the significant association between phosphate and muscle strength was existed in >65 years old age group, not in 20-65 years old. The higher quartiles of phosphate had higher likelihood for predicting the presence of dynapenia rather than sarcopenia in entire population. Our study highlighted that higher quartiles of phosphate had significant association with lower muscle strength and higher risks for predicting the presence of dynapenia.

  18. Maternal and paternal genomes differentially affect myofibre characteristics and muscle weights of bovine fetuses at midgestation.

    Science.gov (United States)

    Xiang, Ruidong; Ghanipoor-Samami, Mani; Johns, William H; Eindorf, Tanja; Rutley, David L; Kruk, Zbigniew A; Fitzsimmons, Carolyn J; Thomsen, Dana A; Roberts, Claire T; Burns, Brian M; Anderson, Gail I; Greenwood, Paul L; Hiendleder, Stefan

    2013-01-01

    Postnatal myofibre characteristics and muscle mass are largely determined during fetal development and may be significantly affected by epigenetic parent-of-origin effects. However, data on such effects in prenatal muscle development that could help understand unexplained variation in postnatal muscle traits are lacking. In a bovine model we studied effects of distinct maternal and paternal genomes, fetal sex, and non-genetic maternal effects on fetal myofibre characteristics and muscle mass. Data from 73 fetuses (Day153, 54% term) of four genetic groups with purebred and reciprocal cross Angus and Brahman genetics were analyzed using general linear models. Parental genomes explained the greatest proportion of variation in myofibre size of Musculus semitendinosus (80-96%) and in absolute and relative weights of M. supraspinatus, M. longissimus dorsi, M. quadriceps femoris and M. semimembranosus (82-89% and 56-93%, respectively). Paternal genome in interaction with maternal genome (Pmaternal genome alone explained most genetic variation in CSA of fast myofibres (93%, Pmaternal genome independently (M. semimembranosus, 88%, Pmaternal weight effect (5-6%, Ppaternal genome on muscle mass decreased from thoracic to pelvic limb and accounted for all (M. supraspinatus, 97%, Pinteraction between maternal and paternal genomes (Pmaternal weight (Pmaternal and paternal genomes on fetal muscle.

  19. Subcellular localization-dependent decrements in skeletal muscle glycogen and mitochondria content following short-term disuse in young and old men

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Suetta, Charlotte; Hvid, Lars G

    2010-01-01

    of disuse and aging on human skeletal muscle glycogen and mitochondria content in subsarcolemmal (SS), intermyofibrillar (IMF), and intramyofibrillar (intra) localizations. Five young (∼23 yr) and five old (∼66 yr) recreationally active men had their quadriceps muscle immobilized for 2 wk by whole leg...... unchanged. A localization-dependent decrease (P = 0.03) in mitochondria content following immobilization was found in both age groups, where SS mitochondria decreased by 33% (P = 0.02), superficial IMF mitochondria decreased by 20% (P = 0.05), and central IMF mitochondria remained unchanged. In conclusion......Previous studies have shown that skeletal muscle glycogen and mitochondria are distributed in distinct subcellular localizations, but the role and regulation of these subcellular localizations are unclear. In the present study, we used transmission electron microscopy to investigate the effect...

  20. EFFECTS OF KINESIOTAPING ALONG WITH QUADRICEPS STRENGTHENING EXERCISES ON PAIN, JOINT RANGE OF MOTION AND FUNCTIONAL ACTIVITIES OF KNEE IN SUBJECTS WITH PATELLOFEMORAL OSTEOARTHRITIS

    OpenAIRE

    M. Harshitha; K. Senthil kumar; K. Madhavi

    2014-01-01

    Background: Patello femoral Osteoarthritis is the most common degenerative disease in older age group, causing pain, physical disability, and decreased quality of life.As many treatment options available, kinesiotaping is an efficacious treatment for management of pain & disability in patellofemoral joint osteoarthritis. Previous studies have shown that kinesiotaping as well as quadriceps strengthening significantly yields functional benefits. But there is lack of evidence revealing combined ...

  1. Effects of progressive strength training on muscle mass in type 2 diabetes mellitus patients determined by computed tomography

    International Nuclear Information System (INIS)

    Cauza, E.; Strehblow, C.; Hanusch-Enserer, U.; Fasching, P.; Metz-Schimmerl, S.; Strasser, B.; Kostner, K.; Dunstan, D.; Haber, P.

    2009-01-01

    To examine the effect of a 4-month progressive strength training program on muscle and fat mass assessed by computed tomography (CT) in type 2 diabetes mellitus (T2DM) patients, and to assess the relationships of changes in muscle cross-section area (CSA) with glycaemic control. Twenty adults (mean age ± SE: 56.4 ± 0.9 a) with T2DM participated in a supervised strength training program for 4 months 3 days/week. Muscle and fat areas of the quadriceps muscle were estimated by CT volumetry before and immediately after the training. Glycaemic (HbA1c) and anthropometric (BMI, skinfolds) measurements were assessed at 0 and 4 months, respectively. After strength training, muscle strength increased significantly in all measured muscle groups. Quadriceps size (CSA of the muscle) was increased by 2.4 % (from 7.99 ± 0.3 cm 3 to 8.18 ± 0.3 cm 3 , p = 0.003) for the right extremity, 3.9 % (from 8.1 ± 0.4 cm 3 to 8.41 ± 0.5 cm 3 , p = 0.04) for the left side. Fat tissue CSA reduced from 0.66 ± 0.1 cm 3 to 0.56 ± 0.12 cm 3 for the right leg (15.3 % reduction) and from 0.58 ± 0.12 cm 3 to 0.37 ± 0.13 cm 3 for the left leg (35.8 % reduction), resulting in a mean fat CSA reduction of 24.8 %. Fat mass assessed by skin folds was significantly reduced and lean body mass was significantly increased. The change in muscle CSA was not correlated with the changes in HbA1c or muscle strength. Strength training significantly improves both muscle mass and the muscle to fat ratio in T2DM. However, changes in muscle observed with computed tomography were not related to changes observed in HbA1c with training. (author) [de

  2. Muscle antioxidant (vitamin E) and major fatty acid groups, lipid oxidation and retail colour of meat from lambs fed a roughage based diet with flaxseed or algae.

    Science.gov (United States)

    Ponnampalam, Eric N; Burnett, Viv F; Norng, Sorn; Hopkins, David L; Plozza, Tim; Jacobs, Joe L

    2016-01-01

    The effect of feeding flaxseed or algae supplements to lambs on muscle antioxidant potential (vitamin E), major fatty acid groups, lipid oxidation and retail colour was investigated. Lambs (n=120) were randomly allocated to one of 4 dietary treatments according to liveweight and fed the following diets for eight weeks: Annual ryegrass hay [60%]+subterranean clover hay [40%] pellets=Basal diet; Basal diet with flaxseed (10.7%)=Flax; Basal diet with algae (1.8%)=Algae; Basal diet with flaxseed (10.7%) and algae (1.8%)=FlaxAlgae. Flaxseed or algae supplementation significantly affected major fatty acid groups in muscle. The addition of algae (average of Algae and FlaxAlgae) resulted in lower vitamin E concentration in muscle (Palgae (average of Basal and Flax). Increasing muscle EPA+DHA by algae supplementation significantly increased lipid oxidation, but retail display colour of fresh meat was not affected. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Neglected rupture of the quadriceps tendon in a patient with chronic ...

    African Journals Online (AJOL)

    Neglected rupture of the quadriceps tendon in a patient with chronic renal failure ... in patients with predisposing diseases such as gout, rheumatoid arthritis and ... disease and received regular hemodialysis treatment for more than 5 years.

  4. Creatine Loading, Resistance Exercise Performance, and Muscle Mechanics.

    Science.gov (United States)

    Stevenson, Scott W.; Dudley, Gary A.

    2001-01-01

    Examined whether creatine (CR) monohydrate loading would alter resistance exercise performance, isometric strength, or in vivo contractile properties of the quadriceps femoris muscle compared with placebo loading in resistance-trained athletes. Overall, CR loading did not provide an ergogenic benefit for the unilateral dynamic knee extension…

  5. Minimal changes in indirect markers of muscle damage after an ...

    African Journals Online (AJOL)

    Creatine kinase (CK) activity, Visual Analogue Scale (VAS) muscle pain ratings, hip, knee and ankle joint range of motion and maximal quadriceps and hamstring isometric strength were measured 24 hours before, one hour and 24 hours after bowling and analysed using a one way ANOVA. Significance was set at p≤0.05.

  6. Surface neuromuscular electrical stimulation for quadriceps strengthening pre and post total knee replacement.

    LENUS (Irish Health Repository)

    Monaghan, Brenda

    2010-01-01

    Total knee replacement has been demonstrated to be one of the most successful procedures in the treatment of osteoarthritis. However quadriceps weakness and reductions in function are commonly reported following surgery. Recently Neuromuscular Electrical Stimulation (NMES) has been used as an adjunct to traditional strengthening programmes. This review considers the effectiveness of NMES as a means of increasing quadriceps strength in patients before and after total knee replacement.

  7. Fibrocartilage in the attachment zones of the quadriceps tendon and patellar ligament of man.

    OpenAIRE

    Evans, E J; Benjamin, M; Pemberton, D J

    1990-01-01

    Differences are reported in the quantities and distribution of uncalcified fibrocartilage at the attachment sites of the quadriceps tendon and the patellar ligament. The largest quantity of fibrocartilage was characteristic of the quadriceps tendon. A prominent wedge of fibrocartilage was seen in the proximal part of the tibial attachment of the patellar ligament, though there was no fibrocartilage in the most superficial fibres. Little fibrocartilage was seen at the patellar attachment of th...

  8. Green tea extracts ameliorate high-fat diet-induced muscle atrophy in senescence-accelerated mouse prone-8 mice.

    Science.gov (United States)

    Onishi, Shintaro; Ishino, Mayu; Kitazawa, Hidefumi; Yoto, Ai; Shimba, Yuki; Mochizuki, Yusuke; Unno, Keiko; Meguro, Shinichi; Tokimitsu, Ichiro; Miura, Shinji

    2018-01-01

    Muscle atrophy (loss of skeletal muscle mass) causes progressive deterioration of skeletal function. Recently, excessive intake of fats was suggested to induce insulin resistance, followed by muscle atrophy. Green tea extracts (GTEs), which contain polyphenols such as epigallocatechin gallate, have beneficial effects on obesity, hyperglycemia, and insulin resistance, but their effects against muscle atrophy are still unclear. Here, we found that GTEs prevented high-fat (HF) diet-induced muscle weight loss in senescence-accelerated mouse prone-8 (SAMP8), a murine model of senescence. SAMP8 mice were fed a control diet, an HF diet, or HF with 0.5% GTEs (HFGT) diet for 4 months. The HF diet induced muscle weight loss with aging (measured as quadriceps muscle weight), whereas GTEs prevented this loss. In HF diet-fed mice, blood glucose and plasma insulin concentrations increased in comparison with the control group, and these mice had insulin resistance as determined by homeostasis model assessment of insulin resistance (HOMA-IR). In these mice, serum concentrations of leukocyte cell-derived chemotaxin 2 (LECT2), which is known to induce insulin resistance in skeletal muscle, were elevated, and insulin signaling in muscle, as determined by the phosphorylation levels of Akt and p70 S6 kinases, tended to be decreased. In HFGT diet-fed mice, these signs of insulin resistance and elevation of serum LECT2 were not observed. Although our study did not directly show the effect of serum LECT2 on muscle weight, insulin resistance examined using HOMA-IR indicated an intervention effect of serum LECT2 on muscle weight, as revealed by partial correlation analysis. Accordingly, GTEs might have beneficial effects on age-related and HF diet-induced muscle weight loss, which correlates with insulin resistance and is accompanied by a change in serum LECT2.

  9. 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)

  10. Effect of growth hormone on aging connective tissue in muscle and tendon - gene expression, morphology and function following immobilization and rehabilitation

    DEFF Research Database (Denmark)

    Boesen, Anders Ploug; Dideriksen, Kasper Juel; Couppe, Christian

    2014-01-01

    assigned to daily injections of recombinant GH(rhGH, n=6) or placebo(Plc, n=6). Cross sectional area(CSA), muscle strength(MVC) and biomechanical properties of m. quadriceps and patellar tendon were determined. Muscle and tendon biopsies were analyzed for gene expressions (mRNA) of collagen(COL1A1/3A1...... pronounced when GH was injected. Furthermore, tendon stiffness increased in GH group. Muscle CSA declined after immobilization in Plc but not in GH group. Muscle CSA increased during re-training with a significant larger increase in GH group compared to Plc. Both a time and group effect was seen for IGF-1Ea....../Ec and COL1A1/3A1 mRNA expression in muscle with a difference between GH and Plc. IGF-1Ea/Ec and COL-1A1/3A1 mRNA expression increased in muscle following immobilization and re-training in subjects receiving GH, whereas an increase in IGF-1Ec mRNA expression was seen in the Plc group only after re...

  11. Ultrasound assessment of hamstring muscle size using posterior thigh muscle thickness.

    Science.gov (United States)

    Abe, Takashi; Loenneke, Jeremy P; Thiebaud, Robert S

    2016-05-01

    Several studies have investigated the relationship between ultrasound-measured muscle thickness (MT) and individual muscle cross-sectional area (CSA) and muscle volume (MV) in extremity and trunk muscles; however, the hamstring muscle has not been studied. The purpose of this study was to examine the relationship between posterior thigh MT by ultrasound and the muscle CSA and MV of the hamstring obtained by magnetic resonance imaging (MRI). Ten young women aged 20-31 had MT measured by ultrasound at three sites on the medial anterior (50% of thigh length; TL) and posterior (50% and 70% of TL) aspects of the thigh. On the same day, a series of continuous muscle CSA along the thigh was measured by MRI. In each slice, the anatomical CSA of the hamstring (biceps femoris, semitendinosus and semimembranosus) and quadriceps muscle was analysed, and the CSAs at 50% and 70% of TL and maximal CSA of the hamstring (CSAmax ) were determined. MV was calculated by multiplying CSA by slice thickness. A significant correlation was observed between posterior 50% MT and 50% hamstring CSA (r = 0·848, P = 0·002) and between posterior 70% MT and 70% hamstring CSA (r = 0·679, P = 0·031). Posterior 50% MT (r = 0·732, P = 0·016) and 50% MTxTL (r = 0·873, P = 0·001) were also correlated to hamstring MV. Anterior:posterior 50% thigh MT ratio was correlated to MV ratio of quadriceps and hamstring muscles (r = 0·803, P = 0·005). Our results suggest that posterior thigh MT reflects hamstring muscle CSA and MV. The anterior:posterior MT ratio may serve as a surrogate for MV ratio of quadriceps and hamstring. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  12. Yacht type and crew-specific differences in anthropometric, aerobic capacity, and muscle strength parameters among international Olympic class sailors.

    Science.gov (United States)

    Bojsen-Møller, Jens; Larsson, Benny; Magnusson, S Peter; Aagaard, Per

    2007-08-01

    Physical fitness and muscular strength are important performance factors for Olympic class sailors, but the physical demands vary greatly between yacht classes, and limited information is available regarding the physical demands for the different crew positions. In the present paper, strength and aerobic capacity data from elite Olympic sailors are presented and compared with previous findings. Furthermore, a system for classification of Olympic class sailors is suggested. Peak aerobic capacity (peak oxygen uptake, VO(2peak)) and maximal isometric and isokinetic muscle strength of the knee extensors and flexors were assessed, together with the hamstring/quadriceps strength ratio (H/Q ratio). Peak aerobic capacity (ml O(2) . min(-1) . kg(-2/3)) was as follows: males - static hikers (n = 5) 215, s = 7; dynamic hikers (n = 8) 252, s = 17; trapezing helmsmen (n = 6) 234, s = 15; trapezing crew (n = 10) 239, s = 16; females - dynamic hikers (n = 6) 194, s = 16; trapezing crew (n = 2) 200, s = 13. Strength data for hikers, presented as peak moments (normalized to body weight) obtained during eccentric, isometric, and concentric contraction (Nm . kg(-1)) respectively were as follows: males - quadriceps: 3.66 (s = 0.68), 3.97 (s = 0.66), 1.82 (s = 0.34); hamstrings: 1.93 (s = 0.22), 1.38 (s = 0.41), 1.05 (s = 0.21); females - quadriceps: 3.84 (s = 0.71), 3.81 (s = 0.58), 1.60 (s = 0.28); hamstrings: 1.75 (s = 0.23), 1.10 (s = 0.16), 0.84 (s = 0.13). The peak moment based H/Q ratios for slow eccentric and concentric contractions were 0.42 (s = 0.11) and 0.39 (s = 0.04) for males and 0.43 (s = 0.06) and 0.39 (s = 0.04) for females respectively. Elite Olympic class sailors demonstrated high VO(2peak) values comparable to those observed in other non-endurance sports. The strength data revealed very high quadriceps strength for hikers, which is likely a result of the high muscle forces encountered during sailing, and a low H/Q ratio. To ensure optimal knee joint stabilization

  13. Alteration in Peripheral Muscle Strength among Overweight and Obese Individuals: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Vikram Mohan

    2017-04-01

    Full Text Available Peripheral muscle dysfunction in Overweight (OW and Obesity (OB leads to fatigue and activity limitations. However, there are contradictory views regarding the exact level with regard to hand grip and quadriceps muscle strength in OW and OB. The main objective of the present systematic review was to synthesize the literature for the strength part of the hand grip and quadriceps muscle strength among OW and OB. Literature search of Scopus, EBSCO and PubMed databases from 01.01.2004 to 30.06.2016, was performed. We set our search strategy using the terms “overweight OR obesity” AND “muscle strength” AND “grip OR quadriceps”. Two reviewers administered established eligible criteria and extracted the data. Strengthening the Reporting of Observational studies in Epidemiology (STROBE was used to assess the risk of bias. Sixteen articles which were included identified Handgrip Strength (HGS, shoulder flexor, elbow flexor and knee extensor were found to be altered. There were consistent results with an increase in quadriceps muscle strength, whereas differed results were found in hand grip to increase and decrease in muscle strength in the presence of OW and OB. It is concluded that HGS appeared to be diversified with findings of increased and decrease strength, whereas regarding the quadriceps muscles, the findings were homogeneous.

  14. The Effects of Group Relaxation Training/Large Muscle Exercise, and Parental Involvement on Attention to Task, Impulsivity, and Locus of Control among Hyperactive Boys.

    Science.gov (United States)

    Porter, Sally S.; Omizo, Michael M.

    1984-01-01

    The study examined the effects of group relaxation training/large muscle exercise and parental involvement on attention to task, impulsivity, and locus of control among 34 hyperactive boys. Following treatment both experimental groups recorded significantly higher attention to task, lower impulsivity, and lower locus of control scores. (Author/CL)

  15. Deltoid contracture: a case with multiple muscle contractures.

    Science.gov (United States)

    Chen, Hsin-Chang; Huang, Tung-Fu; Chou, Po-Hsin; Chen, Tain-Hsiung

    2008-11-01

    Deltoid contracture is relatively uncommon. The literature consists primarily of case reports and few articles on large case series. The pathogenesis has been well studied. Muscle contractures can occur in the deltoid, biceps, triceps, gluteus and quadriceps muscles; however, cases of multiple muscle contractures are rare. We reported a patient with multiple contractures of the bilateral deltoid, bilateral gluteus, and bilateral quadriceps muscles, who had received repeated intramuscular injections during childhood and adulthood. The radiographic, including magnetic resonance imaging (MRI), features of the bone and joint abnormalities are presented. Some literatures reported that damage to the structures of the body due to intramuscular injection is related to the site of injection, age of the patient, and the volume, pH, chemical composition, and diffusional capacity of the injectate. Our patient had muscular contracture induced by needle injection regardless of her age, medication and injection site.

  16. Influence of step rate and quadriceps load distribution on patellofemoral cartilage contact pressures during running.

    Science.gov (United States)

    Lenhart, Rachel L; Smith, Colin R; Vignos, Michael F; Kaiser, Jarred; Heiderscheit, Bryan C; Thelen, Darryl G

    2015-08-20

    Interventions used to treat patellofemoral pain in runners are often designed to alter patellofemoral mechanics. This study used a computational model to investigate the influence of two interventions, step rate manipulation and quadriceps strengthening, on patellofemoral contact pressures during running. Running mechanics were analyzed using a lower extremity musculoskeletal model that included a knee with six degree-of-freedom tibiofemoral and patellofemoral joints. An elastic foundation model was used to compute articular contact pressures. The lower extremity model was scaled to anthropometric dimensions of 22 healthy adults, who ran on an instrumented treadmill at 90%, 100% and 110% of their preferred step rate. Numerical optimization was then used to predict the muscle forces, secondary tibiofemoral kinematics and all patellofemoral kinematics that would generate the measured primary hip, knee and ankle joint accelerations. Mean and peak patella contact pressures reached 5.0 and 9.7MPa during the midstance phase of running. Increasing step rate by 10% significantly reduced mean contact pressures by 10.4% and contact area by 7.4%, but had small effects on lateral patellar translation and tilt. Enhancing vastus medialis strength did not substantially affect pressure magnitudes or lateral patellar translation, but did shift contact pressure medially toward the patellar median ridge. Thus, the model suggests that step rate tends to primarily modulate the magnitude of contact pressure and contact area, while vastus medialis strengthening has the potential to alter mediolateral pressure locations. These results are relevant to consider in the design of interventions used to prevent or treat patellofemoral pain in runners. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Computed tomographic findings of leg muscles in the hemiplegics due to cerebrovascular accidents

    International Nuclear Information System (INIS)

    Odajima, Natsu; Ishiai, Sumio; Kotera, Minoru; Furukawa, Tetsuo; Tsukagoshi, Hiroshi.

    1986-01-01

    The computed tomography (CT) scan was performed in 52 hemiplegics due to cerebrovascular accidents and 12 normal controls on the mid-portion of the thigh and the largest-diameter section of the calf. Muscle size and average CT density of the muscle were measured. The salient feature was hypertrophic gracilis muscle of the hemiplegic side. Other muscles were more atrophied with lower CT density compared with those of the contralateral side. The size of the quadriceps muscle was especially small. The ratio of the quadriceps to all the thigh muscles in cross section was significantly smaller in affected side of hemiplegics than that of normal controls. This was observed even in normal side of the hemiplegics but the ratios of adductor and flexor muscles of the thigh showed no difference. Hypertrophy of gracilis muscle with high CT density was observed only on hemiplegic side. Muscle atrophies were marked in non-ambulatory patients. The ratios of quadriceps and saltorius muscles of thigh in non-ambulatory patients were significantly smaller than those of ambulatory patients. It could not be detected that there is relationship of the sevirity of the muscle atrophy and parietal lobe dysfunction. This atrophy considered to be the result of disuse of the paralyzed leg and pyramidal tract dysfunction. (author)

  18. Muscle area of knee O.A

    International Nuclear Information System (INIS)

    Suzuki, Nobuharu; Onozawa, Toshihiro; Shibata, Minoru; Yamasita, Izumi; Kitsunai, Isamu; Asano, Akira

    1983-01-01

    The cross sectional area of the thigh muscles were studied by means of C.T. scan. Twelve normal knees, twelve primary knee O.A. knees, and six R.A. knees were examined. The cross sectional area of the Quadriceps femoris decreased significantly in the patient of the knee O.A. although flexors did not decrease. We discussed the etiology of the knee O.A. from this result. (author)

  19. Rapid Hamstrings/Quadriceps strength in ACL-reconstructed elite alpine ski racers

    DEFF Research Database (Denmark)

    Jordan, Matthew J; Aagaard, Per; Herzog, Walter

    2015-01-01

    PURPOSE: Due to the importance of hamstrings (HAM) and quadriceps (QUAD) strength for anterior cruciate ligament (ACL) injury prevention, and the high incidence of ACL injury in ski racing, HAM and QUAD maximal and explosive strength was assessed in ski racers with and without ACL reconstruction...... (ACL-R). METHODS: Uninjured (n=13 males; n=8 females) and ACL-R (n=3 males; n=5 females; 25.0±11.3 months post-op) elite ski racers performed maximal voluntary isometric HAM and QUAD contractions to obtain maximal torque (MVC) and rate of torque development (RTD) at 0-50, 0-100, 0-150 and 0-200 ms. MVC...... and RTD (per kg body mass) were calculated for the uninjured group to compare between sexes, and to compare the control group with the ACL-R limb and unaffected limb of the ACL-R skiers. H/Q MVC and RTD strength ratios were also compared RESULTS: The ACL-R limb demonstrated significant HAM and QUAD...

  20. Roller-massager application to the quadriceps and knee-joint range of motion and neuromuscular efficiency during a lunge.

    Science.gov (United States)

    Bradbury-Squires, David J; Noftall, Jennifer C; Sullivan, Kathleen M; Behm, David G; Power, Kevin E; Button, Duane C

    2015-02-01

    Roller massagers are used as a recovery and rehabilitative tool to initiate muscle relaxation and improve range of motion (ROM) and muscular performance. However, research demonstrating such effects is lacking. To determine the effects of applying a roller massager for 20 and 60 seconds on knee-joint ROM and dynamic muscular performance. Randomized controlled clinical trial. University laboratory. Ten recreationally active men (age = 26.6 ± 5.2 years, height = 175.3 ± 4.3 cm, mass = 84.4 ± 8.8 kg). Participants performed 3 randomized experimental conditions separated by 24 to 48 hours. In condition 1 (5 repetitions of 20 seconds) and condition 2 (5 repetitions of 60 seconds), they applied a roller massager to the quadriceps muscles. Condition 3 served as a control condition in which participants sat quietly. Visual analog pain scale, electromyography (EMG) of the vastus lateralis (VL) and biceps femoris during roller massage and lunge, and knee-joint ROM. We found no differences in pain between the 20-second and 60-second roller-massager conditions. During 60 seconds of roller massage, pain was 13.5% (5.7 ± 0.70) and 20.6% (6.2 ± 0.70) greater at 40 seconds and 60 seconds, respectively, than at 20 seconds (P joint ROM was 10% and 16% greater in the 20-second and 60-second roller-massager conditions, respectively, than the control condition (P joint ROM and neuromuscular efficiency during a lunge.

  1. Anticonvulsant Effects of Fractions Isolated from Dinoponera quadriceps (Kempt Ant Venom (Formicidae: Ponerinae

    Directory of Open Access Journals (Sweden)

    Diana Aline Morais Ferreira Nôga

    2016-12-01

    Full Text Available Natural products, sources of new pharmacological substances, have large chemical diversity and architectural complexity. In this context, some toxins obtained from invertebrate venoms have anticonvulsant effects. Epilepsy is a neurological disorder that affects about 65 million people worldwide, and approximately 30% of cases are resistant to pharmacological treatment. Previous studies from our group show that the denatured venom of the ant Dinoponera quadriceps (Kempt protects mice against bicuculline (BIC-induced seizures and death. The aim of this study was to investigate the anticonvulsant activity of compounds isolated from D. quadriceps venom against seizures induced by BIC in mice. Crude venom was fractionated by high-performance liquid chromatography (HPLC resulting in six fractions referred to as DqTx1–DqTx6. A liquid chromatography-mass spectrometry (LC/MS analysis revealed a major 431 Da compound in fractions DqTx1 and DqTx2. Fractions DqTx3 and DqTx4 showed a compound of 2451 Da and DqTx5 revealed a 2436 Da compound. Furthermore, the DqTx6 fraction exhibited a major component with a molecular weight of 13,196 Da. Each fraction (1 mg/mL was microinjected into the lateral ventricle of mice, and the animals were observed in an open field. We did not observe behavioral alterations when the fractions were given alone. Conversely, when the fractions were microinjected 20 min prior to the administration of BIC (21.6 nM, DqTx1, DqTx4, and DqTx6 fractions increased the latency for onset of tonic-clonic seizures. Moreover, all fractions, except DqTx5, increased latency to death. The more relevant result was obtained with the DqTx6 fraction, which protected 62.5% of the animals against tonic-clonic seizures. Furthermore, this fraction protected 100% of the animals from seizure episodes followed by death. Taken together, these findings indicate that compounds from ant venom might be a potential source of new anticonvulsants molecules.

  2. Comparison of Muscle Recovery Following Bi-cruciate Substituting versus Posterior Stabilized Total Knee Arthroplasty in the Asian Population.

    Science.gov (United States)

    Takubo, Akihito; Ryu, Keinosuke; Iriuchishima, Takanori; Tokuhashi, Yasuaki

    2017-09-01

    The purpose of this study was to compare muscle recovery in the lower extremities following the newly developed bi-cruciate substituting (BCS) to posterior stabilized (PS) total knee arthroplasty (TKA) in the Asian population. Forty-one knees in 41 patients undergoing BCS-TKA (41 female, average age: 71 ± 8.8) and 34 knees in 34 patients undergoing PS-TKA (33 female, average age: 73 ± 7.2) were included in this study. The maximum isometric power of the quadriceps and hamstring muscles was measured preoperatively, and at 1, 3, 6, and 12 months after surgery using a handheld dynamometer. Postoperative muscle recovery was calculated regarding preoperative muscle power as 100%. Pre- and postoperative range of knee motion, femorotibial angle, and clinical scores (Knee Society score and function score) were also compared. No significant difference in sex, age, preoperative quadriceps, or preoperative hamstring power was observed between the BCS and PS-TKA groups. When regarding the preoperative muscle power as 100%, quadriceps power at 1, 3, 6, and 12 months following BCS-TKA was 61.2 ± 22%, 86.3 ± 28.3%, 97 ± 27.4%, and 112.4 ± 30.8%, respectively. Quadriceps power at 1, 3, 6, and 12 months following PS-TKA was 72.4 ± 20.8%, 84 ± 16.9%, 95 ± 20.7%, and 110.8 ± 27%, respectively. Hamstring power at 1, 3, 6, and 12 months following BCS-TKA was 96.3 ± 30%, 111.4 ± 35%, 120 ± 37%, and 125 ± 31%, respectively. Hamstring power at 1, 3, 6, and 12 months following PS-TKA was 95 ± 25%, 112.4 ± 27%, 117 ± 38.5%, and 120.4 ± 18.5%, respectively. No significant difference in muscle power recovery was observed at 3 ( p  = 0.995), 6 ( p  = 0.944), and 12 ( p  = 0.917) months after surgery between the two groups. No significant difference of the clinical score was observed between the groups (Knee Society score: p  = 0.479, function score: p  = 0.342). No significant

  3. Pharmacokinetics of a new subcutaneous diclofenac formulation administered to three body sites: quadriceps, gluteus, and abdomen.

    Science.gov (United States)

    Salomone, Salvatore; Piazza, Cateno; Vitale, Daniela Cristina; Cardì, Francesco; Gugliotta, Barbara; Drago, Filippo

    2014-02-01

    To assess the relative bioavailability of a new subcutaneous (SC) diclofenac hydroxypropyl b-cyclodextrin (HPbCD) formulation administered to three body sites: quadriceps, gluteus, and abdomen. This was a pilot, single-dose, randomized, three-way crossover relative bioavailability study. A total of 12 healthy subjects received a single SC injection of diclofenac HPbCD 50 mg/1 mL in the quadriceps, gluteus, or abdomen. The AUC was comparable after SC diclofenac HPbCD in the quadriceps, gluteus, and abdomen. The Cmax was comparable after SC administration in the quadriceps or abdomen, and ~ 17% higher in the gluteus. The absorption was rapid (30 minutes) after administration of the treatment at any site. The treatment was well tolerated. The relative bioavailability of SC diclofenac HPbCD was comparable when administered to the quadriceps, gluteus, and abdomen. The new diclofenac formulation can therefore be administered subcutaneously to any of these sites without clinically significant differences. A further adequately powered study would be necessary to reveal any differences among injection sites in terms of peak plasma concentration.

  4. Quadriceps tendon autograft for arthroscopic knee ligament reconstruction: use it now, use it often.

    Science.gov (United States)

    Sheean, Andrew J; Musahl, Volker; Slone, Harris S; Xerogeanes, John W; Milinkovic, Danko; Fink, Christian; Hoser, Christian

    2018-04-28

    Traditional bone-patellar tendon-bone and hamstring tendon ACL grafts are not without limitations. A growing body of anatomic, biomechanical and clinical data has demonstrated the utility of quadriceps tendon autograft in arthroscopic knee ligament reconstruction. The quadriceps tendon autograft provides a robust volume of tissue that can be reliably harvested, mitigating the likelihood of variably sized grafts and obviating the necessity of allograft augmentation. Modern, minimally invasive harvest techniques offer the advantages of low rates of donor site morbidity and residual extensor mechanism strength deficits. New data suggest that quadriceps tendon autograft may possess superior biomechanical characteristics when compared with bone-patella tendon-bone (BPTB) autograft. However, there have been very few direct, prospective comparisons between the clinical outcomes associated with quadriceps tendon autograft and other autograft options (eg, hamstring tendon and bone-patellar tendon-bone). Nevertheless, quadriceps tendon autograft should be one of the primary options in any knee surgeon's armamentarium. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Joint awareness after total knee arthroplasty is affected by pain and quadriceps strength.

    Science.gov (United States)

    Hiyama, Y; Wada, O; Nakakita, S; Mizuno, K

    2016-06-01

    There is a growing interest in the use of patient-reported outcomes to provide a more patient-centered view on treatment. Forgetting the artificial joint can be regarded as the goal in joint arthroplasty. The goals of the study were to describe changes in joint awareness in the artificial joint after total knee arthroplasty (TKA), and to determine which factors among pain, knee range of motion (ROM), quadriceps strength, and functional ability affect joint awareness after TKA. Patients undergoing TKA demonstrate changes in joint awareness and joint awareness is associated with pain, knee ROM, quadriceps strength, and functional ability. This prospective cohort study comprised 63 individuals undergoing TKA, evaluated at 1, 6, and 12 months postoperatively. Outcomes included joint awareness assessed using the Forgotten Joint Score (FJS), pain score, knee ROM, quadriceps strength, and functional ability. Fifty-eight individuals completed all postoperative assessments. All measures except for knee extension ROM improved from 1 to 6 months. However, there were no differences in any measures from 6 to 12 months. FJS was affected most greatly by pain at 1 month and by quadriceps strength at 6 and 12 months. Patients following TKA demonstrate improvements in joint awareness and function within 6 months after surgery, but reach a plateau from 6 to 12 months. Quadriceps strength could contribute to this plateau of joint awareness. Prospective cohort study, IV. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. Torque and mechanomyogram relationships during electrically-evoked isometric quadriceps contractions in persons with spinal cord injury.

    Science.gov (United States)

    Ibitoye, Morufu Olusola; Hamzaid, Nur Azah; Hasnan, Nazirah; Abdul Wahab, Ahmad Khairi; Islam, Md Anamul; Kean, Victor S P; Davis, Glen M

    2016-08-01

    The interaction between muscle contractions and joint loading produces torques necessary for movements during activities of daily living. However, during neuromuscular electrical stimulation (NMES)-evoked contractions in persons with spinal cord injury (SCI), a simple and reliable proxy of torque at the muscle level has been minimally investigated. Thus, the purpose of this study was to investigate the relationships between muscle mechanomyographic (MMG) characteristics and NMES-evoked isometric quadriceps torques in persons with motor complete SCI. Six SCI participants with lesion levels below C4 [(mean (SD) age, 39.2 (7.9) year; stature, 1.71 (0.05) m; and body mass, 69.3 (12.9) kg)] performed randomly ordered NMES-evoked isometric leg muscle contractions at 30°, 60° and 90° knee flexion angles on an isokinetic dynamometer. MMG signals were detected by an accelerometer-based vibromyographic sensor placed over the belly of rectus femoris muscle. The relationship between MMG root mean square (MMG-RMS) and NMES-evoked torque revealed a very high association (R(2)=0.91 at 30°; R(2)=0.98 at 60°; and R(2)=0.97 at 90° knee angles; Ptorque, between 0.65 and 0.79 for MMG-RMS, and from 0.67 to 0.73 for MMG-PTP. Their standard error of measurements (SEM) ranged between 10.1% and 31.6% (of mean values) for torque, MMG-RMS and MMG-PTP. The MMG peak frequency (MMG-PF) of 30Hz approximated the stimulation frequency, indicating NMES-evoked motor unit firing rate. The results demonstrated knee angle differences in the MMG-RMS versus NMES-isometric torque relationship, but a similar torque related pattern for MMG-PF. These findings suggested that MMG was well associated with torque production, reliably tracking the motor unit recruitment pattern during NMES-evoked muscle contractions. The strong positive relationship between MMG signal and NMES-evoked torque production suggested that the MMG might be deployed as a direct proxy for muscle torque or fatigue measurement during

  7. Rapid changes in the size of different functional organ and muscle groups during refueling in a long-distance migrating shorebird

    NARCIS (Netherlands)

    Piersma, T; Gudmundsson, GA; Lilliendahl, K; Gudmundsson, Gudmundur A.

    1999-01-01

    The adaptive value of size changes in different organ and muscle groups was studied in red knots (Calidris canutus islandica) in relation to their migration. Birds were sampled on five occasions: at arrival in Iceland in May 1994, two times during subsequent refueling, at departure toward, and on

  8. Definitions, End Points, and Clinical Trial Designs for Non-Muscle-Invasive Bladder Cancer: Recommendations From the International Bladder Cancer Group

    NARCIS (Netherlands)

    Kamat, A.M.; Sylvester, R.J.; Bohle, A.; Palou, J.; Lamm, D.L.; Brausi, M.; Soloway, M.; Persad, R.; Buckley, R.; Colombel, M.; Witjes, J.A.

    2016-01-01

    PURPOSE: To provide recommendations on appropriate clinical trial designs in non-muscle-invasive bladder cancer (NMIBC) based on current literature and expert consensus of the International Bladder Cancer Group. METHODS: We reviewed published trials, guidelines, meta-analyses, and reviews and

  9. Assessment of muscle function using hybrid PET/MRI: comparison of {sup 18}F-FDG PET and T2-weighted MRI for quantifying muscle activation in human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Haddock, Bryan; Holm, Soeren; Poulsen, Jakup M.; Enevoldsen, Lotte H.; Larsson, Henrik B.W.; Kjaer, Andreas; Suetta, Charlotte [Rigshospitalet Glostrup, Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Glostrup (Denmark)

    2017-04-15

    The aim of this study was to determine the relationship between relative glucose uptake and MRI T{sub 2} changes in skeletal muscles following resistance exercise using simultaneous PET/MRI scans. Ten young healthy recreationally active men (age 21 - 28 years) were injected with {sup 18}F-FDG while activating the quadriceps of one leg with repeated knee extension exercises followed by hand-grip exercises for one arm. Immediately following the exercises, the subjects were scanned simultaneously with {sup 18}F-FDG PET/MRI and muscle groups were evaluated for increases in {sup 18}F-FDG uptake and MRI T{sub 2} values. A significant linear correlation between {sup 18}F-FDG uptake and changes in muscle T{sub 2} (R {sup 2} = 0.71) was found. for both small and large muscles and in voxel to voxel comparisons. Despite large intersubject differences in muscle recruitment, the linear correlation between {sup 18}F-FDG uptake and changes in muscle T{sub 2} did not vary among subjects. This is the first assessment of skeletal muscle activation using hybrid PET/MRI and the first study to demonstrate a high correlation between {sup 18}F-FDG uptake and changes in muscle T{sub 2} with physical exercise. Accordingly, it seems that changes in muscle T{sub 2} may be used as a surrogate marker for glucose uptake and lead to an improved insight into the metabolic changes that occur with muscle activation. Such knowledge may lead to improved treatment strategies in patients with neuromuscular pathologies such as stroke, spinal cord injuries and muscular dystrophies. (orig.)

  10. Quadriceps exercise intolerance in patients with chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Gifford, Jayson R; Trinity, Joel D; Layec, Gwenael

    2015-01-01

    This study sought to determine if qualitative alterations in skeletal muscle mitochondrial respiration, associated with decreased mitochondrial efficiency, contribute to exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). Using permeabilized muscle fibers from.......05). Overall, this study indicates that COPD is associated with qualitative alterations in skeletal muscle mitochondria that affect the contribution of CI and CII-driven respiration, which potentially contributes to the exercise intolerance associated with this disease....... the vastus lateralis of 13 patients with COPD and 12 healthy controls, complex I (CI) and complex II (CII)-driven State 3 mitochondrial respiration were measured separately (State 3:CI and State 3:CII) and in combination (State 3:CI+CII). State 2 respiration was also measured. Exercise tolerance was assessed...

  11. Skeletal muscle properties and fatigue resistance in relation to smoking history

    OpenAIRE

    W?st, Rob C. I.; Morse, Christopher I.; de Haan, Arnold; Rittweger, J?rn; Jones, David A.; Degens, Hans

    2008-01-01

    Although smoking-related diseases, such as chronic obstructive pulmonary disease (COPD), are often accompanied by increased peripheral muscle fatigability, the extent to which this is a feature of the disease or a direct effect of smoking per se is not known. Skeletal muscle function was investigated in terms of maximal voluntary isometric torque, activation, contractile properties and fatigability, using electrically evoked contractions of the quadriceps muscle of 40 smokers [19 men and 21 w...

  12. 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.

  13. The effects of Kinesiotaping on quadriceps muscle performance at different velocities : A randomized controlled trial

    NARCIS (Netherlands)

    Guedes, Rogerio; Bottaro, Martim; Magalhães, Igor; Trindade, Matheus; Brown, Lee E.; Carmo, Jake Do; Carregaro, Rodrigo Luiz

    2016-01-01

    BACKGROUND: Kinesiotaping (KT) has become popular among athletic trainers and physical therapists. Most of KT studies investigated only the immediate responses, and only a few evaluated the long-term effects. OBJECTIVES: To evaluate the effects of 48 hours of KT on knee extensor performance of

  14. Rodent Research-1 (RR1) NASA Validation Flight: Mouse quadriceps muscle transcriptomic proteomic and epigenomic data

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA s Rodent Research (RR) project is playing a critical role in advancing biomedical research on the physiological effects of space environments. Due to the...

  15. Muscle activity and inactivity periods during normal daily life.

    Directory of Open Access Journals (Sweden)

    Olli Tikkanen

    Full Text Available Recent findings suggest that not only the lack of physical activity, but also prolonged times of sedentary behaviour where major locomotor muscles are inactive, significantly increase the risk of chronic diseases. The purpose of this study was to provide details of quadriceps and hamstring muscle inactivity and activity during normal daily life of ordinary people. Eighty-four volunteers (44 females, 40 males, 44.1±17.3 years, 172.3±6.1 cm, 70.1±10.2 kg were measured during normal daily life using shorts measuring muscle electromyographic (EMG activity (recording time 11.3±2.0 hours. EMG was normalized to isometric MVC (EMG(MVC during knee flexion and extension, and inactivity threshold of each muscle group was defined as 90% of EMG activity during standing (2.5±1.7% of EMG(MVC. During normal daily life the average EMG amplitude was 4.0±2.6% and average activity burst amplitude was 5.8±3.4% of EMG(MVC (mean duration of 1.4±1.4 s which is below the EMG level required for walking (5 km/h corresponding to EMG level of about 10% of EMG(MVC. Using the proposed individual inactivity threshold, thigh muscles were inactive 67.5±11.9% of the total recording time and the longest inactivity periods lasted for 13.9±7.3 min (2.5-38.3 min. Women had more activity bursts and spent more time at intensities above 40% EMG(MVC than men (p<0.05. In conclusion, during normal daily life the locomotor muscles are inactive about 7.5 hours, and only a small fraction of muscle's maximal voluntary activation capacity is used averaging only 4% of the maximal recruitment of the thigh muscles. Some daily non-exercise activities such as stair climbing produce much higher muscle activity levels than brisk walking, and replacing sitting by standing can considerably increase cumulative daily muscle activity.

  16. Determination of muscle fatigue index for strength training in patients with Duchenne dystrophy

    Directory of Open Access Journals (Sweden)

    Adriano Rodrigues Oliveira

    Full Text Available INTRODUCTION: Muscle weakness is the most prominent impairment in Duchenne muscular dystrophy (DMD and often involves the loss of functional ability as well as other limitations related to daily living. Thus, there is a need to maintain muscle strength in large muscle groups, such as the femoral quadriceps, which is responsible for diverse functional abilities. However, the load and duration of training for such rehabilitation has proven to be a great unknown, mainly due to the undesired appearance of muscle fatigue, which is a severe factor for the injury of muscle fibers. OBJECTIVES: The aim of the present study was to determine a fatigue index by means of surface electromyography (EMG for the parameterization of muscle strengthening physiotherapy training. METHODS: A cross-sectional study (case series was carried out involving four patients with DMD. Three pairs of surface electrodes were placed on the motor point of the Rectus femoris, Vastus lateralis and Vastus medialis of the dominant limb, maintaining the knee at 60º of flexion. The participants were instructed to perform the extension movement of this joint at four strength levels (100%, 80%, 60% and 40% of maximal voluntary isometric contraction. RESULTS: The slope of the linear regression line was used for the determination of the fatigue index, performed by Pearson's test on the median frequency of each strength level. CONCLUSION: Electromyographic measurements of the strength index for muscle training proved to be a simple accessible assessment method, as well as an extremely valuable tool, allowing the design of a muscle strength training program with an individualized load threshold.

  17. Position of the quadriceps actuator influences knee loads during simulated squat testing.

    Science.gov (United States)

    Hast, Michael W; Piazza, Stephen J

    2018-05-17

    The "Oxford Rig" cadaveric simulator permits researchers and clinicians to study knee mechanics during a simulated squatting motion. The motion of the lower limb in the Oxford Rig is typically controlled by a single actuator that applies tension to the quadriceps tendon. The location of the quadriceps actuator, however, has differed across published descriptions of the Oxford Rig. Actuators have been placed on the femur and pelvis, and on "grounded" locations external to the specimen, but the consequences of this placement for knee kinematics and kinetics are unknown. The purpose of this study was to examine these effects using a validated computational musculoskeletal model. When the actuator was placed on the femur or pelvis, forces realistically increased with knee flexion, with quadriceps and patellofemoral contact forces exceeding 2000 N and 3000 N, respectively, at 100° flexion. When the actuator was grounded, however, forces were substantially reduced and did not monotonically increase with flexion. Articular joint contact forces were not strongly influenced by changing the location of the actuator from the femur to the pelvis, with small RMS differences in quadriceps forces (48.2 N), patellofemoral forces (83.6 N), and tibiofemoral forces (58.9 N) between these conditions. The location of the actuator did not substantially affect knee kinematics. The results of this study suggest that the quadriceps actuator of the Oxford Rig should be attached to either the femur or the pelvis when the goal is to make realistic estimates of quadriceps forces and articular contact forces within the knee joint. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Tibiofemoral loss of contact area but no changes in peak pressures after meniscectomy in a Lapine in vivo quadriceps force transfer model.

    Science.gov (United States)

    Leumann, Andre; Fortuna, Rafael; Leonard, Tim; Valderrabano, Victor; Herzog, Walter

    2015-01-01

    The menisci are thought to modulate load transfer and to absorb shocks in the knee joint. No study has experimentally measured the meniscal functions in the intact, in vivo joint loaded by physiologically relevant muscular contractions. Right knee joints of seven New Zealand white rabbits were loaded using isometric contractions of the quadriceps femoris muscles controlled by femoral nerve stimulation. Isometric knee extensor torques at the maximal and two submaximal force levels were performed at knee angles of 70°, 90°, 110°, and 130°. Patellofemoral and tibiofemoral contact areas and pressure distributions were measured using Fuji Presensor film inserted above and below the menisci and also with the menisci removed. Meniscectomy was associated with a decrease in tibiofemoral contact area ranging from 30 to 70% and a corresponding increase in average contact pressures. Contact areas measured below the menisci were consistently larger than those measured on top of the menisci. Contact areas in the patellofemoral joint (PFJ), and peak pressures in tibiofemoral and PFJs, were not affected by meniscectomy. Contact areas and peak pressures in all joints depended crucially on knee joint angle and quadriceps force: The more flexed the knee joint was, the larger were the contact areas and the higher were the peak pressures. In agreement with the literature, removal of the menisci was associated with significant decreases in tibiofemoral contact area and corresponding increases in average contact pressures, but surprisingly, peak pressures remained unaffected, indicating that the function of the menisci is to distribute loads across a greater contact area.

  19. Variability of Measurement of Patellofemoral Indices with Knee Flexion and Quadriceps Contraction: An MRI-Based Anatomical Study

    Science.gov (United States)

    Laugharne, Edward; Bali, Navi; Purushothamdas, Sanjay; Almallah, Faris; Kundra, Rik

    2016-01-01

    Purpose The purpose of this study was to investigate the impact of varying knee flexion and quadriceps activity on patellofemoral indices measured on magnetic resonance imaging (MRI). Materials and Methods MRI of the knee was performed in 20 patients for indications other than patellar or patellofemoral pathology. Axial and sagittal sequences were performed in full extension of the knee with the quadriceps relaxed, full extension of the knee with the quadriceps contracted, 30° flexion of the knee with the quadriceps relaxed, and 30° flexion with the quadriceps contracted. Bisect offset, patella tilt angle, Insall-Salvati ratio and Caton-Deschamps index were measured. Results With the knee flexed to 30° and quadriceps relaxed, the mean values of patellar tilt angle, bisect offset, Insall-Salvati ratio and Caton-Deschamps index were all within normal limits. With the knee extended and quadriceps contracted, the mean patellar tilt angle (normal value, patellofemoral indices. MRI taken with the knee in 30° of flexion allows more reliable assessment of the patellofemoral joint and minimises the confounding effect of quadriceps contraction. PMID:27894177

  20. Reducing body fat with altitude hypoxia training in swimmers: role of blood perfusion to skeletal muscles.

    Science.gov (United States)

    Chia, Michael; Liao, Chin-An; Huang, Chih-Yang; Lee, Wen-Chih; Hou, Chien-Wen; Yu, Szu-Hsien; Harris, M Brennan; Hsu, Tung-Shiung; Lee, Shin-Da; Kuo, Chia-Hua

    2013-02-28

    Swimmers tend to have greater body fat than athletes from other sports. The purpose of the study was to examine changes in body composition after altitude hypoxia exposure and the role of blood distribution to the skeletal muscle in swimmers. With a constant training volume of 12.3 km/day, young male swimmers (N = 10, 14.8 ± 0.5 years) moved from sea-level to a higher altitude of 2,300 meters. Body composition was measured before and after translocation to altitude using dual-energy X-ray absorptiometry (DXA) along with 8 control male subjects who resided at sea level for the same period of time. To determine the effects of hypoxia on muscle blood perfusion, total hemoglobin concentration (THC) was traced by near-infrared spectroscopy (NIRS) in the triceps and quadriceps muscles under glucose-ingested and insulin-secreted conditions during hypoxia exposure (16% O2) after training. While no change in body composition was found in the control group, subjects who trained at altitude had unequivocally decreased fat mass (-1.7 ± 0.3 kg, -11.4%) with increased lean mass (+0.8 ± 0.2 kg, +1.5%). Arterial oxygen saturation significantly decreased with increased plasma lactate during hypoxia recovery mimicking 2,300 meters at altitude (~93% versus ~97%). Intriguingly, hypoxia resulted in elevated muscle THC, and sympathetic nervous activities occurred in parallel with greater-percent oxygen saturation in both muscle groups. In conclusion, the present study provides evidence that increased blood distribution to the skeletal muscle under postprandial condition may contribute to the reciprocally increased muscle mass and decreased body mass after a 3-week altitude exposure in swimmers.

  1. Skeletal muscle weakness in osteogenesis imperfecta mice.

    Science.gov (United States)

    Gentry, Bettina A; Ferreira, J Andries; McCambridge, Amanda J; Brown, Marybeth; Phillips, Charlotte L

    2010-09-01

    Exercise intolerance, muscle fatigue and weakness are often-reported, little-investigated concerns of patients with osteogenesis imperfecta (OI). OI is a heritable connective tissue disorder hallmarked by bone fragility resulting primarily from dominant mutations in the proα1(I) or proα2(I) collagen genes and the recently discovered recessive mutations in post-translational modifying proteins of type I collagen. In this study we examined the soleus (S), plantaris (P), gastrocnemius (G), tibialis anterior (TA) and quadriceps (Q) muscles of mice expressing mild (+/oim) and moderately severe (oim/oim) OI for evidence of inherent muscle pathology. In particular, muscle weight, fiber cross-sectional area (CSA), fiber type, fiber histomorphology, fibrillar collagen content, absolute, relative and specific peak tetanic force (P(o), P(o)/mg and P(o)/CSA respectively) of individual muscles were evaluated. Oim/oim mouse muscles were generally smaller, contained less fibrillar collagen, had decreased P(o) and an inability to sustain P(o) for the 300-ms testing duration for specific muscles; +/oim mice had a similar but milder skeletal muscle phenotype. +/oim mice had mild weakness of specific muscles but were less affected than their oim/oim counterparts which demonstrated readily apparent skeletal muscle pathology. Therefore muscle weakness in oim mice reflects inherent skeletal muscle pathology. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. [Variation of muscle mass and weight in critical patient].

    Science.gov (United States)

    Valls-Matarín, J; del Cotillo-Fuente, M; Grané-Mascarell, N; Quintana, S

    2015-01-01

    Quantify the muscle mass and body weight variation in critically ill patients and to identify associated factors. A descriptive follow-up study. Data for demographic variables, body weight, fluid balance, daily kilocalories, the amount of sedation and muscle relaxants received and motor physiotherapy applied were collected. Three consecutive measurements were performed in the brachial biceps and quadriceps rectus by using ultrasound, upon admission and every 5 days until discharge. 68 patients were included. Average age was of 73.5 [57-78,5] years. The median length of stay was 9.5 [5.5 -15] days. The median 16 (SD=5.7) daily kilocalories per kg/weight, 91.2% received sedation, 44.1% received muscle relaxants and 20% received physiotherapy. The patients presented a muscle wasting of 4.9 (SD=3.9)mm, p <.001 in the brachial biceps and 5.6 (SD=4.8)mm, p <.001 in the quadriceps rectus. Regression analysis selected the length of stay and the muscle relaxants are the most influential variables in the brachial biceps muscle wasting (R2=0.4), and length of stay as the most influential in the quadriceps rectus muscle wasting (R2=0.3). Patient's mean body weight on admission was of 81.1 (SD=15)kg and 81.2 (SD=14.2)kg on discharge, p=.95. The critically ill patient presents a significant muscle waste related with the length of stay and the treatment received with muscle relaxants. Patients are being discharged with a similar body weight to which they were admitted but with a significant reduction of muscle mass. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  3. Reconstruction of medial patellofemoral ligament using quadriceps tendon combined with reconstruction of medial patellotibial ligament using patellar tendon: initial experience

    Directory of Open Access Journals (Sweden)

    Betina Bremer Hinckel

    2016-02-01

    Full Text Available ABSTRACT OBJECTIVE: To describe a surgical technique for anatomical reconstruction of the medial patellofemoral ligament using the quadriceps tendon, combined with reconstruction of the medial patellotibial ligament using the patellar tendon; and to present the initial results from a case series. METHOD: The proposed technique was used on a series of cases of patients with diagnoses of patellofemoral instability and indications for surgical treatment, who were attended by the Knee Group of HC-IOT, University of São Paulo. The following were evaluated before and after the operation: range of motion (ROM, apprehension test, lateral translation test, patellar inclination test, inverted J sign, subluxation upon extension, pain from compression of the patella and pain from contraction of the quadriceps. After the operation, the patients were asked whether any new episode of dislocation had occurred, what their degree of satisfaction with the surgery was (on a scale from 0 to 10 and whether they would be prepared to go through this operation again. RESULTS: Seven knees were operated, in seven patients, with a mean follow-up of 5.46 months (±2.07. Four patients who presented apprehension before the operation did not show this after the operation. The lateral translation test became normal for all the patients, while the patellar inclination test remained positive for two patients. The patients with an inverted J sign continued to be positive for this sign. Five patients were positive for subluxation upon extension before the operation, but all patients were negative for this after the operation. None of the patients presented any new episode of dislocation of the patella. All of them stated that they were satisfied: five gave a satisfaction score of 9 and two, a score of 10. All of them said that they would undergo the operation again. Only one patient presented a postoperative complication: dehiscence of the wound. CONCLUSION: Reconstruction of the

  4. Acute and timing effects of beta-hydroxy-beta-methylbutyrate (HMB) on indirect markers of skeletal muscle damage.

    Science.gov (United States)

    Wilson, Jacob M; Kim, Jeong-Su; Lee, Sang-Rok; Rathmacher, John A; Dalmau, Brett; Kingsley, J Derek; Koch, Heather; Manninen, Anssi H; Saadat, Raz; Panton, Lynn B

    2009-02-04

    While chronic β-Hydroxy β-Methylbutyrate (HMB) supplementation (≥ 2 wk) lowers exercise induced muscle damage, its acute or timing effects have not been examined. The purpose of this study was to investigate the acute and timing effects of oral HMB supplementation on serum creatine kinase (CK), lactate dehydrogenase (LDH), muscle soreness, and maximal voluntary contraction (MVC). Sixteen non-resistance trained men (22 ± 2 yrs) were assigned to HMB-Pre or HMB-Post groups. In a crossover design, all subjects performed 55 maximal eccentric knee extension/flexion contractions on 2 occasions on either the right or left leg. HMB-Pre (N = 8) randomly received 3 grams of either a placebo or HMB before and a placebo after exercise. HMB-Post (N = 8) received a placebo before and either 3 grams of HMB or a placebo after exercise. Muscle damage tests were recorded before, at 8, 24, 48, and 72 hrs post exercise. There was a reduction in MVC and an increase in soreness in the quadriceps and hamstrings following exercise (p HMB-Pre approached significance in attenuating soreness for the quadriceps (p = 0.07), there was no time x group effect. Serum indices of damage increased, peaking at 48 hrs for CK (773%) (p HMB on CK and LDH, post hoc analysis revealed that only HMB-Pre showed no significant increase in LDH levels following exercise. Our findings suggest no clear acute or timing effects of HMB supplementation. However, consuming HMB before exercise appeared to prevent increases in LDH.

  5. 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.

  6. Imbalance in SOD/CAT activities in rat skeletal muscles submitted to treadmill training exercise.

    Science.gov (United States)

    Pinho, Ricardo A; Andrades, Michael E; Oliveira, Marcos R; Pirola, Aline C; Zago, Morgana S; Silveira, Paulo C L; Dal-Pizzol, Felipe; Moreira, José Cláudio F

    2006-10-01

    The association between physical exercise and oxidative damage in the skeletal musculature has been the focus of many studies in literature, but the balance between superoxide dismutase and catalase activities and its relation to oxidative damage is not well established. Thus, the aim of the present study was to investigate the association between regular treadmill physical exercise, oxidative damage and antioxidant defenses in skeletal muscle of rats. Fifteen male Wistar rats (8-12 months) were randomly separated into two groups (trained n=9 and untrained n=6). Trained rats were treadmill-trained for 12 weeks in progressive exercise (velocity, time, and inclination). Training program consisted in a progressive exercise (10 m/min without inclination for 10 min/day). After 1 week the speed, time and inclination were gradually increased until 17 m/min at 10% for 50 min/day. After the training period animals were killed, and gastrocnemius and quadriceps were surgically removed to the determination of biochemical parameters. Lipid peroxidation, protein oxidative damage, catalase, superoxide dismutase and citrate synthase activities, and muscular glycogen content were measured in the isolated muscles. We demonstrated that there is a different modulation of CAT and SOD in skeletal muscle in trained rats when compared to untrained rats (increased SOD/CAT ratio). TBARS levels were significantly decreased and, in contrast, a significant increase in protein carbonylation was observed. These results suggest a non-described adaptation of skeletal muscle against exercise-induced oxidative stress.

  7. Effects of quadriceps strength after static and dynamic whole-body vibration exercise.

    Science.gov (United States)

    Bush, Jill A; Blog, Gabriel L; Kang, Jie; Faigenbaum, Avery D; Ratamess, Nicholas A

    2015-05-01

    Numerous studies have shown performance benefits including whole-body vibration (WBV) as a training modality or an acute exercise protocol when used as a component of the resistance training program. Some studies have indicated that performing dynamic exercises as compared with static position exercises while exposed to WBV might be beneficial; however, evidence is lacking. Thus, the purpose of this study was to determine if an acute bout of dynamic versus static squats performed during WBV results in increase in quadriceps force production by means of dynamic isokinetic knee extension and flexion exercise. Nonresistance-trained healthy young men and women (N = 21) of 18-25 years participated in 4 protocols with 2-week rest in-between. Protocol 1 consisted of 5 sets of 10 dynamic squats without vibration; Protocol 2: 5 sets of 30-second static squats without vibration; Protocol 3: 5 sets of 10 dynamic squats with 30-Hz WBV for a total of 2.5 minutes; and Protocol 4: 5 sets of 30-second static squats with 30-Hz WBV for a total of 2.5 minutes. Prestrength tests (1 set of 4 repetitions at 100° · s(-1) for the knee extension exercise) was performed within 5 minutes of starting each protocol, and poststrength testing was performed within 1 minute of completing each protocol. Strength outcomes were analyzed by repeated measures analysis of variance with a significance level set at p ≤ 0.05. A significant decrease in strength was observed after dynamic and static squats without WBV (p = 0.002); an increase in strength after dynamic squats with WBV (p = 0.003); and a decrease in strength after static squats with WBV (p = 0.003). The inclusion of WBV to dynamic resistance exercise can be an added modality to increase strength. Whole-body vibration can have varied effects in altering muscle strength in untrained individuals according to the type of resistance training performed. As a dynamic squat with WBV seems to immediately potentiate neuromuscular functioning, the

  8. Evaluation of central and peripheral fatigue in the quadriceps using fractal dimension and conduction velocity in young females.

    Directory of Open Access Journals (Sweden)

    Matteo Beretta-Piccoli

    Full Text Available Over the past decade, linear and non-linear surface electromyography descriptors for central and peripheral components of fatigue have been developed. In the current study, we tested fractal dimension (FD and conduction velocity (CV as myoelectric descriptors of central and peripheral fatigue, respectively. To this aim, we analyzed FD and CV slopes during sustained fatiguing contractions of the quadriceps femoris in healthy humans.A total of 29 recreationally active women (mean age±standard deviation: 24±4 years and two female elite athletes (one power athlete, age 24 and one endurance athlete, age 30 years performed two knee extensions: (1 at 20% maximal voluntary contraction (MVC for 30 s, and (2 at 60% MVC held until exhaustion. Surface EMG signals were detected from the vastus lateralis and vastus medialis using bidimensional arrays.Central and peripheral fatigue were described as decreases in FD and CV, respectively. A positive correlation between FD and CV (R=0.51, p<0.01 was found during the sustained 60% MVC, probably as a result of simultaneous motor unit synchronization and a decrease in muscle fiber CV during the fatiguing task.Central and peripheral fatigue can be described as changes in FD and CV, at least in young, healthy women. The significant correlation between FD and CV observed at 60% MVC suggests that a mutual interaction between central and peripheral fatigue can arise during submaximal isometric contractions.

  9. Artificial-reflex stimulation for FES-induced standing with minimum quadriceps force

    NARCIS (Netherlands)

    Mulder, A.J.; Mulder, A.J.; Boom, H.B.K.; Hermens, Hermanus J.; Zilvold, G.; Zilvold, G.

    1990-01-01

    A control strategy is proposed to decrease quadriceps activity during standing. Modified on/off (or artificial reflex) control is used: a non-numerical or finite-state control scheme based on feedback of knee angle and angular velocity. The control strategy is evaluated in paraplegic patients in an

  10. Neuromuscular versus quadriceps strengthening exercise in patients with medial knee osteoarthritis and varus malalignment

    DEFF Research Database (Denmark)

    Bennell, Kim L; Kyriakides, Mary; Metcalf, Ben

    2014-01-01

    OBJECTIVE: To compare the effects of neuromuscular exercise (NEXA) and quadriceps strengthening (QS) on the knee adduction moment (an indicator of mediolateral distribution of knee load), pain, and physical function in patients with medial knee joint osteoarthritis (OA) and varus malalignment. ME...

  11. Quadriceps fat pad edema: significance on magnetic resonance images of the knee

    International Nuclear Information System (INIS)

    Shabshin, Nogah; Schweitzer, Mark E.; Morrison, William B.

    2006-01-01

    While clinically reading magnetic resonance (MR) images of the knees we have occasionally noted edema within the suprapatellar fat pad, with mass effect both on the suprapatellar joint recess posteriorly, and on the quadriceps tendon anteriorly. This MR appearance is analogous to Hoffa's disease described in the infrapatellar fat pad. We sought to evaluate the frequency and pattern of this finding and to provide clinical and histological correlation. The suprapatellar (quadriceps) fat pad was evaluated in 770 consecutive MR examinations (on 1.5 T and 0.3 T) in 736 patients (353 females and 383 males, age range 5-86 years, mean 44.3 years). The MR images were retrospectively evaluated by two observers in consensus for the presence of quadriceps fat pad edema with mass effect. In 46 patients who had intravenous administration of gadolinium, the presence of enhancement was also evaluated. Clinical correlation was performed in abnormal cases; in one patient, 1-year follow-up MRI was evaluated and in one patient a percutaneous biopsy as well as 2-year clinical follow-up was performed. Thirty-two (4.2%) knees in 29 patients showed quadriceps fat pad edema and mass effect. In five of these patients imaging of the contralateral knee was also performed and four of these showed symmetric edema. Another five cases had gadolinium-enhanced images with prominent enhancement. Most patients had clinical symptoms of meniscal tears (n=16, 55%) or anterior knee pain (n=8, 27.6%). (orig.)

  12. Comparison of hamstring/quadriceps ratio between isoinertial and isokinetic measurements

    NARCIS (Netherlands)

    Da Silva, Bruna G C; Bottaro, Martim; Weber, Fernanda S.; Radaelli, Regis; Gaya, Anelise R.; Cardoso, Marcelo S.; Brown, Lee E.; Carregaro, Rodrigo; Pinto, Ronei S.

    2013-01-01

    OBJECTIVE: To determine the applicability and predictive accuracy of an isoinertial resistance machine for the assessment of hamstring/quadriceps conventional (concentric) ratio (CR). METHOD: Thirty-two resistance trained young men (23.53 ± 3.2 yrs) were tested using dedicated instruments to obtain

  13. Carcass characteristics, chemical composition and fatty acid profile of longissimus muscle of young bulls from four genetic groups finished in feedlot

    Directory of Open Access Journals (Sweden)

    Roberto Haruyoshi Ito

    2012-02-01

    Full Text Available This experiment was carried out to evaluate the carcass characteristics, chemical composition and fatty acid profile of the longissimus muscle of 32 young bulls from four genetic groups: Caracu; Canchin; Aberdeen Angus × Canchin; and Charolais × Caracu, finished in feedlot and slaughtered at 22 months old. Each group was composed of eight animals. There was no difference for moisture, ash, crude protein or total cholesterol between bulls from different genetic groups. However, total lipids percentage was higher for bulls from Caracu and Aberdeen Angus × Canchin and lower for Canchin and Charolais genetic groups. Polyunsaturated fattty acids and n-6 percentage was higher for Canchin and lower for Caracu, Aberdeen Angus × Canchin and Charolais genetic groups. Canchin and Charolais × Caracu genetic groups presented higher n-3 percentage than Caracu and Aberdeen Angus × Canchin. There was no difference for the n-6/n-3 ratio among the bulls from the four genetic groups.

  14. Epidemiology of Quadriceps Strains in National Collegiate Athletic Association Athletes, 2009–2010 Through 2014–2015

    Science.gov (United States)

    Eckard, Timothy G.; Kerr, Zachary Y.; Padua, Darin A.; Djoko, Aristarque; Dompier, Thomas P.

    2017-01-01

    Context:  Few researchers have examined the rates and patterns of quadriceps strains in student-athletes in the National Collegiate Athletic Association (NCAA). Objective:  To describe the epidemiology of quadriceps strains in 25 NCAA sports during the 2009–2010 through 2014–2015 academic years. Design:  Descriptive epidemiology study. Setting:  Convenience sample of NCAA programs from 25 sports during the 2009–2010 through 2014–2015 academic years. Patients or Other Particpants:  Collegiate student-athletes participating in men's and women's NCAA athletics during the 2009–2010 through 2014–2015 academic years. Main Outcome Measure(s):  Aggregate quadriceps strain injury and exposure data from the NCAA Injury Surveillance Program during the 2009–2010 through 2014–2015 academic years were analyzed. Quadriceps strain injury rates and injury rate ratios (IRRs) were reported with 95% confidence intervals (CIs). Results:  Overall, 517 quadriceps strains were reported, resulting in an injury rate of 1.07/10 000 athlete-exposures (AEs). The sports with the highest overall quadriceps strain rates were women's soccer (5.61/10 000 AEs), men's soccer (2.52/10 000 AEs), women's indoor track (2.24/10 000 AEs), and women's softball (2.15/10 000 AEs). Across sex-comparable sports, women had a higher rate of quadriceps strains than men overall (1.97 versus 0.65/10 000 AEs; IRR = 3.03; 95% CI = 2.45, 3.76). The majority of quadriceps strains were sustained during practice (77.8%). However, the quadriceps strain rate was higher during competition than during practice (1.29 versus 1.02/10 000 AEs; IRR = 1.27; 95% CI = 1.03, 1.56). Most quadriceps strains occurred in the preseason (57.8%), and rates were higher during the preseason compared with the regular season (2.29 versus 0.63/10 000 AEs; IRR = 3.60; 95% CI = 3.02, 4.30). Common injury mechanisms were noncontact (63.2%) and overuse (21.9%). Most quadriceps strains restricted

  15. AMP-activated protein kinase in contraction regulation of skeletal muscle metabolism: necessary and/or sufficient?

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Wojtaszewski, Jørgen; Richter, Erik

    2009-01-01

    In skeletal muscle, the contraction-activated heterotrimeric 5'-AMP-activated protein kinase (AMPK) protein is proposed to regulate the balance between anabolic and catabolic processes by increasing substrate uptake and turnover in addition to regulating the transcription of proteins involved...... in mitochondrial biogenesis and other aspects of promoting an oxidative muscle phenotype. Here, the current knowledge on the expression of AMPK subunits in human quadriceps muscle and evidence from rodent studies suggesting distinct AMPK subunit expression pattern in different muscle types is reviewed. Then......, the intensity and time dependence of AMPK activation in human quadriceps and rodent muscle are evaluated. Subsequently, a major part of this review critically examines the evidence supporting a necessary and/or sufficient role of AMPK in a broad spectrum of skeletal muscle contraction-relevant processes...

  16. Knee joint motion and muscle activation patterns are altered during gait in individuals with moderate hip osteoarthritis compared to asymptomatic cohort.

    Science.gov (United States)

    Rutherford, Derek; Moreside, Janice; Wong, Ivan

    2015-07-01

    Knee replacements are common after hip replacement for end stage osteoarthritis. Whether abnormal knee mechanics exist in moderate hip osteoarthritis remains undetermined and has implications for understanding early osteoarthritis joint mechanics. The purpose of this study was to determine whether three-dimensional (3D) knee motion and muscle activation patterns in individuals with moderate hip osteoarthritis differ from an asymptomatic cohort and whether these features differ between contra- and ipsilateral knees. 3D motions and medial and lateral quadriceps and hamstring surface electromyography were recorded on 20 asymptomatic individuals and 20 individuals with moderate hip osteoarthritis during treadmill walking, using standardized collection and processing procedures. Principal component analysis was used to derive electromyographic amplitude and temporal waveform features. 3D stance-phase range of motion was calculated. A 2-factor repeated analysis of variance determined significant within-group leg and muscle differences. Student's t-tests identified between group differences, with Bonferroni corrections where applicable (α=0.05). Lower sagittal plane motion between early and mid/late stance (5°, P=0.004, effect size: 0.96) and greater mid-stance quadriceps activity was found in the osteoarthritis group (P=0.01). Compared to the ipsilateral knee, a borderline significant increase in mid-stance hamstring activity was found in the contra-lateral knee of the hip osteoarthritis group (P=0.018). Bilateral knee mechanics were altered, suggesting potentially increased loads and knee muscle fatigue. There was no indication that one knee is more susceptible to osteoarthritis than the other, thus clinicians should include bilateral knee analysis when treating patients with hip osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Activity of metabolic enzymes and muscle-specific gene expression in parr and smolts Atlantic salmon Salmo salar L. of different age groups.

    Science.gov (United States)

    Churova, Maria V; Meshcheryakova, Olga V; Veselov, Aleksey E; Efremov, Denis A; Nemova, Nina N

    2017-08-01

    This study was conducted to characterize the energy metabolism level and the features of muscle growth regulation during the development of Atlantic salmon (Salmo salar) inhabiting the Indera River (Kola Peninsula, Russia). The activities of aerobic and anaerobic enzymes (cytochrome c oxidase and lactate dehydrogenase) and carbohydrate metabolism enzymes (glucose-6-phosphate dehydrogenase, glycerol-3-phosphate dehydrogenase, and aldolase) were measured in muscle and liver tissue. Gene expression levels of myosin heavy chain (MyHC), myostatin (MSTN-1a), and myogenic regulatory factors (MRFs-MyoD1a, MyoD1b, MyoD1c, Myf5, myogenin) were measured in the white muscles of salmon parr of ages 0+, 1+, 2+, and 3+ and smolts of ages 2+ and 3+. Multidirectional changes in the activity of enzymes involved in aerobic and anaerobic energy metabolism with age were shown in the white muscles of the parr. The cytochrome c oxidase activity was higher in muscles of underyearlings (0+) and yearlings (1+) and decreased in 2+ and 3+ age groups. The activity of lactate dehydrogenase, in contrast, increased with age. The patterns of changes in expression levels of MyoD1a, MyoD1b, myogenin, MyHC, and MSTN-1a at different ages of the parr were similar. Particularly, the expression of these genes peaked in the yearling parr (1+) and then decreased in elder groups. The differences were revealed in parameters studied between the parr and smolts. The level of aerobic and anaerobic metabolism enzyme activities was higher in the white muscles of smolts than in parr. The activity of carbohydrate metabolism enzymes was decreased in the smolts' livers. The expression levels of MyHC, MyoD1a, MyoD1b, and myogenin were lower in smolts at age 2+ compared to parr. These findings expand our knowledge of age-related and stage-related features of energy metabolism and muscle development regulation in young Atlantic salmon in their natural habitat. The results might be used for monitoring of the salmon

  18. Rapid hamstring/quadriceps force capacity in male vs. female elite soccer players

    DEFF Research Database (Denmark)

    Zebis, Mette K; Andersen, Lars L; Ellingsgaard, Helga

    2011-01-01

    during the very initial phase of muscle contraction. Two female players-both with a markedly low RFD H/Q ratio, but a normal MVC H/Q ratio, compared with the group mean-sustained ACL rupture at a later occasion. The high reliability of the new RFD H/Q strength ratio indicates that the method...

  19. Neuromuscular Activation of the Vastus Intermedius Muscle during Isometric Hip Flexion.

    Directory of Open Access Journals (Sweden)

    Akira Saito

    Full Text Available Although activity of the rectus femoris (RF differs from that of the other synergists in quadriceps femoris muscle group during physical activities in humans, it has been suggested that the activation pattern of the vastus intermedius (VI is similar to that of the RF. The purpose of present study was to examine activation of the VI during isometric hip flexion. Ten healthy men performed isometric hip flexion contractions at 25%, 50%, 75%, and 100% of maximal voluntary contraction at hip joint angles of 90°, 110° and 130°. Surface electromyography (EMG was used to record activity of the four quadriceps femoris muscles and EMG signals were root mean square processed and normalized to EMG amplitude during an isometric knee extension with maximal voluntary contraction. The normalized EMG was significantly higher for the VI than for the vastus medialis during hip flexion at 100% of maximal voluntary contraction at hip joint angles of 110° and 130° (P < 0.05. The onset of VI activation was 230-240 ms later than the onset of RF activation during hip flexion at each hip joint angle, which was significantly later than during knee extension at 100% of maximal voluntary contraction (P < 0.05. These results suggest that the VI is activated later than the RF during hip flexion. Activity of the VI during hip flexion might contribute to stabilize the knee joint as an antagonist and might help to smooth knee joint motion, such as in the transition from hip flexion to knee extension during walking, running and pedaling.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Tendon and skeletal muscle matrix gene expression and functional responses to immobilisation and rehabilitation in young males

    DEFF Research Database (Denmark)

    Boesen, Anders Ploug; Dideriksen, Kasper; Couppé, Christian

    2013-01-01

    weeks followed by six weeks of strength training. Cross sectional area (CSA), maximal muscle strength (MVC) and biomechanical properties of m.quadriceps and patellar tendon were determined. Muscle and tendon biopsies were analysed for mRNA of collagen (COL-1A1/3A1), insulin-like growth factors (IGF-1Ea...... in both groups. Likewise, both groups increased in IGF-1Ea/Ec and COL-1A1/3A1 expression in muscle during re-training after immobilisation compared to baseline, and the rise was more pronounced when subjects recieved GH. The tendon CSA did not change during immobilisation, but increased in both groups...... during six weeks of rehabilitation (~14%). A decline in tendon stiffness after immobilisation was observed only in Plc, and an increase during six weeks rehabilitation was observed only in GH. IGF-1Ea and COL-1A1/3A1 mRNA increased with immobilisation in the GH group only, and LOX mRNA was after...

  2. Muscle activity during knee-extension strengthening exercise performed with elastic tubing and isotonic resistance

    DEFF Research Database (Denmark)

    Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H

    2012-01-01

    muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. METHODS: 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric......BACKGROUND/PURPOSE: While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps...... tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different conditions...

  3. Muscle activity during knee-extension strengthening exercise performed with elastic tubing and isotonic resistance

    DEFF Research Database (Denmark)

    Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H

    2012-01-01

    tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different conditions......BACKGROUND/PURPOSE: While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps...... muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. METHODS: 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric...

  4. α-smooth muscle actin is not a marker of fibrogenic cell activity in skeletal muscle fibrosis.

    Directory of Open Access Journals (Sweden)

    Wanming Zhao

    Full Text Available α-Smooth muscle actin (α-SMA is used as a marker for a subset of activated fibrogenic cells, myofibroblasts, which are regarded as important effector cells of tissue fibrogenesis. We address whether α-SMA-expressing myofibroblasts are detectable in fibrotic muscles of mdx5cv mice, a mouse model for Duchenne muscular dystrophy (DMD, and whether the α-SMA expression correlates with the fibrogenic function of intramuscular fibrogenic cells. α-SMA immunostaining signal was not detected in collagen I (GFP-expressing cells in fibrotic muscles of ColI-GFP/mdx5cv mice, but it was readily detected in smooth muscle cells lining intramuscular blood vessel walls. α-SMA expression was detected by quantitative RT-PCR and Western blot in fibrogenic cells sorted from diaphragm and quadriceps muscles of the ColI-GFP/mdx5cv mice. Consistent with the more severe fibrosis in the ColI-GFP/mdx5cv diaphragm, the fibrogenic cells in the diaphragm exerted a stronger fibrogenic function than the fibrogenic cells in the quadriceps as gauged by their extracellular matrix gene expression. However, both gene and protein expression of α-SMA was lower in the diaphragm fibrogenic cells than in the quadriceps fibrogenic cells in the ColI-GFP/mdx5cv mice. We conclude that myofibroblasts are present in fibrotic skeletal muscles, but their expression of α-SMA is not detectable by immunostaining. The level of α-SMA expression by intramuscular fibrogenic cells does not correlate positively with the level of collagen gene expression or the severity of skeletal muscle fibrosis in the mdx5cv mice. α-SMA is not a functional marker of fibrogenic cells in skeletal muscle fibrosis associated with muscular dystrophy.

  5. Executive functioning, concern about falling and quadriceps strength mediate the relationship between impaired gait adaptability and fall risk in older people.

    Science.gov (United States)

    Caetano, Maria Joana D; Lord, Stephen R; Brodie, Matthew A; Schoene, Daniel; Pelicioni, Paulo H S; Sturnieks, Daina L; Menant, Jasmine C

    2018-01-01

    Reduced ability to adapt gait, particularly under challenging conditions, may be an important reason why older adults have an increased risk of falling. This study aimed to identify cognitive, psychological and physical mediators of the relationship between impaired gait adaptability and fall risk in older adults. Fifty healthy older adults (mean±SD: 74±7years) were categorised as high or low fall risk, based on past falls and their performance in the Physiological Profile Assessment. High and low-risk groups were then compared in the gait adaptability test, i.e. an assessment of the ability to adapt gait in response to obstacles and stepping targets under single and dual task conditions. Quadriceps strength, concern about falling and executive function were also measured. The older adults who made errors on the gait adaptability test were 4.76 (95%CI=1.08-20.91) times more likely to be at high risk of falling. Furthermore, each standard deviation reduction in gait speed while approaching the targets/obstacle increased the odds of being at high risk of falling approximately three fold: single task - OR=3.10,95%CI=1.43-6.73; dual task - 3.42,95%CI=1.56-7.52. Executive functioning, concern about falling and quadriceps strength substantially mediated the relationship between the gait adaptability measures and fall risk status. Impaired gait adaptability is associated with high risk of falls in older adults. Reduced executive function, increased concern about falling and weaker quadriceps strength contribute significantly to this relationship. Training gait adaptability directly, as well as addressing the above mediators through cognitive, behavioural and physical training may maximise fall prevention efficacy. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Discussion about different cut-off values of conventional hamstring-to-quadriceps ratio used in hamstring injury prediction among professional male football players.

    Directory of Open Access Journals (Sweden)

    Monika Grygorowicz

    Full Text Available To measure the sensitivity and specificity of differences cut-off values for isokinetic Hcon/Qcon ratio in order to improve the capacity to evaluate (retrospectively the injury of hamstring muscles in professional soccer screened with knee isokinetic tests.Retrospective study.Medical and biomechanical data of professional football players playing for the same team for at least one season between 2010 and 2016 were analysed. Hamstring strain injury cases and the reports generated via isokinetic testing were investigated. Isokinetic concentric(con hamstring(H and quadriceps(Q absolute strength in addition with Hcon/Qcon ratio were examined for the injured versus uninjured limbs among injured players, and for the injured and non-injured players. 2 x 2 contingency table was used for comparing variables: predicted injured or predicted uninjured with actual injured or actual uninjured. Sensitivity, specificity, accuracy, positive and negative predictive values, and positive and negative likelihood ratio were calculated for three different cut-off values (0.47 vs. 0.6 vs. 0.658 to compare the discriminative power of an isokinetic test, whilst examining the key value of Hcon/Qcon ratio which may indicate the highest level of ability to predispose a player to injury. McNemar's chi2 test with Yates's correction was used to determine agreement between the tests. PQStat software was used for all statistical analysis, and an alpha level of p <0.05 was used for all statistical comparisons.340 isokinetic test reports on both limbs of 66 professional soccer players were analysed. Eleven players suffered hamstring injuries during the analysed period. None of these players sustained recurrence of hamstring injury. One player sustained hamstring strain injury on both legs, thus the total number of injuries was 12. Application of different cut-off values for Hcon/Qcon significantly affected the sensitivity and specificity of isokinetic test used as a tool for

  7. The effect of different physical activity levels on muscle fiber size and type distribution of lumbar multifidus. A biopsy study on low back pain patient groups and healthy control subjects.

    Science.gov (United States)

    Mazis, N; Papachristou, D J; Zouboulis, P; Tyllianakis, M; Scopa, C D; Megas, P

    2009-12-01

    Previous studies examining the multifidus fiber characteristics among low back pain (LBP) patients have not considered the variable of physical activity. The present study sought to investigate the muscle fiber size and type distribution of the lumbar multifidus muscle among LBP patient groups with different physical activity levels and healthy controls. Sixty-four patients were assigned to one of three groups named according to the physical activity level, determined for each patient by the International Physical Activity Questionnaire. These were low (LPA), medium (MPA) and high (HPA) physical activity groups. A control group comprising of 17 healthy individuals was also recruited. Muscle biopsy samples were obtained from the multifidus muscle at the level L4-L5. contrast with the control group, LBP patient groups showed a significantly higher Type II fiber distribution as well as reduced diameter in both fiber types (P0.05) among LPA, MPA and HPA patient groups. Various pathological conditions were detected which were more pronounced in LBP groups compared to the control (P<0.05). Males had a larger fiber diameter compared to females for both fiber types (P<0.05). The results showed that the level of physical activity did not affect muscle fiber size and type distribution among LBP patients groups. These findings suggest that not only inactivity but also high physical activity levels can have an adverse effect on the multifidus muscle fiber characteristics.

  8. The Time Course of Knee Swelling Post Total Knee Arthroplasty and Its Associations with Quadriceps Strength and Gait Speed.

    Science.gov (United States)

    Pua, Yong-Hao

    2015-07-01

    This study examines the time course of knee swelling post total knee arthroplasty (TKA) and its associations with quadriceps strength and gait speed. Eighty-five patients with unilateral TKA participated. Preoperatively and on post-operative days (PODs) 1, 4, 14, and 90, knee swelling was measured using bioimpedance spectrometry. Preoperatively and on PODs 14 and 90, quadriceps strength was measured using isokinetic dynamometry while fast gait speed was measured using the timed 10-meter walk. On POD1, knee swelling increased ~35% from preoperative levels after which, knee swelling reduced but remained at ~11% above preoperative levels on POD90. In longitudinal, multivariable analyses, knee swelling was associated with quadriceps weakness (P<0.01) and slower gait speed (P=0.03). Interventions to reduce post-TKA knee swelling may be indicated to improve quadriceps strength and gait speed. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Muscle MRI in neutral lipid storage disease with myopathy carrying mutation c.187+1G>A.

    Science.gov (United States)

    Xu, Chunxiao; Zhao, Yawen; Liu, Jing; Zhang, Wei; Wang, Zhaoxia; Yuan, Yun

    2015-06-01

    We describe the clinical and muscle MRI changes in 2 siblings with neutral lipid storage disease with myopathy (NLSDM) carrying the mutation c.187+1G>A. Peripheral blood smears, genetic tests, and muscle biopsies were performed. Thigh MRI was performed to observe fatty replacement, muscle edema, and muscle bulk from axial sections. Both siblings had similar fatty infiltration and edema. T1-weighted images of the gluteus maximus, adductor magnus, semitendinosus, and semimembranosus revealed marked and diffuse fatty infiltration. There was asymmetric involvement in biceps femoris and quadriceps. There was extensive fatty infiltration in the quadriceps, except for the rectus femoris. Gracilis and sartorius were relatively spared. Thigh muscle volume was decreased, while the gracilis and sartorius appeared to show compensatory hypertrophy. Compared with previous reports in NLSDM, MRI changes in this myopathy tended to be more severe. Asymmetry and relatively selective fatty infiltration were characteristics. © 2014 Wiley Periodicals, Inc.

  10. Short-term muscle atrophy caused by botulinum toxin-A local injection impairs fracture healing in the rat femur.

    Science.gov (United States)

    Hao, Yongqiang; Ma, Yongcheng; Wang, Xuepeng; Jin, Fangchun; Ge, Shengfang

    2012-04-01

    Damaged bone is sensitive to mechanical stimulation throughout the remodeling phase of bone healing. Muscle damage and muscular atrophy associated with open fractures and subsequent fixation are not beneficial to maintaining optimum conditions for mechanical stability. The aim of this study was to investigate whether local muscle atrophy and dysfunction affect fracture healing in a rat femur fracture model. We combined the rat model of a short period atrophy of the quadriceps with femur fracture. Forty-four-month-old male Wistar rats were adopted for this study. Two units of botulinum toxin-A (BXTA) were administered locally into the right side of the quadriceps of each rat, while the same dose of saline was injected into the contralateral quadriceps. After BXTA had been fully absorbed by the quadriceps, osteotomy was performed in both femurs with intramedullary fixation. Gross observation and weighing of muscle tissue, X-ray analysis, callus histology, and bone biomechanical testing were performed at different time points up to 8 weeks post-surgery. Local injection of BXTA led to a significant decrease in the volume and weight of the quadriceps compared to the control side. At the eighth week, the left side femurs of the saline-injected quadriceps almost reached bony union, and fibrous calluses were completely calcified into woven bone. However, a gap was still visible in the BXTA-treated side on X-ray images. As showed by bone histology, there were no mature osseous calluses or woven bone on the BXTA-treated side, but a resorption pattern was evident. Biomechanical testing indicated that the femurs of the BXTA-treated side exhibited inferior mechanical properties compared with the control side. The inferior outcome following BXTA injection, compared with saline injection, in terms of callus resistance may be the consequence of unexpected load and mechanical unsteadiness caused by muscle atrophy and dysfunction. Copyright © 2011 Orthopaedic Research Society.

  11. Anterior cruciate ligament reconstruction using bone plug-free quadriceps tendon autograft: intermediate-term clinical outcome after 24-36 months.

    Science.gov (United States)

    Schulz, Arndt P; Lange, Vivien; Gille, Justus; Voigt, Christine; Fröhlich, Susanne; Stuhr, Markus; Jürgens, Christian

    2013-01-01

    Although known as a possible graft option for decades, quadriceps tendon grafts have often been termed a second-line graft option. We report a consecutive case series using this method as the primary treatment line. The rationale for this study was to evaluate the midterm results of this method in a prospective and consecutive case series. The primary study question was to determine the clinical results 24-36 months after primary anterior cruciate ligament (ACL) reconstruction using a bone plug-free quadriceps tendon autograft fixed with bioabsorbable cross-pins. The study population included 55 patients, of whom 24 were female (43.6%). The mean age at the index procedure was 31.7 years (15-58 years). All patients received an ACL construction using a bone block-free quadriceps tendon graft fixed with resorbable cross-pins. The postoperative regimen included partial weight-bearing for 3 weeks and flexion limited to 90° for six weeks; an orthosis was not used. The mean follow-up duration was 29.5 months (24.3-38.5 months) after the index procedure. The International Knee Documentation Committee (IKDC) subjective score and examination form was assessed, as well as the Lysholm and Gillquist score and the Tegner activity index. The Rolimeter arthrometer was used to assess the anterior laxity of the knee. Graft harvesting was possible in all cases; a bony extension was never required. On average, graft length was measured at 8.8 cm (7.5-10 cm). The mean IKDC subjective score at follow-up was 80.44 points (55.17-100 points, standard deviation [SD] 12.05). The mean preinjury Tegner activity index was 4.98 (2-7) compared to a mean value of 4.16 (2-7, SD 0.8) at follow-up. There was a mean loss of 0.82 index points. The average Lysholm and Gillquist score was 89 points (65-100, SD 17.7). Of the results, 89.1% were in the good or very good groups; in one case (1.8%), the result was poor, while the rest were fair. ACL reconstruction using a bone plug-free quadriceps tendon

  12. Free Bone Plug Quadriceps Tendon Harvest and Suspensory Button Attachment for Anterior Cruciate Ligament Reconstruction.

    Science.gov (United States)

    Todor, Adrian; Caterev, Sergiu; Nistor, Dan Viorel; Khallouki, Youssef

    2016-06-01

    The most commonly used autografts for anterior cruciate ligament reconstruction are the bone-patellar tendon-bone and hamstring tendons. Each has its advantages and limitations. The bone-patellar tendon-bone autograft can lead to more donor-site morbidity, and the hamstring autograft can be unpredictable in size. The quadriceps tendon, with or without a bone block, has been described as an alternative graft source and has been used especially in revision cases, but in recent years, it has attracted attention even for primary cases. We report a technique for harvesting a free bone quadriceps tendon graft and attaching an extracortical button for femoral fixation for anterior cruciate ligament reconstruction.

  13. Variability and reliability of the vastus lateralis muscle anatomy.

    Science.gov (United States)

    D'Arpa, Salvatore; Toia, Francesca; Brenner, Erich; Melloni, Carlo; Moschella, Francesco; Cordova, Adriana

    2016-08-01

    The aims of this study are to investigate the variability of the morphological and neurovascular anatomy of the vastus lateralis (VL) muscle and to describe the relationships among its intramuscular partitions and with the other muscles of the quadriceps femoris. Clinical implications in its reliability as a flap donor are also discussed. In 2012, the extra- and intramuscular neurovascular anatomy of the VL was investigated in 10 cadaveric lower limbs. In three specimens, the segmental arterial pedicles were injected with latex of different colors to point out their anastomotic connections. The morphological anatomy was investigated with regard to the mutual relationship of the three muscular partitions and the relation of the VL with the other muscles of the quadriceps femoris. The VL has a segmental morphological anatomy. However, the fibers of its three partitions interconnect individually and with the other bellies of the quadriceps femoris, particularly, in several variable portions with the vastus intermedius and mainly in the posterior part of the VL. The lateral circumflex femoral artery and its branches have variable origin, but demonstrate constant segmental distribution. Intramuscular dissection and colored latex injections show a rich anastomotic vascular network among the three partitions. Moderate variability exists in both the myological and the neurovascular anatomy of the VL. Despite this variability, the anatomy of the VL always has a constant segmental pattern, which makes the VL a reliable flap donor. Detailed knowledge of the VL anatomy could have useful applications in a broad clinical field.

  14. A Modified Method for Reconstruction of Chronic Rupture of the Quadriceps Tendon after Total Knee Replacement

    Directory of Open Access Journals (Sweden)

    S Singh

    2008-11-01

    Full Text Available We describe herein a modified technique for reconstruction of chronic rupture of the quadriceps tendon in a patient with bilateral total knee replacement and distal realignment of the patella. The surgery involved the application of a Dacron graft and the ‘double eights’ technique. The patient achieved satisfactory results after surgery and we believe that this technique of reconstruction offers advantages over other methods.

  15. Measuring voluntary quadriceps activation: Effect of visual feedback and stimulus delivery.

    Science.gov (United States)

    Luc, Brittney A; Harkey, Matthew H; Arguelles, Gabrielle D; Blackburn, J Troy; Ryan, Eric D; Pietrosimone, Brian

    2016-02-01

    Quadriceps voluntary activation, assessed via the superimposed burst technique, has been extensively studied in a variety of populations as a measure of quadriceps function. However, a variety of stimulus delivery techniques have been employed, which may influence the level of voluntary activation as calculated via the central activation ratio (CAR). The purpose was to determine the effect of visual feedback, stimulus delivery, and perceived discomfort on maximal voluntary isometric contraction (MVIC) peak torque and the CAR. Quadriceps CAR was assessed in 14 individuals on two days using three stimulus delivery methods; (1) manual without visual feedback, (2) manual with visual feedback, and (3) automated with visual feedback. MVIC peak torque and the CAR were not different between the automated with visual feedback (MVIC=3.25, SE=0.14Nm/kg; CAR=88.63, SE=1.75%) and manual with visual feedback (MVIC=3.26, SE=0.13Nm/kg, P=0.859; CAR=89.06, SE=1.70%, P=0.39) stimulus delivery methods. MVIC (2.99, SE=0.12Nm/kg) and CAR (85.32, SE=2.10%) were significantly lower using manual without visual feedback compared to manual with visual feedback and automated with visual feedback (CAR P<0.001; MVIC P<0.001). Perceived discomfort was lower in the second session (P<0.05). Utilizing visual feedback ensures participant MVIC, and may provide a more accurate assessment of quadriceps voluntary activation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Discussion about different cut-off values of conventional hamstring-to-quadriceps ratio used in hamstring injury prediction among professional male football players.

    Science.gov (United States)

    Grygorowicz, Monika; Michałowska, Martyna; Walczak, Tomasz; Owen, Adam; Grabski, Jakub Krzysztof; Pyda, Andrzej; Piontek, Tomasz; Kotwicki, Tomasz

    2017-01-01

    To measure the sensitivity and specificity of differences cut-off values for isokinetic Hcon/Qcon ratio in order to improve the capacity to evaluate (retrospectively) the injury of hamstring muscles in professional soccer screened with knee isokinetic tests. Retrospective study. Medical and biomechanical data of professional football players playing for the same team for at least one season between 2010 and 2016 were analysed. Hamstring strain injury cases and the reports generated via isokinetic testing were investigated. Isokinetic concentric(con) hamstring(H) and quadriceps(Q) absolute strength in addition with Hcon/Qcon ratio were examined for the injured versus uninjured limbs among injured players, and for the injured and non-injured players. 2 x 2 contingency table was used for comparing variables: predicted injured or predicted uninjured with actual injured or actual uninjured. Sensitivity, specificity, accuracy, positive and negative predictive values, and positive and negative likelihood ratio were calculated for three different cut-off values (0.47 vs. 0.6 vs. 0.658) to compare the discriminative power of an isokinetic test, whilst examining the key value of Hcon/Qcon ratio which may indicate the highest level of ability to predispose a player to injury. McNemar's chi2 test with Yates's correction was used to determine agreement between the tests. PQStat software was used for all statistical analysis, and an alpha level of p hamstring injuries during the analysed period. None of these players sustained recurrence of hamstring injury. One player sustained hamstring strain injury on both legs, thus the total number of injuries was 12. Application of different cut-off values for Hcon/Qcon significantly affected the sensitivity and specificity of isokinetic test used as a tool for muscle injury detection. The use of 0.47 of Hcon/Qcon as a discriminate value resulted in significantly lower sensitivity when compared to 0.658 threshold (sensitivity of 16.7% vs

  17. The embryonic genes Dkk3, Hoxd8, Hoxd9 and Tbx1 identify muscle types in a diet-independent and fiber-type unrelated way

    Directory of Open Access Journals (Sweden)

    Boekschoten Mark V

    2010-03-01

    Full Text Available Abstract Background The mouse skeletal muscle is composed of four distinct fiber types that differ in contractile function, number of mitochondria and metabolism. Every muscle type has a specific composition and distribution of the four fiber types. To find novel genes involved in specifying muscle types, we used microarray analysis to compare the gastrocnemius with the quadriceps from mice fed a low fat diet (LFD or high fat diet (HFD for 8 weeks. Additional qPCR analysis were performed in the gastrocnemius, quadriceps and soleus muscle from mice fed an LFD or HFD for 20 weeks. Results In mice fed the 8-week LFD 162 genes were differentially expressed in the gastrocnemius vs. the quadriceps. Genes with the strongest differences in expression were markers for oxidative fiber types (e.g. Tnni1 and genes which are known to be involved in embryogenesis (Dkk3, Hoxd8,Hoxd9 and Tbx1. Also Dkk2, Hoxa5, Hoxa10, Hoxc9, Hoxc10, Hoxc6 and Tbx15 were detectably, but not differentially expressed in adult muscle tissue. Expression of differentially expressed genes was not influenced by an 8-week or 20-week HFD. Comparing gastrocnemius, quadriceps and soleus, expression of Hoxd8 and Hoxd9 was not related with expression of markers for the four different fiber types. We found that the expression of both Hoxd8 and Hoxd9 was much higher in the gastrocnemius than in the quadriceps or soleus, whereas the expression of Dkk3 was high in quadriceps, but low in both gastrocnemius and soleus. Finally, expression of Tbx1 was high in quadriceps, intermediate in soleus and low in gastrocnemius. Conclusions We found that genes from the Dkk family, Hox family and Tbx family are detectably expressed in adult mouse muscle. Interestingly, expression of Dkk3, Hoxd8, Hoxd9 and Tbx1 was highly different between gastrocnemius, quadriceps and soleus. In fact, every muscle type showed a unique combination of expression of these four genes which was not influenced by diet. Altogether

  18. Quadriceps rate of torque development and disability in individuals with anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Davis, Hope C; Troy Blackburn, J; Ryan, Eric D; Luc-Harkey, Brittney A; Harkey, Matthew S; Padua, Darin A; Pietrosimone, Brian

    2017-07-01

    The purpose of this study was to determine associations between self-reported function (International Knee Documentation Committee Index), isometric quadriceps strength and rate of torque development in individuals with a unilateral anterior cruciate ligament reconstruction. Forty-one individuals [31% male, BMI mean 25 (SD 4) kg/m 2 , months post anterior cruciate ligament reconstruction mean 49 (SD 40)] completed the self-reported function and isometric quadriceps function testing. Rate of torque development was assessed at 0-100ms (early), 100-200ms (late) ms, and peak following the onset of contraction. Associations were examined between rate of torque development, strength, and self-reported function. Linear regression was used to determine the unique amount of variance explained by the combination of rate of torque development and strength. Higher rate of torque development 100-200ms is weakly associated with higher self-reported function in individuals with a unilateral anterior cruciate ligament reconstruction (r=0.274, p=0.091); however, rate of torque development 100-200ms does not predict a significant amount of variance in self-reported function after accounting for strength (ΔR 2 =0.003, P=0.721). Quadriceps strength has a greater influence on self-reported function compared to rate of torque development in individuals with an anterior cruciate ligament reconstruction with time from surgery. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Effects of low-load resistance training with blood flow restriction on muscle size and strength of professional soccer players with muscle imbalance

    Directory of Open Access Journals (Sweden)

    Benedito Sergio Denadai

    2017-12-01

    Full Text Available The purposes of this study were to determine whether low intensity resistance training combined with blood flow restriction (LI-BFR could affect the concentric hamstrings/quadriceps muscle strength ratio (Hcon:Qcon of professional soccer players with Hcon:Qcon imbalance (Study 1, and whether hamstrings strength response observed after LI-BFR is associated with muscle hypertrophy (Study 2. In the Study 1, athletes were randomly divided into a training group (n = 6 and a control group (n = 5. In the Study 2, all athletes (n = 11 have performed the training programme. The athletes participated in a 6-week (twice a week supervised training programme (unilateral knee flexion at 30% 1RM consisting of 12 training sessions. Peak concentric torque of knee flexors (+8%; P < 0.001 and Hcon:Qcon (+9%; P < 0.01 were significantly increased after LI-BFR. Moreover, the cross sectional area (CSA of the hamstrings was significantly increased (+10%; P < 0.001 after LI-BFR. Thus, the addition of hamstrings strength training programme using LI-BFR during preseason is able to enhance both Hcon:Qcon and hamstrings CSA of professional soccer players with Hcon:Qcon imbalance.

  20. An anterior cruciate ligament injury does not affect the neuromuscular function of the non-injured leg except for dynamic balance and voluntary quadriceps activation.

    Science.gov (United States)

    Zult, Tjerk; Gokeler, Alli; van Raay, Jos J A M; Brouwer, Reinoud W; Zijdewind, Inge; Hortobágyi, Tibor

    2017-01-01

    The function of the anterior cruciate ligament (ACL) patients' non-injured leg is relevant in light of the high incidence of secondary ACL injuries on the contralateral side. However, the non-injured leg's function has only been examined for a selected number of neuromuscular outcomes and often without appropriate control groups. We measured a broad array of neuromuscular functions between legs of ACL patients and compared outcomes to age, sex, and physical activity matched controls. Thirty-two ACL-deficient patients (208 ± 145 days post-injury) and active and less-active controls (N = 20 each) participated in the study. We measured single- and multi-joint neuromuscular function in both legs in each group and expressed the overall neuromuscular function in each leg by calculating a mean z-score across all neuromuscular measures. A group by leg MANOVA and ANOVA were performed to examine group and leg differences for the selected outcomes. After an ACL injury, duration (-4.3 h/week) and level (Tegner activity score of -3.9) of sports activity decreased and was comparable to less-active controls. ACL patients showed bilateral impairments in the star excursion balance test compared to both control groups (P ≤ 0.004) and for central activation ratio compared to active controls (P ≤ 0.002). There were between-leg differences within each group for maximal quadriceps and hamstring strength, voluntary quadriceps activation, star excursion balance test performance, and single-leg hop distance (all P joint proprioception, and static balance. Overall neuromuscular function (mean z-score) did not differ between groups, but ACL patients' non-injured leg displayed better neuromuscular function than the injured leg (P neuromuscular deficits despite reductions in physical activity after injury. Therapists can use the non-injured leg as a reference to assess the injured leg's function for tasks measured in the present study, excluding dynamic balance and quadriceps

  1. Skeletal Muscle Ultrasonography in Nutrition and Functional Outcome Assessment of Critically Ill Children: Experience and Insights From Pediatric Disease and Adult Critical Care Studies [Formula: see text].

    Science.gov (United States)

    Ong, Chengsi; Lee, Jan Hau; Leow, Melvin K S; Puthucheary, Zudin A

    2017-09-01

    Evidence suggests that critically ill children develop muscle wasting, which could affect outcomes. Muscle ultrasound has been used to track muscle wasting and association with outcomes in critically ill adults but not children. This review aims to summarize methodological considerations of muscle ultrasound, structural findings, and possibilities for its application in the assessment of nutrition and functional outcomes in critically ill children. Medline, Embase, and CINAHL databases were searched up until April 2016. Articles describing skeletal muscle ultrasound in children and critically ill adults were analyzed qualitatively for details on techniques and findings. Thickness and cross-sectional area of various upper and lower body muscles have been studied to quantify muscle mass and detect muscle changes. The quadriceps femoris muscle is one of the most commonly measured muscles due to its relation to mobility and is sensitive to changes over time. However, the margin of error for quadriceps thickness is too wide to reliably detect muscle changes in critically ill children. Muscle size and its correlation with strength and function also have not yet been studied in critically ill children. Echogenicity, used to detect compromised muscle structure in neuromuscular disease, may be another property worth studying in critically ill children. Muscle ultrasound may be useful in detecting muscle wasting in critically ill children but has not been shown to be sufficiently reliable in this population. Further study of the reliability and correlation with functional outcomes and nutrition intake is required before muscle ultrasound is routinely employed in critically ill children.

  2. Muscle Metabolic Responses During Dynamic In-Magnet Exercise Testing : A Pilot Study in Children with an Idiopathic Inflammatory Myopathy

    NARCIS (Netherlands)

    van Brussel, Marco; van Oorschot, Joep W. M.; Schmitz, Joep P. J.; Nicolay, Klaas; van Royen-Kerkhof, Annet; Takken, Tim; Jeneson, Jeroen A. L.

    Rationale and Objectives: The clinical utility of supine in-magnet bicycling in combination with phosphorus magnetic resonance spectroscopy (P-31 MRS) to evaluate quadriceps muscle metabolism was examined in four children with juvenile dermatomyositis (JDM) in remission and healthy age- and

  3. Experimental muscle pain during a forward lunge--the effects on knee joint dynamics and electromyographic activity

    DEFF Research Database (Denmark)

    Henriksen, Marius; Alkjaer, T; Simonsen, Erik Bruun

    2009-01-01

    . Isotonic saline (0.9%) was used as control. MAIN OUTCOME MEASUREMENTS: Three-dimensional movement analyses were performed and inverse dynamics were used to calculate joint kinematics and kinetics for ankle, knee and hip joints. Electromyographic (EMG) signals of the hamstrings and quadriceps muscles were...

  4. Contraction and AICAR Stimulate IL-6 Vesicle Depletion From Skeletal Muscle Fibers In Vivo

    DEFF Research Database (Denmark)

    Lauritzen, Hans P M M; Brandauer, Josef; Schjerling, Peter

    2013-01-01

    muscle fibers and in live animals in vivo. Using confocal imaging to visualize endogenous IL-6 protein in fixed muscle fibers, we found IL-6 in small vesicle structures distributed throughout the fibers under basal (resting) conditions. To determine the kinetics of IL-6 secretion, intact quadriceps...... muscles were transfected with enhanced green fluorescent protein (EGFP)-tagged IL-6 (IL-6-EGFP), and 5 days later anesthetized mice were imaged before and after muscle contractions in situ. Contractions decreased IL-6-EGFP-containing vesicles and protein by 62% (P

  5. Exercise-Induced Changes in Caveolin-1, Depletion of Mitochondrial Cholesterol, and the Inhibition of Mitochondrial Swelling in Rat Skeletal Muscle but Not in the Liver

    Directory of Open Access Journals (Sweden)

    Damian Jozef Flis

    2016-01-01

    Full Text Available The reduction in cholesterol in mitochondria, observed after exercise, is related to the inhibition of mitochondrial swelling. Caveolin-1 (Cav-1 plays an essential role in the regulation of cellular cholesterol metabolism and is required by various signalling pathways. Therefore, the aim of this study was to investigate the effect of prolonged swimming on the mitochondrial Cav-1 concentration; additionally, we identified the results of these changes as they relate to the induction of changes in the mitochondrial swelling and cholesterol in rat skeletal muscle and liver. Male Wistar rats were divided into a sedentary control group and an exercise group. The exercised rats swam for 3 hours and were burdened with an additional 3% of their body weight. After the cessation of exercise, their quadriceps femoris muscles and livers were immediately removed for experimentation. The exercise protocol caused an increase in the Cav-1 concentration in crude muscle mitochondria; this was related to a reduction in the cholesterol level and an inhibition of mitochondrial swelling. There were no changes in rat livers, with the exception of increased markers of oxidative stress in mitochondria. These data indicate the possible role of Cav-1 in the adaptive change in the rat muscle mitochondria following exercise.

  6. The effects of physical therapy on exaggerated muscle tonicity, balance and quality of life on hemiparetic patients due to stroke

    International Nuclear Information System (INIS)

    Hoseinabadi, M.R.; Taheri, H.R.; Keavanloo, F.

    2013-01-01

    Objective: To determine the effects of physical therapy on balance, exaggerated muscle tonicity and quality of life on patients with hemiparesis. Methods: This quasi-experimental study was conducted in 2011 among male hemiparetic patients secondary to stroke, at a physiotherapy centre in Neyshabur, Iran. Twenty-four patients were randomly assigned to two equal groups representing the cases and the controls. The cases were assigned to do the practical protocol for 4 weeks. To collect the data, Berg Balance Scaling, Modified Ashworth Scale, Barthel Activities of Daily Living Index and demographic questionnaires were used. Paired and un-paired t-tests were used to analyse data. All analyses were done on SPSS 16. Results: The two groups were similar before intervention. Post-test analysis showed that the average balance and quality of life significantly improved (p<0.001) among the cases, and the quadriceps muscle tonicity decreased (p<0.001). Among the controls, there was no significant change between pre-test and post-test readings. Conclusions: Physical therapy can enhance balance and quality of life of hemiparetic patients and reduces their exaggerated muscle tonicity. (author)

  7. Acute and timing effects of beta-hydroxy-beta-methylbutyrate (HMB on indirect markers of skeletal muscle damage

    Directory of Open Access Journals (Sweden)

    Manninen Anssi H

    2009-02-01

    Full Text Available Abstract Background While chronic β-Hydroxy β-Methylbutyrate (HMB supplementation (≥ 2 wk lowers exercise induced muscle damage, its acute or timing effects have not been examined. The purpose of this study was to investigate the acute and timing effects of oral HMB supplementation on serum creatine kinase (CK, lactate dehydrogenase (LDH, muscle soreness, and maximal voluntary contraction (MVC. Methods Sixteen non-resistance trained men (22 ± 2 yrs were assigned to HMB-Pre or HMB-Post groups. In a crossover design, all subjects performed 55 maximal eccentric knee extension/flexion contractions on 2 occasions on either the right or left leg. HMB-Pre (N = 8 randomly received 3 grams of either a placebo or HMB before and a placebo after exercise. HMB-Post (N = 8 received a placebo before and either 3 grams of HMB or a placebo after exercise. Muscle damage tests were recorded before, at 8, 24, 48, and 72 hrs post exercise. Results There was a reduction in MVC and an increase in soreness in the quadriceps and hamstrings following exercise (p p = 0.07, there was no time × group effect. Serum indices of damage increased, peaking at 48 hrs for CK (773% (p p Conclusion Our findings suggest no clear acute or timing effects of HMB supplementation. However, consuming HMB before exercise appeared to prevent increases in LDH.

  8. Computed tomographical findings of skeletal muscles in rimmed vacuole type distal myopathy

    International Nuclear Information System (INIS)

    Kunimoto, Masanari; Kawai, Mitsuru; Goto, Jun; Nakano, Imaharu

    1987-01-01

    Skeletal muscle CT scans of three patients with biopsy-proven rimmed vacuole type distal myopathy(RVDM) from two unrelated families showed unique involvement pattern of the lower extremities. Parents of the patients in both families are first cousins. T.Y. is a 36-year-old woman who noticed mild difficulty in walking at 34 years of age. Now she shows waddling but still indpendent gait. Manual muscle test (MMT) revealed the following results: fair (3+/5) for hip flexion, 3 for hip extension, 3 for knee flexion, normal (5/5) for knee extension, poor (2/5) for ankle dorsi-flexion, good (4/5) for ankle plantar flexion. T.M., a 34-year-old younger sister of T.Y., started dragging her feet on gait at age 27. She could walk neither on toes nor heels. At present, she can walk only with support. MMT showed the following: 3- and trace (1/5) for hip flexion and extension, 3- and 4 for knee flexion and extension, 1 for ankle plantar- and dorsiflexion. K.W., a 33-year-old woman, began to drag her foot tips in walk and became unable to walk on toes at age 21. The leg weakness progressed into the wheelchair-ridden state at age 30. MMT gave the following results: 1 for hip flexion and extension, 2 and 4 for knee flexion and extension, zero for plantar- and dorsi-flexion. The most impressive CT findings common to these three patients are prominent contrast between the quadriceps muscles and the adductor- and hamstring-group: the former is markedly well preserved even in the most advanced patient (K.W.) while the latter are diffusely and severely affected even in the least affected patient (T.Y.). This finding well coincides with the results of MMT: the knee extensor (quadriceps muscles) fairly well keeps its strength even in the most advanced patient but the knee flexors (adductors and hamstrings) are definitely affected in the early stage of the condition. (J.P.N.)

  9. Computed tomographical findings of skeletal muscles in rimmed vacuole type distal myopathy

    Energy Technology Data Exchange (ETDEWEB)

    Kunimoto, Masanari; Kawai, Mitsuru; Goto, Jun; Nakano, Imaharu

    1987-03-01

    Skeletal muscle CT scans of three patients with biopsy-proven rimmed vacuole type distal myopathy(RVDM) from two unrelated families showed unique involvement pattern of the lower extremities. Parents of the patients in both families are first cousins. T.Y. is a 36-year-old woman who noticed mild difficulty in walking at 34 years of age. Now she shows waddling but still indpendent gait. Manual muscle test (MMT) revealed the following results: fair (3+/5) for hip flexion, 3 for hip extension, 3 for knee flexion, normal (5/5) for knee extension, poor (2/5) for ankle dorsi-flexion, good (4/5) for ankle plantar flexion. T.M., a 34-year-old younger sister of T.Y., started dragging her feet on gait at age 27. She could walk neither on toes nor heels. At present, she can walk only with support. MMT showed the following: 3- and trace (1/5) for hip flexion and extension, 3- and 4 for knee flexion and extension, 1 for ankle plantar- and dorsiflexion. K.W., a 33-year-old woman, began to drag her foot tips in walk and became unable to walk on toes at age 21. The leg weakness progressed into the wheelchair-ridden state at age 30. MMT gave the following results: 1 for hip flexion and extension, 2 and 4 for knee flexion and extension, zero for plantar- and dorsi-flexion. The most impressive CT findings common to these three patients are prominent contrast between the quadriceps muscles and the adductor- and hamstring-group: the former is markedly well preserved even in the most advanced patient (K.W.) while the latter are diffusely and severely affected even in the least affected patient (T.Y.). This finding well coincides with the results of MMT: the knee extensor (quadriceps muscles) fairly well keeps its strength even in the most advanced patient but the knee flexors (adductors and hamstrings) are definitely affected in the early stage of the condition. (J.P.N.).

  10. MUSCLE-BONE INTERACTIONS ACROSS AGE IN MEN

    Directory of Open Access Journals (Sweden)

    Ian J. Palmer

    2006-03-01

    Full Text Available This study examined the relationship of muscular strength and lean tissue with age-related patterns in bone mineral density (BMD in men 20-81 years of age. Subjects were assigned to one of three age groups, Young Men (YM, (n = 25, 20-39 yrs, Middle-aged Men (MM (n = 24, 40-59 yrs, and Older Men (OM (n = 23, 60-81 yrs. Isotonic and isokinetic strength was assessed for the quadriceps and hamstrings muscle groups. DXA (Lunar DPX-IQ was used to measure spine, hip, and total body BMD and body composition. OM had significantly lower (p < 0.05 total lean body mass (LBM than MM and lower leg lean mass (LM than YM and MM. OM had significantly lower (p < 0.01 BMD than YM and MM at the femoral neck and total hip sites and a higher proportion of OM were osteopenic and osteoporotic at the total hip site. Isotonic and isokinetic strength for both muscle groups was positively related (p < 0.05 with the hip BMD sites (r = 0.38-.67. Leg LM also was positively related to hip BMD (r = 0.37-.58. Multiple Regression analyses determined that age and lean mass (LBM or leg LM were significant predictors (p < 0.05 of femoral neck, and total hip BMD, while lean mass (LBM or leg LM was a significant predictor (p < 0.05 of BMD at the spine and trochanter sites. Isotonic and isokinetic leg strength variables were significant predictors (p < 0.05 of the total body, total hip and trochanter BMD. In conclusion, leg strength, leg LM, and total LBM were significant predictors of BMD in men, independent of age. These findings emphasize the importance of maintaining lean body mass for the bone health of aging men

  11. Electrical stimulation counteracts muscle atrophy associated with aging in humans

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    Helmut Kern

    2013-07-01

    Full Text Available Functional and structural muscle decline is a major problem during aging. Our goal was to improve in old subjects quadriceps m. force and mobility functional performances (stair test, chair rise test, timed up and go test with neuromuscular electrical stimulation (9 weeks, 2-3times/week, 20-30 minutes per session. Furthermore we performed histological and biological molecular analyses of vastus lateralis m. biopsies. Our findings demonstrate that electrical stimulation significantly improved mobility functional performancies and muscle histological characteristics and molecular markers.

  12. Muscle inactivity and activity patterns after sedentary time--targeted randomized controlled trial.

    Science.gov (United States)

    Pesola, Arto J; Laukkanen, Arto; Haakana, Piia; Havu, Marko; Sääkslahti, Arja; Sipilä, Sarianna; Finni, Taija

    2014-11-01

    Interventions targeting sedentary time are needed. We used detailed EMG recordings to study the short-term effectiveness of simple sedentary time-targeted tailored counseling on the total physical activity spectrum. This cluster randomized controlled trial was conducted between 2011 and 2013 (InPact, ISRCTN28668090), and short-term effectiveness of counseling is reported in the present study. A total of 133 office workers volunteered to participate, from which muscle activity data were analyzed from 48 (intervention, n = 24; control, n = 24). After a lecture, face-to-face tailored counseling was used to set contractually binding goals regarding breaking up sitting periods and increasing family based physical activity. Primary outcome measures were assessed 11.8 ± 1.1 h before and a maximum of 2 wk after counseling including quadriceps and hamstring muscle inactivity time, sum of the five longest muscle inactivity periods, and light muscle activity time during work, commute, and leisure time. Compared with those in the controls, counseling decreased the intervention group's muscle inactivity time by 32.6 ± 71.8 min from 69.1% ± 8.5% to 64.6% ± 10.9% (whole day, P work, P activity time increased by 20.6 ± 52.6 min, from 22.2% ± 7.9% to 25.0% ± 9.7% (whole day, P work, P work time, average EMG amplitude (percentage of EMG during maximal voluntary isometric contraction (MVC) (%EMG MVC)) increased from 1.6% ± 0.9% to 1.8% ± 1.0% (P activity. During work time, average EMG amplitude increased by 13%, reaching an average of 1.8% of EMG MVC. If maintained, this observed short-term effect may have health-benefiting consequences.

  13. Association between Thigh Muscle Volume and Leg Muscle Power in Older Women.

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    Ulrich Lindemann

    Full Text Available The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628, leg push power (r = 0.550, isometric quadriceps strength (r = 0.442, hand grip strength (r = 0.367, fast gait speed (r = 0.291, habitual gait speed (r = 0.256, body mass index (r = 0.411 and age (r = -0.392. Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.

  14. Myoglobin plasma level related to muscle mass and fiber composition: a clinical marker of muscle wasting?

    Science.gov (United States)

    Weber, Marc-André; Kinscherf, Ralf; Krakowski-Roosen, Holger; Aulmann, Michael; Renk, Hanna; Künkele, Annette; Edler, Lutz; Kauczor, Hans-Ulrich; Hildebrandt, Wulf

    2007-08-01

    Progressive muscle wasting is a central feature of cancer-related cachexia and has been recognized as a determinant of poor prognosis and quality of life. However, until now, no easily assessable clinical marker exists that allows to predict or to track muscle wasting. The present study evaluated the potential of myoglobin (MG) plasma levels to indicate wasting of large locomotor muscles and, moreover, to reflect the loss of MG-rich fiber types, which are most relevant for daily performance. In 17 cancer-cachectic patients (weight loss 22%) and 27 age- and gender-matched healthy controls, we determined plasma levels of MG and creatine kinase (CK), maximal quadriceps muscle cross-sectional area (CSA) by magnetic resonance imaging, muscle morphology and fiber composition in biopsies from the vastus lateralis muscle, body cell mass (BCM) by impedance technique as well as maximal oxygen uptake (VO(2)max). In cachectic patients, plasma MG, muscle CSA, BCM, and VO(2)max were 30-35% below control levels. MG showed a significant positive correlation to total muscle CSA (r = 0.65, p max as an important functional readout. CK plasma levels appear to be less reliable because prolonged increases are observed in even subclinical myopathies or after exercise. Notably, cancer-related muscle wasting was not associated with increases in plasma MG or CK in this study.

  15. Thigh muscle activity, knee motion, and impact force during side-step pivoting in agility-trained female basketball players.

    Science.gov (United States)

    Wilderman, Danielle R; Ross, Scott E; Padua, Darin A

    2009-01-01

    Improving neuromuscular control of hamstrings muscles might have implications for decreasing anterior cruciate ligament injuries in females. To examine the effects of a 6-week agility training program on quadriceps and hamstrings muscle activation, knee flexion angles, and peak vertical ground reaction force. Prospective, randomized clinical research trial. Sports medicine research laboratory. Thirty female intramural basketball players with no history of knee injury (age = 21.07 +/- 2.82 years, height = 171.27 +/- 4.66 cm, mass = 66.36 +/- 7.41 kg). Participants were assigned to an agility training group or a control group that did not participate in agility training. Participants in the agility training group trained 4 times per week for 6 weeks. We used surface electromyography to assess muscle activation for the rectus femoris, vastus medialis oblique, medial hamstrings, and lateral hamstrings for 50 milliseconds before initial ground contact and while the foot was in contact with the ground during a side-step pivot maneuver. Knee flexion angles (at initial ground contact, maximum knee flexion, knee flexion displacement) and peak vertical ground reaction force also were assessed during this maneuver. Participants in the training group increased medial hamstrings activation during ground contact after the 6-week agility training program. Both groups decreased their vastus medialis oblique muscle activation during ground contact. Knee flexion angles and peak vertical ground reaction force did not change for either group. Agility training improved medial hamstrings activity in female intramural basketball players during a side-step pivot maneuver. Agility training that improves hamstrings activity might have implications for reducing anterior cruciate ligament sprain injury associated with side-step pivots.

  16. Evaluation of the Combined Application of Neuromuscular Electrical Stimulation and Volitional Contractions on Thigh Muscle Strength, Knee Pain and Physical Performance in Women at Risk for Knee Osteoarthritis: A Randomized Controlled Trial.

    Science.gov (United States)

    Rabe, Kaitlin G; Matsuse, Hiroo; Jackson, Anthony; Segal, Neil A

    2018-05-28

    Knee osteoarthritis (OA) is a leading cause of disability that is associated with quadriceps weakness. However, strengthening in people with or with risk factors for knee OA can be poorly tolerated. To assess the efficacy of a twelve-week low-load exercise program, using a hybrid training system (HTS) that utilizes the combination of neuromuscular electrical stimulation and volitional contractions, for improving thigh muscle strength, knee pain and physical performance in women with or with risk factors for knee OA. Randomized, single-blind, controlled trial SETTING: Exercise training laboratory PARTICIPANTS: Forty-two women, age 44-85 years, with risk factors for knee OA INTERVENTIONS: Participants randomized to 12 weeks of biweekly low-load resistance training either with HTS or on an isokinetic dynamometer (control). Maximum isokinetic knee extensor torque. Secondary measures included: maximum isokinetic knee flexor torque, knee pain (KOOS), and timed 20-meter walk and chair-stand tests. HTS and control both resulted in muscle strengthening, reduced knee pain and improved physical performance. HTS group quadriceps and hamstring strength increased by 0.06±0.04 Nm/kg (p>.05) and 0.05±0.02 Nm/kg (p=.02), respectively. Control group quadriceps and hamstring strength increased by 0.03±0.04 Nm/kg (p>.05) and 0.06±0.02 Nm/kg (p=.009), respectively. Knee pain improved by 11.9±11.5 points (pmeter walk time decreased by 1.60±2.04 seconds (p=.005) and 0.95±1.2 seconds (p=.004), and chair stand time decreased by 4.8±10.0 seconds (p>.05) and 1.9±4.7 seconds (p>.05) in the HTS and control groups, respectively. These results did not differ statistically between HTS and control groups. These results suggest HTS is effective for improving pain and physical performance in women with risk factors for knee OA. However, HTS does not appear to be superior to low-load resistance training for improving muscle strength, pain or physical function. Copyright © 2018 American

  17. Anterior cruciate ligament reconstruction using bone plug-free quadriceps tendon autograft: intermediate-term clinical outcome after 24–36 months

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    Schulz AP

    2013-11-01

    ; a bony extension was never required. On average, graft length was measured at 8.8 cm (7.5–10 cm. The mean IKDC subjective score at follow-up was 80.44 points (55.17–100 points, standard deviation [SD] 12.05. The mean preinjury Tegner activity index was 4.98 (2–7 compared to a mean value of 4.16 (2–7, SD 0.8 at follow-up. There was a mean loss of 0.82 index points. The average Lysholm and Gillquist score was 89 points (65–100, SD 17.7. Of the results, 89.1% were in the good or very good groups; in one case (1.8%, the result was poor, while the rest were fair. Conclusion: ACL reconstruction using a bone plug-free quadriceps tendon autograft achieved satisfactory results in a midterm review. Keywords: ACL reconstruction, arthroscopic treatment, quadriceps tendon, clinical case series

  18. Insulin binding to individual rat skeletal muscles

    International Nuclear Information System (INIS)

    Koerker, D.J.; Sweet, I.R.; Baskin, D.G.

    1990-01-01

    Studies of insulin binding to skeletal muscle, performed using sarcolemmal membrane preparations or whole muscle incubations of mixed muscle or typical red (soleus, psoas) or white [extensor digitorum longus (EDL), gastrocnemius] muscle, have suggested that red muscle binds more insulin than white muscle. We have evaluated this hypothesis using cryostat sections of unfixed tissue to measure insulin binding in a broad range of skeletal muscles; many were of similar fiber-type profiles. Insulin binding per square millimeter of skeletal muscle slice was measured by autoradiography and computer-assisted densitometry. We found a 4.5-fold range in specific insulin tracer binding, with heart and predominantly slow-twitch oxidative muscles (SO) at the high end and the predominantly fast-twitch glycolytic (FG) muscles at the low end of the range. This pattern reflects insulin sensitivity. Evaluation of displacement curves for insulin binding yielded linear Scatchard plots. The dissociation constants varied over a ninefold range (0.26-2.06 nM). Binding capacity varied from 12.2 to 82.7 fmol/mm2. Neither binding parameter was correlated with fiber type or insulin sensitivity; e.g., among three muscles of similar fiber-type profile, the EDL had high numbers of low-affinity binding sites, whereas the quadriceps had low numbers of high-affinity sites. In summary, considerable heterogeneity in insulin binding was found among hindlimb muscles of the rat, which can be attributed to heterogeneity in binding affinities and the numbers of binding sites. It can be concluded that a given fiber type is not uniquely associated with a set of insulin binding parameters that result in high or low binding

  19. Inhibition of muscle fibrosis results in increases in both utrophin levels and the number of revertant myofibers in Duchenne muscular dystrophy.

    Science.gov (United States)

    Levi, Oshrat; Genin, Olga; Angelini, Corrado; Halevy, Orna; Pines, Mark

    2015-09-15

    Duchenne Muscular Dystrophy is characterized by: near absence of dystrophin in skeletal muscles; low percentage of revertant myofibers; up-regulation of utrophin synthesis; and a high degree of muscle fibrosis. In patient quadriceps femoris biopsies (n = 6, ages between 3-9 years) an inverse correlation was observed between the levels of collagen type I - representing fibrosis - and the levels of utrophin. This correlation was independent of the patient's age and was observed in the entire muscle biopsy sections. In the mdx mice diaphragm (n = 6/group), inhibition of fibrosis by halofuginone resulted in increases in the levels of utrophin. The utrophin/fibrosis relationships were not limited to collagen type I, but also applied to other constituents of the fibrosis machinery. The inverse correlation was found also in old mdx mice with established fibrosis. In addition, inhibition of collagen type I levels was associated with increases in the numbers of revertant myofibers, both as single myofibers and in clusters in the diaphragm and the gastrocnemius. In summary, our results demonstrate an inverse correlation between the level of muscle fibrosis and the level of utrophin and that of the number of revertant myofibers. These findings may reveal common links between the fibrotic and utrophin-synthesis pathways and offer new insights into the regulation of utrophin synthesis.

  20. Effect of spa physiotherapy on the range of motion and muscle strength in women with gonarthrosis.

    Science.gov (United States)

    Lizis, Paweł

    2013-01-01

    Degeneration arthritis is a chronic disease of undetermined progressiveness and unknown pathogenesis. It can affect one or more joints. It reveals itself most frequently between 40 - 60 years of age, and affects the lives of professionally active individuals. The aim of the presented study was to assess the impact of a 21-day stay at a rehabilitation facility on the range of motion and muscle strength of the knee in women with gonarthrosis. The study group consisted of 30 women aged 50-74 years diagnosed with degeneration of the knee joint. The average age of the study group was 65.9 ± 7.2 years. Patients remained in the 21-day rehabilitation facility of Rehabilitational Hospital No. 21 in Busko Zdrój SP ZOZ, Poland. We measured with the help of protractor in SFTR range the motion bending and straightening of the knee with an accuracy of 1°. The Lovett strength test was assessed of the ischio-tibial muscles, quadriceps, sartorius--acting on the knee joint of the patient. The study was carried out on the first and the last day of the stay in the rehabilitation facility. There was improvement in the range of flexion and strength of muscles acting on the knee joint of the afflicted women. The study showed that 21-day rehabilitation holiday improved the range and strength of the muscles acting on the knee joint of the afflicted women. This proved that comprehensive rehabilitation improves the function of the knee joint with gonarthrosis, prevents disease progression and is an alternative to drug therapy.

  1. Acute Exercise Induced Mitochondrial H2O2 Production in Mouse Skeletal Muscle: Association with p66Shc and FOXO3a Signaling and Antioxidant Enzymes

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2015-01-01

    Full Text Available Exercise induced skeletal muscle phenotype change involves a complex interplay between signaling pathways and downstream regulators. This study aims to investigate the effect of acute exercise on mitochondrial H2O2 production and its association with p66Shc, FOXO3a, and antioxidant enzymes. Male ICR/CD-1 mice were subjected to an acute exercise. Muscle tissues (gastrocnemius and quadriceps femoris were taken after exercise to measure mitochondrial H2O2 content, expression of p66Shc and FOXO3a, and the activity of antioxidant enzymes. The results showed that acute exercise significantly increased mitochondrial H2O2 content and expressions of p66Shc and FOXO3a in a time-dependent manner, with a linear correlation between the increase in H2O2 content and p66Shc or FOXO3a expression. The activity of mitochondrial catalase was slightly reduced in the 90 min exercise group, but it was significantly higher in groups with 120 and 150 min exercise compared to that of 90 min exercise group. The activity of SOD was not significantly affected. The results indicate that acute exercise increases mitochondrial H2O2 production in the skeletal muscle, which is associated with the upregulation of p66Shc and FOXO3a. The association of p66Shc and FOXO3a signaling with exercise induced H2O2 generation may play a role in regulating cellular oxidative stress during acute exercise.

  2. The The Effects of Cold Water Immersion on Anaerobic Power, Dynamic Balance and Muscle Activation After a karate kumite fighting in Female Karateka

    Directory of Open Access Journals (Sweden)

    Taher Afshar Nezhad

    2017-10-01

    Full Text Available Many athletes are using specific techniques to minimize fatigue and accelerate recovery processes. Cold water immersion (CWI is one of the most popular interventions used by athletes to potentially return to their pre-fatigue performance level. the purpose of this study was to investigate the effects of CWI on anaerobic performance, balance and muscle activation of female karateka after a simulated match. 15 young female karateka (age: 18.7±1.7 years, body mass: 55.5±6.3 kg, height:165±5.1 cm with at least three years' experience in karate kumite fighting were included in the study. After three round 3-minute competition, participants were grouped into a CWI group (20 min at 12±1°C and a control group (CTL. Anaerobic power (30 s Wingate test, and dynamic balance (Star-Excursion test were measured before the competition and 24 h after intervention. Surface electromyography (EMG was sampled from quadriceps femoris muscles. Peak normalized muscle activation levels and force were identified during maximal isometric test. A significant decrease in the anaerobic performance after the competition was observed for both groups (p<0.05. CWI were effective in enhancing the anaerobic performance after competition compared with the CTL. Dynamic balance decreased for two groups, although CWI resulted in the smallest reduction in balance. There was a significant difference in peak and mean RMS values of the EMG in Rectus Femoris but not Vastus muscles after the CWI intervention when compared to CTL (p<0.05. CWI improve recovery related to dynamic balance and anaerobic performance of karate kumite fighter. It can be concluded that CWI appears to promote muscle activation and reduce fatigue that is related to better performance in 24 hours post intervention.

  3. The Acetyl Group Buffering Action of Carnitine Acetyltransferase Offsets Macronutrient-Induced Lysine Acetylation of Mitochondrial Proteins

    Directory of Open Access Journals (Sweden)

    Michael N. Davies

    2016-01-01

    Full Text Available Lysine acetylation (AcK, a posttranslational modification wherein a two-carbon acetyl group binds covalently to a lysine residue, occurs prominently on mitochondrial proteins and has been linked to metabolic dysfunction. An emergent theory suggests mitochondrial AcK occurs via mass action rather than targeted catalysis. To test this hypothesis, we performed mass spectrometry-based acetylproteomic analyses of quadriceps muscles from mice with skeletal muscle-specific deficiency of carnitine acetyltransferase (CrAT, an enzyme that buffers the mitochondrial acetyl-CoA pool by converting short-chain acyl-CoAs to their membrane permeant acylcarnitine counterparts. CrAT deficiency increased tissue acetyl-CoA levels and susceptibility to diet-induced AcK of broad-ranging mitochondrial proteins, coincident with diminished whole body glucose control. Sub-compartment acetylproteome analyses of muscles from obese mice and humans showed remarkable overrepresentation of mitochondrial matrix proteins. These findings reveal roles for CrAT and L-carnitine in modulating the muscle acetylproteome and provide strong experimental evidence favoring the nonenzymatic carbon pressure model of mitochondrial AcK.

  4. Current evidence demonstrates similar effects of kilohertz-frequency and low-frequency current on quadriceps evoked torque and discomfort in healthy individuals: a systematic review with meta-analysis.

    Science.gov (United States)

    da Silva, Vinicius Zacarias Maldaner; Durigan, João Luiz Quaglioti; Arena, Ross; de Noronha, Marcos; Gurney, Burke; Cipriano, Gerson

    2015-01-01

    Neuromuscular electrical stimulation (NMES) is widely utilized to enhance muscle performance. However, the optimal NMES waveform with respect to treatment effect has not been established. To investigate the effects of kilohertz-frequency alternating current (KFAC) and low-frequency pulsed current (PC) on quadriceps evoked torque and self-reported discomfort. PubMed, The Cochrane Library, EMBASE, MEDLINE, Physiotherapy Evidence Database (PEDro), SinoMed, ISI Web of Knowledge, and CINAHL were searched for randomized controlled trials (RCTs) and quasi-randomized controlled trials (QRCTs). Two reviewers independently selected potential studies according to the inclusion criteria, extracted data, and assessed methodological quality. Studies were eligible if they compared KFAC versus PC interventions. Studies that included outcome measures for percentage of maximal isometric voluntary contraction (%MIVC) torque and self-reported discomfort level were eligible for evaluation. Seven studies involving 127 individuals were included. The methodological quality of eligible trials was moderate, with a mean of 5 on the 10-point PEDro scale. Overall, PC was no better than KFAC in terms of evoked torque and there was no difference in self-reported discomfort level. KFAC and PC have similar effects on quadriceps evoked torque and self-reported discomfort level in healthy individuals. The small number and overall methodological quality of currently available studies included in this meta-analysis indicate that new RCTs are needed to better determine optimal NMES treatment parameters.

  5. Quadriceps Contusion

    Science.gov (United States)

    ... lacrosse. And they can happen in sports like skateboarding, skiing, and snowboarding, where there is a chance ... to an opposing player. With skiing, snowboarding, and skateboarding, know your limits. Stay within your capabilities to ...

  6. Specific Adaptations in Performance and Muscle Architecture After Weighted Jump-Squat vs. Body Mass Squat Jump Training in Recreational Soccer Players.

    Science.gov (United States)

    Coratella, Giuseppe; Beato, Marco; Milanese, Chiara; Longo, Stefano; Limonta, Eloisa; Rampichini, Susanna; Cè, Emiliano; Bisconti, Angela V; Schena, Federico; Esposito, Fabio

    2018-04-01

    Coratella, G, Beato, M, Milanese, C, Longo, S, Limonta, E, Rampichini, S, Cè, E, Bisconti, AV, Schena, F, and Esposito, F. Specific adaptations in performance and muscle architecture after weighted jump-squat vs. body mass squat jump training in recreational soccer players. J Strength Cond Res 32(4): 921-929, 2018-The aim of the present study was to compare the effects of weighted jump-squat training (WJST) vs. body mass squat jump training (BMSJT) on quadriceps' muscle architecture, lower-limb lean-mass (LM) and muscle strength, performance in change of direction (COD), and sprint and jump in recreational soccer players. Forty-eight healthy soccer players participated in an offseason randomized controlled trial. Before and after an 8-week training intervention, vastus lateralis pennation angle, fascicle length, muscle thickness, LM, squat 1RM, quadriceps and hamstrings isokinetic peak torque, agility T-test, 10-and 30-m sprints, and squat-jump (SJ) were measured. Although similar increases were observed in muscle thickness, fascicle length increased more in WJST (Effect size [ES] = 1.18, 0.82-1.54) than in BMSJT (ES = 0.54, 0.40-0.68), and pennation angle increased only in BMSJT (ES = 1.03, 0.78-1.29). Greater increases in LM were observed in WJST (ES = 0.44, 0.29-0.59) than in BMSJT (ES = 0.21, 0.07-0.37). The agility T-test (ES = 2.95, 2.72-3.18), 10-m (ES = 0.52, 0.22-0.82), and 30-m sprints (ES = 0.52, 0.23-0.81) improved only in WJST, whereas SJ improved in BMSJT (ES = 0.89, 0.43-1.35) more than in WJST (ES = 0.30, 0.03-0.58). Similar increases in squat 1RM and peak torque occurred in both groups. The greater inertia accumulated within the landing phase in WJST vs. BMSJT has increased the eccentric workload, leading to specific eccentric-like adaptations in muscle architecture. The selective improvements in COD in WJST may be related to the increased braking ability generated by the enhanced eccentric workload.

  7. Workers' Extra-Nest Behavioral Changes During Colony Fission in Dinoponera quadriceps (Santschi).

    Science.gov (United States)

    Medeiros, J; Araújo, A

    2014-04-01

    Ant colonies can reproduce by two strategies: independent foundation, wherein the queen starts a new colony alone, and dependent foundation, in which workers assist the queen. In the queenless species Dinoponera quadriceps (Santschi), the colony reproduces obligatorily by fission, a type of dependent foundation, but this process is not well understood. This study describes a colony fission event of D. quadriceps in the field and analyzes the influence of the fission process on workers' extra-nest behavior. Based on observations of workers outside the nest, five distinct stages were identified: monodomic stage, polydomic stage, split stage, conflict stage, and post-conflict stage. The colony was initially monodomic and then occupied a second nest before it split into two independent colonies, indicating a gradual and opportunistic dependent foundation. After the fission event, the daughter colony had aggressive conflicts with the parental colony, resulting in the latter's disappearance. Colony fission affected workers' extra-nest behavior by increasing the frequency of rubbing the gaster against the substrate (which probably has a chemical marking function) and by decreasing the frequency of foraging during the split stage. After the fission event, the number of foragers was halved and foragers remained nearer to the nest during extra-nest activity. The spatial closeness of the parental and daughter colonies led to competition that caused the extinction or migration of the parental colony. Intraspecific competition was indicated by foraging directionality at the colony level, whereby areas of neighbor colonies were avoided; this directionality was stronger while both colonies coexisted.

  8. A Rare Case of Simultaneous Acute Bilateral Quadriceps Tendon Rupture and Unilateral Achilles Tendon Rupture

    Directory of Open Access Journals (Sweden)

    Wei Yee Leong

    2013-07-01

    Full Text Available Introduction: There have been multiple reported cases of bilateral quadriceps tendon ruptures (QTR in the literature. These injuries frequently associated with delayed diagnosis, which results in delayed surgical treatment. In very unusual cases, bilateral QTRs can be associated with other simultaneous tendon ruptures. Case Report: We present a rare case of bilateral QTR with a simultaneous Achilles Tendon Rupture involving a 31 years old Caucasian man who is a semi-professional body builder taking anabolic steroids. To date bilateral QTR with additional TA rupture has only been reported once in the literature and to our knowledge this is the first reported case of bilateral QTR and simultaneous TA rupture in a young, fit and healthy individual. Conclusion: The diagnosis of bilateral QTR alone can sometimes be challenging and the possibility of even further tendon injuries should be carefully assessed. A delay in diagnosis could result in delay in treatment and potentially worse outcome for the patient. Keywords: Quadriceps tendon rupture; Achilles tendon rupture; Bilateral.

  9. Effects of Patellar Taping on the Patella Position in Presence of Quadriceps Contraction in 20-40 Year-Old Women With Patellofemoral Pain Syndrome Using MRI

    Directory of Open Access Journals (Sweden)

    Mahboobeh Banejad

    2016-06-01

    Discussion: Kinesio taping plus quadriceps contraction reduced the PFCA and LPFA. Patellar taping is effective in the correction of the patellar position in contracted quadriceps. Therefore, both neuromuscular and mechanical effects of patellar taping affect the patellar position over a long period. The combination of patellar taping and exercise reduced pain and improved activity faster than either of the treatment alone.

  10. Evaluation of healthy muscle tissue by strain and shear wave elastography – Dependency on depth and ROI position in relation to underlying bone

    DEFF Research Database (Denmark)

    Ewertsen, Caroline; Carlsen, Jonathan Frederik; Christiansen, Iben Riishede

    2016-01-01

    and methods: Ten healthy volunteers (five males and five females) had their biceps brachii, gastrocnemius, and quadriceps muscle examined with strain- and shear wave elastography at three different depths and in regions located above bone and beside bone. Strain ratios were averaged from cine-loops of 10 s...

  11. Genetic impairment of AMPK{alpha}2 signaling does not reduce muscle glucose uptake during treadmill exercise in mice

    DEFF Research Database (Denmark)

    Maarbjerg, Stine Just; Jørgensen, Sebastian Beck; Rose, Adam John

    2009-01-01

    and female mice over-expressing kinase-dead alpha2-AMPK (AMPK-KD) in skeletal and heart muscles. Wildtype and AMPK-KD mice were exercised at the same absolute intensity and the same relative intensity (30% and 70% of individual maximal running speed) to correct for reduced exercise capacity of the AMPK......-KD mouse. Muscle glucose clearance was measured using [3H]-2-deoxy-glucose as tracer. In wildtype mice glucose clearance was increased at 30% and 70% of maximal running speed by 40% and 350% in the quadriceps muscle, and by 120% and 380% in gastrocnemius muscle, respectively. Glucose clearance...

  12. ROLE OF HAMSTRING MUSCLES IN KNEE JOINT STABILITY PROVIDING AND INJURY PREVENTION

    OpenAIRE

    Pontaga, Inese

    2016-01-01

    The aim of our investigation was to determine the ratio of maximal torque values and the torques in the certain positions of range of movements (ROM) between hamstring (H) and quadriceps femoris (Q) muscles at medium and high velocity of movement in concentric (CC) and eccentric (ECC) action of hamstring muscles. The knee muscles of 15 amateur female short and middle distance runners were tested by the dynamometer system in the isokinetic movements with the angular velocity of 90º/s and 240º...

  13. Nuclear Positioning in Muscle Development and Disease

    OpenAIRE

    Eric eFolker; Mary eBaylies

    2013-01-01

    Muscle disease as a group is characterized by muscle weakness, muscle loss, and impaired muscle function. Although the phenotype is the same, the underlying cellular pathologies, and the molecular causes of these pathologies, are diverse. One common feature of many muscle disorders is the mispositioning of myonuclei. In unaffected individuals myonuclei are spaced throughout the periphery of the muscle fiber such that the distance between nuclei is maximized. However, in diseased muscles, th...

  14. Recovery of atrophic leg muscles in the hemiplegics due to cerebrovascular accidents

    International Nuclear Information System (INIS)

    Odajima, Natsu; Ishiai, Sumio; Okiyama, Ryouichi; Furukawa, Tetsuo; Tsukagoshi, Hiroshi.

    1988-01-01

    Thirty-five patients with hemiplegia due to cerebrovascular accidents were studied with regared to the muscle wastings before and after rehabilitation training. Hemiplegics were composed of 12 improved and 23 non-improved patients. The CT scan was carried out at the midportion of the thigh and largest-diameter section of the calf. Muscle size of each cross-sectional area was measured on CT image and the increase of size (ΔS) in each muscle after training was calculated. The ΔS of quadriceps femoris was correlated with that of whole cross-section of the thigh. The gracilis in non-affected side was not correlated with that of whole muscles. In both legs, there was an increase in leg muscle size after training. These changes were nost marked in the non-affected side of the improved patients. After training the difference between the two limbs remained unchanged. Recovery of muscle wasting in both legs was seen first in the quadriceps in thigh and flexors in calf. Gracilis was relatively unchanged in comparison with other muscles. Remarkable increase of muscle size in non-affected side was worthwhile to note. (author)

  15. Recovery of atrophic leg muscles in the hemiplegics due to cerebrovascular accidents. Computed tomographic study

    Energy Technology Data Exchange (ETDEWEB)

    Odajima, Natsu; Ishiai, Sumio; Okiyama, Ryouichi; Furukawa, Tetsuo; Tsukagoshi, Hiroshi.

    1988-02-01

    Thirty-five patients with hemiplegia due to cerebrovascular accidents were studied with regared to the muscle wastings before and after rehabilitation training. Hemiplegics were composed of 12 improved and 23 non-improved patients. The CT scan was carried out at the midportion of the thigh and largest-diameter section of the calf. Muscle size of each cross-sectional area was measured on CT image and the increase of size (..delta..S) in each muscle after training was calculated. The ..delta..S of quadriceps femoris was correlated with that of whole cross-section of the thigh. The gracilis in non-affected side was not correlated with that of whole muscles. In both legs, there was an increase in leg muscle size after training. These changes were nost marked in the non-affected side of the improved patients. After training the difference between the two limbs remained unchanged. Recovery of muscle wasting in both legs was seen first in the quadriceps in thigh and flexors in calf. Gracilis was relatively unchanged in comparison with other muscles. Remarkable increase of muscle size in non-affected side was worthwhile to note.

  16. Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy.

    Science.gov (United States)

    Tsitkanou, S; Spengos, K; Stasinaki, A-N; Zaras, N; Bogdanis, G; Papadimas, G; Terzis, G

    2017-11-01

    Aim of the study was to investigate whether high-intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty-two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high-intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross-sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P high-intensity interval cycling performed after heavy-resistance exercise may not inhibit resistance exercise-induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high-intensity cycling after heavy-resistance exercise may decrease RFD partly due to muscle architectural changes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Predicting muscle forces of individuals with hemiparesis following stroke

    Directory of Open Access Journals (Sweden)

    Maladen Ryan

    2008-02-01

    Full Text Available Abstract Background Functional electrical stimulation (FES has been used to improve function in individuals with hemiparesis following stroke. An ideal functional electrical stimulation (FES system needs an accurate mathematical model capable of designing subject and task-specific stimulation patterns. Such a model was previously developed in our laboratory and shown to predict the isometric forces produced by the quadriceps femoris muscles of able-bodied individuals and individuals with spinal cord injury in response to a wide range of clinically relevant stimulation frequencies and patterns. The aim of this study was to test our isometric muscle force model on the quadriceps femoris, ankle dorsiflexor, and ankle plantar-flexor muscles of individuals with post-stroke hemiparesis. Methods Subjects were seated on a force dynamometer and isometric forces were measured in response to a range of stimulation frequencies (10 to 80-Hz and 3 different patterns. Subject-specific model parameter values were obtained by fitting the measured force responses from 2 stimulation trains. The model parameters thus obtained were then used to obtain predicted forces for a range of frequencies and patterns. Predicted and measured forces were compared using intra-class correlation coefficients, r2 values, and model error relative to the physiological error (variability of measured forces. Results Results showed excellent agreement between measured and predicted force-time responses (r2 >0.80, peak forces (ICCs>0.84, and force-time integrals (ICCs>0.82 for the quadriceps, dorsiflexor, and plantar-fexor muscles. The model error was within or below the +95% confidence interval of the physiological error for >88% comparisons between measured and predicted forces. Conclusion Our results show that the model has potential to be incorporated as a feed-forward controller for predicting subject-specific stimulation patterns during FES.

  18. Muscle Deoxygenation Causes Muscle Fatigue

    Science.gov (United States)

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D.

    1999-01-01

    Muscle fatigue is a common musculoskeletal disorder in the work place, and may be a harbinger for more disabling cumulative trauma disorders. Although the cause of fatigue is multifactorial, reduced blood flow and muscle oxygenation may be the primary factor in causing muscle fatigue during low intensity muscle exertion. Muscle fatigue is defined as a reduction in muscle force production, and also occurs among astronauts who are subjected to postural constraints while performing lengthy, repetitive tasks. The objectives of this research are to: 1) develop an objective tool to study the role of decreased muscle oxygenation on muscle force production, and 2) to evaluate muscle fatigue during prolonged glovebox work.

  19. Premature loss of muscle mass and function in type 2 diabetes.

    Science.gov (United States)

    Guerrero, N; Bunout, D; Hirsch, S; Barrera, G; Leiva, L; Henríquez, S; De la Maza, M P

    2016-07-01

    Muscle mass and function are among the most relevant factors that contribute to an optimal quality of life, and are strong predictors of mortality in the elderly. Loss of lean tissues and deterioration of muscle function have been described as one of the many complications of type 2 diabetes mellitus (DM2), but most studies do not isolate age as an intervening factor. To study whether adult DM2 patients up to 60years of age have decreased muscle mass and function compared with healthy non-diabetic (ND) subjects of similar age. Appendicular fat-free mass (ApFFM) by dual X-ray absorptiometry (DEXA), handgrip strength (HS), quadriceps strength (QS), 12 min walking capacity (12MW) and the Timed Up and Go test (TUG) were measured in 100 DM2 patients and 39 ND controls. Muscle quality, or the ratio between lean mass and muscle strength of upper and lower limbs, and the functional limitations associated with pain and stiffness assessed according to the Western Ontario and McMaster Universities Arthrosis Index (WOMAC) were also recorded. Specific tests were performed to rule out microvascular diabetic complications (retinal and peripheral nerves), metabolic control, kidney function and vitamin D status and examine their association with ApFFM and function. ApFFM was significantly higher among DM2 female patients and lower among diabetic men. However opposite results were obtained when individual values were corrected for body mass index (BMI), specifically among women, who were more likely to be obese. As for muscle strength and global functionality tests, significantly better performances in TUG, 12MW, QS and HS were observed among ND subjects of both sexes. These differences prevailed even after excluding diabetic patients with microvascular complications as well as those with more than 10years of diabetes. Muscle quality was also significantly better among ND women. Higher scores of pain and stiffness in the WOMAC scale correlated with 12MW and TUG in both groups but

  20. Muscle Cramps

    Science.gov (United States)

    ... Talk to your provider about the risks and benefits of medicines. How can I prevent muscle cramps? To prevent muscle cramps, you can Stretch your muscles, especially before exercising. If you often get leg cramps at night, ...

  1. Muscle-bone Interactions During Fracture Healing

    Science.gov (United States)

    2015-03-01

    muscle resection, isotopic or heterotopic minced muscle implants were placed immediately adjacent to the periosteum. Their control groups consisted of...interacting with surrounding muscle. Addition- ally, Utvag et al. showed that significant muscle injury and ab- sence of muscle by resection, or by traumatic

  2. Arthroscopic evaluation of patellofemoral congruence with rotation of the knee joint and electrical stimulation of the quadriceps.

    Science.gov (United States)

    Suganuma, Jun; Mochizuki, Ryuta; Inoue, Yutaka; Kitamura, Kazuya; Honda, Akio

    2014-02-01

    The aim of this study was to investigate the pathoanatomic features of patellar instability by arthroscopically comparing patellofemoral congruence with rotation of the knee joint and/or electrical stimulation of the quadriceps (ESQ) between knees with and without patellar instability. We retrospectively examined 83 knee joints in 83 patients. The joints were classified into 2 groups: group 1 comprised those without a history of patellar dislocation and included 59 patients (25 male and 34 female patients), and group 2 comprised those with a history of patellar dislocation and included 24 patients (9 male and 15 female patients). Evaluation of patellofemoral congruence at 30° of flexion of the knee joint was conducted based on an axial radiograph and arthroscopic findings. The congruence angle was measured on the radiograph. The position of the patellar central ridge (PPCR) on the trochlear groove during arthroscopy was measured using still video frames of knee joints with rotational stress and/or ESQ. Statistical differences in the measurements between the 2 groups were assessed with the unpaired t test and the area under the receiver operating characteristic curve of each measurement. There were significant differences (P congruence angle on radiographs and PPCR in knee joints with rotational stress and/or ESQ on arthroscopy. External and internal rotation of the knee joint caused lateral and medial patellar shift, respectively, in both groups, but the shift was significantly larger in group 2. ESQ in addition to rotation caused further patellar shift in group 2 but reduced patellar shift in group 1. Measurement of PPCR with external rotation of the knee and ESQ was the only method to show an area under the receiver operating characteristic curve of 1. There were significant differences in the effects of rotation of the knee joint and/or ESQ on patellofemoral congruence at 30° of flexion of the knee joint on arthroscopy between knees with and without patellar

  3. LBNP/ergometer effects on female cardiovascular and muscle deconditioning in 15d head-down bed rest

    Science.gov (United States)

    Wang, Lin-Jie

    2012-07-01

    Female has already been an important part of astronaut corps but gender characteristics in weightlessness and countermeasure effects still not clearly elucidated. In this study the LBNP/Ergometer effects on female cardiovascular deconditioning and muscle atrophy in 15d head-down bed rest were explored. 22 female university students were recruited as volunteers that participated in the 15d head-down bed rest. They were divided into control group (Con,n=8), LBNP exercise group (LBNP,n=7) and LBNP combined with ergometer exercise group (LBNP+Ergo, n=7). Grade negative pressures of -10,-20,-30,-40mmHg 20 or 55min were used in LBNP exercise. In ergometer exercises the subjects must maintain 60-80% VO2peak of pre-bed rest at pedal speed of about 70cycle/min for 15min and the entire exercise duration was 30min. LBNP were performed at 6th,8th,10th,12th,and 13th day and Ergometer were operated at 4th,5th,7th,9th,11th day during bed rest. Before and after bed rest, cardiovascular tilt test were performed to evaluate orthostatic intolerance, supine cycle ergometer were used to test the cardiopulmonary function, MRI tests were operated to examine the volume variations of leg muscle groups and isokinetic test were given to test the muscle strength and endurance of knee. 40% of female subjects did not pass the tilt table test after bed rest and exercises made no difference. Compared with pre-BR, VO2max and VO2max /body weight, VO2/HRmax, maximal power and duration significantly decreased in CON group and LBNP group. For the ERGO+LBNP group, there were no visible different in the parameters of cardiopulmonary function except that maximal power and duration decreased. Muscle maximal voluntary contraction and muscle (quadriceps, rectus femoris, gastrocnemius and soleus) volume decreasing in non-predominant leg was larger in Con group than in LBNP+Ergo group. It is suggested that LBNP combined with ergometer in some degrees can counteract the cardiovascular and muscle deconditioning

  4. Impact of exercising muscles to exhaustion on blood markers in weight-training

    Directory of Open Access Journals (Sweden)

    Roberto Burini

    2008-06-01

    Full Text Available Metabolic markers of physical exhaustion were evaluated in venous blood drawn from 8 men (20-30 years old with at least 3 years’ experience in weight-lifting training. They were submitted, in the morning, to an overload (exhaustion test starting at 80% of 1 RM (one repetition maximum on 8 muscle groups. Heart rate (HR was measured and samples of venous blood were collected before and immediately after the exhaustion test (ET and sent to a laboratory for blood gas analysis (pH, lactate, pO2, pCO2 and HCO-3 and measurement of electrolytes (Na+, Cl-, K+ and Ca++ and glycemia. The HR/kg ratios observed were in the following sequence of descending order: arm and hamstrings > shoulder and back > chest > quadriceps > calf. Results for NH4, pH, lactate and HCO-3 levels were changed in all 8 muscle groups, whereas Ca++, K+, Na+, Cl-, and uric acid did not change significantly after the ET. The muscle groups: back, biceps, triceps, chest, and hamstrings exhibited changes in seven to nine indicators while only 4 to 6 biochemical indicators changed in response to shoulder, calf, and quadriceps exercises. Thus, blood markers indicating acidosis, hemoconcentration and hyperglycemia were sensitive markers although with low specificity for the eight muscle groups. Calf and quadriceps had the highest tolerance for weight loading along with the smallest HR increase and lowest number of biochemical indicators changed. Therefore, it appears possible to reach muscle exhaustion with systemic responses in the blood by working out the arm muscles and hamstrings with lighter weights than for quadriceps and calf muscles.ResumoO impacto da exaustão (com pesos de grupos musculares, sobre indicadores sanguíneos de acidose e de hemoconcentração foi estudado em 8 jovens (20-30 anos treinados em musculação. Todos foram submetidos a sobrecarga inicial de 80% de 1RM, até a exaustão (TE, em 8 exercícios distintos, com coleta de sangue e registro da freqüência card

  5. The impact of obesity on skeletal muscle strength and structure through adolescence to old age.

    Science.gov (United States)

    Tomlinson, D J; Erskine, R M; Morse, C I; Winwood, K; Onambélé-Pearson, Gladys

    2016-06-01

    Obesity is associated with functional limitations in muscle performance and increased likelihood of developing a functional disability such as mobility, strength, postural and dynamic balance limitations. The consensus is that obese individuals, regardless of age, have a greater absolute maximum muscle strength compared to non-obese persons, suggesting that increased adiposity acts as a chronic overload stimulus on the antigravity muscles (e.g., quadriceps and calf), thus increasing muscle size and strength. However, when maximum muscular strength is normalised to body mass, obese individuals appear weaker. This relative weakness may be caused by reduced mobility, neural adaptations and changes in muscle morphology. Discrepancies in the literature remain for maximal strength normalised to muscle mass (muscle quality) and can potentially be explained through accounting for the measurement protocol contributing to muscle strength capacity that need to be explored in more depth such as antagonist muscle co-activation, muscle architecture, a criterion valid measurement of muscle size and an accurate measurement of physical activity levels. Current evidence demonstrating the effect of obesity on muscle quality is limited. These factors not being recorded in some of the existing literature suggest a potential underestimation of muscle force either in terms of absolute force production or relative to muscle mass; thus the true effect of obesity upon skeletal muscle size, structure and function, including any interactions with ageing effects, remains to be elucidated.

  6. The effect of control of diabetes mellitus on plasma T4, T3, rT3 levels and half muscle relaxation period

    International Nuclear Information System (INIS)

    Ismail, A.A.; Hafiez, A.A.; Sayed, S.N.; Abbas, E.Z.; Halawa, F.A.; Youssef, M.M.

    1984-01-01

    25 diabetics of the maturity onset type who showed no clinical evidence of either peripheral neruropathy or diabetic amyotrophy were selected for this study. All patients were subjected to the following investigations: estimation of half muscle relaxation period of the quadriceps muscle knee-jerk, measurement of plasma levels of thyroxine (T 4 ), triiodothyronine (T 3 ) and reverse triiodothronine (rT 3 ), determination of fasting and two hours postprandial blood sugar levels. The quadriceps muscle relaxation period in uncontrolled diabetics was significantly longer than in normals. Control of diabetes by glibenclamide or gliclazide did not cause a significant change in muscle relaxation period. There was also no significant difference between the effects of the two drugs. (author)

  7. Fraqueza muscular esquelética e intolerância ao exercício em pacientes com doença pulmonar obstrutiva crônica Skeletal muscle weakness and exercise intolerance in patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    KR Silva

    2008-06-01

    21cmH2O, p<0.05, palm grip strength (38±6 versus 47±5kg, p<0.05, peak torque (103±21 versus 138±18Nm, p<0.05 and total work of the quadriceps femoris (1570±395 versus 2333±568J, p<0.05 when compared with the control group (independent Student’s t test. There was no correlation between FEV1 and the variables studied, while the FFM correlated with the total work of the quadriceps (Pearson, r=0.6290, p<0.05. CONCLUSIONS: These results indicate that patients with COPD show weakness of the inspiratory and quadriceps muscles and lower functional capacity, when compared with a healthy group. Moreover, they suggest that the degree of airflow obstruction is not a good predictor for quantifying the nutritional and muscle impairments in patients with COPD.

  8. Comparison of Lower Body Specific Resistance Training on the Hamstring to Quadriceps Strength Ratios in Men and Women

    Science.gov (United States)

    Dorgo, Sandor; Edupuganti, Pradeep; Smith, Darla R.; Ortiz, Melchor

    2012-01-01

    In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional…

  9. Neglected rupture of the quadriceps tendon in a patient with chronic renal failure (case report and review of the literature).

    Science.gov (United States)

    Hassani, Zouhir Ameziane; Boufettal, Moncef; Mahfoud, Moustapha; Elyaacoubi, Moradh

    2014-01-01

    Spontaneous ruptures of the quadriceps tendon are infrequent injuries, it is seen primarily in patients with predisposing diseases such as gout, rheumatoid arthritis and chronic renal failure. A 32-year-old man had a history of end stage renal disease and received regular hemodialysis treatment for more than 5 years. He was admitted in our service for total functional impotence of the right lower limb with knee pain after a common fall two months ago. The radiogram showed a ''patella baja" with suprapatellar calcifications. The ultrasound and MRI showed an aspect of rupture of the quadriceps tendon in its proximal end with retraction of 3 cm. Quadriceps tendon repair was performed with a lengthening plasty, and the result was satisfactory after a serial rehabilitation program. The diagnosis of quadriceps tendon ruptures needs more attention in patients with predisposing diseases. They should not be unknown because the treatment of neglected lesions is more difficult. We insist on the early surgical repair associated with early rehabilitation that can guarantee recovery of good active extension.

  10. Quadriceps Tendon Rupture and Contralateral Patella Tendon Avulsion Post Primary Bilateral Total Knee Arthroplasty: A Case Report

    Directory of Open Access Journals (Sweden)

    Gaurav Sharma

    2016-07-01

    Full Text Available Background: Extensor mechanism failure secondary to knee replacement could be due to tibial tubercle avulsion, Patellar tendon rupture, patellar fracture or quadriceps tendon rupture. An incidence of Patella tendon rupture of 0.17% and Quadriceps tendon rupture of around 0.1% has been reported after Total knee arthroplasty. These are considered a devastating complication that substantially affects the clinical results and are challenging situations to treat with surgery being the mainstay of the treatment. Case Description: We report here an interesting case of a patellar tendon rupture of one knee and Quadriceps tendon rupture of the contralateral knee following simultaneous bilateral knee replacement in a case of inflammatory arthritis patient. End to end repair for Quadriceps tear and augmentation with Autologous Hamstring tendon graft was done for Patella tendon rupture. OUTCOME: Patient was followed up for a period of 1 year and there was no Extension lag with a flexion of 100 degrees in both the knees. DISCUSSION: The key learning points and important aspects of diagnosing these injuries early and the management techniques are described in this unique case of bilateral extensor mechanism disruption following knee replacements.

  11. The association between submaximal quadriceps force steadiness and the knee adduction moment during walking in patients with knee osteoarthritis

    DEFF Research Database (Denmark)

    Sørensen, Tina Juul; Langberg, Henning; Aaboe, Jens

    2011-01-01

    in this population. METHODS: Forty-one patients with knee OA (34 females and 7 males) were included in the study. Submaximal isometric quadriceps force steadiness was measured during a force target-tracking task. Peak knee adduction moments during ambulation were measured using a 3-dimensional gait analysis system...

  12. Muscle MRI in Duchenne muscular dystrophy: Evidence of a distinctive pattern.

    Science.gov (United States)

    Polavarapu, Kiran; Manjunath, Mahadevappa; Preethish-Kumar, Veeramani; Sekar, Deepha; Vengalil, Seena; Thomas, PriyaTreesa; Sathyaprabha, Talakad N; Bharath, Rose Dawn; Nalini, Atchayaram

    2016-11-01

    The purpose of this study was to describe the pattern of muscle involvement using MRI findings and correlate with functional as well as muscle strength measurements. Fifty genetically confirmed DMD children with a mean age of 7.6 ± 2.8 (4-15 years) underwent muscle MRI and qualitative assessment was done for muscle changes using Mercuri staging for fibro-fatty replacement on T1 sequence and Borsato score for myoedema on STIR sequence. Detailed phenotypic characterisation was done with Manual muscle testing (modified MRC grading) and Muscular Dystrophy Functional Rating Scale (MDFRS). Mercuri scoring showed severe fibro-fatty changes in Gluteus medius, minimus and Adductor magnus followed by moderate to severe changes in Gluteus maximus and Quadriceps muscles. Total sparing of Gracilis, Sartorius and Semimembranosus muscles was observed. Superficial posterior and lateral leg muscles were preferentially involved with sparing of deep posterior and anterior leg muscles. Myoedema showed significant inverse correlation with fatty infiltration in thigh muscles. Similarly, significant inverse correlation was observed between Mercuri scores and MRC grading as well as MDFRS scores. A direct linear correlation was observed between duration of illness and fibro-fatty changes in piriformis, quadriceps and superficial posterior leg muscles. There was no correlation between MRI findings and genotypic characteristics. However, this specific pattern of muscle involvement in MRI could aid in proceeding for genetic testing when clinical suspicion is high, thus reducing the need for muscle biopsy. Fibro fatty infiltration as measured by Mercuri scoring can be a useful marker for assessing the disease severity and progression. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction With a Free Quadriceps Tendon Autograft.

    Science.gov (United States)

    Caterev, Sergiu; Nistor, Dan Viorel; Todor, Adrian

    2016-10-01

    Anatomic double-bundle anterior cruciate ligament (ACL) reconstruction aims to restore the 2 functional bundles of the ACL in an attempt to better reproduce the native biomechanics of the injured knee and promote long-term knee health. However, this concept is not fully accepted and is not performed on a standard basis. In addition, the superiority of this technique over the conventional single-bundle technique has been questioned, especially the long-term clinical results. One of the down sides of the double-bundle reconstruction is the complexity of the procedure, with increased risks, operative time, and costs compared with the single-bundle procedure. Also, the revision procedure, if necessary, is more challenging. We propose a technique that has some advantages over the traditional double-bundle procedure, using a single femoral tunnel, 2 tibial tunnels, and a free quadriceps tendon autograft.

  14. Outcomes following Hip and Quadriceps Strengthening Exercises for Patellofemoral Syndrome: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Adebisi Bisi-Balogun

    2015-10-01

    Full Text Available There is growing evidence to support change in the rehabilitation strategy of patellofemoral pain syndrome (PFPS from traditional quadriceps strengthening exercises to inclusion of hip musculature strengthening in individuals with PFPS. Several studies have evaluated effects of quadriceps and hip musculature strengthening on PFPS with varying outcomes on pain and function. This systematic review and meta-analysis aims to synthesize outcomes of pain and function post-intervention and at follow-up to determine whether outcomes vary depending on the exercise strategy in both the short and long term. Electronic databases including MEDLINE, EMBASE, CINAHL, Web of Science, PubMed, Pedro database, Proquest, Science direct, and EBscoHost databases were searched for randomized control trials published between 1st of January 2005 and 31st of June 2015, comparing the outcomes of pain and function following quadriceps strengthening and hip musculature strengthening exercises in patients with PFPS. Two independent reviewers assessed each paper for inclusion and quality. Means and SDs were extracted from each included study to allow effect size calculations and comparison of results. Six randomized control trials met the inclusion criteria. Limited to moderate evidence indicates that hip abductor strengthening was associated with significantly lower pain post-intervention (SMD −0.88, −1.28 to −0.47 95% CI, and at 12 months (SMD −3.10, −3.71 to −2.50 95% CI with large effect sizes (greater than 0.80 compared to quadriceps strengthening. Our findings suggest that incorporating hip musculature strengthening in management of PFPS tailored to individual ability will improve short-term and long-term outcomes of rehabilitation. Further research evaluating the effects of quadriceps and hip abductors strengthening focusing on reduction in anterior knee pain and improvement in function in management of PFPS is needed.

  15. Electromyography of the thigh muscles during lifting tasks in kneeling and squatting postures

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, S.; Pollard, J.; Porter, W.L. [NIOSH, Pittsburgh, PA (United States). Pittsburgh Research Laboratory

    2011-07-01

    Underground coal miners who work in low-seam mines frequently handle materials in kneeling or squatting postures. To assess quadriceps and hamstring muscle demands in these postures, nine participants performed lateral load transfers in kneeling and squatting postures, during which electromyographic (EMG) data were collected. EMG activity was obtained at five points throughout the transfer for three quadriceps muscles and two hamstring muscles from each thigh. ANOVA results indicated that EMG data for nine of 10 thigh muscles were affected by an interaction between posture and angular position of the load lifted (p <0.001). Muscles of the right thigh were most active during the lifting portion of the task (lifting a block from the participant's right) and activity decreased as the block was transferred to the left. Left thigh muscles showed the opposite pattern. EMG activity for the majority of thigh muscles was affected by the size of the base of support provided by different postures, with lower EMG activity observed with a larger base of support and increased activity in postures where base of support was reduced (p<0.05). Thigh EMG activity was lowest in postures with fully flexed knees, which may explain worker preference for this posture. However, such postures are also associated with increased risk of meniscal damage.

  16. Light-load resistance exercise increases muscle protein synthesis and hypertrophy signaling in elderly men

    DEFF Research Database (Denmark)

    Agergaard, Jakob; Bülow, Jacob; Jensen, Jacob K

    2017-01-01

    to 13 h of supine rest. After 2.5 h of rest, unilateral LL-RE, consisting of leg extensions (10 sets, 36 repetitions) at 16% of 1 repetition maximum (RM), was conducted. Subsequently, the subjects were randomized to oral intake of 4 g of whey protein per hour (PULSE, n = 10), 28 g of whey protein at 0 h...... and 12 g of whey protein at 7 h postexercise (BOLUS, n = 10), or 4 g of maltodextrin per hour (placebo, n = 10). Quadriceps muscle biopsies were taken at 0, 3, 7, and 10 h postexercise from the resting and the exercised leg of each subject. Myofibrillar FSR and activity of select targets from...... persisted in the placebo group only. Levels of phosphorylated (T37/46) eukaryotic translation initiation factor 4E-binding protein 1 increased throughout the postexercise period in the exercised leg in the placebo and BOLUS groups and peaked at 7 h. In all three groups, phosphorylated (T56) eukaryotic...

  17. Effects of training programs based on ipsilateral voluntary and stimulated contractions on muscle strength and monopedal postural control of the contralateral limb.

    Science.gov (United States)

    Kadri, Mohamed Abdelhafid; Noé, Frederic; Nouar, Merbouha Boulahbel; Paillard, Thierry

    2017-09-01

    To compare the effects of unilateral strength training by stimulated and voluntary contractions on muscle strength and monopedal postural control of the contralateral limb. 36 non-active healthy male subjects were recruited and split randomly into three groups. Two groups of 12 subjects took part in a strength-training program (3 sessions a week over 8 weeks) comprising 43 contractions of the quadriceps femoris of the ipsilateral limb (at 20% of the MVC). One group carried out voluntary contractions exclusively (VOL group), while the other group benefited exclusively from electro-induced contractions (NMES group). The other 12 subjects formed the control (CON) group. Assessments of MVC and monopedal postural control in static and dynamic postural tasks were performed with the ipsilateral (ISPI) and contralateral (CONTRA) limbs before (PRE) and after (POST) completion of the training program. After the training program, the MVC of the IPSI and CONTRA limbs increased similarly for both experimental groups (VOL and NMES). There were no significant improvements of monopedal postural control for the IPSI or CONTRA limbs in either the VOL or NMES experimental group. No change was observed for the CON group over the protocol period. The purposed training program with NMES vs VOL contractions induced strength gains but did not permit any improvement of contralateral monopedal postural control in healthy young subjects. This has potential for therapeutic application and allows clinicians to focus their training programs on dynamic and poly-articular exercises to improve the postural control in young subjects.

  18. Do interindividual differences in cardiac output during submaximal exercise explain differences in exercising muscle oxygenation and ratings of perceived exertion?

    Science.gov (United States)

    Bentley, Robert F; Jones, Joshua H; Hirai, Daniel M; Zelt, Joel T; Giles, Matthew D; Raleigh, James P; Quadrilatero, Joe; Gurd, Brendon J; Neder, J Alberto; Tschakovsky, Michael E

    2018-01-01

    Considerable interindividual differences in the Q˙-V˙O2 relationship during exercise have been documented but implications for submaximal exercise tolerance have not been considered. We tested the hypothesis that these interindividual differences were associated with differences in exercising muscle deoxygenation and ratings of perceived exertion (RPE) across a range of submaximal exercise intensities. A total of 31 (21 ± 3 years) healthy recreationally active males performed an incremental exercise test to exhaustion 24 h following a resting muscle biopsy. Cardiac output (Q˙ L/min; inert gas rebreathe), oxygen uptake (V˙O2 L/min; breath-by-breath pulmonary gas exchange), quadriceps saturation (near infrared spectroscopy) and exercise tolerance (6-20; Borg Scale RPE) were measured. The Q˙-V˙O2 relationship from 40 to 160 W was used to partition individuals post hoc into higher (n = 10; 6.3 ± 0.4) versus lower (n = 10; 3.7 ± 0.4, P exercise (all P > 0.4). Lower cardiac responders had greater leg (P = 0.027) and whole body (P = 0.03) RPE only at 185 W, but this represented a higher %peak V˙O2 in lower cardiac responders (87 ± 15% vs. 66 ± 12%, P = 0.005). Substantially lower Q˙-V˙O2 in the lower responder group did not result in altered RPE or exercising muscle deoxygenation. This suggests substantial recruitment of blood flow redistribution in the lower responder group as part of protecting matching of exercising muscle oxygen delivery to demand. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  19. Fast-twitch glycolytic skeletal muscle is predisposed to age-induced impairments in mitochondrial function

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Díaz, Víctor; Soldini, Lavinia

    2013-01-01

    The etiology of mammalian senescence is suggested to involve the progressive impairment of mitochondrial function; however, direct observations of age-induced alterations in actual respiratory chain function are lacking. Accordingly, we assessed mitochondrial function via high-resolution respirom......The etiology of mammalian senescence is suggested to involve the progressive impairment of mitochondrial function; however, direct observations of age-induced alterations in actual respiratory chain function are lacking. Accordingly, we assessed mitochondrial function via high......-resolution respirometry and mitochondrial protein expression in soleus, quadricep, and lateral gastrocnemius skeletal muscles, which represent type 1 slow-twitch oxidative muscle (soleus) and type 2 fast-twitch glycolytic muscle (quadricep and gastrocnemius), respectively, in young (10-12 weeks) and mature (74-76 weeks......) mice. Electron transport through mitochondrial complexes I and III increases with age in quadricep and gastrocnemius, which is not observed in soleus. Mitochondrial coupling efficiency during respiration through complex I also deteriorates with age in gastrocnemius and shows a tendency (p = .085...

  20. Prognostic factors in non-muscle-invasive bladder tumors - I. Clinical prognostic factors: A review of the experience of the EORTC genito-urinary group - II. Biologic prognostic markers

    NARCIS (Netherlands)

    Kurth, Karl-Heinz; Sylvester, Richard J.

    2007-01-01

    Objectives: To summarize the most important clinical prognostic factors of non-muscle-invasive bladder cancer, as assessed by the European organization for Research and Treatment of Cancer (EORTC) Genito-Urinary Group, to present biologic markers involved in urothelial cell carcinoma, and to address

  1. Muscle size, neuromuscular activation, and rapid force characteristics in elderly men and women

    DEFF Research Database (Denmark)

    Suetta, C; Aagaard, P; Magnusson, S P

    2007-01-01

    quadriceps muscle cross-sectional area (LCSA), contractile rate of force development (RFD, Delta force/Delta time), impulse (integral force dt), muscle activation deficit (interpolated twitch technique), maximal neuromuscular activity [electromyogram (EMG)], and antagonist muscle coactivation in elderly men......%), contractile RFD (W: 17-26%; M: 15-24%), impulse (W: 10-19%, M: 19-20%), maximal EMG amplitude (W: 22-25%, M: 22-28%), and an increased muscle activation deficit (-18%) compared with UN. Furthermore, women were less strong (AF: 40%; UN: 39%), had less muscle mass (AF: 33%; UN: 34%), and had a lower RFD (AF: 38......-50%; UN: 41-48%) compared with men. Similarly, maximum EMG amplitude was smaller for both agonists (AF: 51-63%; UN: 35-61%) and antagonist (AF: 49-64%; UN: 36-56%) muscles in women compared with men. However, when MVC and RFD were normalized to LCSA, there were no differences between genders. The present...

  2. Role of adenosine in regulating the heterogeneity of skeletal muscle blood flow during exercise in humans

    DEFF Research Database (Denmark)

    Heinonen, Ilkka; Nesterov, Sergey V; Kemppainen, Jukka

    2007-01-01

    receptor blockade. BF heterogeneity within muscles was calculated from 16-mm(3) voxels in BF images and heterogeneity among the muscles from the mean values of the four QF compartments. Mean BF in the whole QF and its four parts increased, and heterogeneity decreased with workload both without......Evidence from both animal and human studies suggests that adenosine plays a role in the regulation of exercise hyperemia in skeletal muscle. We tested whether adenosine also plays a role in the regulation of blood flow (BF) distribution and heterogeneity among and within quadriceps femoris (QF...... and with theophylline (P heterogeneity among the QF muscles, yet blockade increased within-muscle BF heterogeneity in all four QF muscles (P = 0.03). Taken together, these results show that BF becomes less heterogeneous with increasing...

  3. Pre-mRNA Processing Is Partially Impaired in Satellite Cell Nuclei from Aged Muscles

    Directory of Open Access Journals (Sweden)

    Manuela Malatesta

    2010-01-01

    Full Text Available Satellite cells are responsible for the capacity of mature mammalian skeletal muscles to repair and maintain mass. During aging, skeletal muscle mass as well as the muscle strength and endurance progressively decrease, leading to a condition termed sarcopenia. The causes of sarcopenia are manifold and remain to be completely elucidated. One of them could be the remarkable decline in the efficiency of muscle regeneration; this has been associated with decreasing amounts of satellite cells, but also to alterations in their activation, proliferation, and/or differentiation. In this study, we investigated the satellite cell nuclei of biceps and quadriceps muscles from adult and old rats; morphometry and immunocytochemistry at light and electron microscopy have been combined to assess the organization of the nuclear RNP structural constituents involved in different steps of mRNA formation. We demonstrated that in satellite cells the RNA pathways undergo alterations during aging, possibly hampering their responsiveness to muscle damage.

  4. Hip and trunk muscles activity during nordic hamstring exercise

    Science.gov (United States)

    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

  5. 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.

  6. Quantitative muscle ultrasonography in amyotrophic lateral sclerosis.

    NARCIS (Netherlands)

    Arts, I.M.P.; Rooij, F.G. van; Overeem, S.; Pillen, S.; Janssen, H.M.; Schelhaas, H.J.; Zwarts, M.J.

    2008-01-01

    In this study, we examined whether quantitative muscle ultrasonography can detect structural muscle changes in early-stage amyotrophic lateral sclerosis (ALS). Bilateral transverse scans were made of five muscles or muscle groups (sternocleidomastoid, biceps brachii/brachialis, forearm flexor group,

  7. Strength training to contraction failure increases voluntary activation of the quadriceps muscle shortly after total knee arthroplasty

    DEFF Research Database (Denmark)

    Mikkelsen, Elin Karin; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders

    2016-01-01

    to the abstract to increase trial transparency.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed...

  8. Muscle area and muscle density of osteoarthritis of the knee joint studied by computerized tomography

    International Nuclear Information System (INIS)

    Suzuki, Nobuharu; Onosawa, Toshihiro; Shibata, Minoru; Yamashita, Izumi; Yoshimura, Shinichiro; Muraoka, Shunichi; Asano, Akira

    1985-01-01

    In order to investigate the etiology and pathology of osteoarthritis of the knee joints (OA), the areas and density of the muscle 10 cm above the knee were compared using computerized tomography (CT) in 26 knees from 19 normal persons, 30 knees from 17 patients with OA, and 14 knees from 7 patients with rheumatoid arthritis. The areas of the quadriceps musculi of thigh were remarkably decreased and the areas of the flexor musculi were comparatively maintained in the patients with OA. Muscle density was markedly lowered in the musculi semimembranosus and biceps femoris long head. Fatty tissues were seen in the whole area of the venter on CT in some of the patients with OA. These findings are considered to be of major importance when studying the etiology of OA. (Namekawa, K.)

  9. Effects of low-level laser therapy applied before or after plyometric exercise on muscle damage markers: randomized, double-blind, placebo-controlled trial.

    Science.gov (United States)

    Fritsch, Carolina Gassen; Dornelles, Maurício Pinto; Severo-Silveira, Lucas; Marques, Vanessa Bernardes; Rosso, Isabele de Albuquerque; Baroni, Bruno Manfredini

    2016-12-01

    Promising effects of phototherapy on markers of exercise-induced muscle damage has been already demonstrated in constant load or isokinetic protocols. However, its effects on more functional situations, such as plyometric exercises, and when is the best moment to apply this treatment (pre- or post-exercise) remain unclear. Therefore, the purpose of this study was to investigate the effect of low-level laser therapy (LLLT) before or after plyometric exercise on quadriceps muscle damage markers. A randomized, double-blinded, placebo-controlled trial was conducted with 24 healthy men, 12 at pre-exercise treatment group and 12 at post-exercise treatment group. Placebo and LLLT (810 nm, 200 mW per diode, 6 J per diode, 240 J per leg) were randomly applied on right/left knee extensor muscles of each volunteer before/after a plyometric exercise protocol. Muscular echo intensity (ultrasonography images), soreness (visual analogue scale - VAS), and strength impairment (maximal voluntary contraction - MVC) were assessed at baseline, 24, 48, and 72 h post-exercise. Legs treated with LLLT before or after exercise presented significantly smaller increments of echo intensity (values up to 1 %) compared to placebo treatments (increased up to ∼7 %). No significant treatment effect was found for VAS and MVC, although a trend toward better results on LLLT legs have been found for VAS (mean values up to 30 % lesser than placebo leg). In conclusion, LLLT applied before or after plyometric exercise reduces the muscle echo intensity response and possibly attenuates the muscle soreness. However, these positive results were not observed on strength impairment.

  10. Compartmentalization of NO signaling cascade in skeletal muscles

    International Nuclear Information System (INIS)

    Buchwalow, Igor B.; Minin, Evgeny A.; Samoilova, Vera E.; Boecker, Werner; Wellner, Maren; Schmitz, Wilhelm; Neumann, Joachim; Punkt, Karla

    2005-01-01

    Skeletal muscle functions regulated by NO are now firmly established. However, the literature on the compartmentalization of NO signaling in myocytes is highly controversial. To address this issue, we examined localization of enzymes engaged in L-arginine-NO-cGMP signaling in the rat quadriceps muscle. Employing immunocytochemical labeling complemented with tyramide signal amplification and electron microscopy, we found NO synthase expressed not only in the sarcolemma, but also along contractile fibers, in the sarcoplasmic reticulum and mitochondria. The expression pattern of NO synthase in myocytes showed striking parallels with the enzymes engaged in L-arginine-NO-cGMP signaling (arginase, phosphodiesterase, and soluble guanylyl cyclase). Our findings are indicative of an autocrine fashion of NO signaling in skeletal muscles at both cellular and subcellular levels, and challenge the notion that the NO generation is restricted to the sarcolemma

  11. The muscle CT of thigh in chronic Werdnig-Hoffmann disease

    International Nuclear Information System (INIS)

    Horikawa, Hirosei; Konagaya, Masaaki; Takayanagi, Tetsuya; Otsuji, Hideaki

    1986-01-01

    In this paper, the muscle CT of thigh in chronic Werdnig-Hoffmann disease (chronic WH) was evaluated. The subjects were five cases of chronic WH (3 males and 2 females, ages ranging from 6 to 22 years) and four control males. All cases showed symmetrical muscular weakness. The proximal muscle were more affected than the distal in the upper limbs. But the muscle strength of hip adduction was relatively spared as compared with other strength of lower limbs. The CT scan was carried out at the upper quarter level between lesser trochanter and medial condyle of the femur. The muscle CT of cases aged 6 and 7 years showed the severely decreased cross-sectional area of muscle without significant decrease in density. The atrophic muscles were surrounded by a large amount of low density area. The hamstring muscles and the adductor muscles, especially adductor longus muscle (ALM), were less affected than the quadriceps femoris muscles. Spotty and moth-eaten low density areas were observed dominantly in the severely affected muscles. In the advanced cases, only ALM could be identified on the CT image. The other muscles were unable to be identified because of severe atrophy with extremely low density. These CT findings suggest the process of muscular wastings of chronic WH as follows; at first muscle fibers are atrophied due to denervation and sooner or later replaced with fat tissue. Moreover, the preservation of ALM suggests that loss of anterior horn cells does not always go on homogeneously. (author)

  12. Effects of Low- vs. High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men.

    Science.gov (United States)

    Schoenfeld, Brad J; Peterson, Mark D; Ogborn, Dan; Contreras, Bret; Sonmez, Gul T

    2015-10-01

    The purpose of this study was to compare the effect of low- versus high-load resistance training (RT) on muscular adaptations in well-trained subjects. Eighteen young men experienced in RT were matched according to baseline strength and then randomly assigned to 1 of 2 experimental groups: a low-load RT routine (LL) where 25-35 repetitions were performed per set per exercise (n = 9) or a high-load RT routine (HL) where 8-12 repetitions were performed per set per exercise (n = 9). During each session, subjects in both groups performed 3 sets of 7 different exercises representing all major muscles. Training was performed 3 times per week on nonconsecutive days, for a total of 8 weeks. Both HL and LL conditions produced significant increases in thickness of the elbow flexors (5.3 vs. 8.6%, respectively), elbow extensors (6.0 vs. 5.2%, respectively), and quadriceps femoris (9.3 vs. 9.5%, respectively), with no significant differences noted between groups. Improvements in back squat strength were significantly greater for HL compared with LL (19.6 vs. 8.8%, respectively), and there was a trend for greater increases in 1 repetition maximum (1RM) bench press (6.5 vs. 2.0%, respectively). Upper body muscle endurance (assessed by the bench press at 50% 1RM to failure) improved to a greater extent in LL compared with HL (16.6 vs. -1.2%, respectively). These findings indicate that both HL and LL training to failure can elicit significant increases in muscle hypertrophy among well-trained young men; however, HL training is superior for maximizing strength adaptations.

  13. Identification of skeletal muscle mass depletion across age and BMI groups in health and disease--there is need for a unified definition.

    Science.gov (United States)

    Bosy-Westphal, A; Müller, M J

    2015-03-01

    Although reduced skeletal muscle mass is a major predictor of impaired physical function and survival, it remains inconsistently diagnosed to a lack of standardized diagnostic approaches that is reflected by the variable combination of body composition indices and cutoffs. In this review, we summarized basic determinants of a normal lean mass (age, gender, fat mass, body region) and demonstrate limitations of different lean mass parameters as indices for skeletal muscle mass. A unique definition of lean mass depletion should be based on an indirect or direct measure of skeletal muscle mass normalized for height (fat-free mass index (FFMI), appendicular or lumbal skeletal muscle index (SMI)) in combination with fat mass. Age-specific reference values for FFMI or SMI are more advantageous because defining lean mass depletion on the basis of total FFMI or appendicular SMI could be misleading in the case of advanced age due to an increased contribution of connective tissue to lean mass. Mathematical modeling of a normal lean mass based on age, gender, fat mass, ethnicity and height can be used in the absence of risk-defined cutoffs to identify skeletal muscle mass depletion. This definition can be applied to identify different clinical phenotypes like sarcopenia, sarcopenic obesity or cachexia.

  14. Polymorphisms in the vitamin D receptor gene are associated with muscle strength in men and women.

    Science.gov (United States)

    Windelinckx, A; De Mars, G; Beunen, G; Aerssens, J; Delecluse, C; Lefevre, J; Thomis, M A I

    2007-09-01

    Vitamin D receptor (VDR) polymorphisms have been associated with fracture risk and muscle strength, although evidence for the latter is limited and conflicting. BsmI, TaqI and FokI VDR polymorphisms were genotyped in 253 men (54.9 +/- 10.2 yr) and 240 women (41.5 +/- 13.2 yr). Haplotypes were constructed for BsmI and TaqI. Handgrip, isometric (at 60 degrees , 120 degrees and 180 degrees joint angle) and eccentric torques (60 degrees /s) of knee extension and flexion were analysed using AN(C)OVA. Torque-velocity curves were constructed for concentric torques at 60 degrees /s, 180 degrees /s and 240 degrees /s and analysed using multivariate AN(C)OVA. Age, height and fat-free mass were included as covariates. Quadriceps isometric and concentric strength were higher in female f/f homozygotes compared to F allele carriers. Adjustment for confounding factors rendered results for quadriceps isometric strength at 120 degrees non-significant. No significant association was found with BsmI-TaqI haplotype in women. In contrast, male Bt/Bt homozygotes had higher isometric quadriceps strength at 150 degrees and higher concentric quadriceps strength than bT allele carriers without and with adjustment for confounding factors. No association was observed with FokI in men. In both genders, no interaction effect was present between BsmI-TaqI haplotype and FokI. Different VDR gene polymorphisms are associated with quadriceps strength in men and women.

  15. [Selective training of the vastus medialis muscle using electrical stimulator for chondromalacia patella].

    Science.gov (United States)

    Guo, K; Ye, Q; Lin, J; Shen, J; Yang, X

    1996-04-01

    Chondromalacia patella is closely related with subluxation and tilt of patella, as well as with muscular atrophy of quadriceps, especially in vastus medialis muscle. 364 cases of chondromalacia patella were treated with selective training of the vastus medialis muscle using electrical stimulator in our hospital. 211 cases were followed up after treatment from 6 months to 3 years. Among them excellent and good results were seen in 130 cases (62%), fair results were seen in 69 cases (33%) and no change was seen in 12 cases (5%). Significant reduction of CA (P chondromalacia patella.

  16. Combined inhibition of nitric oxide and prostaglandins reduces human skeletal muscle blood flow during exercise

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Langberg, Henning; Gemmer, Carsten

    2002-01-01

    The vascular endothelium is an important mediator of tissue vasodilatation, yet the role of the specific substances, nitric oxide (NO) and prostaglandins (PG), in mediating the large increases in muscle perfusion during exercise in humans is unclear. Quadriceps microvascular blood flow......, respectively (P exercise in humans. These findings demonstrate an important synergistic role of NO and PG for skeletal muscle vasodilatation and hyperaemia during muscular contraction....... was quantified by near infrared spectroscopy and indocyanine green in six healthy humans during dynamic knee extension exercise with and without combined pharmacological inhibition of NO synthase (NOS) and PG by L-NAME and indomethacin, respectively. Microdialysis was applied to determine interstitial release...

  17. A comparison of hamstring muscle activity during different screening tests for non-contact ACL injury

    DEFF Research Database (Denmark)

    Husted, Rasmus S; Bencke, Jesper; Andersen, Lars Louis

    2016-01-01

    phenomenon and thereby observable independently of the type of clinical screening tests used is not known. This cross sectional study investigated the rank correlation of knee joint neuromuscular activity between three different ACL injury risk screening tests. METHODS: Sixty-two adolescent female elite......BACKGROUND: Reduced ability to activate the medial hamstring muscles during a sports-specific sidecutting movement has been found to be a potential risk factor for non-contact ACL injury. However, whether a reduced ability to activate the medial hamstring muscle is a general neuromuscular...... football and handball players (16.7±1.3years) participated in the study. Using surface electromyography (EMG) assessment, the neuromuscular activity of medial hamstring muscle (semitendinosus, ST), lateral hamstring muscle (biceps femoris, BF) and quadriceps muscle (vastus lateralis, VL) were monitored...

  18. Quadriceps Tendon Autograft in Anterior Cruciate Ligament Reconstruction: A Systematic Review.

    Science.gov (United States)

    Hurley, Eoghan T; Calvo-Gurry, Manuel; Withers, Dan; Farrington, Shane K; Moran, Ray; Moran, Cathal J

    2018-05-01

    To systematically review the current evidence to ascertain whether quadriceps tendon autograft (QT) is a viable option in anterior cruciate ligament reconstruction. A literature review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Cohort studies comparing QT with bone-patellar tendon-bone autograft (BPTB) or hamstring tendon autograft (HT) were included. Clinical outcomes were compared, with all statistical analyses performed using IBM SPSS Statistics for Windows, version 22.0, with P < .05 being considered statistically significant. We identified 15 clinical trials with 1,910 patients. In all included studies, QT resulted in lower rates of anterior knee pain than BPTB. There was no difference in the rate of graft rupture between QT and BPTB or HT in any of the studies reporting this. One study found that QT resulted in greater knee stability than BPTB, and another study found increased stability compared with HT. One study found that QT resulted in improved functional outcomes compared with BPTB, and another found improved outcomes compared with HT, but one study found worse outcomes compared with BPTB. Current literature suggests QT is a viable option in anterior cruciate ligament reconstruction, with published literature showing comparable knee stability, functional outcomes, donor-site morbidity, and rerupture rates compared with BPTB and HT. Level III, systematic review of Level I, II, and III studies. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  19. How the condition of occlusal support affects the back muscle force and masticatory muscle activity?

    OpenAIRE

    石岡, 克; 河野, 正司; Ishioka, Masaru; Kohno, Shoji

    2002-01-01

    This study was conducted to determine how the condition of occlusal support affects the back muscle force and masticatory muscle activity. Two groups of subjects were enlisted: sport-trained group and normal group. While electrodes of the electromyography (EMG) were attached to the surface of the masticatory muscles, each subject's back muscle force was recorded during upper body stretching using a back muscle force-measuring device. The task was performed under four different occlusal suppor...

  20. Effect of enzyme replacement therapy on isokinetic strength for all major muscle groups in four patients with Pompe disease-a long-term follow-up

    DEFF Research Database (Denmark)

    Andreassen, Christer Swan; Schlütter, Jacob Mørup; Vissing, John

    2014-01-01

    Pompe disease is a rare, inherited metabolic myopathy characterized by progressive weakness of the proximal limb and respiratory muscles. We report the findings from four patients with late-onset Pompe disease treated with α-glucosidase (Myozyme) for 2 (n=2) and 6 (n=2) years, and monitored with ...

  1. Thigh muscle volume predicted by anthropometric measurements and correlated with physical function in the older adults.

    Science.gov (United States)

    Chen, B B; Shih, T T F; Hsu, C Y; Yu, C W; Wei, S Y; Chen, C Y; Wu, C H; Chen, C Y

    2011-06-01

    (1) to correlate thigh muscle volume measured by magnetic resonance image (MRI) with anthropometric measurements and physical function in elderly subjects; (2) to predict MRI-measured thigh muscle volume using anthropometric measurements and physical functional status in elderly subjects. Cross-sectional, nonrandomized study. Outpatient clinic in Taiwan. Sixty-nine elderly subjects (33 men and 36 women) aged 65 and older. The anthropometric data (including body height, body weight, waist size, and thigh circumference), physical activity and function (including grip strength, bilateral quadriceps muscle power, the up and go test, chair rise, and five meters walk time) and bioelectrical impedance analysis data (including total body fat mass, fat-free mass, and predictive muscle size) were measured. MRI-measured muscle volume of both thighs was used as the reference standard. The MRI-measured thigh volume was positively correlated with all anthropometric data, quadriceps muscle power and the up and go test as well as fat-free mass and predictive muscle mass, whereas it was negatively associated with age and walk time. In predicting thigh muscle volume, the variables of age, gender, body weight, and thigh circumference were significant predictors in the linear regression model: Muscle volume (cm3) =4226.3-42.5 × Age (year)-955.7 × gender (male=1, female=2) + 45.9 × body weight(kg) + 60.0 × thigh circumference (cm) (r2 = 0.745, P estimate = 581.6 cm3). The current work provides evidence of a strong relationship between thigh muscle volume and physical function in the elderly. We also developed a prediction equation model using anthropometric measurements. This model is a simple and noninvasive method for everyday clinical practice and follow-up.

  2. Do peak torque angles of muscles change following anterior cruciate ligament reconstruction using hamstring or patellar tendon graft?

    Science.gov (United States)

    Yosmaoğlu, Hayri Baran; Baltacı, Gül; Sönmezer, Emel; Özer, Hamza; Doğan, Deha

    2017-12-01

    This study aims to compare the effects of anterior cruciate ligament (ACL) reconstruction using autogenous hamstring or patellar tendon graft on the peak torque angle. The study included 132 patients (103 males, 29 females; mean age 29±9 year) who were performed ACL reconstruction with autogenous hamstring or patellar tendon graft. The peak torque angles in the quadriceps and hamstring muscles were recorded using an isokinetic dynamometer. Angle of peak knee flexion torque occurred significantly earlier within the range of motion on the operated side than nonoperated side at 180°/second in the hamstring tendon group. Angle of peak knee extension torque occurred significantly earlier within the range of motion on the operated side than nonoperated side at 180°/second in the patellar tendon group. There were no statistically significant differences in the flexion and extension peak torque angles between the operated and nonoperated knees at 60°/second in both groups. The angle of peak torque at relatively high angular velocities is affected after ACL reconstruction in patients with hamstring or patellar tendon grafts. The graft donor site directly influences this parameter. This finding may be important for clinicians in terms of preventing re-injury.

  3. Muscle Contraction.

    Science.gov (United States)

    Sweeney, H Lee; Hammers, David W

    2018-02-01

    SUMMARYMuscle cells are designed to generate force and movement. There are three types of mammalian muscles-skeletal, cardiac, and smooth. Skeletal muscles are attached to bones and move them relative to each other. Cardiac muscle comprises the heart, which pumps blood through the vasculature. Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance. Smooth muscle does not contain sarcomeres but uses the contraction of filaments of actin and myosin to constrict blood vessels and move the contents of hollow organs in the body. Here, we review the principal molecular organization of the three types of muscle and their contractile regulation through signaling mechanisms and discuss their major structural and functional similarities that hint at the possible evolutionary relationships between the cell types. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

  4. Active stretching for lower extremity muscle tightness in pediatric patients with lumbar spondylolysis.

    Science.gov (United States)

    Sato, Masahiro; Mase, Yasuyoshi; Sairyo, Koichi

    2017-01-01

    It was reported that hamstring muscle tightness may increase mechanical loading on the lumbar spine. Therefore, we attempt to decrease tightness in the leg muscles in pediatric patients. Forty-six pediatric patients with spondylolysis underwent rehabilitation. We applied active stretching to the hamstrings, quadriceps, and triceps surae. Tightness in each muscle was graded as good, fair, or poor. We educated each patient on how to perform active stretching at home. They were re-evaluated for muscle tightness 2 months later. Tightness at baseline and after 2 months was as follows: for the hamstrings, good in 3 patients, fair in 9, and poor in 34 and significant improved after 2 months (p<0.05), with improvement by least 1 grade seen in 86% of patients with fair or poor at baseline; for the quadriceps, 7, 3, and 30 patients had good, fair and poor, with significant improvements in 72% (p<0.05). For the triceps surae, 6, 3 and 10 patients had good, fair and poor, which improved significantly (p<0.05). Home-based active stretching was effective for relieving muscle tightness in the leg in a pediatric population. Adolescent athletes should perform such exercise to maintain flexibility and prevent lumbar disorders. J. Med. Invest. 64: 136-139, February, 2017.

  5. Changes in muscle size and MHC composition in response to resistance exercise with heavy and light loading intensity

    DEFF Research Database (Denmark)

    Holm, L.; Reitelseder, S.; Pedersen, T.G.

    2008-01-01

    resonance imaging, muscle biopsies were obtained bilaterally from vastus lateralis for determination of myosin heavy chain (MHC) composition, and maximal muscle strength was assessed by 1RM testing and in an isokinetic dynamometer at 60 degrees /s. Quadriceps muscle cross-sectional area increased (P ...Muscle mass accretion is accomplished by heavy-load resistance training. The effect of light-load resistance exercise has been far more sparsely investigated with regard to potential effect on muscle size and contractile strength. We applied a resistance exercise protocol in which the same...... individual trained one leg at 70% of one-repetition maximum (1RM) (heavy load, HL) while training the other leg at 15.5% 1RM (light load, LL). Eleven sedentary men (age 25 +/- 1 yr) trained for 12 wk at three times/week. Before and after the intervention muscle hypertrophy was determined by magnetic...

  6. Effects of Growth Hormone Replacement on Peripheral Muscle and Exercise Capacity in Severe Growth Hormone Deficiency

    Directory of Open Access Journals (Sweden)

    Susana Gonzalez

    2018-02-01

    Full Text Available ObjectiveThe aim of this study is to evaluate the effect of growth hormone therapy (rGH on mitochondrial function on peripheral muscle and to correlate with exercise capacity in subjects with severe adult growth hormone deficiency (GHD.DesignSix months, double-blind, randomized, crossover, placebo-controlled trial of subcutaneous rGH in 17 patients with GHD.MeasurementsQuadriceps muscle biopsies were obtained at baseline, 3 months, and 6 months to measure succinate dehydrogenase (SDH to assess mitochondrial activity. Exercise capacity was measured with cardiopulmonary exercise testing. Lipids, glycemic parameters, and body fat levels were also measured.ResultsSerum insulin-like growth factor 1 (IGF1 levels reduced fat mass by 3.2% (p < 0.05 and normalized with rGH in the active phase (p < 0.005. Patients showed an increase in SDH (p < 0.01 from base line that differed between placebo and rGH therapy treatment groups (p < 0.05: those treated by rGH followed by placebo showed a significant increase in SDH (p < 0.001 followed by a decrease, with a significant between group difference at the end of 6 months (p < 0.05. No significant improvements or correlation with exercise capacity was found.ConclusionShort-term rGH for 3 months normalized IGF1 levels, reduced fat mass, and had a significant effect on mitochondrial function, but exercise capacity was unchanged.Clinical Trial RegistrationNumber ISRCTN94165486.

  7. Effect of tendon vibration during wide-pulse neuromuscular electrical stimulation (NMES) on muscle force production in people with spinal cord injury (SCI).

    Science.gov (United States)

    Bochkezanian, Vanesa; Newton, Robert U; Trajano, Gabriel S; Vieira, Amilton; Pulverenti, Timothy S; Blazevich, Anthony J

    2018-02-13

    Neuromuscular electrical stimulation (NMES) is commonly used in skeletal muscles in people with spinal cord injury (SCI) with the aim of increasing muscle recruitment and thus muscle force production. NMES has been conventionally used in clinical practice as functional electrical stimulation (FES), using low levels of evoked force that cannot optimally stimulate muscular strength and mass improvements, and thus trigger musculoskeletal changes in paralysed muscles. The use of high intensity intermittent NMES training using wide-pulse width and moderate-intensity as a strength training tool could be a promising method to increase muscle force production in people with SCI. However, this type of protocol has not been clinically adopted because it may generate rapid muscle fatigue and thus prevent the performance of repeated high-intensity muscular contractions in paralysed muscles. Moreover, superimposing patellar tendon vibration onto the wide-pulse width NMES has been shown to elicit further increases in impulse or, at least, reduce the rate of fatigue in repeated contractions in able-bodied populations, but there is a lack of evidence to support this argument in people with SCI. Nine people with SCI received two NMES protocols with and without superimposing patellar tendon vibration on different days (i.e. STIM and STIM+vib), which consisted of repeated 30 Hz trains of 58 wide-pulse width (1000 μs) symmetric biphasic pulses (0.033-s inter-pulse interval; 2 s stimulation train; 2-s inter-train interval) being delivered to the dominant quadriceps femoris. Starting torque was 20% of maximal doublet-twitch torque and stimulations continued until torque declined to 50% of the starting torque. Total knee extensor impulse was calculated as the primary outcome variable. Total knee extensor impulse increased in four subjects when patellar tendon vibration was imposed (59.2 ± 15.8%) but decreased in five subjects (- 31.3 ± 25.7%). However, there were no

  8. Interactions between Skeletal Muscle Myoblasts and their Extracellular Matrix Revealed by a Serum Free Culture System.

    Science.gov (United States)

    Chaturvedi, Vishal; Dye, Danielle E; Kinnear, Beverley F; van Kuppevelt, Toin H; Grounds, Miranda D; Coombe, Deirdre R

    2015-01-01

    Decellularisation of skeletal muscle provides a system to study the interactions of myoblasts with muscle extracellular matrix (ECM). This study describes the efficient decellularisation of quadriceps muscle with the retention of matrix components and the use of this matrix for myoblast proliferation and differentiation under serum free culture conditions. Three decellularisation approaches were examined; the most effective was phospholipase A2 treatment, which removed cellular material while maximizing the retention of ECM components. Decellularised muscle matrices were then solubilized and used as substrates for C2C12 mouse myoblast serum free cultures. The muscle matrix supported myoblast proliferation and differentiation equally as well as collagen and fibronectin. Immunofluorescence analyses revealed that myoblasts seeded on muscle matrix and fibronectin differentiated to form long, well-aligned myotubes, while myoblasts seeded on collagen were less organized. qPCR analyses showed a time dependent increase in genes involved in skeletal muscle differentiation and suggested that muscle-derived matrix may stimulate an increased rate of differentiation compared to collagen and fibronectin. Decellularized whole muscle three-dimensional scaffolds also supported cell adhesion and spreading, with myoblasts aligning along specific tracts of matrix proteins within the scaffolds. Thus, under serum free conditions, intact acellular muscle matrices provided cues to direct myoblast adhesion and migration. In addition, myoblasts were shown to rapidly secrete and organise their own matrix glycoproteins to create a localized ECM microenvironment. This serum free culture system has revealed that the correct muscle ECM facilitates more rapid cell organisation and differentiation than single matrix glycoprotein substrates.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-10-01

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

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

    International Nuclear Information System (INIS)

    Horikawa, Hirosei; Mano, Yukio; Takayanagi, Tetsuya; Takahashi, Keiichi; Nishio, Hisahide.

    1992-01-01

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

  11. Injury and subsequent regeneration of muscles for activation of local innate immunity to facilitate the development and relapse of autoimmune myositis in C57BL/6 mice.

    Science.gov (United States)

    Kimura, Naoki; Hirata, Shinya; Miyasaka, Nobuyuki; Kawahata, Kimito; Kohsaka, Hitoshi

    2015-04-01

    To determine whether injury and regeneration of the skeletal muscles induce an inflammatory milieu that facilitates the development and relapse of autoimmune myositis. The quadriceps of C57BL/6 mice were injured with bupivacaine hydrochloride (BPVC) and evaluated histologically. Macrophages and regenerating myofibers in the treated muscles and differentiating C2C12 myotubes were examined for cytokine expression. Mice were immunized with C protein fragments at the base of the tail and in the right hind footpads (day 0) to evoke systemic anti-C protein immunity and to induce local myositis in the right hind limbs. The contralateral quadriceps muscles were injured with BPVC or phosphate buffered saline (PBS) on day 7 or after spontaneous regression of myositis (day 42). The quadriceps muscle in nonimmunized mice was injured with BPVC on day 7. The muscles were examined histologically 14 days after treatment. The BPVC-injured muscles had macrophage infiltration most abundantly at 3 days after the injection, with emergence of regenerating fibers from day 5. The macrophages expressed inflammatory cytokines, including tumor necrosis factor α, interleukin-1β, and CCL2. Regenerating myofibers and C2C12 myotubes also expressed the cytokines. The BPVC-injected muscles from nonimmunized mice had regenerating myofibers with resolved cell infiltration 14 days after treatment. In mice preimmunized with C protein fragments, the muscles injected with BPVC on day 7 as well as on day 42, but not those injected with PBS, had myositis accompanied by CD8+ T cell infiltration. Injury and regeneration could set up an inflammatory milieu in the muscles and facilitate the development and relapse of autoimmune myositis. Copyright © 2015 by the American College of Rheumatology.

  12. Effects of muscle composition and architecture on specific strength in obese older women.

    Science.gov (United States)

    Rastelli, F; Capodaglio, P; Orgiu, S; Santovito, C; Caramenti, M; Cadioli, M; Falini, A; Rizzo, G; Lafortuna, C L

    2015-10-01

    What is the central question of this study? Do obesity-specific factors affect skeletal muscle performance in older individuals? What is the main finding and its importance? Older obese women have a larger quadriceps femoris size but develop lower tension per unit of skeletal muscle than their normal-weight counterparts. Muscle impairment and excess body mass are very common among older people. Given that the effect of obesity on strength production has scarcely been studied in older individuals, we analysed functional and structural characteristics of quadriceps femoris (QF) in obese (OB) and normal-weight (NW) older women with comparable habitual physical activity. In five OB (body mass index 36.8 ± 1.9 kg m(-2), age 72.4 ± 2.3 years) and six NW well-functioning older women (body mass index 24.3 ± 1.8 kg m(-2), age 72.7 ± 1.9 years), peak knee-extension torque (KET) was measured in isometric (90 deg knee flexion) and isokinetic conditions (240, 180, 120 and 60 deg s(-1)). Mid-thigh QF cross-sectional area (CSA) and muscle tissue fat content (MF%) were determined with magnetic resonance imaging (Dixon sequence). Muscle fascicle length and pennation angle (PA) were assessed with ultrasonography for each muscle belly of the QF (vastus lateralis, vastus intermedius, rectus femoris and vastus intermedius). Despite similar values of KET, CSA was 17.0% larger in OB than in NW women (P Muscle composition and architecture seem to be important determinants of KET/CSA in elderly women. In fact, owing to the effect of obesity overload, OB women have a larger QF size than NW women, but unfavourable muscle composition and architecture. The higher MF% and steeper PA observed in OB women are associated with reduced levels of muscle specific strength. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

  13. Effects of loaded voluntary wheel exercise on performance and muscle hypertrophy in young and old male C57Bl/6J mice.

    Science.gov (United States)

    Soffe, Z; Radley-Crabb, H G; McMahon, C; Grounds, M D; Shavlakadze, T

    2016-02-01

    This study compared the capacity of young and old male C57Bl/6J mice to exercise with increasing resistance over 10 weeks, and its impact on muscle mass. Young mice (aged 15-25 weeks) were subjected to low (LR) and high (HR) resistance exercise, whereas only LR was used for old mice (107-117 weeks). Weekly patterns of voluntary wheel activity, food consumption and body weights were measured. Running patterns changed over time and with age, with two peaks of activity detected for young, but only one for old mice: speed and distance run was also less for old mice. The mass for six limb muscles was measured at the end of the experiment. The most pronounced increase in mass in response to exercise was for the soleus in young and old mice, and also quadriceps and gastrocnemius in young mice. Soleus and quadriceps muscles were analyzed histologically for myofiber number and size. A striking feature was the many small myofibers in response to exercise in young (but not old) soleus, whereas these were not present after exercise in young or old quadriceps. Overall, there was a striking difference in response to exercise between muscles and this was influenced by age. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Mechanomyography-Based Wearable Monitor of Quasi-Isometric Muscle Fatigue for Motor Neural Prostheses.

    Science.gov (United States)

    Krueger, Eddy; Popović-Maneski, Lana; Nohama, Percy

    2018-02-01

    A motor neural prosthesis based on surface functional electrical stimulation (sFES) can restore functional movement (e.g., standing, walking) in patients with a spinal cord injury (SCI). sFES generates muscle contractions in antigravity muscles and allows balance-assisted standing. This induced standing has several benefits, such as improved cardiovascular function, decreased incidence of urinary infections, reduced joint contractures, and muscle atrophy. The duration of sFES assisted standing is limited due to the quick onset of muscle fatigue. Currently, there is no method available to reliably estimate real-time muscle fatigue during sFES. Simply monitoring the M-wave changes is not suitable due to the high signal disturbances that arise during multi-channel electrical stimulation. Mechanomyography (MMG) is immune to electrical stimulation artifacts and can be used to detect subtle vibrations on the surface of the skin related to activation of the underlying muscle's motor units (MU). The aim of this study was to develop a method for detecting muscle fatigue brought on by sFES. The method was tested in three different heads of the quadriceps muscle in SCI patients during electrically elicited quasi-isometric contraction. Six spinal cord-injured male volunteers, with no voluntary control of the quadriceps muscle participated in the study. Electrical bursts of voltage-controlled monophasic square pulses at frequencies of 1 kHz (50% duty cycle) at 50 Hz (15% duty cycle) were used to generate thigh muscle contractions that controlled the knee joint in the sagittal plane. The pulse amplitudes were set to position the knee joint at a 5° angle from the horizontal plane and when the knee angle dropped to 20° (e.g., the quadriceps were unable to hold the lower leg in the desired position), the test was terminated. Two data segments lasting 10 s each, at the beginning and end of each test, were analyzed. The muscle contraction was assessed by MMG sensors positioned on

  15. Influence on muscle oxygenation to EMG parameters at different skeletal muscle contraction

    Science.gov (United States)

    Zhang, Li; Song, Gaoqing

    2010-02-01

    The purpose of this study is to investigate the influence of muscle oxygenation on EMG parameters during isometric and incremental exercises and to observe the relationship between EMG parameters and muscle oxygenation. Twelve rowers took part in the tests. Near infrared spectrometer was utilized for measurements of muscle oxygenation on lateral quadriceps. sEMG measurement is performed for EMG parameters during isometric and incremental exercises. Results indicated that Oxy-Hb decrease significantly correlated with IEMG, E/T ratio and frequency of impulse signal during 1/3 MVC and 2/3 MVC isometric exercise, and it is also correlated with IEMG, E/T ratio and frequency of impulse signal. Increase of IEMG occurred at the time after Oxy-Hb decrease during incremental exercise and highly correlated with BLa. It is concluded that no matter how heavy the intensity is, Oxy-Hb dissociation may play an important role in affecting EMG parameters of muscle fatigue during isometric exercise. 2) EMG parameters may be influenced by Oxy-Hb dis