Academic literature on the topic 'Knee extensor muscle'
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Journal articles on the topic "Knee extensor muscle"
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Suter, Esther, Walter Herzog, and Robert Bray. "Quadriceps Activation during Knee Extension Exercises in Patients with ACL Pathologies." Journal of Applied Biomechanics 17, no. 2 (May 2001): 87–102. http://dx.doi.org/10.1123/jab.17.2.87.
Full textAbstract:
This study assessed muscle inhibition in patients with chronic anterior cruciate ligament (ACL) deficiency or ACL reconstruction. A series of protocols were tested for their effectiveness in increasing activity of the individual knee extensor muscles and decreasing muscle inhibition of the whole quadriceps group. Quadriceps muscle inhibition was measured by superimposing an electrical twitch onto the quadriceps muscle during a maximal voluntary knee extension. The level of activation of the individual knee extensor and knee flexor muscles was assessed via electromyography (EMG). Patients with ACL pathologies showed strength deficits and muscle inhibition in the knee extensors of the involved leg and the contralateral leg. Muscle inhibition was statistically significantly greater in ACL-deficient patients compared to ACL-reconstructed patients. When a knee extension was performed in combination with a hip extension, there was a significant increase,p< 0.05, in activation of the vastus medialis and vastus lateralis muscles compared to isolated knee extension. The use of an anti-shear device, designed to help stabilize the ACL-deficient knee, resulted in increased inhibition in the quadriceps muscle. Furthermore, a relatively more complete activation of the vasti compared to the rectus femoris was achieved during a fatiguing isometric contraction. Based on the results of this study, it is concluded that performing knee extension in combination with hip extension, or performing fatiguing knee extensor contractions, may be more effective in fully activating the vasti muscles than an isolated knee extensor contraction. Training interventions are needed to establish whether these exercise protocols are more effective than traditional rehabilitation approaches in decreasing muscle inhibition and achieving better functional recovery, including equal muscle strength in the injured and the contralateral leg.
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Lanza, I. R., T. F. Towse, G. E. Caldwell, D. M. Wigmore, and J. A. Kent-Braun. "Effects of age on human muscle torque, velocity, and power in two muscle groups." Journal of Applied Physiology 95, no. 6 (December 2003): 2361–69. http://dx.doi.org/10.1152/japplphysiol.00724.2002.
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The purpose of this study was to test the hypotheses that, under isovelocity conditions, older compared with young humans would 1) be slower to reach target velocity and 2) exhibit a downward shift in the torque-velocity and power-velocity relationships in the ankle dorsiflexor and knee extensor muscles. We studied 12 young (26 ± 5 yr, 6 men/6 women) and 12 older (72 ± 6 yr, 6 men/6 women) healthy adults during maximal voluntary concentric contractions at preset target velocities (dorsiflexion: 0–240°/s; knee extension: 0–400°/s) using an isokinetic dynamometer. The time to target velocity was longer in older subjects in the dorsiflexors and knee extensors (both P ≤ 0.02). Averaged across all velocities, older subjects produced ∼26% less concentric torque and power in the dorsiflexors ( P < 0.01) and ∼32% less in the knee extensors ( P < 0.01). The downward shift in the torque-velocity relationship persisted even when torque was expressed relative to each subject's maximum. In the knee extensors only, the age-related decrement in power increased with increasing velocities, suggesting that this muscle group may be more susceptible to age-related losses of function than the dorsiflexor muscles are. In support of our hypotheses, these results demonstrate an age-related impairment in the dynamic performance of two functionally distinct muscle groups in healthy older adults. With age, the impairment of dynamic performance appears to exceed the loss of isometric performance, particularly in the knee extensor muscles.
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Santos, Gislaine Regina Santos dos, Jeam Marcel Geremia, Paola Zambelli Moraes, Raquel de Oliveira Lupion, Marco Aurélio Vaz, and Felipe P. Carpes. "Bilateral assessment of knee muscle relationships in healthy adults." Motriz: Revista de Educação Física 20, no. 3 (September 2014): 310–16. http://dx.doi.org/10.1590/s1980-65742014000300010.
Full textAbstract:
Asymmetric performance of flexor and extensor muscles of the knee may be a risk factor for knee injuries, especially the anterior cruciate ligament. Additionally, asymmetries in power and work may have correlations with fatigue and performance during functional tasks. Among untrained individuals, such asymmetries may be of potential interest for training prescription. Here, we investigated the bilateral performance of knee flexors and extensors muscle groups of untrained individuals. We quantified the torque-angle and torque-velocity relationships, as well as work, power and asymmetry indexes in 20 untrained male (25 ± 4 years old; height 1.74 ± 0.05 m; body mass 76 ± 9 kg). No significant asymmetry was observed for torque-angle and torque-velocity relationships, work and power output for knee flexor and extensor muscle groups (p < .05). Our results suggest that untrained male present symmetry in the knee flexion and extension bilateral performance. Changes in this behavior due to physical training must be monitored.
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Valtonen, Anu, Tapani Pöyhönen, Ari Heinonen, and Sarianna Sipilä. "Muscle Deficits Persist After Unilateral Knee Replacement and Have Implications for Rehabilitation." Physical Therapy 89, no. 10 (October 1, 2009): 1072–79. http://dx.doi.org/10.2522/ptj.20070295.
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BackgroundKnee joint arthritis causes pain, decreased range of motion, and mobility limitation. Knee replacement reduces pain effectively. However, people with knee replacement have decreases in muscle strength (“force-generating capacity”) of the involved leg and difficulties with walking and other physical activities.Objective and DesignThe aim of this cross-sectional study was to determine the extent of deficits in knee extensor and flexor muscle torque and power (ability to perform work over time) and in the extensor muscle cross-sectional area (CSA) after knee joint replacement. In addition, the association of lower-leg muscle deficits with mobility limitations was investigated.MethodsParticipants were 29 women and 19 men who were 55 to 75 years old and had undergone unilateral knee replacement surgery an average of 10 months earlier. The maximal torque and power of the knee extensor and flexor muscles were measured with an isokinetic dynamometer. The knee extensor muscle CSA was measured with computed tomography. The symmetry deficit between the knee that underwent replacement surgery (“operated knee”) and the knee that did not undergo replacement surgery (“nonoperated knee”) was calculated. Maximal walking speed and stair-ascending and stair-descending times were assessed.ResultsThe mean deficits in knee extensor and flexor muscle torque and power were between 13% and 27%, and the mean deficit in the extensor muscle CSA was 14%. A larger deficit in knee extension power predicted slower stair-ascending and stair-descending times. This relationship remained unchanged when the power of the nonoperated side and the potential confounding factors were taken into account.LimitationsThe study sample consisted of people who were relatively healthy and mobile. Some participants had osteoarthritis in the nonoperated knee.ConclusionsDeficits in muscle torque and power and in the extensor muscle CSA were present 10 months after knee replacement, potentially causing limitations in negotiating stairs. To prevent mobility limitations and disability, deficits in lower-limb power should be considered during rehabilitation after knee replacement.
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Perell, Karen L., Robert J. Gregor, and A. M. Erika Scremin. "Muscle-Strength and Gait-Speed Changes after Bicycle Exercise in Participants with Unilateral CVA." Journal of Aging and Physical Activity 9, no. 4 (October 2001): 386–97. http://dx.doi.org/10.1123/japa.9.4.386.
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The purpose of this study was to determine the effect of bicycle exercise on knee-muscle strength and gait speed in 8 male participants with cerebrovascular accident (CVA). Isokinetic knee-extensor and -flexor strength were measured in both concentric- and eccentric-contraction modes. Fifty-foot walking tests were used for gait speed. After only 4 weeks of stationary recumbent cycling (12 sessions), participants improved eccentric muscle strength of the knee extensors, bilaterally. Walking-speed improvements approached but did not achieve significance with training. Improvement in concentric muscle strength of the knee extensors was observed in the involved limb, although most participants demonstrated a nonsignificant increase in muscle strength in the contralateral limb, as well. No improvements were demonstrated in the knee-flexor muscles. Thus, bicycle exercise serves to improve knee-extensor strength. In addition, these strength improvements might have implications for better control of walking in terms of bilateral improvement of eccentric muscle strength.
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Doldo, Neil A., Matthew J. Delmonico, Jason A. Bailey, Brian D. Hand, Matthew C. Kostek, Karma M. Rabon-Stith, Kalapurakkal S. Menon, Joan M. Conway, Craig R. Carignan, and Ben F. Hurley. "Muscle-Power Quality: Does Sex or Race Affect Movement Velocity in Older Adults?" Journal of Aging and Physical Activity 14, no. 4 (October 2006): 411–22. http://dx.doi.org/10.1123/japa.14.4.411.
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To determine sex and race differences in muscle power per unit of muscle contraction, knee-extensor muscle power normalized for knee-extensor muscle volume was measured in 79 middle-aged and older adults (30 men and 49 women, age range 50–85 years). Results revealed that women displayed a 38% faster peak movement velocity than men and African Americans had a 14% lower peak movement velocity than Whites of a similar age when expressed per unit of involved muscle (p< .001). As expected, men exhibited greater knee-extensor strength and peak power per unit of muscle than women, but women had a faster knee-extension movement velocity per unit of muscle than men at the same relative strength level. Moreover, African Americans had greater knee-extensor muscle volume than Whites but exhibited lower knee-extensor strength and lower movement velocity per unit of muscle when tested at the same relative strength levels.
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de Ruiter, C. J., M. D. de Boer, M. Spanjaard, and A. de Haan. "Knee angle-dependent oxygen consumption during isometric contractions of the knee extensors determined with near-infrared spectroscopy." Journal of Applied Physiology 99, no. 2 (August 2005): 579–86. http://dx.doi.org/10.1152/japplphysiol.01420.2004.
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Fatigue resistance of knee extensor muscles is higher during voluntary isometric contractions at short compared with longer muscle lengths. In the present study we hypothesized that this would be due to lower energy consumption at short muscle lengths. Ten healthy male subjects performed isometric contractions with the knee extensor muscles at a 30, 60, and 90° knee angle (full extension = 0°). At each angle, muscle oxygen consumption (mV̇o2) of the rectus femoris, vastus lateralis, and vastus medialis muscle was obtained with near-infrared spectroscopy. mV̇o2 was measured during maximal isometric contractions and during contractions at 10, 30, and 50% of maximal torque capacity. During all contractions, blood flow to the muscle was occluded with a pressure cuff (450 mmHg). mV̇o2 significantly ( P < 0.05) increased with torque and at all torque levels, and for each of the three muscles mV̇o2 was significantly lower at 30° compared with 60° and 90° and mV̇o2 was similar ( P > 0.05) at 60° and 90°. Across all torque levels, average (± SD) mV̇o2 at the 30° angle for vastus medialis, rectus femoris, and vastus lateralis, respectively, was 70.0 ± 10.4, 72.2 ± 12.7, and 75.9 ± 8.0% of the average mV̇o2 obtained for each torque at 60 and 90°. In conclusion, oxygen consumption of the knee extensors was significantly lower during isometric contractions at the 30° than at the 60° and 90° knee angle, which probably contributes to the previously reported longer duration of sustained isometric contractions at relatively short muscle lengths.
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Kafkas, A., M. E. Kafkas, and S. Savaş. "Effect of long-term training adaptation on isokinetic strength in college male volleyball players." Physical education of students 23, no. 5 (October 26, 2019): 236–41. http://dx.doi.org/10.15561/20755279.2019.0504.
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Background and Study Aim: Most of this study focused on endurance, power, and anthropometric measurements but no research declared isokinetic strength changes during two years. The purpose of this study was to assess the effect of resistance exercises on two seasonal alters in isokinetic strength of knee muscles at different angular velocities, in college volleyball players. Material and Methods: Thirteen college volleyball players, (age: 21.75 years, body mass: 78.60 kg, and height: 187.0 cm) participated in the study. All college volleyball players take part in the two-year (8 month each year) volleyball-specific training and competitions. The measurement of peak isokinetic concentric knee extension and knee flexion torque in both legs were taken at 2 angular velocities of movement, low at 60° s-1, and intermediate at 180° s-1. Results: The pre- and post-test values of the peak isokinetic strength found that statistical significance difference, at 60° s-1 and 180° s-1 for knee extensor-flexor both dominant and non-dominant in favor of post-tests. Significant enhances were observed in the baseline dominant knee extensor-flexor muscle strength (extensor knee strength 60° s-1: 19.0%, 180° s-1: 20.5%, flexor knee strength, 60° s-1: 33.4%, 180° s-1: 31.4%) respectively. Non-dominant knee extensor-flexor muscle strength increased significantly over the two-year period (extensor knee strength 60° s-1: 21.3%, 180° s-1: 23.0%, flexor knee strength, 60° s-1: 37.4%, 180° s-1: 33.9%) respectively. Conclusion: As a result, our data suggests that the two-year planned program of specific volleyball and resistance training can increase the knee muscle extensor-flexor strength and H:Q ratios of volleyball players. Especially, at a 60° s-1 and 180° s-1 angular velocities, whilst the knee muscle extensor-flexor strength and H:Q ratios for dominant and non-dominant legs were increasing, also H:Q ratios disproportion were decreasing. Therefore, these alters indicated that regular specific-volleyball and resistance training can increase knee muscle extensor-flexor strength and H:Q ratios for dominant and non-dominant legs.
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YUE, YIBO, and YUCHENG YANG. "BIOMECHANICAL STUDY OF MUSCLE MOVEMENT IN THE PROCESS OF FOOTBALL TECHNICAL TRAINING." Journal of Mechanics in Medicine and Biology 20, no. 02 (March 2020): 1950082. http://dx.doi.org/10.1142/s0219519419500829.
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Study of biomechanical characteristics of muscles can provide an effective reference for the training of athletes. Football is a vigorous sport, and physical collision and damage are frequent during competition and training. In order to improve football skills and prevent sports injuries, 10 athletes from Sport College of Shaoyang University, Hunan, China, were tested for isokinetic muscle strength. The moment of flexors and extensors was measured when the flexion and extension angular speed of hip and knee joints was 50∘, 100∘, 150∘, 200∘, 250∘, 300∘, 350∘ and 400∘, respectively. Moreover the characteristics of force moment of flexor and extensor were verified by testing the electromyographic signal of the flexor and extensor of the hip and knee joints with isokinetic concentric exercise using piezoelectric sensor. The results showed that the electromyographic signal of the flexor and extensor of the hip and knee joint decreased with the increase of angular velocity of isokinetic concentric exercise; the electromyographic signal obtained by the piezoelectric sensor verified the law that the output of the flexor and extensor decreased, the extensor of the hip joint had incoordination during rapid movement, and the output of the extensor was always larger than that of the flexor no matter how fast the extensor moved.
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Bohannon, Richard W. "Measuring Knee Extensor Muscle Strength." American Journal of Physical Medicine & Rehabilitation 80, no. 1 (January 2001): 13–18. http://dx.doi.org/10.1097/00002060-200101000-00004.
Full textDissertations / Theses on the topic "Knee extensor muscle"
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Shaw, I., BS Shaw, JF Cilliers, and DT Goon. "Influence of visual feedback on knee extensor isokinetic concentric and eccentric peak torque." African Journal for Physical, Health Education, Recreation and Dance, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001651.
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Abstract
Isokinetic normative data can be invaluable in identifying an individual’s strengths and
weaknesses, and thus lead to a more effective use of the individual’s time to minimise or
overcome his weaknesses while maintaining or improving existing strength. However, visual
feedback (VF) may significantly affect the result of isokinetic testing, resulting in erroneous
conclusions if not accounted for. Additionally, the previous use of VF to obtain increased
strength values has resulted in inconsistent findings. The purpose of this study was to examine
the effect of VF on concentric and eccentric knee extensor peak torque. Twenty-two sedentary,
college-aged male and female volunteers were assigned to either Group 1 (n = 11) or Group 2 (n
= 11) to either perform knee extensor concentric-eccentric (con-ecc) isokinetic testing with VF or
without VF (no-VF) using a crossover method. After a one-week rest, the two groups underwent
knee extensor con-ecc isokinetic testing using the alternative testing condition. Each test
consisted of five maximal knee extensor con-ecc isokinetic testing contractions at 60° per second
on the Cybex Norm system. The data indicated significant (p < 0.05) differences in the
concentric peak torque of Group 1, Group 2 and Combined Group following VF when compared
to no-VF. The eccentric peak torque of Group 1, Group 2 and Combined Group was found not to
be significantly different following VF when compared to no-VF. Further, no significant
interaction effect as a result of the different groups was found. Visual feedback of torque output
can improve maximum voluntary concentric contraction in isokinetic dynamometry, but not
maximum voluntary eccentric contraction. It is thus recommended that VF should be consistently
provided during isokinetic testing, since it can also be used to help detect and correct errors in
performance as well as derive reinforcement from correct performances.
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LEE, SEUNGYONG. "THE EFFECT OF ACUTE BEETROOT JUICE SUPPLEMENTATION ON MUSCLE FATIGUE IN KNEE EXTENSOR EXERCISE." UKnowledge, 2013. http://uknowledge.uky.edu/khp_etds/11.
Full textAbstract:
To examine the effect of acute beetroot juice supplementation on the rate of fatigue as measured by changes in peak torque.
Placebo-controlled, double-blind, cross-over study, 35 recreationally active subjects consumed beetroot (BR) juice or black currant juice (PL) 12 and 2.5 hours before the exercise procedure. Peak torque was measured on the BIODEX dynamometer by performing 50, maximal effort, concentric knee extensions at 90°/s. Blood pressure (BP) was recorded before and after exercise.
No significant difference between BR and PL in the rate of fatigue measured by change in peak torque. By stage 3, subjects retained 87.6±6.9% of strength with BR and 86.7±6.3% with PL (p= 0.363). Stages 10 was as follows: BR 47.9±12.6 vs. PL 46.9±12.9% (p= 0.419). The rate of work fatigue showed no significant differences. By stage 4, mean percent work fatigue showed 20.6±9% with BR and 21.8±10.1% with PL (p= 0.224). Stage 10 was as follows: BR 52.5±12.6% vs. PL 53.2±13% (p= 0.571). Post-exercise diastolic BP (BR: 67.2±9.8 vs. PL: 64.5±7.9mmHg, p= 0.039) and MAP (BR: 91.6±9.3 vs. PL: 88.8±8.2mmHg, p= 0.011) were higher with BR supplementation.
Acute bouts of beetroot juice supplementation had no significant effect on knee extensor muscle fatigue measured during isokinetic contractions
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Elmqvist, Lars-Gunnar. "Chronic anterior cruciate ligament tear : knee function and knee extensor muscle size, morphology and function before and after surgical reconstruction." Doctoral thesis, Umeå universitet, Ortopedi, 1988. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-102562.
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Knee function was evaluated by knee score, activity level, clinical findings and performance tests, muscle size by computerized tomography (CT), morphology by light (LM) and electron microscopy (EM), muscle function by electromyography (EMG) and isokinetic performance in 29 patients with chronic anterior cruciate ligament (ACL) tear. Preoperatively CT disclosed a significant mean atrophy of the quadriceps and nonsignificant changes of the other muscle areas of the injured leg. Morphology of m vastus lateralis of the injured leg was normal in more than half of the biopsies preoperatively, the rest showed signs of nonoptimal activation. Significant decreases in all isokinetic parameters were noticed together with significantly decreased EMG of the quadriceps muscle of the injured leg. Âfter surgical reconstruction the knees were immobilized in a cast for 6 weeks at either 30° or 70° of knee flexion. After cast removal CT showed significant decreases of all areas which also remained after training. The 30° group showed larger fibres (intracellular oedema) and more frequent morphological abnormalities than the 70° group. Fourteen weeks postoperatively the patients were allocated to either a combination of isometric and progressive resistance training or isokinetic training for 6 weeks. CT showed slightly larger areas at 20 weeks postoperatively than at 6 weeks. Morphological abnormalities were still prominent at 20 weeks postoperatively. Maximum isokinetic knee extensor mechanical output and endurance were markedly decreased at 14 weeks postoperatively but both improved progressively during the one year rehabilitation, mostly during the intensive 6 week training period but irrespective of training programme used. Fatiguability/endurance level improved over the preoperative level. Muscular work/integrated EMG was stable while EMG/t increased indicating neuromuscular relearning. The clinical result at 28 months foliowup was excellent or good in 93% of the patients and clinical stability improved in 66%. Independent upon primary knee immobilization angle or training programmes no differences could be demonstrated with respect to stability, range of motion, function or isokinetic mechanical output. Isokinetic performance was still significantly lower in the injured compared to the noninjured leg and not significantly different from the preoperative values. Morphology, only 6 cases, showed abnormalities similar to preoperative findings. In conclusion, the reason for the decreased maximum and total knee extensor performance in these patients with ACL tears is suggested to be nonoptimal activation of normal functioning muscle fibres depending on changes in knee joint receptor afferent inflow. No differences concerning the markedly improved postoperative clinical result could be seen between the different treatment modalities used. A nonoptimal muscular activation might explain the still decreased isokinetic performance present at followup.S. 1-40: sammanfattning, s. 43-137: 5 uppsatser
digitalisering@umu.se
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Boerem, David L. "Peak isokinetic torque of knee flexors and extensor muscles of college football players." Scholarly Commons, 1987. https://scholarlycommons.pacific.edu/uop_etds/499.
Full textAbstract:
The problem of the study addressed knee injuries in college football. Imbalance of the musculature surrounding the knee would predispose the athlete to knee injury. Recognition of those who have muscular deficiencies would be a primary way of preventing knee injuries. The focus of the study was to determine if there was a significant difference in peak isokinetic torque of knee flexor and extensor muscles across speeds (60 degrees/second, 180 degrees/ second and 300 degrees/second) of a college football team subsequent to participation in a spring football season.
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Glenn, L. Lee, and Brad G. Samojla. "A Critical Reexamination of the Morphology, Neurovasculature, and Fiber Architecture of Knee Extensor Muscles in Animal Models and Humans." Digital Commons @ East Tennessee State University, 2002. https://dc.etsu.edu/etsu-works/7526.
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The purposes of the present study were to resolve a number of major inconsistencies found in the literature on the structure of the quadriceps femoris muscle and to extend knowledge of its structure using descriptive, qualitative methodology. The quadriceps femoris muscle was investigated in 41 cats, and the findings were confirmed in 6 human cadavers. Two aponeuroses with major biomechanical functions (rectus-vastus and vastus aponeurosis), neither of which had been previously described in the literature, were characterized in both species. The study also resolved many major inconsistencies in the literature: The muscle sometimes described as vastus intermedius (VI) was found to be the articularis genu, the muscle sometimes described as vastus medialis (VM) was found to be the VI, the rectus femoris head was found to have an additional proximal nerve branch not previously recognized, no anomalous 5th head was ever found, and the distal VM were not found to have 2 heads (in either cats or humans). The authors’ anatomical descriptions and bimechanical models of the muscles, tendons, and neurovascular should provide a helpful foundation for future studies on the quadriceps. Two general recommendations are made: 1) that the feline model be considered a viable model to elucidate human knee pathomechanics; and 2) that regardless of the anatomical structure of interest, orthopedic nurses, orthopedic surgeons, and research investigators should routinely use the research literature for anatomical guidance instead of standard anatomical textbooks. © 2002, Sage Publications. All rights reserved.
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Nienkerk, Andrée. "Förändring av olika fysiologiska parametrar vid styrketräning hos äldre." Thesis, Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:gih:diva-3134.
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Sammanfattning Syfte och frågeställningar. Syftet med denna studie var att på äldre personer studera olika fysiologiska parametrar före och efter en period på åtta veckor med styrketräning som utförs tre gånger i veckan. Frågeställningarna var: Hur påverkas statisk och dynamisk maximal styrka i främre lårmuskulaturen av styrketräning? Är det någon skillnad i resultat mellan koncentrisk och excentrisk styrka i lårmuskulaturen före och efter styrketräningsperioden? Är det någon skillnad i förändring mellan benstyrka uppmätt med isokinetisk teknik jämfört med uthållighetsstyrka och ett kort funktionellt benstyrketest? Hur påverkas maximal syreupptagningsförmåga registrerad via submaximalt cykeltest respektive vid pyramidtestet av träningsperioden? Metod. I studien deltog 20 generellt ej påtagligt aktiva män och kvinnor i åldrarna 66-79 år. Av dessa var 11 individer slumpvis indelade i en styrketräningsgrupp och övriga nio utgjorde en inaktiv kontrollgrupp. Ett flertal olika fysiologiska tester, som bl.a. prövade testpersonernas styrka samt kondition, utfördes innan och efter träningsperioden. De deltagare som utgjorde träningsgruppen tränades i relativt tung styrketräning i åtta veckor. Resultat. Undersökningen resulterade i en signifikant ökad koncentrisk-, excentrisk- samt statisk momentan benstyrka för träningsgruppen efter de åtta veckorna med relativt tung styrketräning. Vidare kunde även utläsas för dem en signifikant förbättring av uthållighetsstyrka i benen (hastighet vid 50 uppresningar från stol, med 16,9 %) samt vid ett kort funktionellt test (5 uppresningar från stol, med 12,8 %). De träningsgenererade signifikanta ökningarna för träningsgruppen tyder inte på några stora procentuella skillnader mellan statisk (10,4 %) och dynamisk excentrisk (7,8 %) eller koncentrisk maximal styrka (9,5 %). Vid testerna cykelergometertest (kondition), effekt i 5-minuterspyramidtest (ett modifierat steptest) samt distans vid 6-minuters gångtest framkom inga signifikanta förbättringar för träningsgruppen. Ingen i kontrollgruppen visade en signifikant förbättring i någon av de nämnda testerna. Slutsats. Studien visar att interventioner, med åtta veckors intensiv styrketräning, tre gånger per vecka för äldre kvinnor och män, påtagligt kan förbättra resultaten vid styrkemätningar såväl momentant som uthållighetsmässigt och vid ett kort funktionellt test, medan tester av maximal syreupptagningsförmåga (VO2max) inte förbättras. Emellertid framkom i cykelergometertestet en tendens till förbättring för träningsgruppen.
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Massey, Garry J. "Muscle-tendon unit morphology, architecture and stiffness in relation to strength and responses to strength training." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/24712.
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This thesis examined the change in skeletal muscle architecture with contractile force production, the relationship of architecture with muscle strength parameters and if muscle tendinous tissue stiffness determines in vivo explosive strength (i.e. rate of torque development, RTD). Muscle and tendinous tissue adaptations to contrasting strength training regimes, and the potential capacity of these tissues to adapt following chronic strength training were also explored. Quadriceps femoris fascicle length (FL) decreased, while the pennation angle (PA) increased in a curvi-linearly manner from rest to maximal voluntary contraction (MVC) torque. Consequently, effective physiological cross-sectional area (effPCSA) during MVC was 27% greater than at rest, although effPCSA measured at rest and during MVC had similar correlations to maximal strength. In the earliest phase of contraction, FL, but not PA, was negatively related (R2=0.187) to voluntary RTD. Neither FL nor PA was related to maximal isometric or dynamic strength. Muscle-tendon unit (MTU) and patellar tendon (PT) stiffness were unrelated to voluntary and evoked RTD. Relative PT stiffness was also unrelated to relative RTD, although relative MTU stiffness was related to voluntary RTD (25-55%MVT, R2≤0.188) and evoked RTD (5-50%MVT, R2≤0.194). MTU stiffness increased after sustained-contraction (SCT, +21%), though not explosive-contraction strength training (ECT). PT stiffness increased similarly after ECT (+20%) and SCT (+16%), yet neither induced tendon hypertrophy. SCT produced modest muscle (+8%) and aponeurosis (+7%) hypertrophy. Chronic strength trained (CST: >3 years) males had substantially greater muscle and aponeurosis size, but similar tendon size as untrained controls (UNT) and short-term (12 weeks) strength trained (STT) individuals. Between these groups, at the highest common force, MTU stiffness was indifferent, while PT stiffness was similarly greater in STT and CST than UNT. These results suggest FL and PA have little influence on muscle strength and tendon stiffness has no influence on RTD. Maximum strength negated any qualitative influence of MTU stiffness on in vivo RTD. Component MTU tissues (muscle-aponeurosis vs. external tendon) adapt differentially depending on the strength training regime. Specifically, free tendon appeared to adapt to high magnitude loading, while loading duration is also an important stimulus for the muscle-aponeurosis. However, chronic strength training was not concordant with greater higher force MTU stiffness, and does not further increase higher force PT stiffness beyond the adaptations that occur after 12 weeks of strength training. Finally, no evidence was found for tendon hypertrophy in response to strength training.
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Serrão, Paula Regina Mendes da Silva. "Aspectos funcionais, morfológicos e imunohistoquímicos do músculo quadríceps femoral de indivíduos com graus I ou II de osteoartrite de joelho." Universidade Federal de São Carlos, 2012. https://repositorio.ufscar.br/handle/ufscar/5138.
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Previous issue date: 2012-02-24Universidade Federal de Minas Gerais
The quadriceps muscle weakness is common in subjects with knee osteoarthritis (OA), leading to functional deficits. Some risk factors are causes, such as morphological changes (atrophy and reduced number of muscle fibers), changes in non-contractile proteins of muscle and changes in the level of muscle activation. However, these factors are not well understood, particularly with respect if they are already present in earlier stages of the disease. Therefore, the aim of this study was to verify if men with early degrees of knee OA have functional and morphological impairments and immunohistochemical changes of the quadriceps muscle, as well as investigate if this subjects had compromising of their quality of life . The men (40-65 years) who participated in this study were divided into two groups: Control Group (CG) with healthy subjects and Osteoarthritis Group (OAG) with individuals with knee OA grade I or II. A biopsy of the vastus lateralis (VL) was performed for morphological (through the ATPase reaction) and immunohistochemical analysis(analysis of expression and localization of the receptor for advanced glycation end products - RAGE, and analysis of the expression of collagen type I and III ) . An evaluation of knee extensor torque (KET), concentric and eccentric at 90°/s and 180°/s, was performed simultaneously with an evaluation of the electromyographic activity of the VL (RMS value). Moreover, the WOMAC questionnaire was used. For the intergroup analysis, we used the independent t-test and the Mann-Whitney U test. Spearman s correlation coefficient was used to detect the relationship between the three subscales of WOMAC questionnaire and the average knee extensor peak torque (α<0.05). The collagen was analyzed by semiquantitative analysis. We found lower values for the GOA in eccentric knee extensor peak torque at 90 °/s (p = 0.01) and 180°/s (p = 0.04), and in electromyography activity (RMS) during eccentric contraction, in two angular velocities (p <0.01). Higher values were found for the GOA in the proportion (p = 0.03) and in the relative crosssectional area of type 2b fibers (p = 0.02). It was found a negative correlation between the concentric and eccentric knee extensor torque and the three subscales of the WOMAC questionnaire (p<0.05). In the analysis of RAGE no difference was found between the groups. In semiquantitative analysis of collagen was found increased expression of collagen type I and type III for the GOA. Thus, men with knee OA grades I or II present functional, morphological and immunohistochemical changes of the quadriceps muscle, indicating possible neuromuscular adaptations. Therefore, in the early stages of knee OA, exercises should be recommended in order to minimize or delay the functional deficits resulting from OA.
A fraqueza do músculo quadríceps é comum em sujeitos com osteoartrite (OA) de joelho, levando a déficits funcionais. Alguns fatores são apontados como causas, tais como alterações morfológicas, como atrofia e redução no número de fibras musculares, alterações nas proteínas não contráteis do músculo e alterações no nível de ativação muscular. No entanto, esses fatores ainda não estão bem esclarecidos, principalmente com relação se os mesmos já estão presentes em estágios mais precoces da doença. Diante disso, o objetivo dessa tese foi verificar se homens com graus iniciais de OA de joelho apresentam alterações funcionais, morfológicas e imunohistoquímicas do músculo quadríceps, bem como comprometimento de sua qualidade de vida. Participaram desse estudo homens, com idade entre 40 e 65 anos, divididos em dois grupos: Grupo Controle (GC) com indivíduos saudáveis e Grupo Osteoartrite (GOA) com indivíduos com OA de joelho graus I ou II. Foi realizada biópsia do músculo vasto lateral (VL) para análise morfológica (por meio da reação de ATPase) e imunohistoquímica (análise da expressão e localização dos receptores dos produtos finais da glicosilação RAGE, e análise da expressão dos colágenos tipo I e III). A avaliação do torque extensor do joelho, concêntrico e excêntrico, a 90º/s e 180º/s, foi realizada simultaneamente à avaliação da atividade eletromiográfica do músculo VL (valor de RMS). O questionário WOMAC foi aplicado para análise da qualidade de vida. Na análise intergrupo, foi utilizado o teste T de student para amostras independentes e o teste não-paramétrico U Mann-Whitney. Foi utilizado o coeficiente de correlação de Spearman para analisar a relação entre as três seções do questionário WOMAC e os picos de torque extensor do joelho (α<0.05). Para os colágenos foi feita análise semiquantitativa. Foram encontrados menores valores para o GOA no pico de torque extensor excêntrico a 90º/s (p=0,01) e a 180º/s (p=0,04), e na atividade eletromiográfica (valor RMS), durante contração excêntrica, nas duas velocidades angulares (p<0,01). Maiores valores para o GOA foram encontrados na proporção (p=0,03) e área transversa relativa das fibras tipo 2b (p=0,02). Foi encontrada correlação negativa entre as três seções do questionário WOMAC e os valores de pico de torque para os indivíduos com OA de joelho (p>0,05). Na análise do RAGE não foi encontrada diferença entre os grupos. Na análise semiquantitativa foi encontrada maior expressão dos colágenos tipo I e tipo III para o GOA. Assim, homens com OA de joelho graus I ou II apresentam alterações funcionais, morfológicas e imunohistoquímica do músculo quadríceps, podendo essas alterações serem possíveis adaptações neuromusculares. Dessa forma, desde os graus iniciais de OA de joelho, devem se recomendados exercícios com o objetivo de minimizar ou retardar os déficits funcionais decorrentes da OA.
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Street, Darrin. "Skeletal Muscle Interstitium and Blood pH at Rest and During Exercise in Humans." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15850/.
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The aims of this thesis were to: 1) develop a new method for the determination of interstitial pH at rest and during exercise in vivo, 2) systematically explore the effects of different ingestion regimes of 300 mg.kg-1 sodium citrate on blood and urine pH at rest, and 3) to combine the new interstitial pH technique with the findings of the second investigation in an attempt to provide a greater understanding of H+ movement between the extracellular compartments. The purpose of the first study was to develop a method for the continuous measurement of interstitial pH in vastus lateralis was successfully developed using microdialysis and 2,7-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). To avoid the presence of an artificial alkalosis during exercise, it was necessary to add 25 mM HCO3- to the perfusate. The outlet of the probe was cut less than 10 mm from the skin and connected to a stainless steel tube completing the circuit to a microflow-through cuvette (8 fÝl) within a fluorescence spectrophotometer. This prevented the loss of carbon dioxide from the dialysate and any subsequent pH artefact. Interstitial pH was collected from six subjects before, during and after five minutes of knee-extensor exercise at three intensities 30, 50, and 70 W. Mean,,bSEM interstitial pH at rest was 7.38,,b0.02. Exercise reduced interstitial pH in an almost linear fashion. The nadir value for interstitial pH at 30, 50 and 70 W exercise was 7.27, 7.16 and 7.04, respectively. The lowest pH was obtained 1 min after exercise, irrespective of workload, after which the interstitial pH recovered in a nearly exponential manner. The mean half time of interstitial recovery was 5.2 min. The changes in interstitial pH exceeded the changes in venous blood pH. This study demonstrated that interstitial pH can be measured using microdialysis and that it is continuously decreased during muscle activity. The purpose of the second study was to establish an optimal ingestion regime for the ingestion of 300 mg.kg-1 of sodium citrate and maximise the alkalotic effect while minimising any side effects. Increasing the effectiveness of alkali ingestion may lead to further increases in muscle performance. Ingesting 300 mg.kg-1 sodium citrate at a rate of 300 mg.min-1 was identified as the optimal ingestion regime to maximise alkalosis at rest, which occurred 3.5 h post-ingestion. This was determined by monitoring eight human subjects ingesting 300 mg.kg-1 sodium citrate at five different rates, control (no ingestant), bolus, 300, 600 and 900 mg.kg.min-1 on five days separated by at least 48 hours. Sodium citrate was ingested in capsule form with water ad libitum, with the exception of bolus, which was combined with 400 ml less than 25 percent orange juice and consumed in less than 1 min. Arterialised blood (mean 71.3,,b3.5 mmHg) acid-base and electrolyte status was assessed via the withdrawal of ~5 ml of blood every 30 min across an eight hour duration, placed on ice and analysed within five minutes. No alkalotic difference was found between ingestion rates (mean 7.445,,b0.004, 7.438,,b0.004 and 7.442,,b0.004 for 300, 600 and 900 mg.min-1, respectively). All experimental ingestion regimes were associated with elevations in [HCO3-] (29.6, 29.7, 29.8, 29.9 and 26.3 mmol.l-1 for bolus, 300, 600, 900 and control, respectively). The 300 ingestion regime had the greatest impact on [H+], a 0.66 meq.l-1,,e10-8 change. Bolus ingestion (3.93,,b0.08 mmol.l-1) of sodium citrate had no effect on control (4.06,,b0.08 mmol.l-1) blood [K+], however, 300 mg.min-1 decreased blood [K+] (p less than 0.05). There was no effect of sodium citrate on blood [Cl-], but after 2.5 h blood [Cl-] was lower than pre-ingestion values (p less than0.05). All ingestion rates of sodium citrate increased (p less than 0.05) urine pH above control. This is the first study to investigate the effect of varying ingestion rates on acid-base status at rest in humans. The results suggest that ingesting sodium citrate in small doses in quick succession induce a greater blood alkalosis than the commonly practised bolus protocol. Using the interstitial pH technique described above and the optimal ingestion regime (300 mg.min-1) identified above, the final experiment was designed to assess the influence of sodium citrate ingestion on interstitial pH at both rest and during exercise. Five subjects ingested 300 mg.kg-1 sodium citrate at 300 mg.min-1 again in capsule form with water ad libitum. Prior to ingestion, each subject had a cannula placed into their cephalic vein and one microdialysis probe (CMA-60) inserted into their left thigh, orientated along the fibres of vastus lateralus. This probe was used for the measurement of pH as described above. At the end of this period, an exercise protocol required five subjects to perform light exercise (10 W) for 10 min, before starting an intense exercise period (~90-95% leg VO2peak) to exhaustion followed by a 15 min recovery period. Dialysate and blood samples were collected across all periods. Mean,,bSEM interstitial pH for placebo and alkalosis were 7.38,,b0.12 and 7.24,,b0.16, respectively. Sodium citrate ingestion was not associated with an interstitial alkalosis. An exercise induced acidosis was observed in the interstitium during placebo but not during alkalosis (p less than 0.05). Mean,,bSEM venous pH were 7.362,,b0.003 and 7.398,,b0.003 for placebo and alkalosis, respectively. Sodium citrate ingestion was not associated with a venous alkalosis. Sodium citrate ingestion was associated with an increase in mean,,bSEM venous [HCO3-] (placebo 25.5,,b0.2, alkalosis 28.1,,b0.2). This increase in the blood bicarbonate buffer system was not associated with an increase in time to exhaustion (placebo 352,,b71, alkalosis 415,,b171). This was the first study to investigate the effects of sodium citrate ingestion on interstitial pH. The results of this study demonstrated that an interstitial alkalosis does not ensue after alkali ingestion, however, it was associated with the lack of an exercise induced acidosis suggesting an improved pH regulation during exercise.
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Danielsson, Sebastian. "Physiological characteristics of sodium lactate infusion during resistance exercise." Thesis, Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:gih:diva-5782.
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Previous studies that utilized sodium lactate infusion did not use resistance exercise protocol or analyzed muscle biopsies, or performed sex specific analysis. Aim: We initiated a project where resistance exercise was performed with low and high levels of lactate, acquired by venous lactate infusion where the specific aim of this study was to investigate and chart the physiological characteristics of sodium lactate infusion during a bout of resistance exercise on whole group level and sexes separated Method: A randomized, placebo controlled, cross-over design was implemented where male (n = 8) and female (n = 8) subjects accustomed to resistance exercise visited the laboratory three times for preliminary testing and training familiarization. In the following two experimental trials subjects arrived in an overnight fasted state. A resting state muscle biopsy was extracted from m. vastus lateralis and repeated blood samples were initiated which followed by 20 minute of baseline infusion of either infusate in resting state at 0.05 mmol/kg/min infusion rate with additional bolus doses during subsequent exercise. Following a brief warm up, unilateral knee-extensions (6 x 8-10 reps at 75% of 1-RM) were performered with or without venous infusion of sodium lactate, with volume matched saline as control. Exercise load and volume were matched between trials. Four additional biopsies were extracted at post-exercise, recovery period, and 24-hour post-exercise. Results: Sodium lactate infusion vs saline infusion respectively during resistance exercise yielded significantly higher blood lactate with sodium lactate (6.78 ± 0.33 mmol/l vs 2.99 ± 0.17 mmol/l), plasma lactate (8.86 ± 0.39 mmol/l vs 4.39 ± 0.22 mmol/l), blood sodium (143 ± 0.4 mmol/l vs 142 ± 0.3 mmol/l), blood pH (7.42 ± 0.01 vs 7.34 ± 0.01), but lower blood potassium (3.9 ± 0.1 mmol/l vs 4.2 ± 0.1 mmol/l), all immediately following exercise. Sodium lactate infusion elicited main effect of trials and muscle lactate increased from baseline (8.5 ± 0.9 mmol·kg-1 dw vs 7.0 ± 0.6 mmol·kg-1 dw) to post-exercise (31.5 ± 2.8 mmol·kg-1 dw vs 26.9 ± 3.2 mmol·kg-1 dw) with sodium lactate and saline infusion respectively. Blood glucose, hemoglobin and muscle pH was not affected by sodium lactate infusion. Conclusions: Utilization of the sodium lactate infusion method during a bout of resistance exercise may be used as tool to effectively increase blood/plasma lactate and, to lesser extent, muscle content of lactate. However, a concomitant slightly alkalizing effect of blood likely will occur.Tidigare studier som använt natriumlaktat infusion använde inte styrketräningsprotokoll, eller analyserade muskelbiopsier eller utförde könsspecifika analyser. Syfte och frågeställningar: Vi initierade ett projekt där styrketräning utfördes med låga eller höga nivåer av laktat som erhölls genom venös natriumlaktat infusion med det specifika syftet att undersöka och kartlägga fysiologisk karakteristiska av naturiumlaktat infusion under styrketräningsövning på helgrupps- och könsseparerad nivå. Följande frågeställningar inrättades; hur påverkar natriumlaktat infusion under styrketräning helblod- och plasma laktat, glukos, natrium, kalium, plasma volym genom hemoglobin och hematokrit, blod pH, muskellaktat- och muskel pH samt om skillnader i respons finns efter att könsspecifika analyser utförts på dessa variabler. Metod: En randomiserad, placebokontrollerad cross-over design implementerades där styrketräningsvana män (n = 8) och kvinnor (n = 8) besökte laboratoriet tre gånger för preliminäraför tester och träningsfamiliarisering. I efterföljande två experimentella försök anlände försökspersonerna i ett över nattligt fastande tillstånd. En baslinje biopsi extraherades från m. vastus lateralis och repeterade blodprover initierades med efterföljande 20 minuter av baslinje infusion av endera infusat i vilotillstånd med 0.05 mmol/kg/min infusionshastighet med ytterligare bolusdoser under efterföljande träning. Efter en kort uppvärmning utfördes unilaterala knäextensioner (6 x 8-10 reps vid 75% av 1-RM) med eller utan venös infusion av natrium laktat, med volymmatchande saltlösning som kontroll. Träningsbelastning och volym matchades mellan försök. Ytterligare fyra biopsier extraherades vid efter-träning, återhämtningsperiod, och efter 24 timmar. Resultat: Natriumlaktat respektive saltlösnings infusion under styrketräning gav signifikant högre blodlaktat med natriumlaktat infusion (6.78 ± 0.33 mmol/l mot 2.99 ± 0.17 mmol/l), plasmalaktat (8.86 ± 0.39 mmol/l mot 4.39 ± 0.22 mmol/l), blodnatrium (143 ± 0.4 mmol/l mot 142 ± 0.3 mmol/l), blod pH (7.42 ± 0.01 mot 7.34 ± 0.01), men lägre blod kalium (3.9 ± 0.1 mmol/l mot 4.2 ± 0.1 mmol/l), alla direkt efter träning. Natriumlaktat infusion framkallade huvudeffekt av försök och muskellaktat ökade från baslinje (8.5 ± 0.9 mmol·kg-1 dw mot 7.0 ± 0.6 mmol·kg-1 dw) till efter-träning (31.5 ± 2.8 mmol·kg-1 dw mot 26.9 ± 3.2 mmol·kg-1 dw) med natriumlaktat respektive saltlösnings infusion. Blodglukos, hemoglobin och muskel pH påverkades inte av natriumlaktat infusion. Slutsats: Användande av natriumlaktat infusion som metod under styrketräning kan effektivt användas som verktyg för att höja blod/plasma laktat, och i mindre utsträckning, muskellaktat. Emellertid är samtidig alkalisering av blod en sannolik följd.
Potential sex differences in the molecular response to resistance exercise with lactate infusion
Books on the topic "Knee extensor muscle"
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The effect of two types of isotonic resistance training on strength, movement time, and reaction time in the knee extensor muscles. 1985.
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Shaibani, Aziz. Quadriceps Weakness. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190661304.003.0014.
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Quadriceps muscles extend the knees and are important for walking and balance. Knee buckling (sudden giving away of the knees) is the most common presentation of quadriceps weakness. Knee buckling is common in the elderly, as it can also be caused by knee arthritis. Patients with quadriceps weakness often modify their lifestyle for years before they seek medical advice. Quadriceps muscles are very sensitive to immobility, and they may lose half their bulk within 2 weeks. On the other hand, they build mass quickly with exercise. Sometimes quadriceps muscles are selectively and severely involved, leading to early disability. Severe thigh pain, if it continues for a few weeks, may lead to disuse atrophy. Severe neuropathic thigh pain and atrophy are typically seen in diabetic amyotrophy. Other causes of thigh pain include L3 radiculopathy, meralgia paresthetica, and muscle infarction. Examination of the knee extension should always be part of neuromuscular evaluation.
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Shaibani, Aziz. Quadriceps Weakness. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199898152.003.0014.
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Quadriceps muscles extend the knees and are important for walking and balance. Knee buckling is the most common presentation of quadriceps weakness. Knee buckling is common in the elderly as it can also be caused by knee arthritis. Patients with quadriceps weakness often modify their lifestyle for years before they seek medical advice. Quadriceps muscles are very sensitive to immobility and they may lose 50% of their bulk within 2 weeks of immobility. On the other hand, they build mass quickly by exercises. Sometimes, quadriceps muscles are selectively and severely involved, leading to an early disability. Severe thigh pain, if continued for a few weeks, may lead to disuse atrophy. Severe neuropathic thigh pain and atrophy are typically seen in diabetic amyotrophy. Other causes of thigh pain include L3 radiculopathy, meralgia paresthetica, and muscle infarction. Examination of the knee extension should never be deleted from neuromuscular evaluation.
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Peterson, A. Brad. The effect of the vastus medialis muscle on knee extension and patella position. 1990.
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Machado, Pedro M. Inclusion body myositis. Edited by Hector Chinoy and Robert Cooper. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198754121.003.0011.
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Sporadic inclusion body myositis (IBM) is an acquired muscle disorder associated with ageing, for which there is no effective treatment. It is characterized by a typical early clinical phenotype with (often asymmetric) weakness of the knee extensors and finger flexors, potential involvement of pharyngeal and upper-oesophageal muscles (which may contribute to malnutrition and aspiration), and progressive and slow deterioration, which may lead to severe disability and loss of quality of life. Muscle biopsy shows chronic myopathic features, lymphocytic infiltration with invasion of non-necrotic fibres, rimmed vacuoles, mitochondrial changes, and pathological accumulation of proteins in the muscle tissue. It remains uncertain whether IBM is primarily an immune-mediated inflammatory myopathy or a degenerative myopathy with an associated inflammatory component. This chapter will describe the clinical features, natural history, investigations, current pathogenic concepts, outcome measures, and therapeutic approaches in IBM. Despite recent clues, in many respects IBM remains an unsolved mystery.
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(Editor), W. Norman Scott, and Elizabeth Roselius (Illustrator), eds. Ligament and Extensor Mechanism Injuries of the Knee: Diagnosis and Treatment. Mosby Elsevier Health Science, 1991.
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Norman, Scott W., ed. Ligament and extensor mechanism injuries of the knee: Diagnosis and treatment. St. Louis: Mosby Year Book, 1991.
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The effects of various forms of stabilization on the rectus abdominis during isometric knee extension. 1986.
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Campbell, Cari M. The effect of patellofemoral pain on isometric knee extension torque. 1992.
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Omnikinetic knee extension and flexion exercise: Reliability and comparative analysis for male college athletes. 1987.
Find full textBook chapters on the topic "Knee extensor muscle"
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Wu, Ge. "Muscle Action Pattern and Knee Extensor Strength of Older Tai Chi Exercisers." In Medicine and Sport Science, 30–39. Basel: KARGER, 2008. http://dx.doi.org/10.1159/000134282.
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Allen, Gina M., and Jon A. Jacobson. "Ultrasonography: Sports Injuries." In IDKD Springer Series, 229–45. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-71281-5_16.
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AbstractUltrasonography is a valuable imaging method to evaluate for sports injuries. In the upper extremity, rotator cuff evaluation is most common. Other applications include examination of the biceps and subacromial-subdeltoid bursa in the shoulder, biceps, triceps, common extensor tendon and ulnar collateral ligament in the elbow and tendon tear, pulley injury and skier’s thumb in the wrist and hand. In the lower extremity, ankle sprains, muscle injury and groin pain are the most common problems benefiting from imaging, and ultrasound plays a vital role. Tendinopathy, tendon injury and ligament injury are well visualised in the hip, knee, ankle and foot by diagnostic ultrasound.
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Andrews, Shawn, Ghassan Hamarneh, Azadeh Yazdanpanah, Bahareh HajGhanbari, and W. Darlene Reid. "Probabilistic Multi-shape Segmentation of Knee Extensor and Flexor Muscles." In Lecture Notes in Computer Science, 651–58. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-23626-6_80.
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Ueda, Chihoko, and Atsuko Kagaya. "Muscle Reoxygenation Difference Between Superficial and Deep Regions of the Muscles During Static Knee Extension." In Advances in Experimental Medicine and Biology, 329–34. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-1-4419-1241-1_47.
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Keeratihattayakorn, Saran, and Shigeru Tadano. "Muscle Force Prediction during Knee Flexion/Extension Using EMG-Driven Model." In IFMBE Proceedings, 349–51. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-02913-9_89.
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Úbeda, A., M. Sartori, A. J. del-Ama, Á. Gil-Agudo, J. M. Azorín, and D. Farina. "Decoding Muscle Excitation Primitives from Slow Cortical Potentials During Knee Flexion-Extension." In Converging Clinical and Engineering Research on Neurorehabilitation II, 1151–56. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-46669-9_187.
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Yanagisawa, Osamu. "Functional Differences Among Hamstring Muscles in Hip Extension and Knee Flexion Exercises." In Sports Injuries and Prevention, 279–88. Tokyo: Springer Japan, 2015. http://dx.doi.org/10.1007/978-4-431-55318-2_23.
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Haga, N., S. Nakamura, K. Taniguchi, T. Akune, K. Yoshida, and T. Iwaya. "Magnetic Resonance Imaging of Hip Extensor and Knee Flexor Muscles in Patients with Spina Bifida." In Spina Bifida, 302–6. Tokyo: Springer Japan, 1999. http://dx.doi.org/10.1007/978-4-431-68373-5_63.
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Neligan, Peter C. "The Rectus Femoris Flap for Groin Reconstruction." In Operative Plastic Surgery, edited by Gregory R. D. Evans, 817–22. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190499075.003.0079.
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The rectus femoris muscle is an important but expendable knee extensor. It is a bipennate muscle with a dense and strong fascia on its undersurface. This feature makes it extremely attractive for the repair of defects of the lower abdominal wall and groin as a pedicled flap. It is centrally located between the vastus medialis and vastus lateralis muscles. It is generally used as a pedicled muscle and usually taken as a muscle flap without a skin paddle. The muscle is then grafted. Following harvest, the extensor tendons need to be centralized and repaired for a distance of 6–8 cm above the knee. In many situations this flap has been superseded by the ALT flap.
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Tesconi, Mario, Enzo Pasquale Scilingo, Pierluigi Barba, and Danilo De Rossi. "Wearable Kinesthetic System for Joint Knee Flexion-Extension Monitoring In Gait Analysis." In Encyclopedia of Healthcare Information Systems, 1390–97. IGI Global, 2008. http://dx.doi.org/10.4018/978-1-59904-889-5.ch174.
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Posture and motion of body segments are the result of a mutual interaction of several physiological systems such as nervous, muscle-skeletal, and sensorial. Patients who suffer from neuromuscular diseases have great difficulties in moving and walking, therefore motion or gait analysis are widely considered matter of investigation by the clinicians for diagnostic purposes. By means of specific performance tests, it could be possible to identify the severity of a neuromuscular pathology and outline possible rehabilitation planes. The main challenge is to quantify a motion anomaly, rather than to identify it during the test. At first, visual inspection of a video showing motion or walking activity is the simplest mode of examining movement ability in the clinical environment. It allows us to collect qualitative and bidimensional data, but it does not provide neither quantitative information about motion performance modalities (for instance about dynamics and muscle activity), nor about its changes. Moreover, the interpretation of recorded motion pattern is demanded to medical personnel who make a diagnosis on the basis of subjective experience and expertise. A considerable improvement in this analysis is given by a technical contribution to quantitatively analyse body posture and gesture. Advanced technologies allow us to investigate on anatomic segments from biomechanics and kinematics point of view, providing a wide set of quantitative variables to be used in multi-factorial motion analysis. A personal computer enables a realtime 3D reconstruction of motion and digitalizes data for storage and off-line elaboration. For this reason, the clinicians have a detailed description of the patient status and they can choose a specific rehabilitation path and verify the subject progress.
Conference papers on the topic "Knee extensor muscle"
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Suh, MJ, and BR Kim. "AB0810 Correlation between knee extensor muscle strength and gait endurance after total knee arthroplasty." In Annual European Congress of Rheumatology, 14–17 June, 2017. BMJ Publishing Group Ltd and European League Against Rheumatism, 2017. http://dx.doi.org/10.1136/annrheumdis-2017-eular.1043.
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Neptune, Richard R., Kotaro Sasaki, and Steven A. Kautz. "Muscle Mechanical Work Adaptations With Increasing Walking Speed." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176567.
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Recent modeling studies of walking at self-selected speeds have identified how individual muscles work in synergy to satisfy the task demands including body support, forward propulsion and swing initiation (e.g. [1, 6]). These analyses revealed that young adults walking at a self-selected speed utilize a distribution of hip and knee extensor muscle force in early stance and ankle plantar flexor and rectus femoris force in late stance to provide support and forward propulsion [6]. However, how these muscles’ putative contributions to these functional tasks change with walking speed is not well understood. Intuitively, increasing walking speed would necessitate an increase in activity for muscles that contribute to forward propulsion. However, increasing walking speed is also associated with longer stride lengths (e.g., [2]), which may require increased activity from those muscles contributing to swing initiation, and increased activity from those muscles contributing to vertical support because the vertical excursion of the body’s center of mass increases.
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Eriten, Melih, and Harry Dankowicz. "A Rigorous Dynamical-Systems-Based Analysis of the Self-Stabilizing Influence of Muscles." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34469.
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In this paper, dynamical systems analysis and optimization tools are used to investigate the local dynamic stability of periodic task-related motions of simple models of the lower-body musculoskeletal apparatus and to seek parameter values guaranteeing their stability. In particular, the dynamics of a two-link model of a leg undergoing periodic excitation through one or several contractile muscle elements corresponding to a simple knee-bending motion is studied. Several muscle models incorporating various active and passive elements are included and the notion of self-stabilization of the rigid-body dynamics through the imposition of muscle-like actuation is investigated. It is found that self-stabilization depends both on muscle architecture and configuration as well as the properties of the reference motion. Additionally, antagonistic muscles (flexor-extensor muscle couples) are shown to enable stable motions over larger ranges in parameter space and that even the simplest neuronal feedback mechanism can stabilize the repetitive motions. The work provides a review of the necessary concepts of stability and a commentary on existing incorrect results that have appeared in the literature on muscle self-stabilization.
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Kek, Khai Jun, Takahiro Miyakawa, Nobuki Kudo, and Katsuyuki Yamamoto. "Functional imaging of muscle oxygenation and oxygen consumption in the knee extensor muscles during isometric contractions by spatially resolved near-infrared spectroscopy." In Biomedical Optics (BiOS) 2007, edited by Britton Chance, Robert R. Alfano, Bruce J. Tromberg, Mamoru Tamura, and Eva M. Sevick-Muraca. SPIE, 2007. http://dx.doi.org/10.1117/12.698783.
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Manal, Kurt, and Thomas S. Buchanan. "Predictions of Condylar Contact During Normal and Medial Thrust Gait." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80560.
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The medial compartment of the knee is the joint most often affected in those with osteoarthritis (OA). The knee adduction moment is a widely used surrogate measure of joint loading as direct measures are not possible except for a few individuals fitted with a force sensing prosthesis. A reduction in the frontal plane moment is believed to be associated with reduced joint compression. As such, treatments and/or gait alterations to reduce the magnitude of the adduction moment have been sought for those with knee OA. Walking with a medial thrust gait has been shown to reduce the magnitude of the knee adduction moment. The purpose of this paper is to apply our EMG-driven musculoskeletal model of the knee to predict muscle forces and condylar loading during normal and medial thrust gait for an individual fitted with an instrumented knee. It was anticipated that walking with a medial thrust gait would produce a reduced knee adduction moment. We propose however that a reduced knee adduction moment may not necessarily be associated with a decrease in medial compartment loading, and importantly, one must consider how the knee extensor moment changes before making inferences about joint loading.
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Hakansson, Nils A., and Maury L. Hull. "Influence of Pedaling Rate on Muscle Mechanical Energy in Low Power Recumbent Pedaling Using Forward Dynamic Simulations." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-35108.
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An understanding of the muscle power contributions to the crank and limb segments in recumbent pedaling would be useful in the development of rehabilitative pedaling exercises. The objectives of this work were to (i) develop a forward dynamic model to simulate low-power pedaling in the recumbent position, (ii) use the model to quantify the power contributions of the muscles to driving the crank and limb segments, and (iii) determine whether there were differences in the muscle power contributions required to simulate recumbent pedaling at three different pedaling rates. A forward dynamic model was used to determine the individual muscle excitation amplitude and timing to drive simulations that best replicated experimental kinematics and kinetics of recumbent pedaling. The segment kinematics, pedal reaction forces, and electromyograms (EMG) of 10 muscles of the right leg were recorded from 16 subjects as they pedaled a recumbent ergometer at 40, 50, and 60 rpm and a constant 50 W workrate. Intersegmental joint moments were computed using inverse dynamics and the muscle excitation onset and offset timing were determined from the EMG data. All quantities were averaged across ten cycles for each subject and averaged across subjects. The model-generated kinematic and kinetic quantities tracked almost always within 1 SD of the experimental data for all three pedaling rates. The uniarticular hip and knee extensors generated 65 percent of the total mechanical work in recumbent pedaling. The triceps surae muscles transferred power from the limb segments to the crank and the bi-articular muscles that crossed the hip and knee delivered power to the crank during the leg transitions between flexion and extension. The functions of the individual muscles did not change with pedaling rate, but the mechanical energy generated by the knee extensors and hip flexors decreased as pedaling rate increased. By varying the pedaling rate, it is possible to manipulate the individual muscle power contributions to the crank and limb segments in recumbent pedaling and thereby design rehabilitative pedaling exercises to meet specific objectives.
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Nagel, Vincent, Sarah Chu, Jack Forney, Lyle Kosinski, and Vimal Viswanathan. "Design and Control of an Assistive Bionic Joint for Leg Muscle Rehabilitation." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-71143.
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This project aims to create an electronically powered and controlled knee brace to aid stroke victims with partial paralysis with their leg muscle rehabilitation process. The newly designed assistive bionic joint takes the functionality of the existing assistive knee braces to the next level by incorporating a control algorithm that uses sensor signals gathered from the patient’s leg muscles. Electromyography (EMG) is used for gathering impulse signals from electrodes placed on key muscles as inputs for the device. The action of each major leg muscle is replicated using a set of fluidic muscles that mimic the functionality of the actual leg muscles. A microcontroller is used to interpret sensor data and adjust the contraction length of the muscles, thereby providing the wearer with augmented strength and mobility. Initial testing of a proof-of-concept prototype has led to finite control over muscle contraction length based on sensor data and has a response time of 280ms from full extension to contraction. Further testing of the brace assembly, fluidic muscles and control system is conducted and the results indicate a 600ms response time due to a step input. This personalized, powered brace has many implications for the enrichment of muscle rehabilitation such as higher patient morale, more muscle activity, and shortened recovery times.
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Higginson, J., T. Kesar, R. Perumal, and S. Binder-Macleod. "Simulation-Guided Stimulation for Paretic Ankle Muscles During Stroke Gait." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176365.
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Stroke is the leading cause of long-term adult disability in the U.S. Neuronal damage in the brain results in impaired muscle coordination which induces asymmetric and abnormal walking patterns. Muscle-actuated forward dynamic simulation of walking patterns of healthy young adults has elucidated unique and synergistic roles of the uniarticular and biarticular plantarflexors. Neptune and colleagues (2001) reported that soleus delivers energy to the trunk, gastrocnemius accelerates the leg forward, and both contribute significantly to vertical support of the center of mass [1]. In a simulation of post-stroke hemiparetic gait, Higginson et al. (2006) observed that non-paretic muscles mimicked the function of healthy muscles, while paretic ankle plantarflexor function was limited and required supplemental effort by hip and knee extensors [2].
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Nicolella, Daniel P., Barron Bichon, W. Loren Francis, and Travis D. Eliason. "Dynamic Modeling of Knee Mechanics." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63940.
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It is widely accepted that the mechanical environment within the knee, or more specifically, increased or altered stresses or strains generated within the cartilage, is a leading cause of knee osteoarthritis (OA). However, a significant unfulfilled technological challenge in musculoskeletal biomechanics and OA research has been determining the dynamic mechanical environment of the cartilage (and other components) resulting from routine and non-routine physical movements. There are two methods of investigating musculoskeletal joint mechanics that have been used to date: 1) forward and inverse multibody dynamic simulations of human movement and 2) detailed quasi-static finite element modeling of individual joints. The overwhelming majority of work has been focused on musculoskeletal multibody dynamics modeling. This method, in combination with experimental motion capture and analysis, has been integral to understanding torques, muscle and ligament forces, and reaction forces occurring at the joint during activities such as walking, running, squatting, and jumping as well as providing key insights into musculoskeletal motor control schemes. However, multibody dynamics simulations do not allow for the detailed continuum level analysis of the mechanical environment of the cartilage and other knee joint structures (meniscus, ligaments, and underlying bone) within the knee during physical activities. This is a critical technology gap that is required to understand the relationship between functional or injurious loading of the knee and cartilage degradation. We have developed a detailed neuromuscularly activated dynamic finite element model of the human lower body and have used this model to simultaneously determine the dynamic muscle forces, joint kinematics, contact forces, and detailed (e.g., continuum) stresses and strains within the knee (cartilage, meniscus, ligaments, and bone) during several increasingly complex neuromuscularly controlled and actuated lower limb movements. Motion at each joint is controlled explicitly via deformable cartilage-to-cartilage surface contact at each articular surface (rather than idealized as simple revolute or ball and socket joints). The major muscles activating the lower limb are explicitly modeled with Hill-type active force generating springs using anatomical muscle insertion points and geometric wrapping. Muscle activation dynamics were determined via a constrained optimization scheme to minimize muscle activation energy. Time histories of the mechanical environment of all soft tissues within the knee are determined for a simulated leg extension.
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Lee, Woo-Eun, Hyun-Woo Uhm, and Yoon-Su Nam. "Estimation of tendon slack length of knee extension/flexion muscle." In 2008 International Conference on Control, Automation and Systems (ICCAS). IEEE, 2008. http://dx.doi.org/10.1109/iccas.2008.4694625.
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