The relation between force and velocity in human muscle

Wilkie, D.

doi:10.1113/jphysiol.1949.sp004437

Cited by 538 publications

(246 citation statements)

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“…The metabolic demands during eccentric exercise are lower, resulting in less oxygen consumption and energy expenditure. [11][12][13][14] Therefore, blood flow to the working muscle would not have to increase as much to maintain regulatory function.…”

Section: Discussionmentioning

confidence: 99%

“…10 It is unclear, however, whether this difference in metabolic demand alters circulatory responses in muscle as seen with concentric-eccentric and isometric contractions. During eccentric contractions, the breakdown of adenosine triphosphate is slowed, resulting in lower requirements for energy 11,12 and oxygen consumption to rarely elevate from rest. 13,14 Several studies have examined the effect of isometric or concentriceccentric contractions on blood flow.…”

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confidence: 99%

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Microvascular Perfusion Increases After Eccentric Exercise of the Gastrocnemius

Selkow

Herman

Liu

et al. 2013

Journal of Ultrasound in Medicine

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epeated contractions of skeletal muscle, as in exercise, have been shown to increase local blood flow. [1][2][3][4][5][6][7][8] This increase in blood flow is proportional to the metabolic demands of the muscle tissue being exercised. 9 Metabolic demand changes depending on the type of exercise performed. Eccentric contractions produce more force with less metabolic demand than concentric or isometric contractions. 10 It is unclear, however, whether this difference in metabolic demand alters circulatory responses in muscle as seen with concentric-eccentric and isometric contractions. During eccentric contractions, the breakdown of adenosine triphosphate is slowed, resulting in lower requirements for energy 11,12 and oxygen consumption to rarely elevate from rest. 13,14 Several studies have examined the effect of isometric or concentriceccentric contractions on blood flow. 2-8 However, eccentric-only Noelle M. Selkow, PhD, ATC, Daniel C. Herman, MD, PhD, Zhenqi Liu, MD, Jay Hertel, PhD, ATC, Joseph M. Hart, PhD, ATC, Susan A. Saliba, PhD, MPT, ATC Received July 13, 2012, ORIGINAL RESEARCHObjectives-The purpose of this study was to assess microvascular perfusion immediately after eccentric exercise using contrast-enhanced sonography.Methods-An intravenous catheter was placed in the antecubital vein of the arm contralateral to the leg being tested for the delivery of microbubbles to 18 healthy volunteers (mean age ± SD, 22.2 ± 2.2 years; height, 166.0 ± 11.9 cm; weight, 69.4 ± 25.0 kg). Eccentric exercises were performed unilaterally in a randomized leg. Calf-lowering repetitions off a raised step were performed to the beat of a metronome over 3 seconds in the sequence of 50 repetitions, 5 minutes of rest, and 50 repetitions. Microvascular perfusion (blood volume, blood flow, and blood flow velocity) was measured before and immediately after exercise using replenishment kinetics.Results-Blood volume and flow both significantly increased after exercise (P < .001). Baseline measurements were 5.88 ± 1.33 dB and 2.34 ± 0.41 dB/s and increased to 12.20 ± 3.31 dB and 4.52 ± 1.05 dB/s, respectively. There was a significant decrease in blood flow velocity (P = .035) after exercise (0.38 ± 0.03 s -1 ) from baseline (0.41 ± 0.06 s -1 ).Conclusions-Circulatory responses were altered after eccentric exercise, which may be due to the metabolic demand placed on the body. On the basis of this finding, eccentric exercise may be used as a model to assess the effect modalities have on the circulatory system after an elevated state of microvascular perfusion is reached.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Microvascular Perfusion Increases After Eccentric Exercise of the Gastrocnemius

Selkow

Herman

Liu

et al. 2013

Journal of Ultrasound in Medicine

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“…The seat was adjusted by means of a moving system near the fixed column so that the subject's forearm rested on the forearm support. The motor rotation axis was aligned with the epitrochlea-epicondyle axis of the humerus, which gives the elbow a remarkably constant radius of rotation (Wilkie, 1950). The hand was placed in the prone position by taking a horizontal grip, the distance of which from the motor rotation axis could be adjusted.…”

Section: Experimental Protocolmentioning

confidence: 99%

Muscle and joint elastic properties during elbow flexion in Duchenne muscular dystrophy

Cornu

Goubel

Fardeau

2001

The Journal of Physiology

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Duchenne muscular dystrophy (DMD) is characterized by a direct effect on muscle fibres leading to muscle atrophy and weakness due to a lack of muscle dystrophin. Dystrophin is a sarcolemma cytoskeletal protein whose deficit leads to segmental necrosis of the muscle fibre. DMD is thus characterized by a decrease in the number of muscle fibres, which are progressively replaced by fibroadipose tissue. The first observed clinical signs relate to difficulties in running or climbing stairs and calf hypertrophy. Gait then becomes lordotic and waddling. Between 6 and 11 years of age, limb and torso muscles progressively and steadily decrease in strength. Loss of ambulation occurs (average 10.5 years of age) and all torso and limb muscles decrease in size.The assessment of muscle mechanical properties in DMD patients is mostly limited to a more or less sensitive evaluation of strength production, generally in static conditions and occasionally during a locomotor act. Two kinds of non-invasive technique are generally used to characterize muscle functional properties in DMD patients. (i) Semi-quantitative measurements (manual testing, timed scores during motor acts) are performed in routine clinical practice and afford a functional evaluation (Edwards & Hide, 1977;Brooke et al. 1981;Aitkens et al. 1989). For instance, manual testing (scored from 0 to 5) is based on an international graduated scale of muscle ability: MRC scale (Medical Research Council, 1943) reorganized from 0 to 10 (Brooke et al. 1981).(ii) Quantitative measurements (manual dynamometry) can be performed in some muscle groups and give a maximal voluntary contraction (MVC) measurement (Munsat, 1989).Understanding of the mechanisms responsible for muscle adaptation to altered functional demand (pathology or training) requires quantification of muscle mechanical properties. For instance, muscle contractility and muscle elasticity were experimentally found to be sensitive to periods of hyperactivity as well as hypoactivity (Goubel & Marini, 1987; Almeida Silveira et al. 1994;Canon & Goubel, 1995 1. Maximal voluntary contraction (MVC), series elastic stiffness and total joint stiffness during elbow flexion were investigated in healthy boys and in boys with Duchenne muscular dystrophy (DMD) in order to assess changes in mechanical properties induced by the disease.2. Two methods were used to perform stiffness measurements: (i) the application of sinusoidal perturbations to the joint during flexion efforts, allowing the calculation of total joint stiffness; (ii) the use of quick-release movements of the elbow, which had previously been maintained in isometric contraction, allowing the calculation of series elastic stiffness. In each case, stiffness was linearly related to torque, leading to the calculation of a normalized stiffness index as the slope of this stiffness-torque relationship.3. As expected, mean MVC was found to be much higher for healthy boys (20.02 ± 5.20 N m) than for DMD patients (3.09 ± 2.44 N m). Furthermore, the results showed that it was poss...

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“…The triceps connections to the olecranon process of the ulna were retracted 20 mm by the addition of three rigid beams to increase the length of the triceps lever arm. The lower arm muscles, brachioradialis, pronator teres, and extensor carpi radialis longus, all of which contribute to elbow flexion (Wilkie 1950;Murray et al 2000), are also included in the model. A summary of the muscles included, division into number of elements, muscle action, and muscle specific parameters can be found in Table 1.…”

Section: Musculoskeletal Modelmentioning

confidence: 99%

Active muscle response using feedback control of a finite element human arm model

Östh

Brolin

Happee

2012

Computer Methods in Biomechanics and Biomedical Engineering

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Mathematical Human Body Models (HBM) are important research tools that are used to study the human response in car crash situations. Development of automotive safety systems requires the implementation of active muscle response in HBM, as novel safety systems also interact with vehicle occupants in the precrash phase. In this study, active muscle response was implemented using feedback control of a non-linear muscle model in the right upper extremity of a Finite Element (FE) HBM. Hill-type line muscle elements were added and the active and passive properties were assessed. Volunteer tests with low impact loading resulting in elbow flexion motions were performed. Simulations of posture maintenance in a gravity field and the volunteer tests were successfully conducted. It was concluded that feedback control of a non-linear musculoskeletal model can be used to obtain posture maintenance and human-like reflexive responses in an FE HBM.Keywords: finite element; human body model; active muscle; feedback control; posture maintenance; upper extremity 2 1 Introduction Road traffic accidents are among the top leading causes of death worldwide. In the European Union, there are about 43,000 reported deaths (ETSC 2008) and 1.3 million casualties because of road traffic accidents each year (European Commission 2001). To prevent accidental injuries, it is vital to understand the mechanics of injury in biological tissues. For traffic safety research addressing this problem Human Body Models (HBM) are important tools. The HBM can be Multi Body (MB) or Finite Element (FE) models. The MB models consist of rigid bodies connected with joints defined by kinematical constraints and can predict occupant kinematics at a relatively low computational cost with relatively simple models. FE models can be more detailed and have the advantage of providing stress and strain data for individual tissues. Therefore, they are well suited to study injury mechanics, to find injury tolerances, determine risk functions, and in the design of preventive systems.Recent development of automotive safety systems imposes new requirements on HBM. Systems that can detect and prevent accidents are integrated with systems that become active when the accident is occurring (Aparicio 2005). The occupant's interaction with safety systems in the pre-crash phase will change the injury outcome in the crash phase. Therefore, HBM that are biofidelic in the pre-crash phase and during the crash phase can be used to study how the integrated safety systems change the injury risk during crash scenarios. FE HBM models used today lack two features that are important for simulation of pre-crash scenarios:

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The relation between force and velocity in human muscle

Cited by 538 publications

References 16 publications

Microvascular Perfusion Increases After Eccentric Exercise of the Gastrocnemius

Microvascular Perfusion Increases After Eccentric Exercise of the Gastrocnemius

Muscle and joint elastic properties during elbow flexion in Duchenne muscular dystrophy

Active muscle response using feedback control of a finite element human arm model

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