Muscle Elasticity and Human Performance

Shorten, Martyn R.

doi:10.1159/000414393

Cited by 107 publications

(124 citation statements)

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“…SEC stiffness increased (Shorten, 1987). However, the quick-release estimate of human SEC stiffness is in fair agreement with those obtained with alternative methods such as small amplitude oscillation experiments (Cannon & Zahalak, 1982) and the free vibration technique (Shorten, 1987). Furthermore, the characteristics of SEC stiffness of human muscle were also found to change according to the functional demand (Pousson et al 1990;Goubel, 1997;Lambertz et al 2001).…”

Section: Series Elastic Stiffness: S Qr and Si Qrsupporting

confidence: 75%

“…Agonistic compliance can then be minimized, i.e. SEC stiffness increased (Shorten, 1987). However, the quick-release estimate of human SEC stiffness is in fair agreement with those obtained with alternative methods such as small amplitude oscillation experiments (Cannon & Zahalak, 1982) and the free vibration technique (Shorten, 1987).…”

Section: Series Elastic Stiffness: S Qr and Si Qrsupporting

confidence: 55%

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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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Section: Series Elastic Stiffness: S Qr and Si Qrsupporting

confidence: 75%

Section: Series Elastic Stiffness: S Qr and Si Qrsupporting

confidence: 55%

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

Cornu

Goubel

Fardeau

2001

The Journal of Physiology

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“…Resultados semelhantes foram encontrados neste estudo, já que os grupos tratados tiveram melhor desempenho do que o controle, porém sem diferença entre si. Aliás, talvez nem seja possí-vel falar apenas sobre aumento de força muscular, mas também de um mecanismo de maior vantagem mecâni-ca possibilitando um melhor rendimento 21 pela otimização do uso da energia potencial elástica [22][23][24] . Tendo em mente esse mecanismo de aproveitamento de energia potencial elástica, é possível relacionar os resultados de força muscular com o encurtamento dos músculos isquiotibiais, pois os dois grupos alongados se comportaram de maneira semelhante, ganhando igualmente flexibilidade e vantagem mecânica.…”

Section: Discussionunclassified

Reeducação postural global e alongamento estático segmentar na melhora da flexibilidade, força muscular e amplitude de movimento: um estudo comparativo

Rosário¹,

Sousa

Cabral

et al. 2008

Fisioter. Pesqui.

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RESUMO: Exercícios de alongamento são usados para aumentar a flexibilidade e amplitude de movimento (ADM). Entre os métodos existentes, destacam-se a reeducação postural global (RPG), que promove o alongamento global das cadeias musculares, e o alongamento segmentar, que alonga um músculo ou grupo muscular específico. Este estudo visou comparar o alongamento segmentar e o global pela técnica de RPG quanto ao ganho de flexibilidade, ADM e força muscular. Trinta mulheres foram distribuídas aleatoriamente em três grupos (n=10 em cada): o grupo global fez alongamento de cadeias musculares; o grupo segmentar realizou alongamento segmentar; e o grupo controle não fez alongamento. Antes e depois do tratamento, em todos os grupos, foram avaliadas a ADM de extensão da perna, flexibilidade pelo teste 3o dedo-solo e força isométrica de flexão da perna em 45°e 90°. Os dois grupos experimentais realizaram oito sessões de alongamento de 30 minutos cada, duas vezes por semana. Toda a análise estatística foi realizada com p<0,05. Os resultados dos grupos global e segmentar foram semelhantes entre si e superiores aos do grupo controle na ADM, flexibilidade e força muscular em 45° e 90° (p<0,05). Na avaliação intra-sessões, os dois grupos também tiveram desempenhos semelhantes, com ganho relativo da ADM maior nas primeiras e decrescendo ao longo das sessões. Ambas as técnicas de alongamento foram pois igualmente eficientes no aumento de flexibilidade, ADM e força muscular. DESCRITORES:Amplitude de movimento articular; Elasticidade; Exercícios de alongamento muscular; Força muscular ABSTRACT: Stretching exercises are prescribed to increase flexibility and range of motion (ROM). Two current stretching methods are the global posture reeducation (GPR), where muscle chains are stretched, and segmentary exercises, where a single muscle or muscle group is stretched. The aim of this study was to compare these two techniques, assessing their effects on improving flexibility, ROM and muscle strength. Thirty women were randomly distributed into three groups (n=10 each): global group performed stretching following GPR method; segment group performed segment stretching exercises; and control group did no exercise. Before and after treatment, in all groups, knee extension ROM, flexibility by means of the fingertip-to-floor test, and isometric muscular strength at 45° and 90° knee flexion were measured. Each treated group performed eight stretching 30-minute sessions for four weeks, twice a week. Data were statistically analysed and the significance level set at p<0.05. Global and segment group results were similar and better than control group's concerning ROM, flexibility and muscle strength at 45° and 90° knee flexion (p<0.05). When assessing improvement inter-sessions, both groups had better ROM improvement at the first sessions, decreasing along the others. Both global and segmentary stretching techniques were hence found effective in improving flexibility, ROM and leg muscle strength.

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“…To obtain these two measures, the subjects adopt the same position at the ad hoc measurement device designed previously by the same authors (París-García, Barroso, Cañas, Ribas, & París, 2013). The position of the subject and the development of the measurement device are based on previous studies (Cavagna, 1970;Shorten, 1987) as earlier proposals and as the latest proposals that obtain the same variables (Babic & Lenarcic, 2004;Faria, Gabriel, Abrantes, Brás, & Moreira, 2009;Fukashiro et al, 2001;McLachlan et al, 2006;Murphy et al, 2003;París-García et al, 2013) (Basically, related to the position, the subjects were asked to keep angles of 90 degree at ankle, knee and hip articulation). The details of the procedure to obtain these measures are described at 2.3 MVCI test.…”

Section: Testing Proceduresmentioning

confidence: 99%

“…The stiffness of the muscle-tendon unit (MTU) is related to performance during fast and slow stretch shortening cycle (SSC) movements (Wilson, Murphy, & Pryor, 1994).This concept of stiffness can be applied to bigger structures likes the legs. Defining the legs as spring-mass model, its mechanical response depends of the Leg stiffness (Butler, 2003;Shorten, 1987). Leg stiffness is defined as the ratio of maximal ground reaction force to maximum leg compression at the middle of the stance phase (Butler, 2003;Farley, Blickhan, Saito, & Taylor, 1991).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Level of Physical Activity Through Musculo-Articular Stiffness in Young Adults

París-García¹,

Oviedo‐Caro²,

Antequera³

2017

Revista INFAD de Psicología

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The purpose of the study is to evaluate the level of physical activity of young adults by means of the Musculo-articular stiffness and to analyse its correlation with the physical performance measured in jump capacity. The proposed protocol includes a Muscle-articular test of both legs, a test of maximum voluntary contraction in isometric conditions (MVCi), a countermovement jump test (CMJ), and a drop jump (DJ) protocol from different heights (20, 40 and 60 cm). 21 healthy young adult subjects (12 males and 9 females). The mechanical variables are: force (f), Muscle-articular stiffness (k) and Muscle-articular Unitary stiffness (k u ). Physical variables: Jump flight height (h) and force generated (f). An Anova of repeated measurements was performed to analyse the influence of gender and laterality and a Pearson correlation to analyse the relationship between mechanical and physical parameters. The results obtained show a clear symmetry in physical and mechanical parameters. There were significant differences between men and women (f and k) (p<0.05) being in absolute terms higher in men than in women but not in relative terms (k u ). A clear correlation was obtained between mechanical parameters and MVCi in absolute terms (p<0.05). K u allows comparisons between different subjects but its interpretation is not as intuitive as in absolute terms due to the application of the Hill's model on the mechanical response of muscle-tendon complexes that establishes a nonlinear relationship between f and k.

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Muscle Elasticity and Human Performance

Cited by 107 publications

References 0 publications

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

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

Reeducação postural global e alongamento estático segmentar na melhora da flexibilidade, força muscular e amplitude de movimento: um estudo comparativo

Evaluation of the Level of Physical Activity Through Musculo-Articular Stiffness in Young Adults

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