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Musculotendinous stiffness of triceps surae, maximal rate of force development, and vertical jump performance.

Driss T, Lambertz D, Rouis M, Jaafar H, Vandewalle H - Biomed Res Int (2015)

Bottom Line: The subjects were subdivided in 3 groups in function of CMJ (groups H, M, and L for high, medium, and low performers, resp.).There was a downward curvature of the torque-stiffness relationship at high torques in group H or M and the torque-stiffness regression was linear in group L only.These results suggested that torque-stiffness relationships with a plateau at high torques are more frequent in the best jumpers.

View Article: PubMed Central - PubMed

Affiliation: CeRSM (EA 2931), Equipe de Physiologie, Biomécanique et Imagerie du Mouvement, UFR STAPS, Université Paris Ouest Nanterre La Défense, 200 avenue de la République, 92000 Nanterre, France.

ABSTRACT
The relationships between ankle plantar flexor musculotendinous stiffness (MTS) and performance in a countermovement vertical jump (CMJ) and maximal rate of torque development (MRTD) were studied in 27 active men. MTS was studied by means of quick releases at 20 (S0.2), 40 (S0.4), 60 (S0.6), and 80% (S0.8) of maximal voluntary torque (T(MVC)). CMJ was not correlated with strength indices but was positively correlated with MRTD/BM, S 0.4/BM. The slope α 2 and intercept β 2 of the torque-stiffness relationships from 40 to 80% T(MVC) were correlated negatively (α 2) and positively (β 2) with CMJ. The different stiffness indices were not correlated with MRTD. The prediction of CMJ was improved by the introduction of MRTD in multiple regressions between CMJ and stiffness. CMJ was also negatively correlated with indices of curvature of the torque-stiffness relationship. The subjects were subdivided in 3 groups in function of CMJ (groups H, M, and L for high, medium, and low performers, resp.). There was a downward curvature of the torque-stiffness relationship at high torques in group H or M and the torque-stiffness regression was linear in group L only. These results suggested that torque-stiffness relationships with a plateau at high torques are more frequent in the best jumpers.

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(a) The ankle ergometer system. (A) Actuator, with its power supply unit, angular displacement, angular velocity, and torque transducers, and its associated electronics; (B) driving unit controlled by a personal computer; (C) adjustable table. (b) Foot strapping on the actuator.
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fig1: (a) The ankle ergometer system. (A) Actuator, with its power supply unit, angular displacement, angular velocity, and torque transducers, and its associated electronics; (B) driving unit controlled by a personal computer; (C) adjustable table. (b) Foot strapping on the actuator.

Mentions: Ankle plantar flexor MTS was studied by means of the ankle ergometer designed by the University of Technology of Compiègne (France) for the measurement of ankle plantar flexor MTS before and after long-term spaceflights [17]. This ankle ergometer (Figure 1) consists of two main units: (1) a power unit that contained the actuator, its power supply unit, angular displacement, angular velocity and torque transducers, and its associated electronics; (2) a driving unit controlled by a personal computer equipped with a 12-bit analog-to-digital board; (3) adjustable table. Angular displacement was measured with an optical digital sensor, and angular velocity was captured from a resolver bound to the rotor, except for velocities >15.7 rad·s−1 that required a tachometer. Torque was obtained by means of a strain gauge torque transducer. All mechanical data were sampled at 1 kHz. A dual beam oscilloscope gave the subjects visual feedback about the procedure in progress.


Musculotendinous stiffness of triceps surae, maximal rate of force development, and vertical jump performance.

Driss T, Lambertz D, Rouis M, Jaafar H, Vandewalle H - Biomed Res Int (2015)

(a) The ankle ergometer system. (A) Actuator, with its power supply unit, angular displacement, angular velocity, and torque transducers, and its associated electronics; (B) driving unit controlled by a personal computer; (C) adjustable table. (b) Foot strapping on the actuator.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4325552&req=5

fig1: (a) The ankle ergometer system. (A) Actuator, with its power supply unit, angular displacement, angular velocity, and torque transducers, and its associated electronics; (B) driving unit controlled by a personal computer; (C) adjustable table. (b) Foot strapping on the actuator.
Mentions: Ankle plantar flexor MTS was studied by means of the ankle ergometer designed by the University of Technology of Compiègne (France) for the measurement of ankle plantar flexor MTS before and after long-term spaceflights [17]. This ankle ergometer (Figure 1) consists of two main units: (1) a power unit that contained the actuator, its power supply unit, angular displacement, angular velocity and torque transducers, and its associated electronics; (2) a driving unit controlled by a personal computer equipped with a 12-bit analog-to-digital board; (3) adjustable table. Angular displacement was measured with an optical digital sensor, and angular velocity was captured from a resolver bound to the rotor, except for velocities >15.7 rad·s−1 that required a tachometer. Torque was obtained by means of a strain gauge torque transducer. All mechanical data were sampled at 1 kHz. A dual beam oscilloscope gave the subjects visual feedback about the procedure in progress.

Bottom Line: The subjects were subdivided in 3 groups in function of CMJ (groups H, M, and L for high, medium, and low performers, resp.).There was a downward curvature of the torque-stiffness relationship at high torques in group H or M and the torque-stiffness regression was linear in group L only.These results suggested that torque-stiffness relationships with a plateau at high torques are more frequent in the best jumpers.

View Article: PubMed Central - PubMed

Affiliation: CeRSM (EA 2931), Equipe de Physiologie, Biomécanique et Imagerie du Mouvement, UFR STAPS, Université Paris Ouest Nanterre La Défense, 200 avenue de la République, 92000 Nanterre, France.

ABSTRACT
The relationships between ankle plantar flexor musculotendinous stiffness (MTS) and performance in a countermovement vertical jump (CMJ) and maximal rate of torque development (MRTD) were studied in 27 active men. MTS was studied by means of quick releases at 20 (S0.2), 40 (S0.4), 60 (S0.6), and 80% (S0.8) of maximal voluntary torque (T(MVC)). CMJ was not correlated with strength indices but was positively correlated with MRTD/BM, S 0.4/BM. The slope α 2 and intercept β 2 of the torque-stiffness relationships from 40 to 80% T(MVC) were correlated negatively (α 2) and positively (β 2) with CMJ. The different stiffness indices were not correlated with MRTD. The prediction of CMJ was improved by the introduction of MRTD in multiple regressions between CMJ and stiffness. CMJ was also negatively correlated with indices of curvature of the torque-stiffness relationship. The subjects were subdivided in 3 groups in function of CMJ (groups H, M, and L for high, medium, and low performers, resp.). There was a downward curvature of the torque-stiffness relationship at high torques in group H or M and the torque-stiffness regression was linear in group L only. These results suggested that torque-stiffness relationships with a plateau at high torques are more frequent in the best jumpers.

Show MeSH
Related in: MedlinePlus