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

Tarak Driss,Daniel Lambertz,Henry Vandewalle,Hamdi Jaafar,Majdi Rouis

doi:10.1155/2015/797256

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 (S 0.2), 40 (S 0.4), 60 (S 0.6), and 80% (S 0.8) 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.

Highlights

Since its presentation in 1921 by Sargent as “the physical test of a man” [1], vertical jump is often used as field or laboratory test
There was no significant difference in Body mass (BM) and body height (BH) between the different groups (Table 1)
countermovement vertical jump (CMJ) was independent of BM and BH (0.031 < r < 0.133; P > 0.05)

Summary

Introduction

Since its presentation in 1921 by Sargent as “the physical test of a man” [1], vertical jump is often used as field or laboratory test. The interest of vertical jump test as power tests was confirmed by the significant correlations between maximal power measured on a cycle ergometer (Pmax) and vertical jump [2,3,4,5] In these studies, the prediction of vertical jump height with countermovement (CMJ) or squat jump (SJ) from Pmax is not accurate which suggested that the performances in vertical jump tests depend on other factors than the maximal power of the lower limbs. The rise in the force exerted on the ground depends on the rate of force development by the lower limb muscles. As the rate of force development depends on the series elastic component [6], CMJ should be positively correlated with musculotendinous stiffness (MTS) of the lower limb muscles.

Methods

Results

Discussion

Conclusion