S Nadeau, D Gravel, A B Arsenault
School of Rehabilitation, Faculty of Medicine, University of Montreal, Quebec, Canada.
DOI: 10.2340/165019771997294955

This study investigated the relationships existing between torque, velocity and power output during plantarflexion. Using a Biodex dynamometric system, 15 healthy subjects performed three maximal dynamic tests, ranging from -12 degrees (-0. 209 rad) of dorsiflexion to +47 degrees (+0. 818 rad) of plantarflexion and one static test (test 4) at an angle of +10 degrees (+0. 174 rad). The dynamic assessment included a 30 degrees s-1 (0. 52 rad s-1) concentric isokinetic test (test 1) preceded by a 2-sec maximal pre-loading contraction. The other two dynamic tests were performed using the isotonic mode of testing with a selected torque of 27 N m; one of these tests was executed with pre-loading (test 2) while the other was performed without pre-loading (test 3). The results indicated that the dynamic peak torque, the peak power and the peak velocity were obtained in test 1, test 2 and test 3, respectively. These peak values, as well as the values of torque (test 1 and test 4), power (test 2) and velocity (test 3) obtained at a constant angle +10 degrees (+0. 174 rad), were selected for the correlation analyses. The results showed that the torque, velocity and power output during plantarflexion were linearly related to one another with significant correlations (0. 71 < r < 0. 92; p < 0. 01). This finding suggests that a common factor of muscular performance is assessed. Furthermore, these results indicated that the maximal torque produced by a subject can be predictive of his or her maximal velocity and power. Consequently, a stronger subject can generate higher velocity and power than a weaker subject when tested with the same load during maximal effort.