Force-Velocity Profile: Imbalance Determination and Effect on Lower Limb Ballistic Performance

This study sought to lend experimental support to the theoretical influence of force-velocity (F-v) mechanical profile on jumping performance independently from the effect of maximal power output (P-max). 48 high-level athletes (soccer players, sprinters, rugby players) performed maximal squat jumps with additional loads from 0 to 100% of body mass. During each jump, mean force, velocity and power output were obtained using a simple computation method based on flight time, and then used to determine individual linear F-v relationships and P-max values. Actual and optimal F-v profiles were computed for each subject to quantify mechanical F-v imbalance. A multiple regression analysis showed, with a high-adjustment quality (r(2) = 0.931, P < 0.001, SEE = 0.015 m), significant contributions of P-max, F-v imbalance and lower limb extension range (h(PO)) to explain interindividual differences in jumping performance (P < 0.001) with positive regression coefficients for P-max and h(PO) and a negative one for F-v imbalance. This experimentally supports that ballistic performance depends, in addition to P-max, on the F-v profile of lower limbs. This adds support to the actual existence of an individual optimal F-v profile that maximizes jumping performance, a F-v imbalance being associated to a lower performance. These results have potential strong applications in the field of strength and conditioning.