Optimal Force-Velocity Profile in Ballistic Push-off: Measurement and Relationship with Performance

Training or rehabilitation programs have to induce changes in force(F)-velocity(v)-power(P) capabilities according to both mechanical demands of the targeted task and actual athlete’s muscle capabilities. To determine individual strengths and weaknesses and then individualize strength training modalities, it is essential to know which mechanical capabilities lower limb muscles have to present to maximize ballistic push-off performances. In this chapter, we explore the relationship between the different lower limb muscle mechanical capabilities and ballistic push-off performances. A biomechanical model is presented to bring new insights on the effect of F-v profile on ballistic performances, notably on the existence of an optimal F-v profile. The latter can be accurately determined for each athlete using equations given in this chapter and usual squat jump FvP profile evaluations, including testing using the simple field method presented in Chap. 4. This makes possible the determination of F-v imbalance (towards force or velocity capabilities) and the quantification of the magnitude of the associated force or velocity deficits. These indexes constitute interesting tools to individualize athlete’s training programs aiming to improve athletes’ ballistic performance. These individual programs should focus on increasing lower limb maximal power and/or decreasing force-velocity imbalance. The effectiveness of such an individualized “optimized” training was shown to be greater than a traditional strength training similar for all athletes. This supports the great interest for strength and conditioning coaches, who aim to improve athlete’s ballistic performance, to evaluate FvP profile on each of their athlete and to consider F-v imbalance to design individually training regimen.