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

Abstract

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 (r²=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.

Jump height is a poor indicator of lower limb maximal power output: theoretical demonstration, experimental evidence and practical solutions

“…Force-velocity profile and optimal profile Samozino et al [9,21] have clearly shown, using a theoretical approach [10] confirmed by experimental evidence [19,26], that SJ height was almost entirely explained by the following variables: Pmax, hPO and the slope of the Fv profile. Thus, added to the previous section about the influence of hPO, it is clear that the relationship between maximal jump height and Pmax is confounded by the balance between the athletes' force and velocity capabilities, as described by their Fv profile.…”

“…Thus, added to the previous section about the influence of hPO, it is clear that the relationship between maximal jump height and Pmax is confounded by the balance between the athletes' force and velocity capabilities, as described by their Fv profile. The two implications shown by Samozino et al's works are that (i) for a same hPO and Pmax, different levels of SJ height may be achieved depending on the Fv profile of the athletes and (ii) the theoretical maximal SJ height for a given individual (given their hPO and Pmax) is only reached if the actual Fv profile is equal to the calculated optimal Fv profile (and in this case, body mass is the Lopt) [8,10,19,26]. In other words, an athlete with an optimal Fv profile for jump height will have his own body mass as Lopt, and thus produce Pmax during vertical jump without additional load.…”

“…In other words, an athlete with an optimal Fv profile for jump height will have his own body mass as Lopt, and thus produce Pmax during vertical jump without additional load. The relative influences of hPO, Pmax and Fv profile on SJ performance are summarized in the following equation, that has been validated experimentally [19,26]: In this equation, hmax is the maximal possible SJ height reached with an optimal Fv profile SFvopt. Note that these demonstrations have been initially published using SJ as the jump modality, but subsequent works by Jimenez-Reyes et al have shown that similar conclusions could be drawn for the CMJ modality [7].…”

Influence of Isoinertial-Pneumatic Mixed Resistances on Force–Velocity Relationship

“…On the one hand, given that our findings demonstrate the significant impact of resistance ratio on force and movement velocity, the type of resistance modality can be considered as an interesting exercise variable that can be adjusted to induce the targeted gains in force or velocity. On the other hand, for athletes with similar maximal power capability, a significant imbalance between force and velocity capacities can negatively impact their respective ballistic performance 30 .…”

Force-Velocity Profiles of Elite Athletes Tested on a Cycle Ergometer

“…The parameters obtained from the linear F-V relationship have consistently revealed high reliability (Jaric, 2015). In addition, the abilities to generate high movement velocity or resistance to high external load have been shown to be determined by V 0 (Feeney, Stanhope, Kaminski, Machi, & Jaric, 2016) and F 0 (Driss, Vandewalle, Le Chevalier, & Monod, 2002), respectively, while ballistic performance is largely dependent not only on P M (Samozino, Rejc, Di Prampero, Belli, & Morin, 2012;Vandewalle, Peres, Heller, Panel, & Monod, 1987) but also on an optimum balance between F 0 and V 0 (i.e., F-V slope) (Jiménez-Reyes, Samozino, Brughelli, & Morin, 2017;Samozino et al, 2014).…”