Force–velocity profile during vertical jump cannot be assessed using only bodyweight jump and isometric maximal voluntary contraction tasks

Abstract

Recently, the two-point method of force–velocity (F–V) profiling of multi-joint human movements has been introduced and validated. In this study, we investigated the validity of estimating the jumping F–V profile using only bodyweight jump and isometric maximal voluntary contraction (MVC) task. Participants (n = 30) performed 3 repetitions of squat (SJ) and counter-movement jumps (CMJ), each at loads that were progressively increased by 10 kg increments, with the number of loads depending on the individual’s ability. Then, 3 isometric MVC trials were performed in 3 knee angles (30°, 60° and 90°). F–V profiling of SJ and CMJ were performed using the multiple-point method, the two-point method, and the novel Jump-MVC method. The results showed poor to fair validity of the novel Jump-MVC method for assessing jumping F–V profile (most ICC < 0.5, most CV > 10%, significant systematic bias present, and the presence of proportional bias). The exception was the estimation of theoretical maximal power, which was highly valid for both SJ and CMJ (ICC = 0.91–0.95; CV = 5.0–6.3%). In contrast, validity of the two-point method was excellent (all ICC > 0.90; CV = 2–6%). Although additional studies are needed, present results suggest that the F–V profiling of vertical jumps should be performed using the two-point method with distal loads.

Feasibility of the 2-point method to determine the load−velocity relationship variables during the countermovement jump exercise

“… 35 , 36 More importantly, our results are in agreement with previous studies showing that the 2-point method is a reliable and valid procedure for the assessment of muscle mechanical capacities through the F−V relationship parameters obtained during the CMJ and SJ exercises. 18 , 19 , 20 Due to the high linearity of the L−V relationship ( r ≥ 0.97), it is evident that the addition of intermediate loads should not meaningfully improve the precision of the relationship modeling compared to using only the 2 most distant experimental points. 23 However, it is worth noting that the reliability of the A line was greater for the multiple-point method than for the 2-point method, likely because the error in determining A line is affected by the errors of both L 0 and v 0 .…”

“… 11 , 12 , 16 , 17 However, since the F−V relationship in multi-joint tasks is highly linear, 10 it is generally accepted that the same F–V relationship parameters could be obtained more efficiently (i.e., less time and fatigue) from the modeling of the force and velocity outputs against only 2 distant loads (i.e., 2-point method). 18 , 19 , 20 Specifically, in order to maximize the accuracy of the F−V relationship parameters in the CMJ exercise, the 2-point method should be based on the minimum possible loading condition and a CMJ against a load that allows reaching a jump height of about 10 cm. 19 Previous studies have sought to identify the optimal combination of experimental points (i.e., loads) to determine the F−V relationship in exercises such as vertical jumping, 19 bench press throw, 21 or cycling.…”

“…We hypothesized that the 2-point methods would provide the L−V relationship variables with high and comparable reliability to that of the multiple-point methods, and that their outcomes would be highly valid. 18 , 19 We also hypothesized a greater reliability (a) when using the heavy squat load compared to the heavier CMJ load due to a greater distance between the experimental points and increased proximity of the heavier experimental point to L 0 , 19 , 21 and (b) for PV compared to MV and MPV because PV can be obtained with a greater reliability during loaded vertical jumps. 26 , 27 …”

Applications smartphones pour l’analyse de la performance : un laboratoire dans votre poche

“…Ensuite, la masse étant entrée dans le profil d'utilisateur, l'application calcule la puissance de l'athlète, et on peut obtenir son profil force-vitesse ainsi que son profil optimal (Samozino, Rejc, Di Prampero, Belli, & Morin, 2012) en quelques clics sur l'écran, juste en réalisant quelques sauts supplémentaires. Le protocole typique consiste à réaliser 3 à 5 sauts avec des charges allant de 20 kg à environ 75 % de la masse corporelle sur les épaules (Sarabon, Kozinc & Markovic, 2020) Stanton, Kean, & Scanlan, 2015). Les données de hauteur de saut obtenues avec l'application ont montré une corrélation très élevée avec celles obtenues par mesures sur plateforme de force (r < 0,99), ainsi qu'un coefficient de corrélation intraclasse de 0,997 (intervalle de confiance à 95 % : 0,996-0,998, et un biais moyen de 1,2 ± 0,5 cm.…”

Validity and reliability of “My Jump app” to assess vertical jump performance: A meta-analytic review

“…Vertical jump activities have been performed to evaluate and improve physical tness for over a century [11]. This explosive strength activity, which can be performed by various members of the population, such as athletes, adults, children, the elderly, males, and females, is also accepted as a distinctive physical performance characteristic for many sports disciplines [12][13][14]. It is a relatively low-cost and straightforward way to evaluate and improve critical physical performance factors, such as the effectiveness of a training intervention, an athlete's readiness for a competition, determining neuromuscular strength outputs, monitoring a rehabilitation process, evaluating muscle function, and measuring explosive power [4].…”