Fig. 1

Force–velocity relationship and power-velocity relationship during acyclic lower-limb extensions. Adapted from data from Table 2 in Riviere et al. [1]. A and B show the reported force–velocity (F–V) and power–velocity (P–V) data by Riviere et al. [1], respectively. Note that one trial (red open symbol) does not fulfill the physiological inclusion criteria for the P–V relationship. Only data fulfilling the physiological criteria (black open symbols) will be considered for further analyses here (except for the linear equation in E and F). C and D show the different results that two linear models applied to different portions of the F–V and P–V relationships provide, respectively. Based on this, the hypothesis that the F–V relationship is linear should be rejected. E and F show the different results that the hybrid and linear equations yield regarding F–V and P–V data, respectively. As previously reported [4], linear models tend to underestimate F₀ and V₀ and overestimate P_max, while showing clear deviations for the actual recorded data, in comparison with the hybrid equation.