Force–velocity relationship of leg extensors obtained from loaded and unloaded vertical jumps

Purpose Resent research has suggested that loaded multi-joint movements could reveal a linear force–velocity ( F – V ) relationship. The aim of the present study was to evaluate the F – V relationship both across different types of vertical jumps and across different F and V variables. Methods Ten healthy subjects performed maximum various vertical jumps that were either loaded or unloaded by constant external forces of up to 30 % of their body weight. Both the maximum and averaged F and V data were recorded. Results The observed F – V relationships proved to be strong (median correlation coefficients ranged 0.78–0.93) and quasi-linear. Their F - and V -intercepts and the calculated maximum power ( P ) were highly reliable (0.85