Lower Limb Force, Velocity, Power Capabilities during Leg Press and Squat Movements

The aim was to compare lower-limb power, force, and velocity capabilities between squat and leg press movements. Ten healthy sportsmen performed ballistic lower-limb push-offs against 5-to-12 different loads during both the squat and leg press. Individual linear force-velocity and polynomial power-velocity relationships were determined for both movements from push-off mean force and velocity measured continuously with a pressure sensor and linear encoder. Maximal power output, theoretical maximal force and velocity, force-velocity profile and optimal velocity were computed. During the squat, maximal power output (17.7±3.59 vs. 10.9±1.39 W·kg^-1), theoretical maximal velocity (1.66±0.29 vs. 0.88±0.18 m·s^-1), optimal velocity (0.839±0.144 vs. 0.465±0.107 m·s^-1), and force-velocity profile (-27.2±8.5 vs. -64.3±29.5 N·s·m^-1·kg^-1) values were significantly higher than during the leg press (p=0.000, effect size=1.72-3.23), whereas theoretical maximal force values (43.1±8.6 vs. 51.9±14.0 N·kg^-1, p=0.034, effect size=0.75) were significantly lower. The mechanical capabilities of the lower-limb extensors were different in the squat compared with the leg press with higher maximal power due to much higher velocity capabilities (e.g. ability to produce force at high velocities) even if moderately lower maximal force qualities.