Estimation of maximum lower limb muscle strength from vertical jumps

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Determining one-repetition maximum (1RM) is vital for training load prescription but is time-consuming, strenuous, and risky.
• Vertical jumps are a less demanding test of lower limb explosive power, potentially enabling 1RM estimation in squatting.

Purpose of the Study:

• To develop and validate a model for estimating 1RM back squat using ground reaction forces from vertical jumps.

Main Methods:

• Thirteen participants performed 1RM back squats, countermovement jumps, and squat jumps.
• Ground reaction forces were measured using a force plate to derive kinematic and kinetic variables.
• Stepwise regression analysis was employed to build the predictive model.

Main Results:

• Five kinematic/kinetic variables strongly correlated with 1RM in both jump types (r = .76–.95, p < .05).
• A regression model using peak kinetic energy during countermovement jumps accurately estimated 1RM back squat (adjusted R² = .90, mean error = 7.4%).
• Estimated 1RM values showed no significant difference from measured 1RM, with low estimation errors (7.4%–10.7%).

Conclusions:

• Estimating 1RM back squat from vertical jump forces provides a practical, safer alternative to traditional testing.
• This method can reduce injury risk, testing time, and participant effort.
• The proposed model offers coaches and sports professionals an efficient tool for monitoring and adjusting training loads.