Balancing Injury Risk and Power Development by Weighted Jump Squat Through Controlling Eccentric Loading

Area of Science:

• Sports Science
• Biomechanics
• Strength and Conditioning

Background:

• Weighted jump squat (WJS) training effectively enhances neuromuscular power.
• Higher landing impact in WJS increases injury risk compared to traditional resistance training.
• Optimal eccentric loading strategies to balance power development and injury risk in WJS remain unclear.

Purpose of the Study:

• To investigate the effects of different eccentric braking conditions on power production and landing impact during WJS.
• To determine the optimal eccentric loading strategy for balancing injury risk and power output in WJS.

Main Methods:

• Twenty-two male varsity basketball players performed WJS with 30% additional 1RM load under four conditions: no braking (B0), 25% braking (B25), 50% braking (B50), and 100% braking with release at touchdown (B100R).
• Dependent variables included peak power output, peak force, peak velocity, and impulse, analyzed using repeated measures ANOVA.

Main Results:

• The 100% braking reduction with release at touchdown (B100R) condition yielded the highest concentric peak power.
• B100R significantly reduced eccentric peak force and impulse in the initial 50 milliseconds compared to other conditions.
• Traditional loading (B0) resulted in significantly lower concentric peak power and peak velocity than the other conditions.

Conclusions:

• The 100% braking reduction with release at touchdown (B100R) is a favorable loading condition for WJS.
• This strategy effectively balances injury risk mitigation with enhanced power production during WJS training.