Post-Activation Performance Enhancement of Lower Limb with Variable Resistance Back Squat at Different Depths

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Investigating the acute effects of different squat variations on jump performance.
• Examining post-activation performance enhancement (PAPE) using variable resistance (VR).

Purpose of the Study:

• To compare the acute effects of quarter squat (QS) and parallel squat (PS) with VR on countermovement jump (CMJ) performance.
• To analyze changes in jump kinematics and kinetics following QS and PS.

Main Methods:

• Fifteen resistance-trained athletes participated in a within-subjects design.
• Participants performed three repetitions of either QS or PS at their three-repetition maximum load.
• CMJ performance was assessed pre- and post-squat intervention after a five-minute recovery period.

Main Results:

• Both QS and PS with VR significantly increased CMJ height.
• QS led to decreased countermovement depth and time to take-off, with increased mean propulsion force.
• PS resulted in increased countermovement depth and time to take-off, with decreased mean propulsion force. PS showed a greater increase in jump height.

Conclusions:

• Both parallel squats and quarter squats with variable resistance are effective for enhancing countermovement jump height.
• The choice of squat variation influences subsequent jump strategy and kinematic/kinetic outcomes.
• Athletes may adopt different movement strategies post-intervention depending on the squat type performed.