Kinematic and Kinetic Analysis of the Squat with and Without Knee Wraps

Abstract

Powerlifters, bodybuilders, Olympic-style weightlifters and strength/power athletes often use knee wraps in the squat exercise in an attempt to maximize repetitions performed at a certain load or to increase 1RM. Little research has investigated the effects of knee wrap use on the biomechanics of the squat. PURPOSE: To determine if the use of knee wraps affects squat kinematics and kinetics in trained powerlifters. METHODS: In a counterbalanced design, ten trained powerlifters performed squats to a femur-parallel position both with (W) and without (NW) knee wraps. Each powerlifter performed a structured warm-up with rest periods ranging from four to six minutes between sets depending on load, followed by one set of six repetitions at the subject's 12 RM for both W and NW conditions. Global squat characteristics (e.g., repetition time, percent cycle descent-ascent transition, center of mass, vertical displacement) were assessed by dependent t-test. Further, two 3 (joint position) x 2 (wrap condition) repeated measure ANOVAs with a Bonferroni correction were performed for (1) concentric and eccentric work, and (2) peak flexion. RESULTS: There were no significant differences (p<0.5) in global squat characteristics or in interactions between joint position and wrap condition. However, collectively a significant main effect (p<.05) was found for joint in peak flexion and in concentric and eccentric work (hip > knee > ankle). CONCLUSIONS: While the significant main effects suggest subjects performed a correct squatting technique, the use of knee wraps did not alter subjects' biomechanics. In addition, the use of knee wraps did not influence work performed at relevant joints. Further research is warranted to elucidate the effects of knee wraps on a subject's ability to perform maximal repetitions at submaximal loads and on a subject's 1 RM. The present research project helps narrow the possible mechanisms involved in such an effect. PRACTICAL APPLICATIONS: This data does not support any practice whereby strength and conditioning specialists either promote the use of knee wraps or dissuade athletes from using them. Practically, as many athletes describe a feeling of enhanced confidence with the use of knee wraps during the squat, the strength and conditioning specialist has no reason to believe the use of knee wraps will negatively affect the transfer of strength/power from the squat to the target sport activity.