The Effect of Knee Sleeves on Muscle Function During the Squat Exercise

Abstract

Knee sleeves (KS); made of neoprene; provide compression around the knee without restricting flexibility. KS are commonly used by weightlifters, powerlifters, and fitness competition athletes, who report attenuated knee discomfort and increased performance. Purportedly the use of KS helps to stabilize the knee, improve strength performance, and reduce the risk of injury during lower body resistance training. PURPOSE: To assess the impact of KS use on muscle activity and power output during the performance of the squat exercise, 19 subjects (age 26.0 ± 2 yr, ht 172.9 ± 3.6 cm, body mass 74.8 ± 3.7 kg, 13 ♂), with a minimum of six months training with squat exercise were randomly assigned to KS or no KS (NKS) trials with a repeated-measures design. METHODS: EMG data were obtained on the vastus lateralis (VL), semitendinosus (S) and gluteus maximus (G) muscles with a baseline obtained by two isometric maximal voluntary contractions (MVC) for five seconds, using an immovable and secure barbell at mid-range of the squat position. A warm-up of 10 reps of unloaded barbell and 5 reps @ 65% of self-reported 1RM preceded (5 min) the trial (KS or NKS) of 5 reps @ 85% 1 RM (94.1 kg). Following an 8 minute rest, subjects completed the cross over trial. EMG normalized to MVC was recorded for each trial. Peak power (PP) and average power (AP) were determined by measuring the bar speed with a micro-computer system. Statistical analysis by ANOVA (p<.05) was applied to the data. RESULTS: VL: 65.0 ± 44.7 & 64.5 ± 46.0, S: 71.6 ± 35.0 & 69.9 ± 37.9, and G: 48.4 ± 25.3 & 49.7 ± 24.2 for K and NKS, respectively, revealed no significant difference between conditions. In addition, %MVC for VL: 171.9 ± 126 & 180.9 ± 111, S: 215.1 ± 160 & 230.2 ± 166, and G: 145.6 ± 96 & 147.8 ± 111 for K and NKS, respectively were not significantly different. PP(watts): 624.1 ± 216 and 638.5 ± 229 and AP: 349.3 ± 100 and 345.7 ± 113 for KS and NKS trials, respectively were not significantly different. CONCLUSION: The use of KS during the squat exercise required almost identical motor unit recruitment and provided comparable power output, thus the use of KS is a subjective decision.