The Rap on Knee Wraps
By Dr. Paul C. Henning, PhD, CSCS
The back squat is an extremely popular exercise and forms the basis of many strength and conditioning programs and powerlifting competitions . Support equipment (e.g. knee wraps) is often worn during this exercise due to the heavy loads utilized . Knee wraps are worn to support the knee joint and gain a mechanical advantage during the back squat exercise. Anecdotal evidence suggests that wearing knee wraps allows the weight trainer to lift greater loads or perform more repetitions with a given load .
Knee wraps must be applied as tightly as possible in order to gain the perception of support around the knee joint or provide a mechanical advantage. This tight fit often causes considerable discomfort and can create a “wedge”-like physical barrier at the back of the knee joint that can change biomechanics of the exercise by tipping the client forward . There is little evidence of the effect knee wraps have on mechanical output and performance characteristics of the back squat. A group from the University of Chichester, Chichester, United Kingdom performed a study to investigate the outcome that wearing knee wraps have on mechanical output and performance characteristics of the back squat exercise. Ten resistance trained men performed 6 single back squats with 80% 1RM (repetition maximum), 3 wearing knee wraps, 3 without. Mechanical output and performance characteristics were measured.
Results showed that knee wraps provided a mechanical advantage by increasing vertical impulse and decreasing lowering and lifting phase duration indicating that vertical force applied to the center of mass increased, particularly during the lowering phase of the movement. The lowering phase was performed faster with knee wraps decreasing the time in which the mechanical work performed by vertically displacing the barbell and center of mass through a standardized range of motion was performed. This was reflected by an increase in peak power.
There was also a large reduction (lowering and lifting phase) in horizontal displacement of the barbell when knee wraps were worn. This finding raises concerns of the effect wearing knee wraps has on back squat technique, both in terms of training specificity and injury potential .
This study suggests that wearing knee wraps with loads used in this study (80% 1RM for single reps) creates a mechanical advantage that occurs when elastic energy is released. The authors also believe that wearing knee wraps alters the back squat technique in a way that 1) development of balanced lower-body musculature may be compromised and 2) the combination of the modified body position with knee wraps and the physical barrier at the back of the knee joint may compromise the integrity of the knee joint . These authors propose that knee wraps should not be worn during the back squat and if the client feels additional support is needed for the knee; the integrity of the joint should be thoroughly assessed and treated rather than relying on artificial aid that may possibly worsen any underlying issues . This was a well-conducted and very recent study that demonstrates knee wraps should not be used when performing maximum loads on the back squat. Trainers should emphasize this to their clients if they are adamant on wearing knee wraps during the back squat exercise!
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