Knee Wraps – What does science recommend?

Ever heard some not so strong guys from your gym tell you the best way to wrap your knees? Ever wondered what is recommended by science about wrapping your knees? Stop learning from your local gym bros, and Start Learning From Science.

What topics does this knee wraps review cover?
•    Why do we see an increase in load lifted with wraps vs without?
•    What are the changes seen in the movement and speed of the squat with wraps vs without?
•    What does science say is the best way to wrap your knees? – Cross wrapped vs straight wrapped vs spiral wrapped.
•    What type of knee wrap does science recommend? – Hard vs Soft.
For those of you who would rather read a quick summary of this review, I have written all of the most important findings and how they can be applied to your training below. If you want to read the entire review, keep scrolling.

Summary

What is the mechanism behind the increase in load lifted with wraps vs without?

• The force being applied to the center of mass of the lifter + load is significantly increased when compared to a lift without knee wraps. This is due to the stored elastic energy of the knee wraps, providing a greater stretch out of the hole which causes a stronger upward propulsion at the start of the concentric portion.

What are the changes in the movement and speed of the squat from using knee wraps?

• Horizontal displacement of the barbell during the eccentric portion of the lift is diminished, improving the efficiency of the lift.
• The duration of the descent was reduced with knee wraps, whereas the ascent remained the same with/without knee sleeves at relative 1 RMs. Thus less time spent handling weights on the eccentric portion affords more effort to be placed into the concentric portion.

What is the best method to wrapping your knees?

• Both the straight and cross wrapped technique significantly improved peak torque and the angle at which peak torque occurred, though the cross wrapped technique improved peak torque above and beyond the improvements of the straight wrapped technique, thus making it the best method.
• A spiral wrapping technique was also shown to increase peak torque when compared to no knee wraps, though no difference was found between spiral wrapping and cross wrapping when compared.

What type of knee wrap should I use?

• When compared with no knee wraps, peak torque increased by 21% with soft wraps, and 22% with hard wraps. Such a small difference between the two would lead me to recommend that weightlifters use softer wraps as they tend to allow for greater knee flexion which is needed when receiving a bar low, and powerlifters use hard knee wraps.

But what does this all mean to me, and how can I benefit?

• Put simply, using knee wraps will allow you to lift more weight, though knee wraps will not provide you with additional gains in muscle size/strength beyond that of a raw squat. Knee wraps will improve your squatting technique through minimising horizontal movement, and increase peak force at certain parts of the lift.
• It is therefore clear that knee wraps will indeed benefit an athlete who is primarily concerned with moving maximal loads. If you are interested in increasing the amount of weight that you can squat or clean, then knee wraps certainly play an important role in that. It is no wonder that power lifters have with and without knee wrap competitions…

If you are currently without wraps and feel you have been recommended by science to get some, I’ve linked some of the best knee wraps  around at the bottom of the article.

Now onto the full lit review below. What does Science recommend?

A Review of the Kinetic and Kinematic Effects of Using Knee Wraps During the Back Squat Exercise.

The ability to generate high force against large resistances and to produce a high work rate is an integral component of contact sport performance (McMaster et al., 2013); as such, resistance training has become an influential component of an athlete’s training with regard to the enhancement of athletic abilities (McGuigan et al., 2012), particularly within the sport of powerlifting (Blatnik et al., 2012). Furthermore, since the goal of many athletes who participate in competitive sport today is to win, many investments are being made in performance enhancement, by both athletes and coaches alike (Holowchak, 2002). Hence, a key issue for athletes and coaches at levels ranging from amateur to elite is the efficiency of training, or rather more, achieving the greatest gains in performance for a set amount of work effort (Young, 2006). In pursuit of maximal performance transfer, the utilisation of biomechanical ergogenic aids has become widespread due to their ability to maximise athletic performance during training or competition (Fink and Mikesky, 2015).

One particular method of enhancing the back and front squat exercise is through the utilisation of knee wraps. Knee wraps are traditionally made from elastic and have been described in literature as being ‘designed to provide maximum support and stability and to aid in proper knee position during weightlifting’ (Club Industry, 2012:42). Due to the use of relatively heavy loads during the back or front squat exercise, mechanical support equipment is often worn, with knee wraps being first implemented in the 1990’s (Harman and Frykman, 1990: Totten, 1990). Harman and Frykman (1990) found that when knee wraps were worn during a simulated back squat exercise, significantly greater forces were applied to the center of mass at the final stage of the squat descent. They further concluded that the increased forces were a reflection of elastic energy generated, and stored, as the wraps were stretched across the knee joint during the descent phase (Harman and Frykman 1990).  However, whilst these findings offer a level of insight into the mechanisms that may underpin the mechanical advantage that wearing knee wraps may contribute, the methodology afforded by Harman and Frykman (1990) was crude, and did not allow a detailed study of changes in the mechanical output and performance characteristics of back squat
exercise.

Of greater significance is a study conducted by Lake et al (2012), who showed that wearing knee wraps during the back squat exercise significantly reduced horizontal displacement of the barbell during the lowering phase (p = 0.037) but not the lifting phase (p = 0.407). Additionally, the lowering phase vertical (p = 0.366) and horizontal (p = 0.409) impulse applied to the center of mass were not affected by wearing knee wraps, whereas the lifting phase equivalents were affected, with both demonstrating a moderate to large effect size (ES) (vertical ES: 1.12, horizontal ES: 0.81). Wearing knee wraps was also shown to significantly reduce the absolute lowering phase duration (p = 0.006) but not absolute lifting (p = 0.391), relative lowering (p = 0.083), or relative lifting (p = 0.083) phase
duration. Critically however, was the demonstration that wearing knee wraps significantly increased peak power (p = 0.019,) due to elastic energy generated and stored within the knee wraps during the descent phase. Lake et al (2012) attributed the increase in peak power to the elastic stored energy being released, increasing vertical force applied to the center of mass. In further support of this observation, Eitner et al (2011) showed that there were no significant differences (p<0.5) in squat biomechanics or in interactions between joint position and wrap condition; however, a significant main effect (p<.05) was found for joints in peak flexion and in concentric and eccentric work, with the hip performing the least work and flexion, followed by the knee and then the ankle in the group wearing knee wraps, ultimately causing a more upright posture.

With regard to the method with which knee wraps are applied to the knee joint, there appears to be contradiction in literature in relation to the effects of the crossed and straight wrap technique on peak torque and the angle at which peak torque occurred in athletes. Fincher et al (2011) found that regardless of whether the straight or crossed wrapping method was utilised, significant improvements were seen in both peak torque and the angle at which peak torque occurred in highly strength trained male athletes; however, the data also indicated that the crossed wrapping method attained significantly  greater peak torque than the straight method, although there is no significant difference between wrapping methods with respect to the angle at which peak torque occurs. However, Marchetti et al (2015) found no differences on the peak force attained during the back squat when a spiral wrapping technique was compared to a crossed wrapping technique, although significant differences were shown when each knee wrap condition was compared to a no wrap condition. Furthermore, it was shown by Marchetti et al (2015) that independent of the employed wrapping  technique, an increase in the external load squatted by the subjects in the knee wrap condition (compared to no knee wrap condition) was achieved due to elastic energy stored in the knee wrap material under  the present mechanical deformation.

Aside from the method with which the knee wraps are applied with, another variable which may affect the athlete is the kindof knee wraps used.  In a study by Gomes et al (2014) which compared the effects of soft and hard knee wraps on maximal isometric force attained at the knee joint during a back squat, it was shown that peak force increased by 21% between the no knee wrap condition and the soft knee wrap condition, whilst a 22% increase was shown between the no knee wrap condition and the hard knee wrap condition.  However, it must be noted that using knee wraps during sub-maximal lifts (60%) decreases the muscular activity around the knee joint, meaning overload must be increased at the cost of greater knee joint loading in order to attain the same muscular adaptations that may be achieved if knee wraps were not used (Gomes et al., 2015).

In conclusion, whilst the significant main effects of using knee wraps during the back squat suggests that a correct squatting technique can be achieved, (and that peak force and the load lifted may increase), knee wraps do not appear to significantly influence the work performed at the hip, knee and ankle joints (Eitner et al., 2011). Therefore, at this time it appears that the use of knee wraps is feasible when used with the intention of increasing 1RM squat performance (Lake et al., 2012); however, if the aim is to increase muscular activity of the knee musculature, then using knee wraps seems to provide little contribution to quadriceps activation (Gomes et al., 2015).