After all, does a soft, neoprene knee sleeve have any effect over a squat, a snatch or a clean and jerk?
A good orthopedist will positively tell you: from a mechanical point of view, NO. A knee sleeve offers no mechanical support. This is why it is allowed in raw (or unequipped) powerlifting competitions. A knee sleeve is very different from a knee wrap. While the latter is designed to compress the knee so that the forces active at the joint are significantly reduced, providing a carry-over effect of 30% or more over the unequipped lift, the knee sleeve does not provide this type of help.
Why, then, so many high performance lifters and Strongmen use this equipment?
The reasons are not very intuitive and point to something I repeat so much that my students turned into a mantra: STABILITY IS THE MOTHER OF STRENGTH.
The use of knee sleeves by athletes started long before there was any scientific evidence explaining their eventual favorable effect. One of the research lines today in this matter suggests proprioceptive improvement in the movements involving the knee joint when the knee sleeve is used. According to studies using MRI images, the gentle compressive effect of the equipment results in higher activation at the primary sensorymotor cortex. Apparently, the peripheral proprioceptive input at the knee provokes this neural reaction, which promotes a motor response leading to precise movement adjustments, resulting in higher stability and precision (Thijs ET AL 2010). Another study suggests that for individuals with good proprioception (athletes, for example), the effects are only manifested under fatigue (Tiggelen ET AL 2008).
The second line of evidence is related to pain. In osteoarthritis patients, knee sleeve use immediately improves gait by reducing pain (Bryk ET AL 2011). If this dramatic effect on pain and discomfort is related to what athletes report, it is hard to infer from studies carried out under pathological conditions. However, anecdotal evidence points in that direction.
Effects such as maintenance of heat at the joint, improved blood flow as a result of compression, favoring both performance as recovery, remain in the realm of speculation.
Scientific evidence frequently has a few years lag from anecdotal evidence at the training field to the published paper. This applies not only to sports equipment, but to training protocols, sports nutrition and other sub-areas of sports science, where methodological issues are hard to deal with in experimental research project design.
Anyway, I offer a personal advice from the scientist, the coach and the athlete in me: knee sleeves are a good acquisition for your training.
Does bracing influence brain activity during knee movement: an fMRI study.
Immediate effect of the elastic knee sleeve use on individuals with osteoarthritis.
*photo: Marcelo Kaneshira