** Update on 23/6/2010 **
I came across this article (8 Stupid Myths about Squatting) by world renowned strength coach, Charles Poliquin. Look what he has to say about Squats are bad for knees on Myths #2 .
Myth #2: Squats are bad for the knees. Not only are squats not bad for the knees, every legitimate research study on this subject has shown that squats improve knee stability and therefore help reduce the risk of injuries. The National Strength and Conditioning Association has published an excellent position paper on this subject with an extensive literature review, and data from the Canadian National Alpine Ski Team suggests that regular squatting reduces not only the rate of injuries but also the time it takes to recuperate from injuries that do occur.
When I was hired to work with the Canadian National Women’s Volleyball Team, I found all of them suffered from varying degrees of an overuse injury called patellar tendinitis, or jumper’s knee. I believed the problem was partially caused by a structural imbalance in the lower quadriceps muscle called the vastus medialis oblique (the teardrop-shaped muscle that inserts at the knee). To correct it, I had these athletes perform Petersen step-ups and then gradually progress into full squats. Only one athlete still had jumper’s knee after less than three months of proper training.
Providing you don’t relax or bounce in the bottom position of the squat, you’ve got nothing to worry about. When you relax, the knee joint opens up slightly, exposing the connective tissue to stress levels higher than their tensile strength. Does that mean you should never pause in the bottom position? No. It simply means that if you pause in the bottom position, you must keep the muscles under tension, holding the static (isometric) contraction. In other words, don’t relax at the bottom of the squat and allow your connective tissue to stretch out like a piece of saltwater taffy.
** Original post on 11 June 2010 **
I was warming up with full range of motion (ROM) body-weight squats, squatting as deep as I can with my knee extending beyond my toes. One trainer came over telling me that it’s bad for my knees and it’s not safe – I should be doing half squats and knees should be behind the toes instead. Knowing his background, I believe he’s speaking from the input of a certain textbook.
So I explained my point to him that I opt for full ROM + knee extending beyond toes as I believe in getting full functional range of motion and with knees extending beyond the toes are part of natural human movements. While I also told him that he was not wrong to say it’s bad for my knees.
According to Kreighbaum (1996) deep squats with knees extending beyond toes are absolutely fine. However there are 3 concerns to look into; (1) Speed of descent, (2) size of calves and thighs, (3) Strength of controlling muscles. Let’s see what he has to say;
The primary danger to the knee occurs when the tissues of the calf and thigh press together altering the center of rotation back to the contact area creating a dislocation effect. The danger of knee injury in this situation may be prevented if either of the following factor are present:
- center of gravity of the body system is kept forward of the altered center of rotation
- muscles of the thigh are strong enough to prevent the body from resting or bouncing on the calves.
Kreighbaum concludes the deep squat is of little danger to the knees unless these variables and factors are disregarded
The reason I told the trainer that he was not wrong is because it would be dangerous for me, IF I neglected the mentioned concerns by Kreighbaum. Noticed the IF ?