2016 NPAA Magazine 2016 - Volume 1 - Page 30

Ass to Grass SQuating to depth I often chuckle when I hear your proverbial “meat head” explain why he is adding an extra plate on top of the stack on the leg extension machine saying “to get diamond cut quads maaan” while giving you the wink wink thumbs up, yet squatting a weight that would be more suitable for a group exercise class. From a personal trainers perspective, one of the most painful sites to see on the gym floor is the poor execution of a squat. It’s no wonder there has been such negative connotations that have been attached to such an important and highly effective exercise whether you are an athlete, weekend warrior, or post-rehab client. There are many athletes and coaches that have recommended against full depth squats (full depth being hamstrings touching calves). In this article I will bust through this common myth that has plagued the exercise community. Even though forces on the connective tissues of the knee increase this does not lead to injury when squatting with proper form. Commonly, inadequate 26. movement preparation (balance and stability training, static/ dynamic stretching) usually is the cause to the discomfort in 2 main principles that explain why squats won’t cause injury to the knee come from simple laws of physics applied to biomechanics; the law of shearing forces and the law of compressive forces. Shearing forces act “sideways” on a joint. In the case of the knee, they would be loads acting cross-wise on the tibia (chin bone) and femur (leg bone). Exercises like leg extensions and leg curls have a large “grinding” affect acting on two main ligaments, the anterior cruciate ligament ACL and the posterior cruciate ligament PCL, which are largely responsible for front and back knee stability. Compressive forces act more vertically on a downward force. These forces act along the length of a bone like the squat. The bones themselves are designed to accept this kind of force especially the tibia (chin bone) and femur (leg bone).