In the majority of cases, if Doctors and Health Professionals tell their patients not to squat, one of two things is happening:
- They think their patients don’t know how to squat.
- They don’t know how to squat themselves.
What they should be telling them is that they shouldn’t squat incorrectly – they shouldn’t half squat. Not only will a squat done correctly not hurt the knees, it will restore healthy joint function and reduce damage, deformity, dysfunction and pain.
We classify a half squat by defining a full squat. A full squat occurs when the hips are pushed back and down (not knees pushed forwards) until the crease at the front of the hip drops below the top of the patella (kneecap). A half squat is anything that fails to reach this point.
So why is the full thing is better for you.
The initial part of the squat (before the hip crease drops below the patella) is an ‘anterior chain’ dominated movement. This basically means that the muscles at the front of the leg (namely the quadriceps muscle group between the hip and the knee) are doing all the work.
To understand what happens, put one finger on the bony point at the front of your hip. Run it down the front of your leg until it almost gets to the patella. You have just traced the quadriceps muscle group, and your finger is now sitting on the quadriceps tendon. Trace your finger lower until it is sitting on the patella. Lower still you will find the patella tendon (just below the patella). If you follow that down you will find the bony protuberance where it attaches to the tibia (the shin). This point is called the tibial tuberosity, and provides a major clue to why half squats ain’t so good for you.
When you half squat, the entire chain you have just traced is under tension. The patella tendon (between the patella and the tibial tuberosity) pulls on the tibia and causes it to slide forward slightly, grinding against the femur (thigh bone) as it does so. This is known as a shear force. It causes uneven loading of the articular cartilage over the ends of the bones in your knee. The result? Cartilage damage and knee pain.
A full squat changes all this. By dropping right down into the bottom of a deep squat, the POSTERIOR chain (everything up the back of your leg) kicks in. The hamstrings (the muscle at the back of your leg) have the opposite effect as the quadriceps and oppose the shearing caused by the anterior chain.
The forces around your knee are now equal, the muscles are strengthened, and you are correctly performing the most important exercise there is.