Why it is Safe To Squat Below Parallel (and why you should)

For a long time, we were taught to not squat below parallel, to not let your knees go past your toes for fear that it will damage your knees. Not only is this not true, but it is doing your body a disservice, can hurt your knees more, and place excess strain on your spinal column. Studies have found that squatting only to 90 degrees places the highest compressive forces at the patella (kneecap), with compressive forces decreasing as you increase your squat depth below parallel with something called “the wrapping effect”. Squatting past 90 degrees demonstrated greater load distribution and transfer of forces, ultimately decreasing the load in your knees.

Looking up the chain to the hips and the trunk, halting movement at 90 degrees, the angle of the hips and the trunk increases. With this increase, there is additional anterior shear forces placed upon the intervertebral discs and ligaments in the spine and a greater demand on the hip musculature. The shearing loads to the spine were the lowest with squat depth below parallel. What this means is with limiting the squat to 90 degrees, a greater load was placed on the discs in the spine and the hip musculature when compared to a below parallel squat in which the knees must travel past the toes.

In picture A below, you can see that by allowing the knees to travel past the toes it allows for a more upright torso position than compared to picture B where his knees are blocked and travel past the toes is prevents. Adding to the benefits of squatting below parallel, studies found a thickening of cartilage in areas of the knee joint along with the quadriceps tendon meaning greater stress tolerance and tolerance to load.

“When compared with half and quarter squats, in the deep squat, lower knee joint and spinal joint stress can be expected… the deep squat presents an effective training exercise for protection against injuries and strengthening of the lower extremity.”

The caveat with all of this is that if squatting below parallel causes knee pain or reproduces your knee pain, then for that period it is encouraged to only squat through your pain-free motion and gradually increase range of motion as symptoms improve.

If you have knee pain with squatting, contact us at Movement Physio and let us help you return to full and pain-free squatting!

Sources:

Hartmann, H., Wirth, K., & Klusemann, M. (2013). Analysis of the load on the knee joint and vertebral column with

changes in squatting depth and weight load. Sports Medicine, 43(10), 993–1008.

https://doi.org/10.1007/s40279-013-0073-6

FRY, ANDREW C., SMITH, J. CHADWICK, & SCHILLING, BRIAN K. (2003). Effect of knee position on hip and knee

torques during the barbell squat. The Journal of Strength and Conditioning Research, 17(4), 629.

https://doi.org/10.1519/1533-4287(2003)017<0629:eokpoh>2.0.co;2