I am sure I have written on this before, but a student shared a link1 with me the other day that has prompted a return to the topic of squat depth. In the video, the claim is made that the science supports squatting only to a depth of 90-degrees of knee flexion. This is not the case. In fact, I would say that the opposite is better supported. In other words, it is to our benefit to move through the full joint range of motion.
It is unfortunate that the phrase “ass-to-grass” or ATG is used in reference to squatting. This implies, much like Dr. Joel Seedman does in the linked video, that everyone should squat to the same depth. I prefer to recommend a full range-of-motion (ROM) squat.
The squat acts on the hip and ankle joints, as well as the knee joint. When the focus is only on the knee (e.g., 90-degrees of knee flexion) hip and ankle mobility are ignored. Moreover, the spine’s ability to support greater loads can suffer. It is easier to lift heavy weights to only 90-degrees (in the video, Dr. Seedman seems to suggest rough 90-degree at all three joints, though this is not mechanically possible without elevating the heels), the load on the spine will eventually become too great. Ideally, the three joints are moving synchronal to move the weight the greatest possible distance—without injury.
Everyone has different hip, knee, and ankle joint structures that suggest out squats will be inherently different. The shape of the hip joint and the femoral angle, alone, will define foot position (width, as well as angle) during the squat. Ankle mobility (something Dr. Seedman seems to either lack or ignore in his video) may also limit the depth of the squat. Unlike hip structure, ankle mobility (i.e., dorsiflexion) can be increased with training (up to the structural limitations of the ankle joint, of course). Maximizing mobility can benefit most people.
How deep should one squat, then? I would suggest as deep as possible (see2). (With the caveat that some individuals, such as powerlifters, may not need to squat to their full depth in their heaviest set as this is counterproductive to the goal of lifting as much as possible within the defined limits of the sport—which requires a depth no greater than the hip crease passing the line parallel to the knee joint. Going “too deep” for a powerlifter in competition is just extra work.) “Deep as possible” is what might be considered the “primal squat” position. The primal squat position to the position in which one can squat comfortably for an extended period of time—the natural resting position. To find this, simply drop into a squat position with the feet flat on the floor. Position the feet as they are most natural—turned out to some varying degree. Keep the natural curvature of the spine and position the elbow such as to push out slightly on the knees. This is your full ROM squat. Depending on your body structure, this will be your variation of ATG. This should be the target when squatting. Technically, you will necessarily fall somewhat short of this distance as going all the way to the bottom will negate the stretch-reflex that will be necessary to maximize force production (i.e., you won’t want to relax into this position at the bottom of your squat). For effective training, a weight should be selected that will permit you to squat to a depth somewhere between parallel and the primal squat depth with every repetition in good form. If lifting more weight means you have to go less than parallel (e.g., closer to Dr. Seedman’s 90-degrees), then you need to check the ego at the gym door and lower the weight.
Of course, there are health and physical reasons for not squatting. Certainly, follow your doctor’s recommendations. However, if you can physically squat to a primal squat position without pain or injury, you can squat. How much weight you add to your body weight in said full ROM squat will be driven by your ability to do so with proper technique and without injury. No one gets injured squatting. One gets injured squatting with poor technique and poor fatigue management.
Be your best today; be better tomorrow.
Carpe momento!
1https://www.youtube.com/watch?v=j7sa76uxrd8
2https://www.catalystathletics.com/video/1421/Full-Squat-Depth-Variation-For-Olympic-Weightlifting/