No, I am not disregarding the earlier post about toilets. Let me explain. After my freshman year in college, I worked as a housepainter for two weeks. That career choice came to a screeching halt after I fell off a roof and shattered multiple bones including my left ankle. I now have a very stiff, arthritic ankle. It doesn’t even dorsiflex to neutral. In my twenties, I began having back pain and didn’t know why. I was sedentary but thin and very busy with my medical training. I eventually realized that I had a lumbar disc herniation with occasional right leg pain. Why?
Disc herniations happen when you have excessive flexion or twisting through a disc. We bend over more than a thousand times a day which requires squatting. Squatting requires full hip flexion, knee flexion, and ankle dorsiflexion. The picture below shows a natural full squat with a lot of ankle dorsiflexion.
Notice her degree of ankle dorsiflexion. Also, note how upright her lumbar spine is. Her upper body is leaning on her thighs thus taking the stress off the lumbar spine which is in essence “hanging” from her thoracic spine and not taking any significant torque.
Below is an example of a Western squat, in which the person comes up on their toes in order to get down.
Note her degree of ankle dorsiflexion. Also, note how perpendicular her spine is to being upright. This creates more torque on the lumbar discs than the upright posture and thus more stress on the discs.
I believe taking the weight off the heels leads to increased calf muscle activity, which leads to hamstring overactivity and inhibition of the hip muscles (ie- gluts), which lead to overactivity of lumbar paraspinal muscles and increased stress on lumbar spine. This aligns with the work of the great Neurologist, Dr Janda.
In the above picture on the left, lack of ankle flexibility prevents her from squatting further. If she squats further with same angle in her ankle, then she will have to lean back and thus lose her balance (also, her lumbar spine is now more parallel to the ground and thus more stressed). In the picture on the right, having a lift under her heels allows her to keep her center of balance forward (and her lumbar spine more upright) and do a deeper squat. This is a happier lumbar spine!
In short, healthy backs require full range of motion and strength of the whole chain. From the lumbar spine, pelvis, hips, knees, ankles and feet. When you have back pain, the whole system must be assessed. The back pain is often a result of a problem elsewhere in the chain.
Valley Sports & Spine Clinic
Giving you Back your Life
Dr. Ethan Colliver