Single Leg Squat vs Double Leg Squat
Squats using one or two legs will offer training emphasis to different muscles. Squats in general offers excellent primary muscle training of the gluteus maximus and quadriceps and secondary muscle training of the erector spinae, transverse abdominus, gluteus medius/minimus, adductors, soleus, gastrocnemius, and hamstrings. Unlike the double leg squat, the single leg squat (pistol squat) increases utilization of the gluteus medius for hip stability while the athlete descends down to a squatting position. This could explain why the patient in our case was presenting with posterolateral hip pain near the body of the gluteus medius.
New athletes attempting to do a single leg squat would tend to bow their knees inward during descent to maintain balance when their gluteus medius muscles are not well conditioned (See image). Bowing the knee inward while dipping down could cause additional tension on the lateral rotator muscle group, causing additional straining and worsening symptoms. Irritation of the piriformis muscle (1 of the 6 lateral rotator muscles) can occasionally lead to impingement of the sciatic nerve due to its position. There were no neuropathy presented at the time, but a positive inward log roll test could still suggest irritation to the lateral rotator muscles including the obturator externus/internus and superior/inferior gamellus muscle.
The patient in this case was referred for further imaging, which eventually showed inflammation to the obturator, gluteus medius, and piriformis muscle. The patient recovered with physical therapy and conservative measures.
Albert Hsia, MS-IV
Dr. David Carfagno, DO, CAQSM
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