Recessed buttocks may be physiological or pathological. Physiological factors are usually caused by people who often do muscle exercises for the buttocks or often do heavy physical work for the lower limbs, and because the line of the buttocks is more perfect and the muscles are more developed, there will be depressions on the back and outside of the buttocks bilaterally. If the problem is pathological, it is usually caused by muscle atrophy in the buttocks, for example, a herniated lumbar disc compressing the nerves in the buttocks, resulting in hip atrophy over time or nerve damage in the lumbar region resulting in hip muscles not being able to contract actively, resulting in severe atrophy and depression over time. It is also possible that necrosis of the femoral head may lead to this symptom after a long period of inactivity.