Two fossae in a man’s posterior waist may be physiologic sacral concavity, or it may be caused by sacral spondylolisthesis, sacrum, spinal cord abnormalities and so on.
1. Physiological sacral recess: the two fossae in the lower back are the posterior superior iliac crest and the sacral recess on both sides, which is a normal anatomical phenomenon. The position is where the lumbar dorsal fascia connects with the bone stop of the posterior superior iliac crest. Due to the pulling of the fascia and the bone, it makes localized subsidence, thus forming two depressions. Sacral depression is more obvious in thin people or people with medium-sized and proportionate body, and it is not obvious or disappears in obese people.
2. Sacral spina bifida: mainly related to genetic factors, viral infection can induce this disease, but also can be manifested in the waist and buttock skin depression, and the color deepens.
3. Abnormalities of the sacrum and spinal cord: The above symptoms can be caused by congenital factors or diseases (such as tuberculosis cavities) that cause abnormalities of the sacrum and spinal cord.
If the above symptoms are accompanied by other uncomfortable symptoms (e.g. pain), you should go to the hospital in a timely manner to clarify the cause and provide targeted treatment.