Lennan's symptom, or symptom of decubital ulcer, is a rare symptom of the consequences of trauma to the gluteus medius muscle and sciatic nerve as a result of decupation - immersing the patient in water in an uncomfortable position. Underwater towing can cause displaced compression of the nerve trunk, which manifests itself as follows: the patient complains of deep pain at the point of innervation of the sciatic nerve; The patient has an asymmetry in the position of the head of the femur below the lumbar level 35.
Upon examination, the following is revealed: asymmetry in the position of the femoral head (the head can be either higher or lower than the sacrum), the skin fold over the thigh and buttock can be located asymmetrically; When the patient moves from a horizontal to a vertical position, additional pain occurs in the midline of the buttocks