Hip depression is usually caused by one’s own thinness or sedentary, if sitting for a long time every day, it may lead to flattening of the hip, atrophy of the upper hip muscles, and in serious cases, depression may occur, which is the cause of hip depression in most people, other rare pathological causes are mainly the following: 1, hip muscle contracture: if the hip shape is seriously depressed and affects the normal activity function of the hip joint, the Patients can’t even squat completely, it is usually caused by hip muscle contracture, which may be caused by injection of drugs or trauma or infection in the hip muscles as a child; 2, muscle malnutrition: if insufficient feeding, long-term bed rest and suffering from diabetes, etc. can cause hip muscle malnutrition, resulting in hip depression; 3, neurological injury: if in patients with paraplegia, hip muscles are directly hit or impacted, etc. When trauma occurs, it leads to related nerve injury, which may cause muscle atrophy in the hip and subsequently make it concave; 4, other: hip concavity can also be seen in patients with serious hip lesions, such as old hip dislocation without reset, or congenital hip dislocation, or serious hip osteoarthritis, etc., which can lead to hip concavity.