[Controversial rotation function of certain muscles in the hip joint].

The disputed rotating function of certain muscles in the hip joint. A device constructed for that study allows to determine the rotating function of the iliopsoas muscle as well as of the uniarticular adductor muscles of the thigh in every position of the hip joint by the method of threads. The iliac muscle rotates the thigh inward in every position of flexion/extension or abduction/adduction of the hip joint. The adductor magnus muscle always is a lateral rotator by those fibres which are inserted into the medical edge of the linea aspera, while the fibres attached to the adductor tubercle rotate the thigh inward. The psoas major, pectineus, adductor longus and adductor brevis muscles are able to rotate the thigh inward as well as outward. Their rotating function depends on the specific position of flexion/extension and abduction/adduction of the hip joint: Flexion and abduction intensify the lateral rotating function of these muscles, extension and adduction intensify the medial rotating function.