Function and Anatomy: The hip is a ball and socket type joint, formed by the articulation of the head of the femur with the pelvis. Normal range of motion includes: abduction 45 degrees, adduction 20-30 degrees, flexion 135 degrees, extension 30 degrees, internal and external rotation. Hip pathology can cause symptoms anywhere around the joint, though frequently pain is anterior and radiates to the groin region. Additionally, pathology outside of the hip can be referred to this region. History and exam obviously help in making these distinctions.