Fig. 3From: Femoroacetabular impingement: question-driven review of hip joint pathophysiology from asymptomatic skeletal deformity to end-stage osteoarthritisPincer FAI. The rim-to-neck collision is geometrically determined and represents a firm endpoint for joint range of motion (COR center of rotation, r radius). a Neutral joint position; b end range of motionBack to article page