Inability to move a joint through its full range of motion due to a mechanical defect or obstruction within the joint. It may result in an inability to fully extend the joint, or the fixation of a joint in one position. Locking or inability to move a joint can be caused by extreme pain due to a muscle spasm or by interference from a foreign body or torn cartilage. Locking of the knee-joint, for example, maybe due to a spasm of the hamstrings, a meniscal tear, or loose bodies (joint mice).
Subjects: Sports and Exercise Medicine.