Torn cartilage, occurring frequently in the knees of athletes, is damage to the articular discs which lie between the ends of some bones. Removal, to prevent erosion and arthritis, is usually accomplished by arthroscopy. B. Factors Affecting Movement at a Diarthrosis 1. Joint flexibility may also be affected by hormones such as relaxin, which relaxes the pubic symphysis during childbirth. C. Types of Diarthroses 1.
Examples are the joints found between the carpals and between the tarsals.
A summary of joints based on functional classiflcation is presented. D. Common Types of Movement at Diarthroses 1. Flexion decreases the angle between articulating bones. Extension increases the angle between articulating bones, often to restore a body part to its anatomical position after it has been flexed. Hyperextension is continuation of extension beyond the anatomical position.