Comparative study of the properties of the shoulder joint capsule with those of other joint capsules.

To compare the collagen structure of the shoulder joint with that of other joints, the collagen of shoulder, elbow, and hip joints was examined electron microscopically, electrophoretically, and by its response to mechanical stress. Collagen Types I, III, and V were common to joint capsules. Electron microscopy of shoulder and elbow joint capsules did not identify any structural difference. When subjected to a mechanical force, the shoulder joint showed a greater capacity to stretch than the elbow joint, and greater force was required to break the shoulder joint than the elbow joint.