Rotator cuff tear infraspinatus, teres minor, and subscapularis, may also be injured. The amount of stress needed to tear a rotator cuff tendon acutely will depend on the underlying condition of the tendon prior to the stress. In the case of a healthy tendon, the stress needed will be high, such as a fall on the outstretched arm. This stress may occur coincidentally with other injuries such as a dislocation of the shoulder, or separation of the acromioclavicular joint. In the case of a tendon with pre-existing degeneration, the force may be surprisingly modest, such as a sudden lift, particularly with the arm
Tendon Tendon A tendon or sinew is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments; both are made of collagen. Ligaments join one bone to bone, while tendons connect muscle to bone for a proper functioning of the body. Histologically, tendons consist of dense regular connective tissue fascicles encased in dense irregular connective tissue sheaths. Normal healthy tendons are composed mostly of parallel arrays of collagen fibers closely packed together. They are anchored to bone by Sharpey's fibres. The dry mass of normal tendons, which