Rotator cuff tear factors contribute to degenerative, or chronic, rotator cuff tears of which repetitive stress is the most significant. This stress consists of repeating the same shoulder motions frequently, such as overhead throwing, rowing, and weightlifting. Many jobs that require frequent shoulder movement such as lifting and overhead movements also contribute. Another factor in older populations is impairment of blood supply. With age, circulation to the rotator cuff tendons decreases, impairing natural ability to repair, ultimately leading to, or contributing to, tears. The final common factor is impingement syndrome, the most common non-sports related injury and which occurs when the tendons of
Mucous sheaths of the tendons around the ankle Mucous sheaths of the tendons around the ankle The mucous sheaths of the tendons around the ankle protect tendons in the ankle. All the tendons crossing the ankle-joint are enclosed for part of their length in mucous sheaths which have an almost uniform length of about 8 cm. each. On the front of the ankle the sheath for the Tibialis anterior extends from the upper margin of the transverse crural ligament to the interval between the diverging limbs of the cruciate ligament; those for the Extensor digitorum longus and Extensor hallucis longus reach upward to just above the level of