Ruptures and tears of various tendons and muscles of the body are not so rare as is supposed generally. I have mentioned the literature pertaining to ruptures of the long head of the biceps in three articles1on that subject. Little is to be found concerning such lesions in American or English medical literature. Even less has been written on similar lesions in the lower extremity, which I shall consider in this paper. Many patients with such injuries are treated for weeks or months for sprains, arthritis, neuritis or similar disabilities. In a great majority of these cases, if the rupture is extensive, an accurate diagnosis and surgical repair will not only improve the ultimate function of the limb but return the patient to activity much sooner than the usual conservative measures. ETIOLOGY Any one of many factors may cause a tear or rupture in a muscle or tendon,