DH: The biomechanical properties of tendon in relation to muscular strength

"By the.exercise of the tendons (and their exercise is in the act of being pulled upon by the muscles, or having a strain upon them) they become firmer and stronger "—Sir CHARLES BELL (1828). TENDONS exist to transmit muscular tension to a movable bone, and it was stated first by Leonardo da Vinci (MacCurdy, 1938) that tendons must carry out as much work as is entrusted to them. The structure of a tendon reflects its function, and the longitudinal orientation of its collagenous fibres supports the hypothesis of mechanical influence on tendon growth. Roux (1895) postulated that tissue tension is the specific stimulus for the proliferation of connective tissue, pulling force for fibrous tissue, compression for bone, and shearing force for cartilage. This suggestion was later supported by the observation of rapid multiplication and orientation of fibroblasts when exposed to regional tensions in tissue culture (Weiss, 1929) and by the orientation of collagen fibres formed in relation to local stresses in the transparent ear chamber of the rabbit (Stearns, 1940a, b). It was, however, shown in the mature rabbit that there is no strict correlation between the thickness of tendons and the strength of their muscles, and that whereas 1 kg