A fibrous cord that joins muscle to bone or muscle to muscle. Tendons are strong and flexible, but inelastic. Those in the hands, wrists, and feet are enclosed in synovial sheaths (fibrous capsules) that secrete a lubricating fluid.
A tendon – also known as sinew, or leader – is the cord of tissue that attaches the end of a muscle to the bone or other structure upon which the muscle acts when it contracts. Tendons are composed of bundles of white ?brous tissue arranged in a very dense manner, and are of great strength. Some are rounded, some ?attened bands, whilst others are very short – the muscle-?bres being attached almost directly to the bone. Most tendons are surrounded by sheaths lined with membrane similar to the SYNOVIAL MEMBRANE lining joint-cavities: in this sheath the tendon glides smoothly over surrounding parts. The ?bres of a tendon pass into the substance of the bone and blend with the ?bres composing it. One of the largest tendons in the body is the Achilles tendon, or tendo calcaneus, which attaches the muscle of the calf to the calcaneus or heel-bone.
Tendon injuries are one of the hazards of sports (see SPORTS MEDICINE). They usually result from indirect violence, or overuse, rather than direct violence.
Rupture usually results from the sudden application of an unbalanced load. Thus, complete rupture of the Achilles tendon is common in taking an awkward step backwards playing squash. There is sudden pain; the victim is often under the impression that he or she has received a blow. This is accompanied by loss of function, and a gap may be felt in the tendon.
Partial Rupture is also accompanied by pain, but there is no breach of continuity or complete loss of function. Treatment of a complete rupture usually means surgical repair followed by immobilisation of the tendon in plaster of Paris for six weeks. Partial rupture usually responds to physiotherapy and immobilisation, but healing is slow.
n. a tough whitish cord, consisting of numerous parallel bundles of collagen fibres, that serves to attach a muscle to a bone. Tendons are inelastic but flexible; they assist in concentrating the pull of the muscle on a small area of bone. Some tendons are surrounded by tendon sheaths – these are tubular double-layered sacs lined with synovial membrane and containing synovial fluid. Tendon sheaths enclose the flexor tendons at the wrist and ankle, where they minimize friction and facilitate movement. See also aponeurosis. —tendinous adj.
A thick tendon that joins the calf muscles to the heel bone (calcaneus) and pulls up that bone. The tendon is prone to rupture in middle-aged people playing vigorous sports such as squash or tennis. Named after the classical Greek hero Achilles, who was reputedly vulnerable to his enemies only in his heel.... achilles tendon
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