Tendon the Achilles tendon stretches as the ankle joint dorsiflexes. During the last portion of the stride, as the foot plantar-flexes (pointing the toes down), the stored elastic energy is released. Furthermore, because the tendon stretches, the muscle is able to function with less or even no change in length, allowing the muscle to generate greater force. The mechanical properties of the tendon are dependent on the collagen fiber diameter and orientation. The collagen fibrils are parallel to each other and closely packed, but show a wave-like appearance due to planar undulations, or crimps, on a scale of several micrometers. In
Achilles tendon rupture opinions are divided what is to be preferred. Non-surgical management traditionally was selected for minor ruptures, less active patients, and those with medical conditions that prevent them from undergoing surgery. It traditionally consisted of restriction in a plaster cast for six to eight weeks with the foot pointed downwards (to oppose the ends of the ruptured tendon). But recent studies have produced superior results with much more rapid rehabilitation in fixed or hinged boots. Some surgeons feel an early surgical repair of the tendon is beneficial. The surgical option was long thought to offer a significantly smaller risk of "re-rupture"