ACHILLES TENDONITIS
Achilles tendonitis is a common lower limb overuse injury. The damage to the tendon is caused when repetitive and excessive forces accumulate to overload the tendon.
Studies have linked a variety of factors to Achilles tendonitis, including calf muscle inflexibility, excessive rear-foot pronation and ankle muscle weakness.
Lack of strength in the calf muscles (to which the Achilles tendon attaches) may mean insufficient control of the ankle when the foot makes contact with the ground. In running, the calf muscles are most active during the first half of the contact phase, when they are absorbing the impact with the ground. At this point the calf muscles and Achilles tendon are lengthening to eccentrically control the forward motion of the lower leg and inflammation can occur.
Pronation or inwards movement of the rear foot during contact with the ground is necessary to absorb impact forces. A normal amount of pronation is a good thing, but excessive inward motion will over-rotate the lower leg inwards, which means that during push-off, the ankle muscles are in a poor mechanical position and greater stress is placed upon the Achilles tendon.
A good Achilles tendon program should thus focus on developing eccentric strength, as this is related to the function of the calf muscle during the running movement, as well as a restoration of optimal biomechanics via taping, felting and orthotic prescription and the deep massage of tight calf musculature and tendon fibrosis.
