Tendonitis means inflammation of a tendon. Although the work â€œTendonitisâ€ is often used, it is actually an out-dated term. The suffix â€œitisâ€ means inflammation, however, research has shown that it is really a build up of scar tissue and decrease in collagen that is the problem, not inflammation. Therefore the newer term that replaces tendonitis is â€œTendinosisâ€, which denotes the scar tissue accumulation, and change in tendon composition.
The Achilles tendon is the largest tendon in the body. It connects the muscles of the calk to the foot through its junction at the heel. The Achilles tendon is critical for transmitting the force of contraction of the calf muscles to the foot: pushing the foot downwards as when stepping on a gas pedal. During locomotion, the Achilles tendon allows for the push-off phase during running.
Achilles tendinosis is a condition where the Achilles tendon, at or near its insertion into the heel, becomes irritated and causes pain. The demands on the Achilles tendon are high in running and jumping sports. Pain is often felt with running hills, doing speed work or jumping activities. It is thought that over-pronation puts excessive pressure on the tendon of the calf muscle causing irritation of the Achilles tendon. A sudden increase in running mileage or overtraining of any sort contributes to this injury.
Local tenderness is made worse by stretch and/or stretch and contraction. Achilles tendinosis may be viewed as a spectrum that ranges from initial overuse inflammatory changes to chronic degenerative breakdown. In the last stage of this condition the Achilles tendon can completely rupture. Rupture of this tendon is a devastating injury that heals very poorly. Thus properly treating Achilles tendinosis is essential.