Classifications & types
The Achilles tendon does not contain good blood supply or good cell activity. As a result any injury to this tendon heals at a snail's pace. Once an injury happens to the tendon, cells from surrounding structures migrate into the tendon to aid in healing. Some of these cells arrive from blood vessels that go into the tendon to make available direct blood circulation to boost healing. Along with the blood vessels comes the nerve fiber. These nerve fibers can be the reason of the tenderness.
The Achilles tendon is formed by the gastrocnemius and soleus muscle which are crucial muscular tissues for walking.
Tendinitis due to overuse is most common reason in younger individuals and can happen in walkers, runners, and in individual involved in sporting activities like basketball that involve jumping. Jumping places a great amount of stress on the Achilles tendon.
Tendinitis from arthritis is more widespread in middle-aged aged population.