Tendonitis
Tendons are straps or bands of tissue that attach muscle to bone. As such, tendons are passive and do not get tight by themselves; they get tight when attached muscles tighten and shorten. Tendinitis (or tendonitis) occurs when a muscle stays tight for long periods, as happens when protective reflexes get activated by injury. Strain on the tendon and friction of the tendon on surrounding tissue irritate the tendon and lead to inflammation and pain: tendonitis