Overuse injuries and related disorders of tendons (tendinopathies) are one of the most common, irritating and long-lasting musculoskeletal problems among competitive and recreational athletes and those predisposed to repetitive, monotonous movements at work. The aetiology and pathogenesis of these tendon disorders are, however, largely unknown and even the role of repetitive strains is unclear in their development. Therefore, it is not surprising that many current treatments and therapies of tendinopathies are based on clinical experience and anecdotal experiments only rather than on evidence-based solutions and their testing in randomized controlled trials.
Randomized controlled trials have shown that corticosteroid-injections and rehabilitations of the symptomatic muscle-tendon unit by eccentric training are effective methods of treatment in tendinopathy. The former has been shown to be effective in tendinopathies of the shoulder (rotator cuff problems, supraspinatus tendinopathy and adhesive capsulitis or fozen shoulder), elbow (tennis elbow), hand (trigger finger), knee (patellar tendinopathy) and ankle (Achilles tendinopathy). The latter is effective in Achilles tendinopathy, patellar tendinopathy, tennis elbow and adductor tendinopathy of the groin. All other conservative therapies have either not been studied in randomized controlled trials or proper investigations have given contradictory results.
What causes the pain in chronic tendinopahty is presently not known. Why most patients become clearly less symptomatic or even entirely asymptomatic over time regardless of the initial therapy is also a mystery. Many interesting and challenging questions on tendinopathy remain to be answered.