Most common cause of inseional tendonitis of tendoachilles is -

ACHILLES TENDINITIS: Athletes, joggers and hikers often develop pain and swelling around the tendo Achillis, due to local irritation of the tendon sheath or the paratenon.Clinical features :The condition may come on gradually, or rapidly following a change in spoing activity (or a change of spos footwear). Less commonly there is a history of direct trauma to the Achilles tendon. The area above the heel may look inflamed and function is inhibited because of pain in the heel-cord, especially at pushoff. The tendon feels thickened in the watershed area about 4 cm above its inseion. In chronic cases an ultrasound scan may be helpful in confirming the diagnosis. REF:Apley&;s system of ohopaedics- 9th edn- pg no 613 .