Irritation or inflammation of the calcaneum with a similar aetiology and, if for some reason it is x-rayed, appearance to Osgood-Schlatter's disease at the tibial tubercle.
Seen in children, particularly boys.
It can be expected to settle, with relative rest from competitive sports that strain it.
Sever JW. Apophysitis of the os calcis.; N Y Med J 1912;95:1025-9