An ankle sprain in which there is little outward sign of injury except, possibly, a slight swelling, but there is great pain and limited movement. Internal bleeding in the damaged joint causes the blood-filled joint capsules to bulge outwards on either side of the Achilles tendon. The condition can lead to permanent stiffness if it is not treated quickly and properly (e.g. by aspiration). See also ankle sprain.
Subjects: Sports and Exercise Medicine.