Effects of prophylactic ankle supports on pronation during gait.

We performed a gait analysis of 12 healthy subjects in order to analyse the rear foot pronation-supination angle and the shift of centre of pressure (COP) during walking. We used a video system and a force plate and examined the effects of semi-rigid Air-Stirrup brace, lace-up cloth RocketSoc brace, ankle taping and no bracing. Both the lace-up cloth brace and taping increased the maximum pronation angle during the stance phase. The lace-up cloth brace alone was associated with a larger maximum pronation velocity. With the lace-up cloth brace and taping, the COP was more laterally placed, allowing greater leverage about the subtalar axis and thus increasing the tendency toward pronation. The two braces and the tape did not similarly affect ankle joint biomechanics during gait. The ability to reduce excessive amounts of pronation is an important design consideration for prophylactic ankle supports.