ORTHOTIC DEVICES IN FUNCTIONAL TREATMENT OF ANKLE SPRAIN - STABILIZING EFFECTS DURING REAL MOVEMENTS

Various orthotic devices generally employed for therapy of ankle sprai n were tested under functional conditions. The experimental setup comp rised inversion stimuli of 20 and 30 degrees (13 subjects) while stand ing on a tiltplatform as well as running movements of 8 and 12 km . h- 1 on a treadmill (12 subjects). Ankle joint displacements were registe red together with the surface EMGs from mm. peroneus long., tibialis a nt., gastrocnemius med. and vastus med. In an additional study the rel ation between achilles tendon angle and talar tilt was determined unde r static conditions. Ten subjects with chronical instability were exam ined both in uni- and bipedal stance with the foot inverted to 20, 30 and 40 degrees. None of the tested devices could reduce achilles tendo n angle movements completely neither during a sudden inversion nor dur ing running. However, there were significant differences among the tes ted devices in the dorsal-plantar and in the eversion-inversion plane. In bipedal stance talar tilts were observed only when the foot was in verted more than 30 degrees. In unipedal stance these tilts were clear ly reduced or disappeared totally. It is concluded that for functional rehabilitation, loading of the ankle joint is desirable in order to i ncrease joint stability The central importance of the treatment by ort hotic devices may be regarded in an optimal passive joint stabilizatio n combined with a correct fitting in order to preserve proprioceptive neuromuscular function for an active muscular stabilization.