Abstract des Autors

The purpose of this study was to measure the effectiveness of the nonrigid subtalar stabilizer (STS) ankle brace under conditions similar to an unexpected fall that could lead to a lateral ligament injury. The calcaneal inversion angles, times, and ground reaction forces were measured when the subject's right foot, bearing body weight, was suddenly inverted to a side slope of 22ø. Thirty subjects, 15 women and 15 men, participated in the study. The overall inversion drop was divided into two phases, free fall and loading. Based on the data of this study it is suggested that the major function of a brace is to restrict the amount of foot inversion during the fall before actual landing occurs rather than functioning as a force bypass for the lateral ligaments during loading after foot contact. The results showed that the brace significantly reduced the maximum calcaneal inversion angle from 27.4+/-6.1 to 18.3+/-6.0ø for the overall drop, significantly lengthened the inversion time from 0.14+/-0 .04 to 0.18+/-0.04 s for the overall drop, and significantly reduced the calcaneal peak inversion velocity from 324.6+/-111.9 to 165.2+/-66.5ø/s during loading, and from 278.7+/-120.0 to 183.0+/-108.7ø/s for the overall drop. Following exercise, which incorporated lateral movements and sprinting, the STS ankle brace continued to provide significant reduction in the calcaneal inversion angle and velocity, although some of its effectiveness was reduced. The results of this study suggest that the nonrigid STS ankle brace provides support that could reduce injuries by significantly restricting the degree of calcaneal inversion range of motion during an unexpected fall; significantly lengthening the time of inversion, thereby decreasing the rate at which the calcaneus inverts during a sudden inversion drop; and maintaining this support following sprinting and lateral movement exercises. Verf.-Referat