Objective： This study aimed to visualize trunk posture control patterns during ankle inversion strength exertion in three groups: healthy individuals with no trauma history, individuals with no subjective instability post-ankle inversion sprain (history group), and individuals with subjective instability post-ankle inversion sprain (CAI group). The study examined differences among these groups.
Methods： Involving 44 lower limbs from 22 healthy adults, participants were classified into healthy, history, and CAI groups based on a questionnaire. In a supine position with gravity influence eliminated using a red cord, the trunk's frontal plane movement patterns during ankle inversion strength exertion were recorded on video. These patterns were categorized into three types: ideal (trunk remained stable), fluctuating (trunk temporarily stable then fluctuated), and abnormal (trunk unstable or immobile). Differences between the groups were analyzed using Kruskal-Wallis tests and multiple comparisons.
Results： In the healthy group, 10 limbs displayed the ideal pattern, none had the fluctuating pattern, and 1 had the abnormal pattern. In the history group, 7 limbs showed the ideal pattern, 5 the fluctuating pattern, and 10 the abnormal pattern. The CAI group had 2 limbs with the ideal pattern, 6 with the fluctuating pattern, and 3 with the abnormal pattern. The ideal pattern was significantly more prevalent in the healthy group and less so in the CAI group. No significant differences were found in the patterns of the history group compared to the others.
Discussion： Results indicate both the CAI and history groups show posture control difficulties in exerting ankle inversion strength adequately, suggesting a risk for recurring ankle sprains. This underlines the importance of evaluating the feedforward mechanism affecting ankle joint movements for preventing sprain recurrence.
