Impact of chronic ankle instability on gait loading strategy in individuals with chronic ankle instability: a comparative study.

Background: Lateral ankle sprains rank among the most prevalent musculoskeletal injuries, while chronic ankle instability (CAI) is its most common cascade. In addition to the conflicting results of the previous studies and their methodological flaws, the specific gait loading strategy is still not well studied.

Purpose: The study aimed to investigate the fluctuations in gait loading strategy in people with chronic ankle instability compared to health control.

Methods: A total of 56 male subjects participated in this study and were allocated into two groups: (A) CAI group: 28 subjects with unilateral CAI (age 24.79 ± 2.64 and BMI 26.25 ± 3.50); and (B) control group: 28 subjects without a history of ankle sprains (age 24.57 ± 1.17 and BMI 26.46 ± 2.597). Stance time, weight acceptance time, and load distribution were measured to investigate gait loading strategy.

Results: The study findings revealed that the CAI group had a significant higher load over the lateral rearfoot. However, MANOVA indicates that there was no overall significant difference in gait loading strategy between the CAI and control groups. Furthermore, in terms of stance time, time of weight acceptance phase, load over medial foot, and load over lateral foot, CAI and healthy controls seemed to walk similarly.

Conclusions: The findings revealed that individuals with CAI had the significant alteration in the lateral rearfoot loading, suggesting a potential compensatory mechanism to address instability during the weight acceptance phase. This could manifest a laterally deviated center of pressure and increased frontal plane inversion during the early stance phase. However, it is acknowledged that these alterations could be both the result and the origin of CAI. The study highlights the vulnerability of CAI during the early stance phase, emphasizing the need for gait reeducation as individuals return to walking as healthcare clinicians should focus on treatment modalities aimed at reducing rearfoot inversion in individuals with CAI.