The Impact of Hyperarch Fascia Training on Perceived Ankle Instability and Vertical Jump Performance in Physically Active Men and Women

Chronic ankle instability (CAI) is a prevalent musculoskeletal condition that impairs physical performance and increases reinjury risk; yet, training programs emphasizing fascia-targeted techniques remain an understudied rehabilitation strategy. The purpose of this study was to examine the effects of 12 weeks of a multicomponent training intervention emphasizing fascia-targeted techniques (Hyperarch Fascia Training (HFT)) on perceived ankle instability and function, and vertical jump performance in individuals with CAI. In this decentralized, randomized controlled trial, 66 participants were randomized (HFT n = 44, CON n = 22), with 43 participants completing the study and being analyzed (HFT n = 22; CON n = 21). Selected subjects confirmed perceived ankle instability (CAIT score ≤ 25) and were assigned to either a structured, multicomponent HFT program with various foot and ankle strengthening exercises, or a passive control condition instructed to maintain activities of daily living. The HFT group experienced disproportionately higher attrition (n = 22 excluded from analysis) than CON (n = 1 excluded from analysis due to becoming unresponsive). The reasons for attrition in the HFT group were due to becoming unresponsive (n = 13), self-reported difficulty with the protocol (n = 3), scheduling conflicts (n = 3), or adverse events (n = 3, reported as moderate). Outcomes were assessed at baseline, week 8, and week 12 using the Cumberland Ankle Instability Tool (CAIT) (primary outcome), Foot and Ankle Ability Measure (FAAM) (primary outcome), countermovement jump (CMJ) (secondary outcome), and Short Form Health Survey 12 (SF-12) (exploratory outcome). The HFT group demonstrated significantly greater improvements in CAIT scores compared to CON (group × time interaction p = 0.008), with large within-group effect sizes in the HFT group relative to baseline (d = 1.49 and 1.54, at weeks 8 and 12, respectively). Significant group × time interactions also favored HFT for CMJ jump height (p = 0.017) and flight time (p = 0.005) (co-secondary outcomes), as well as the CMJ algorithmic derivatives of mean velocity (p = 0.001) and take-off velocity (p = 0.008) (exploratory outcomes). No significant group × time interactions were observed for FAAM ADL or Sport subscales. Significant group × time interactions were found for SF-12 survey results for Physical Function (p = 0.045), Limits due to Physical Health (p = 0.030) and General Health (p = 0.043), with CON tending to decline over time and HFT tending to improve. The HFT group was higher than CON on Physical Function at Week 8 (d = 1.04, p = 0.009), and on Perceived Pain at Week 12 (d = 0.88, p = 0.047). Overall, these findings suggest that a multicomponent fascia-centered training program may represent a viable intervention for improving perceived ankle stability and increasing the explosive vertical jump performance in individuals with CAI.