Relationship of Chronic Ankle Instability With Foot Alignment and Dynamic Postural Stability in Adolescent Competitive Athletes

BACKGROUND: Competitive adolescent athletes should be aware of the early signs of chronic ankle instability (CAI) and the connection between the condition and performance. PURPOSE: To investigate whether CAI is related to foot alignment and morphology as well as dynamic postural stability after a jump landing among adolescent competitive athletes with and without a history of a lateral ankle sprain and CAI. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Between July 2020 and August 2021, adolescent competitive athletes (N = 85; n = 49 boys; n = 36 girls) were classified into 3 groups using Cumberland Ankle Instability Tool (CAIT) scores: healthy athletes (n = 55), coper athletes (n = 19), and athletes with CAI (n = 11). Results of foot alignment assessments involving the leg-heel angle (LHA) and navicular height, intrinsic foot muscle morphology, dynamic postural stability index (DPSI), and other parameters were compared among the 3 groups. The relationship between the CAIT score and the LHA and dynamic postural stability and instability were examined using multiple linear regression. RESULTS: Compared with the healthy group, the CAI group had a significantly greater LHA (8.73°± 3.22° vs 6.09°± 3.26°; P < .05), higher DPSI (0.336 ± 0.046 vs 0.298 ± 0.035), and higher vertical stability index (0.303 ± 0.048 vs 0.264 ± 0.037; P < .05 for all). Multiple regression analysis showed that the LHA (β = −0.228; P = .033) and DPSI (β = −0.240; P = .025) were significantly associated with the CAIT score . CONCLUSION: Valgus rearfoot alignment and poorer dynamic postural control were associated with CAI among adolescent athletes.