Proximal Adaptations in Chronic Ankle Instability: Systematic Review and Meta-analysis

INTRODUCTION: Chronic ankle instability (CAI) is known to induce impairments throughout the lower quarter kinetic chain, however there is currently no synthesized information on proximal adaptations of the trunk, hip, thigh, and knee for neuromuscular and biomechanical outcomes during strength, balance, jumping, and gait among CAI patients. The purpose of this systematic review and meta-analysis was to synthesize trunk, hip, thigh and knee neuromuscular and biomechanical outcome measures during functional assessments when comparing CAI to healthy groups. METHODS: Cumulative Index of Nursing and Allied Health Literature and Medical Literature Analysis and Retrieval System Online with PubMed databases were searched on June 3, 2019. Studies comparing outcomes at the trunk, hip, thigh, or knee regardless of assessment type in CAI versus healthy groups were considered for inclusion. Assessment categories were used to differentiate adaptations by assessment type after inclusion. Two independent reviewers assessed methodological quality using the Physiotherapy Evidence Database scoring criteria. Data pertaining to study methodology and primary proximal adaptation outcomes were extracted. Separate random effects meta-analyses were performed for consistently reported outcome measures. RESULTS: Pooled estimates reflected that CAI patients had decreased triplanar isometric hip strength outcomes (P < 0.001, effect size range: 0.52-0.93). Knee kinematics did not differ from healthy groups during dynamic balance testing (P = 0.26). Few studies found CAI patients have altered knee kinematics during jumping tasks. The remaining findings were isolated to individual studies and thus inconclusive. CONCLUSIONS: The CAI groups demonstrated triplanar hip strength deficits and altered knee flexion angles during jumping assessments. Clinicians should consider proximal evaluations and interventions for CAI patients.