Predicting Manual Therapy Treatment Success in Patients With Chronic Ankle Instability: Improving Self-Reported Function

Abstract

Context:  Therapeutic modalities that stimulate sensory receptors around the foot-ankle complex improve chronic ankle instability (CAI)–associated impairments. However, not all patients have equal responses to these modalities. Identifying predictors of treatment success could improve clinician efficiency when treating patients with CAI. Objective:  To conduct a response analysis on existing data to identify predictors of improved self-reported function in patients with CAI. Design:  Secondary analysis of a randomized controlled clinical trial. Setting:  Sports medicine research laboratories. Patients or Other Participants:  Fifty-nine patients with CAI, which was defined in accordance with the International Ankle Consortium recommendations. Intervention(s):  Participants were randomized into 3 treatment groups (plantar massage [PM], ankle-joint mobilization [AJM], or calf stretching [CS]) that received six 5-minute treatments over 2 weeks. Main Outcome Measure(s):  Treatment success, defined as a patient exceeding the minimally clinically important difference of the Foot and Ankle Ability Measure–Sport (FAAM–S). Results:  Patients with ≤5 recurrent sprains and ≤82.73% on the Foot and Ankle Ability Measure had a 98% probability of having a meaningful FAAM–S improvement after AJM. As well, ≥5 balance errors demonstrated 98% probability of meaningful FAAM–S improvements from AJM. Patients <22 years old and with ≤9.9 cm of dorsiflexion had a 99% probability of a meaningful FAAM–S improvement after PM. Also, those who made ≥2 single-limb–stance errors had a 98% probability of a meaningful FAAM–S improvement from PM. Patients with ≤53.1% on the FAAM–S had an 83% probability of a meaningful FAAM–S improvement after CS. Conclusions:  Each sensory-targeted ankle-rehabilitation strategy resulted in a unique combination of predictors of success for patients with CAI. Specific indicators of success with AJM were deficits in self-reported function, single-limb balance, and <5 previous sprains. Age, weight-bearing–dorsiflexion restrictions, and single-limb balance deficits identified patients with CAI who will respond well to PM. Assessing self-reported sport-related function can identify CAI patients who will respond positively to CS.