Preoperative and Postoperative Cutaneous Reflexes and Perceived Instability During Gait in an Individual With Chronic Ankle Instability

Context: Recent studies exploring chronic ankle instability (CAI) have found alterations in cutaneous reflexes of musculature surrounding the ankle which may contribute to perceived instability and recurrent LAS seen in this population. CAI is considered a multifaceted condition, making it difficult to determine the underlying cause of these altered reflexes. Objective: To observe how mechanical laxity of the ankle affects lower limb cutaneous reflexes and perceived instability during gait and how surgical intervention to correct laxity affects these measures. Design: Clinical Case Report Setting: Research Laboratory Patient: A physically active 25-year-old female (64in;130lbs) with 7 previous lateral ankle sprains (LAS) and met CAI diagnostic criteria based on CAI questionnaire scores. The patient underwent a Broström reconstruction of the CFL via allograft and partial synovectomy. Main Outcome Measures: CAI questionnaire scores, middle latency lower limb cutaneous reflexes, and perceived instability following sural nerve stimulation during gait. Results: Post-surgery, the patient's CAIT and FAAM questionnaire scores aligned with those of a healthy individual. PL reflexes were diminished or inhibitory during the stance phases of gait. Pronounced variability of PL reflexes may have contributed to this lack of facilitation. BF facilitation at midstance was absent during both testing sessions while BF and RF facilitation was generally reduced post-surgical intervention. The patient's average perceived instability following sural stimulation was markedly reduced from the pre-surgical (6.5±0.48) to post-surgical (1.9±0.24) session. Conclusions: Mechanical instability likely contributed to the reflex variations seen in this patient pre- surgically, while the enhanced static stability provided by the surgical procedure may have reduced the need for dynamic stability via lower limb cutaneous reflexes observed in the follow-up session. Identifying the specific limitations experienced by an individual with CAI will allow for a more effective monitoring and treatment and provide improved long-term health-related quality of life outcomes.