OBJECTIVES: Our main objective was to find a complex relationship between chronic ankle instability (CAI) and factors contributing to lower limb proximal-distal muscle imbalance. METHODS: This cross-sectional study, conducted in the physiotherapy department of Krishna Vishwa Vidyapeeth, Karad, included 111 volunteers selected through simple random sampling. Outcome assessments involved manual muscle testing, range of motion evaluation, and gait pattern analysis based on specific inclusion and exclusion criteria. RESULTS: The study interpreted that individuals with CAI exhibited significant muscle imbalances on the affected side compared to the unaffected side. Core muscle weakness was present in 97 (87.2%) of patients involving multifidus and rectus abdominals majorly, while 90 (84.6%) experienced lower limb muscle weakness. The ankle joint's range of motion was the most affected, with ankle plantar flexors and evertors showing the greatest weakness. Abnormalities in gait were also noted, with cautious gait observed in 83 (75%) patients, knee hyperextension in 24 (22%), and foot slap in four (3%). CONCLUSION: The present study concluded that CAI could cause abnormal gait patterns due to weak muscle strength, impaired muscle length-tension relationships, and reduced range of motion. An efficient core gives optimal efficiency in the entire kinetic chain during movements like acceleration, deceleration, and dynamic stabilization and provides proximal stability to the lower extremities. In the study, lower limb muscle imbalance and core muscle weakness are significant contributors to CAI, impacting both stability and functional performance. Considering the study findings as an important part of patient assessment, it will be used to customize the rehabilitation programs as per the patient's requirement and, thus, enhance positive outcomes.