The Effects of Vestibulo-Ocular Reflex Exercises Added to Postural Stabilization Training in Amateur Athletes With Chronic Ankle Instability

Chronic ankle instability (CAI) is a common condition following lateral ankle sprain and is characterized by mechanical and/or functional instability, recurrent episodes of "giving way," and activity limitations persisting for at least 12 months after the initial injury. Contemporary models suggest that CAI should not be explained only by biomechanical or neuromuscular deficits, but rather as a multidimensional condition influenced by motor-behavioral, sensory-perceptual, psychological, and environmental factors. In amateur athletes, CAI may be overlooked or undertreated despite the high sensorimotor and cognitive demands of sport-specific activities. During dynamic sport-related tasks, athletes must rapidly perceive visual information, select an appropriate motor response, and execute this response while maintaining postural control. Therefore, visuo-motor reaction performance assessed during dynamic balance may provide a meaningful functional outcome for evaluating sport-specific sensorimotor control in individuals with CAI.

Postural stabilization training is commonly used in CAI rehabilitation to improve balance, proprioceptive function, and neuromuscular control. However, individuals with CAI may demonstrate increased reliance on visual information and altered visual-vestibular sensory reweighting during postural control tasks. The vestibulo-ocular reflex (VOR) contributes to gaze stability and visual clarity during head movements. Therefore, integrating VOR exercises into postural stabilization training may support visual stabilization, sensory integration, and motor response performance during dynamic balance tasks.

Psychological factors may also influence functional performance and return-to-sport behavior after musculoskeletal injury. Fear-avoidance behavior related to sports injuries and kinesiophobia may lead individuals to avoid movement or sport-specific activities due to fear of reinjury. These factors may be associated not only with traditional motor performance outcomes, but also with visual attention strategies, attentional resource allocation, and reactive motor response processes.

This study is designed as a randomized controlled, prospective, parallel-group, pretest-posttest design trial to investigate whether VOR exercises added to postural stabilization training improve visuo-motor reaction performance, fear avoidance behavior related to sports injuries and kinesiophobia in amateur athletes with CAI. Visuo-motor reaction performance will be assessed using a Reactive Balance Test, Fear-avoidance behavior related to sports injuries will be evaluated through Athlete Fear Avoidance Questionnaire - Turkish Version and kinesiophobia will be assessed using Tampa Scale for Kinesiophobia - Turkish Version. Approximately 56 participants with CAI will participate in an exercise program for six weeks, three days a week. Each session will last approximately 45 minutes, including 40 minutes of exercise and 5 minutes of ankle mobilization. Participants will be randomized into either a Postural Stabilization Training Group or a Postural Stabilization Training plus Vestibulo-Ocular Reflex (VOR) Exercises Group. Outcomes will be assessed at baseline, at the end of the six week intervention and at 4-week follow-up.

Inclusion criteria

• Being between 18 and 35 years of age.
• Being classified as a Tier 2 athlete according to the McKay et al. Participant Classification Framework (trained/developmental level).
• Having a history of at least one lateral ankle sprain (LAS) occurring at least 12 months before enrollment, resulting in swelling, pain, and functional impairment, and followed by persistent instability.
• Having the most recent ankle sprain at least 3 months before study enrollment.
• Having a history of recurrent ankle sprains or episodes of "giving way."
• Having a diagnosis of unilateral chronic ankle instability (CAI).
• Having a Cumberland Ankle Instability Tool - Turkish Version (CAIT-T) score of ≤24.
• Having a Foot and Ankle Ability Measure (FAAM) score of <90%.
• Having a Foot and Ankle Ability Measure Sports subscale (FAAM-S) score of <80%.
• A side-to-side difference of ≥2.5 cm in Weight-Bearing Lunge Test distance, with the affected side demonstrating less dorsiflexion than the unaffected side.

Exclusion criteria

• History of acute lateral ankle sprain within the last 3 months.
• History of lower extremity surgery.
• History of acute injury to other musculoskeletal structures of the lower extremity joints within the last 3 months that affected joint integrity and function and caused interruption of desired physical activity for at least one day.
• History of balance or vestibular disorders, including cerebellar, vestibular, cochlear, or inner ear dysfunction.
• Visual problems that may affect the administration or interpretation of the Dynamic Visual Acuity Test, including a history of amblyopia, diplopia, or significant visual loss.
• Persistent symptoms related to a previous concussion or traumatic brain injury.