Chronic ankle instability (CAI) is associated with recurrent ankle sprains, impaired postural control, and reduced functional performance. Traditional functional performance tests are commonly used to assess athletes with CAI; however, these assessments are typically conducted under isolated motor conditions and may not adequately reflect the neurocognitive demands encountered during sports participation.

The aim of this randomized crossover study is to investigate the acute effects of neurocognitively enriched testing conditions on balance and functional performance in athletes with CAI. Participants will perform functional performance tests under four different conditions: standard testing, internal focus of attention, external focus of attention, and cognitive dual-task conditions. Dynamic balance, vertical jump performance, single-leg hop performance, figure-of-8 hop performance, and dual-task cost will be assessed and compared across conditions.

The findings of this study may contribute to the development of more ecologically valid assessment approaches for athletes with CAI and provide insights into the influence of attentional focus and cognitive load on functional performance.

Chronic ankle instability (CAI) is a common consequence of lateral ankle sprains and is characterized by recurrent episodes of giving way, repeated sprains, impaired sensorimotor control, and persistent functional limitations. Although functional performance tests are widely used to assess readiness for sports participation and return-to-sport status, these assessments are typically performed under isolated motor conditions and may not adequately represent the complex neurocognitive demands encountered during athletic activities.

Recent evidence from motor learning and sports medicine literature suggests that attentional focus strategies and cognitive loading can substantially influence movement performance, postural control, and motor execution. Internal focus of attention directs individuals toward body movements and joint positions, whereas external focus of attention emphasizes movement outcomes and environmental effects. In addition, dual-task paradigms introduce cognitive demands that may alter motor performance by increasing attentional load and competing for cognitive resources. Understanding how these neurocognitive factors influence functional performance may provide valuable information for the assessment and management of athletes with CAI.

The present study aims to examine the acute effects of neurocognitively enriched testing conditions on balance and functional performance in athletes with CAI. By comparing performance under standard testing, internal focus, external focus, and cognitive dual-task conditions, the study seeks to determine whether commonly used functional performance tests are sensitive to variations in attentional focus and cognitive load.

This investigation is expected to contribute to a better understanding of the interaction between cognitive processes and motor performance in athletes with CAI. The findings may support the development of more ecologically valid assessment strategies and provide clinically relevant information for rehabilitation planning, functional evaluation, and return-to-sport decision-making in athletic populations with chronic ankle instability.

Inclusion Criteria:

• Aged between 16 and 25 years.
• Actively participating as a licensed football, basketball, or volleyball athlete.
• History of at least one lateral ankle sprain occurring ≥12 months before study participation, associated with pain and/or swelling and resulting in at least one day of restricted physical activity.
• History of recurrent ankle instability, defined as at least two episodes of giving way during the previous 6 months and/or recurrent ankle sprains.
• Cumberland Ankle Instability Tool (CAIT) score ≤25.
• Participating in regular sports training at least 3 times per week.
• No ankle surgery within the previous 6 months.
• Able to safely perform all functional performance tests.
• Willing to undergo assessment of the more symptomatic ankle; in participants with bilateral chronic ankle instability, the ankle with the lower CAIT score will be evaluated.

Exclusion Criteria:

• Acute ankle sprain within the previous 6 weeks accompanied by significant pain, swelling, or functional limitation.
• History of major lower-extremity surgery (e.g., knee, hip, or ankle surgery).
• History of neurological, vestibular, or systemic disorders that may affect balance or motor performance.
• Visual or cognitive impairments that could interfere with test performance.
• Lower-extremity injuries other than ankle instability within the previous 6 months that may negatively affect functional performance.

Individual participant data (IPD) will not be made publicly available in order to maintain participant confidentiality and comply with institutional ethical requirements.