Balance Training With Progressive Intermittent Visual Occlusions in Chronic Ankle Instability(RCT)

The Effects of Balance Training With Progressive Intermittent Visual Occlusions on Balance, Instability, Muscle Strength, and Functional Performance in Patients With Chronic Ankle Instability (RCT)

Based on the purpose of this study, the following hypotheses were established:

There will be a significant difference in balance changes within and between groups following balance training with progressive intermittent visual occlusions compared to general balance training.

There will be a significant difference in instability changes within and between groups following balance training with progressive intermittent visual occlusions compared to general balance training.

There will be a significant difference in muscle strength changes within and between groups following balance training with progressive intermittent visual occlusions compared to general balance training.

There will be a significant difference in functional performance changes within and between groups following balance training with progressive intermittent visual occlusions compared to general balance training.

In this study, participants were voluntarily recruited through social networking services, university bulletin boards, and in-hospital advertisements at N Hospital in Seoul. A total of 28 participants were provided with sufficient information regarding the purpose, procedures, and assessment methods of the study. After obtaining written informed consent, the participants were randomly assigned into either the experimental group (n = 14), which received balance training with progressive intermittent visual occlusions, or the control group (n = 14), which received general balance training only, using the randomization website (www.randomizer.org). Random assignment was conducted in a single-blind manner, and participants were unaware of their group allocation.

During the pre-intervention assessment, general characteristics (sex, side tested, age, height, weight, BMI, leg length) were recorded. Measures of balance, instability, muscle strength, and functional performance were taken. Each variable was measured three times to reduce error, and the average value was calculated.

Interventions were conducted individually in a designated private space, and participants were scheduled according to their availability. The experimental group participated in balance training with progressive intermittent visual occlusions twice a week for four weeks (eight sessions in total), with each session lasting 30 minutes. The control group performed the same balance training protocol without wearing stroboscopic glasses.

All interventions were administered by an experienced physical therapist with more than 10 years of clinical experience. Pre- and post-assessments were conducted by a blinded assessor who was unaware of the participants' group allocation. All procedures before and after the intervention were conducted under the same conditions. Following the intervention, balance, instability, muscle strength, and functional performance were reassessed using the same protocols as in the pretest.

During the intervention period, one participant in the experimental group dropped out due to plantar foot pain, resulting in a final sample size of 13 in the experimental group and 14 in the control group for the statistical analysis.

Inclusion Criteria

History of recurrent ankle sprains within the 12 months prior to the study

At least two episodes of the ankle "giving way"

Current ankle instability, indicated by a Cumberland Ankle Instability Tool (CAIT) score of 24 or less

Exclusion Criteria

History of lower extremity fracture or musculoskeletal surgery

Lower extremity injury within the past 3 months

Vestibular disorders or uncorrectable visual impairments