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

NCT ID: NCT07108491

Last Updated: 2025-08-07

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 28 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-02-24
• Study Completion Date: 2025-04-04

Brief Summary

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.

Detailed Description

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.

Conditions

Ankle Injuries

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Stroboscopic Balance Training Group

The experimental group performed balance training with stroboscopic glasses twice a week for four weeks

Group Type: EXPERIMENTAL

Balance Training with Stroboscopic Glasses

Intervention Type: BIOLOGICAL

The difficulty level of intermittent visual occlusion was structured from Level 1 to Level 8 based on frequency. As the flicker speed of the lenses decreased and the frequency lowered, the difficulty increased. For example, a setting of 6 Hz means the lenses flicker six times per second, whereas 1 Hz indicates one flicker per second.

Levels 1 to 5 are suitable for dynamic movements such as catching or hitting a ball, while Levels 3 to 8 are appropriate for balance and proprioceptive training.

In this study, participants wore stroboscopic glasses (Senaptec Strobe, Senaptec, USA, 2016) and began at Level 1 (6 Hz). The difficulty was gradually increased each week, with the setting adjusted to Level 3 (4 Hz) in Week 2, Level 4 (3 Hz) in Week 3, and Level 5 (2.25 Hz) in Week 4 (see Table 5).

The training was conducted using the standard Mode A, in which both lenses flicker simultaneously.

Control Group (General Balance Training)

The control group performed the same balance training twice a week for four weeks

Group Type: ACTIVE_COMPARATOR

Balance Training without Glasses

Intervention Type: BIOLOGICAL

The exercise program consisted of six types of exercises and was conducted in a 30-minute circuit training format repeated twice per session. Participants took part in two sessions per week for four weeks, totaling eight sessions. The six exercises were completed as a circuit, repeated twice per session. A 30-second rest was provided between exercises and a 2-minute rest between circuits. All exercises were conducted by a licensed physical therapist to ensure safety.

Interventions

Balance Training with Stroboscopic Glasses

The difficulty level of intermittent visual occlusion was structured from Level 1 to Level 8 based on frequency. As the flicker speed of the lenses decreased and the frequency lowered, the difficulty increased. For example, a setting of 6 Hz means the lenses flicker six times per second, whereas 1 Hz indicates one flicker per second.

Levels 1 to 5 are suitable for dynamic movements such as catching or hitting a ball, while Levels 3 to 8 are appropriate for balance and proprioceptive training.

In this study, participants wore stroboscopic glasses (Senaptec Strobe, Senaptec, USA, 2016) and began at Level 1 (6 Hz). The difficulty was gradually increased each week, with the setting adjusted to Level 3 (4 Hz) in Week 2, Level 4 (3 Hz) in Week 3, and Level 5 (2.25 Hz) in Week 4 (see Table 5).

The training was conducted using the standard Mode A, in which both lenses flicker simultaneously.

Intervention Type: BIOLOGICAL

Balance Training without Glasses

The exercise program consisted of six types of exercises and was conducted in a 30-minute circuit training format repeated twice per session. Participants took part in two sessions per week for four weeks, totaling eight sessions. The six exercises were completed as a circuit, repeated twice per session. A 30-second rest was provided between exercises and a 2-minute rest between circuits. All exercises were conducted by a licensed physical therapist to ensure safety.

Intervention Type: BIOLOGICAL

Eligibility Criteria

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

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 39 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Sahmyook University

OTHER

Sponsor Role: lead

Responsible Party

Miyong Jeong

Graduate Student Researcher

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

MIYONG JEONG, MSc

Role: PRINCIPAL_INVESTIGATOR

Sahmyook University Graduate School

Locations

Sahmyook University

Seoul, , South Korea

Countries

South Korea

Other Identifiers

IRB Number

Identifier Type: OTHER

Identifier Source: secondary_id

SYU 2025-01-011-002

Identifier Type: -

Identifier Source: org_study_id