The Effect of Stroboscopic Vision-Assisted Exercise Training on Ankle Muscle Architecture in Chronic Ankle Instability Rehabilitation

NCT07067931 | Completed

• 1 other identifier: Medipol
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of this study is to investigate the effects of an 8-week combined balance and plyometric exercise program using stroboscopic glasses on muscle morphology, dynamic balance, and proprioception in athletes with a history of ankle sprains. The primary objective is to assess the effectiveness of innovative rehabilitation strategies and their integration into clinical practice. Ultimately, the study seeks to accelerate recovery, reduce recurrence risk, and support long-term functional outcomes. Additionally, the findings are expected to fill current gaps in the literature on muscle architecture and performance, contributing scientifically to rehabilitation protocols. Hypotheses: Hypothesis 1: Stroboscopic visual feedback exercise training affects ankle muscle architecture in athletes. Hypothesis 2: Stroboscopic visual feedback exercise training affects dynamic balance in athletes. Hypothesis 3: Stroboscopic visual feedback exercise training affects ankle proprioception in athletes. Hypothesis 4: Stroboscopic visual feedback exercise training affects postural stability in athletes.

Conditions

Chronic Ankle Instability; Muscle Architecture

Keywords

chronic ankle instabilty; stroboscopic vision; muscle architecture; piliometric

Outcome Measures

Primary Outcomes (4)

• Muscle Architecture Assessment

  Muscle architectural variables will be assessed using an HS60 (Samsung Medicine, Gangwon-do, Korea) ultrasound system equipped with a 5-13 MHz linear probe. Muscle cross-sectional area (MCA) measurements of the ankle circumference muscles will be performed under two different conditions, resting and maximal voluntary contraction (MVC), using the B-mode (brightness mode) ultrasound method. All measurements will be completed under these two conditions. Ultrasound imaging procedures will be performed by a researcher physical therapist experienced in musculoskeletal ultrasound.

  1 hour

• Dynamic Balance Assessment

  The Y balance test, a short and practical variation of the star balance test, will be used to assess dynamic stability. Athletes will perform the Y balance test according to the test procedures defined by Plisky et al. Three white bands, each 125 cm in length, will be affixed to the ground to form a Y shape, with the small angle at 90° and the two larger angles at 135°, and centimeter-scale markings will be added to the bands by hand.Participants will be positioned at the center of the apparatus with the second phalanges of the extremity being tested in the coronal plane and the metatarsophalangeal joints in the sagittal plane, both aligned with the midline. Participants will be asked to stand with their hands at the level of the iliac crest, adjacent to their bodies, and with the foot to be measured on the ground, to reach out with the other foot in the anterior, posteromedial, and posterolateral directions, once in each direction, and to lightly touch the final point they can reach.

  15 minute

• Proprioception Assessment

  An ankle joint position sense test will be administered to assess deficiencies in ankle proprioception. An electronic goniometer will be used to assess ankle joint position sense. The reliability of this test among recreational athletes with ankle instability has been reported as ICC = 0.94-0.98 \[45\]. Athletes will be seated with their knees flexed at 90°, and their eyes will be closed to eliminate visual cues. The ankle subtalar joint (STJN) will be held in a neutral position, and the goniometer will be set to zero. The ankle will be passively moved through 10° dorsiflexion, 10° eversion, 15° plantar flexion, or 15° inversion, and then returned to the neutral position \[46\]. Participants will then be asked to actively perform these movements as closely as possible to the previous movements. Three repeated measurements will be taken for each test angle, and deviations from the target angle will be recorded.

  15 minute

• Postural Stability Assessment

  Athletes' postural stability and center of pressure (CoP) assessments will be performed using the Prokin force platform (Prokin PK 252). The Prokin PK 252 is a proprioceptive system used for static and dynamic balance assessment and training. In this study, the "Static and Dynamic Stability Assessment Program" will be used to provide detailed and accurate data on participants' static standing posture through the stabilometry platform and sensors placed on the body \[47\]. During the test, participants' standing position will be determined with their feet shoulder-width apart, and their foot positions will be aligned at equal distances from the origin point, using the lines on the platform's x and y axes as references.First, a single-leg static stability test will be performed. This test will be administered in two sub-tests: with eyes open and with eyes closed.

  20 minute

Secondary Outcomes (2)

• Foot and Ankle Ability Measure (FAAM)

  15 minute

• Cumberland Ankle Instability Tool (CAIT)

  10 minute

Study Arms (3)

The non-stroboscopic group

EXPERIMENTAL

The non-stroboscopic group will perform the exercises without glasses. The exercise training groups will follow an 8-week program, two sessions per week, involving combined balance and plyometric exercises. Plyometric training emphasizes the stretch-shortening cycle of the muscle-tendon complex, enhancing elastic capacity and neuromuscular responsiveness. Therefore, these exercises are often referred to as reactive neuromuscular training \[46\]. The program combines plyometric jumps and landings with balance-enhancing movements, all performed on the affected extremity. The program consists of three main phases: a warm-up, the main training session, and a cool-down. The warm-up includes 5 minutes of slow jogging and 5 minutes of high-knee running. The main session involves progressively intensified combined balance and plyometric exercises. The cool-down includes 5 minutes of low-intensity running followed by static stretching exercises targeting lumbar extensors, hamstrings, quadriceps

Other: Exercise

The stroboscopic group

EXPERIMENTAL

The stroboscopic group will perform all exercises wearing stroboscopic glasses (SENAPTEC, Beaverton, Oregon). These glasses use liquid crystal lenses that alternate between transparent and (nearly) opaque states via electric current.a mid-range opacity setting will be used to avoid extreme visual deprivation \[50,51\]. Plyometric training emphasizes the stretch-shortening cycle of the muscle-tendon complex, enhancing elastic capacity and neuromuscular responsiveness. Therefore, these exercises are often referred to as reactive neuromuscular training \[46\]. The program combines plyometric jumps and landings with balance-enhancing movements, all performed on the affected extremity. The program consists of three main phases: a warm-up, the main training session, and a cool-down. Exercise volume, repetitions, and rest intervals are systematically planned. Each set is followed by 15-30 seconds of rest. Intensity progresses from low to moderate throughout the program.

Other: Exercise stroboscopic

Control group

OTHER

The control group will continue with their routine training program and will not participate in any intervention.

Other: training

Interventions

Exercise stroboscopic OTHER

In this study, balance and plyometric exercises will be performed by one group using stroboscopic glasses.

The stroboscopic group

training OTHER

routine training program

Control group

Exercise OTHER

balance and plyometric exercises

The non-stroboscopic group

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• At least 5 years of active participation in any sports branch.
• At least two significant LAS incidents associated with inflammatory symptoms (pain, swelling).
• Most recent sprain occurred at least 3 months before study commencement.
• Feeling of ankle giving way at least twice in the past 6 months.
• No history of surgical intervention affecting lower extremity sensorimotor function and no history of ankle fractures.
• Cumberland Ankle Instability Tool (CAIT) score ≤25.
• Foot and Ankle Ability Measure (FAAM) score below 90%.
• FAAM Sports subscale score below 80%.

You may not qualify if:

• History of any ankle fracture.
• Surgical intervention or systemic disease affecting lower extremity sensorimotor function.
• History of neurological disorders.
• Acute musculoskeletal injury to the lower extremity within the last month.
• Visual or vestibular disorders affecting balance or coordination.

Sponsors & Collaborators

• Yeditepe University: lead

Study Sites (1)

Medipol University

Istanbul, Turkey (Türkiye)

Location

MeSH Terms

Interventions

Exercise

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 6, 2025
• First Posted: July 16, 2025
• Study Start: February 15, 2025
• Primary Completion: February 15, 2025
• Study Completion: February 15, 2025
• Last Updated: July 16, 2025

Record last verified: 2025-07

Locations

TU (1)