Effects of SVT on Balance and Proprioception (Effects of SVT)

Effects of Stroboscopic Visual Training on Balance and Proprioception in Adolescent Male Volleyball Players: A Controlled Study

This study was conducted to scientifically investigate the effects of a training program utilizing stroboscopic glasses on balance and proprioceptive performance in adolescent male volleyball players. A quantitative research approach was adopted, and a pre-test-post-test experimental design with a control group was employed to rigorously examine the cause-effect relationships between variables.

The study sample consisted of 30 adolescent male volleyball players aged between 12 and 18 years. Inclusion criteria required participants to have been licensed volleyball players for at least one year and to be regularly engaged in training sessions at least twice per week. To ensure objectivity, participants were randomly assigned, using a computer-based randomization method, into an experimental group (n = 15) and a control group (n = 15).

The experimental intervention lasted six weeks and was specifically designed to complement volleyball-specific technical training. Both groups participated in training sessions twice per week, at the same time of day and with identical training volumes. Within the stroboscopic visual stimulus protocol, athletes in the experimental group used stroboscopic glasses continuously for a total of 2.5 minutes during each training session. This 150-second exposure was determined to encourage athletes to rely more heavily on proprioceptive and vestibular mechanisms under conditions of reduced visual input. The glasses, equipped with LED-filtered lenses that alternated between transparent and opaque states at specific frequencies, manipulated the transmission of visual information to the central nervous system, thereby forcing athletes to maintain motor control with limited visual input. In contrast, the control group completed the same 2.5-minute segment and the entire training protocol under normal visual conditions, without any visual restriction.

All training sessions were conducted in an indoor sports facility under the supervision of an experienced coach, ensuring a controlled environment free from external disturbances. Athletes' fatigue levels, adherence to the protocol, and overall health status were monitored on a session-by-session basis. Following the completion of the six-week intervention, both groups underwent post-intervention assessments to determine the effects of the training program on performance parameters.

Dynamic balance performance was evaluated using the Y Balance Test, a widely accepted and validated assessment tool in the literature. During testing, participants performed barefoot while maintaining single-leg stance on the dominant limb and reaching as far as possible with the contralateral limb in the anterior, posteromedial, and posterolateral directions. The best score from three trials in each direction was recorded. All reach distances were normalized to limb length to minimize the influence of anthropometric differences.

Proprioception was assessed through joint position sense and movement perception tests. During these assessments, participants' vision was occluded to eliminate visual input and isolate somatosensory function. The extremity was passively positioned at predetermined target angles by the researcher, and participants were then asked to actively reproduce the same position. The absolute angular difference between the target and reproduced positions was measured in degrees using a goniometer and recorded as the "proprioceptive error score."

Data collection was completed in two phases: baseline measurements conducted prior to the intervention (pre-test) and follow-up measurements performed after the six-week training program (post-test).

The findings of this study indicate that conventional volleyball training significantly improves both static and dynamic balance performance. However, stroboscopic visual training appears to produce more pronounced and selective improvements in proprioceptive awareness. These results suggest that, rather than directly enhancing overall performance outcomes, stroboscopic training may serve as an effective tool for targeting sensory-motor subcomponents that underpin athletic performance.

Study Overview

• Status: Completed
• Conditions: Proprioception; Balance; Volleyball; Stroboscopic Visual Training
• Intervention / Treatment: Other: Stroboscopic visual training; Other: control group C

Detailed Description

This study was conducted to scientifically investigate the effects of a training program utilizing stroboscopic glasses on balance and proprioceptive performance in adolescent male volleyball players. A quantitative research approach was adopted, and a pre-test-post-test experimental design with a control group was employed to rigorously examine the cause-effect relationships between variables.

The study sample consisted of 30 adolescent male volleyball players aged between 12 and 18 years. Inclusion criteria required participants to have been licensed volleyball players for at least one year and to be regularly engaged in training sessions at least twice per week. To ensure objectivity, participants were randomly assigned, using a computer-based randomization method, into an experimental group (n = 15) and a control group (n = 15).

The experimental intervention lasted six weeks and was specifically designed to complement volleyball-specific technical training. Both groups participated in training sessions twice per week, at the same time of day and with identical training volumes. Within the stroboscopic visual stimulus protocol, athletes in the experimental group used stroboscopic glasses continuously for a total of 2.5 minutes during each training session. This 150-second exposure was determined to encourage athletes to rely more heavily on proprioceptive and vestibular mechanisms under conditions of reduced visual input. The glasses, equipped with LED-filtered lenses that alternated between transparent and opaque states at specific frequencies, manipulated the transmission of visual information to the central nervous system, thereby forcing athletes to maintain motor control with limited visual input. In contrast, the control group completed the same 2.5-minute segment and the entire training protocol under normal visual conditions, without any visual restriction.

All training sessions were conducted in an indoor sports facility under the supervision of an experienced coach, ensuring a controlled environment free from external disturbances. Athletes' fatigue levels, adherence to the protocol, and overall health status were monitored on a session-by-session basis. Following the completion of the six-week intervention, both groups underwent post-intervention assessments to determine the effects of the training program on performance parameters.

Dynamic balance performance was evaluated using the Y Balance Test, a widely accepted and validated assessment tool in the literature. During testing, participants performed barefoot while maintaining single-leg stance on the dominant limb and reaching as far as possible with the contralateral limb in the anterior, posteromedial, and posterolateral directions. The best score from three trials in each direction was recorded. All reach distances were normalized to limb length to minimize the influence of anthropometric differences.

Proprioception was assessed through joint position sense and movement perception tests. During these assessments, participants' vision was occluded to eliminate visual input and isolate somatosensory function. The extremity was passively positioned at predetermined target angles by the researcher, and participants were then asked to actively reproduce the same position. The absolute angular difference between the target and reproduced positions was measured in degrees using a goniometer and recorded as the "proprioceptive error score."

Data collection was completed in two phases: baseline measurements conducted prior to the intervention (pre-test) and follow-up measurements performed after the six-week training program (post-test).

The findings of this study indicate that conventional volleyball training significantly improves both static and dynamic balance performance. However, stroboscopic visual training appears to produce more pronounced and selective improvements in proprioceptive awareness. These results suggest that, rather than directly enhancing overall performance outcomes, stroboscopic training may serve as an effective tool for targeting sensory-motor subcomponents that underpin athletic performance.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Sakarya
    • Adapazarı, Sakarya, Turkey (Türkiye), 54400
      • Sakarya Uygulamalı Bilimler Üniversitesi

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• To have been a licensed volleyball player for at least one year.
• To participate in a regular training program at least twice per week.

Exclusion Criteria:

• A history of epilepsy, migraine, or photosensitive reactions.
• To have undergone a surgical procedure involving the upper or lower extremity within the past year.
• To have an acute injury that would prevent compliance with the tests.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Stroboscopic visual training; Volleyball training sessions were performed with the use of stroboscopic glasses.	Other: Stroboscopic visual training; Volleyball training was conducted using stroboscopic glasses.
Active Comparator: control group; The volleyball training program was implemented under normal visual conditions.	Other: control group C; The volleyball training program was implemented under normal visual conditions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Balance	Dynamic balance performance was evaluated using the Y Balance Test, a widely accepted and validated assessment tool in the literature. During testing, participants performed barefoot while maintaining single-leg stance on the dominant limb and reaching as far as possible with the contralateral limb in the anterior, posteromedial, and posterolateral directions. The best score from three trials in each direction was recorded. All reach distances were normalized to limb length to minimize the influence of anthropometric differences.	Dynamic balance was assessed before the exercise program and after the 6-week intervention.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proprioception	Proprioception was assessed through joint position sense and movement perception tests. During these assessments, participants' vision was occluded to eliminate visual input and isolate somatosensory function. The extremity was passively positioned at predetermined target angles by the researcher, and participants were then asked to actively reproduce the same position. The absolute angular difference between the target and reproduced positions was measured in degrees using a goniometer and recorded as the "proprioceptive error score.	Proprioception was assessed before the exercise program and after the 6-week intervention.

Collaborators and Investigators

• Sponsor: Hacettepe University

Study record dates

Study Major Dates

• Study Start (Actual): June 30, 2025
• Primary Completion (Actual): August 30, 2025
• Study Completion (Actual): August 30, 2025

Study Registration Dates

• First Submitted: April 14, 2026
• First Submitted That Met QC Criteria: April 14, 2026
• First Posted (Actual): April 21, 2026

Study Record Updates

• Last Update Posted (Actual): April 21, 2026
• Last Update Submitted That Met QC Criteria: April 14, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Balance; Proprioception; Volleyball; Stroboscopic visual training
• Other Study ID Numbers: SUBU 6

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No