NCT07542457

Brief Summary

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.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
30

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Jun 2025

Shorter than P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

June 30, 2025

Completed
2 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 30, 2025

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

August 30, 2025

Completed
8 months until next milestone

First Submitted

Initial submission to the registry

April 14, 2026

Completed
7 days until next milestone

First Posted

Study publicly available on registry

April 21, 2026

Completed
Last Updated

April 21, 2026

Status Verified

April 1, 2026

Enrollment Period

2 months

First QC Date

April 14, 2026

Last Update Submit

April 14, 2026

Conditions

Keywords

VolleyballStroboscopic visual trainingBalanceProprioception

Outcome Measures

Primary Outcomes (1)

  • 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 Outcomes (1)

  • Proprioception

    Proprioception was assessed before the exercise program and after the 6-week intervention.

Study Arms (2)

Stroboscopic visual training

EXPERIMENTAL

Volleyball training sessions were performed with the use of stroboscopic glasses.

Other: Stroboscopic visual training

control group

ACTIVE COMPARATOR

The volleyball training program was implemented under normal visual conditions.

Other: control group C

Interventions

Volleyball training was conducted using stroboscopic glasses.

Stroboscopic visual training

The volleyball training program was implemented under normal visual conditions.

control group

Eligibility Criteria

Age12 Years - 18 Years
Sexmale
Healthy VolunteersYes
Age GroupsChild (0-17), Adult (18-64)

You may qualify if:

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

You may not qualify if:

  • 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.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Sakarya Uygulamalı Bilimler Üniversitesi

Adapazarı, Sakarya, 54400, Turkey (Türkiye)

Location

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
OUTCOMES ASSESSOR
Masking Details
The data analyst was blinded to group allocation.
Purpose
OTHER
Intervention Model
PARALLEL
Model Details: 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.
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Research Assisstant

Study Record Dates

First Submitted

April 14, 2026

First Posted

April 21, 2026

Study Start

June 30, 2025

Primary Completion

August 30, 2025

Study Completion

August 30, 2025

Last Updated

April 21, 2026

Record last verified: 2026-04

Data Sharing

IPD Sharing
Will share
Shared Documents
STUDY PROTOCOL

Locations