WBV Reflex Latency and Mechanical Load (WBV-BMR)

September 24, 2025 updated by: Selim Sezikli

Effect of Mechanical Load Magnitude on Reflex Latency Induced by Whole-Body Vibration: A Latency-Based Evaluation of Bone Myoregulation Reflex and Tonic Vibration Reflex

This study aims to investigate how the magnitude of mechanical loading affects reflex latency patterns induced by whole-body vibration (WBV). WBV can trigger two types of reflexes: the tonic vibration reflex (TVR) and the bone myoregulation reflex (BMR), which may be influenced by load-bearing condition. The study will include healthy adult volunteers aged 20-50 years. Reflex responses will be recorded from the soleus muscle using surface EMG during both WBV. Different conditions of mechanical loading (i.e., standing on one foot, both feet) and vibration frequencies (30-36 Hz) will be tested. The main outcome will be the latency of the reflex responses, which will help distinguish between TVR and BMR activation. The goal is to better understand how mechanical load modifies reflex response timing and to characterize the underlying afferent pathways. This knowledge may contribute to optimizing vibration-based rehabilitation strategies.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This study investigates how the magnitude of mechanical loading alters reflex latency patterns during whole-body vibration (WBV), focusing specifically on the tonic vibration reflex (TVR) and the bone myoregulation reflex (BMR). Experimental data suggest that WBV may activate different reflex mechanisms depending on the level of postural loading, frequency, and amplitude of the vibration. Previous studies have shown that low-amplitude WBV tends to activate TVR under voluntary contraction, while higher mechanical loads and neutral standing posture are more likely to induce BMR.

Surface electromyography (sEMG) recordings will be obtained from the soleus muscle during vibration stimuli applied at different frequencies (30, 32, 34, and 36 Hz). Recordings will be taken under multiple loading conditions: standing on both feet, standing on one foot. Reflex latency will be calculated using cumulative averaging techniques, and data will be analyzed offline using Spike2 software.

Findings from this study may contribute to a deeper understanding of reflex integration during vibratory stimulation and inform future neurorehabilitation protocols that utilize WBV as a therapeutic modality.

Study Type

Interventional

Enrollment (Actual)

36

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey (Türkiye)
    • Istanbul
      • Istanbul, Istanbul, Turkey (Türkiye), 34186
        • Istanbul Physical Medicine and Rehabilitation Training and Research Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Aged between 18 and 40 years
  • Healthy adult volunteers with no known neurological or musculoskeletal disorders
  • Able to provide informed consent
  • Willing to comply with the procedures of the study, including EMG and vibration exposure

Exclusion Criteria:

  • History of any neurological condition (e.g., peripheral neuropathy, spinal cord injury, stroke)
  • Musculoskeletal injury or surgery involving the lower extremities
  • Use of medications affecting neuromuscular function
  • Pregnancy
  • Presence of implanted electronic devices (e.g., pacemaker)
  • Known intolerance to vibration exposure

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Whole-Body Vibration in Healthy Volunteers
Participants will receive whole-body vibration (WBV) under mechanical loading conditions. Surface EMG recordings from the soleus muscle will be used to evaluate reflex latency at vibration frequencies of 30, 32, 34, and 36 Hz. All interventions will be applied in a single-session experimental design in healthy adult volunteers.
Device: Whole-Body Vibration
Participants will receive whole-body vibration (WBV) at 30-36 Hz under different mechanical loading conditions (e.g., standing on one foot, both feet,). Vibration-induced reflex responses will be recorded from the soleus muscle using surface electromyography. The intervention is designed to evaluate latency differences between tonic vibration reflex (TVR) and bone myoregulation reflex (BMR) under controlled biomechanical scenarios.
Other Names:
  • WBV
  • Reflex Latency Vibration Protocol

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Reflex latency (milliseconds) in the soleus muscle during vibration stimulation
Time Frame: Day 1 (single-session, during each experimental condition)
Reflex latency will be calculated based on surface EMG recordings from the soleus muscle during whole-body vibration at frequencies of 30-36 Hz. Latency will be analyzed using cumulative averaging techniques and expressed in milliseconds.
Day 1 (single-session, during each experimental condition)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Reflex type classification (TVR vs BMR) based on latency and mechanical load
Time Frame: Day 1 (single-session, during each experimental condition)
Reflex responses will be categorized as tonic vibration reflex (TVR) or bone myoregulation reflex (BMR) based on latency values and mechanical loading condition. Classification will be supported by comparisons of reflex latency and EMG suppression patterns across experimental conditions.
Day 1 (single-session, during each experimental condition)
Reflex latency variability under different mechanical loading conditions
Time Frame: Day 1 (single-session, during each experimental condition)
Variability in reflex latency will be assessed across different postural load conditions (e.g., single-leg, double-leg, prone) to determine how load magnitude influences the consistency of reflex timing. Standard deviation and coefficient of variation will be calculated for each condition.
Day 1 (single-session, during each experimental condition)
Effect of vibration frequency on reflex latency and amplitude
Time Frame: Day 1 (single-session, during each experimental condition)
Reflex latency and EMG amplitude will be compared across vibration frequencies (30, 32, 34, and 36 Hz) to investigate frequency-dependent modulation of neuromuscular responses in the soleus muscle.
Day 1 (single-session, during each experimental condition)
EMG amplitude of reflex response in the soleus muscle during vibration stimulation
Time Frame: Day 1 (single-session, during each experimental condition)
The magnitude of EMG response during whole-body vibration will be recorded from the soleus muscle. Reflex amplitude differences will be analyzed across various postural loading conditions to evaluate suppression or facilitation effects.
Day 1 (single-session, during each experimental condition)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Selim Sezikli

Investigators

  • Principal Investigator: Selim Sezikli, MD, Istanbul Physical Medicine and Rehabilitation Training and Research Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 2, 2025

Primary Completion (Actual)

September 20, 2025

Study Completion (Actual)

September 24, 2025

Study Registration Dates

First Submitted

August 29, 2025

First Submitted That Met QC Criteria

September 5, 2025

First Posted (Estimated)

September 12, 2025

Study Record Updates

Last Update Posted (Estimated)

September 29, 2025

Last Update Submitted That Met QC Criteria

September 24, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • WBV-BMR-2025-01
  • 2017.124.IRB2.038 (Other Identifier: Koç University IRB)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Following publication of the main study results, de-identified individual participant data (IPD) and relevant supporting documents will be made available to qualified researchers upon submission of a valid research proposal. Data will be provided exclusively for research purposes and under a formal data sharing agreement.

IPD Sharing Time Frame

Data will be available beginning 6 months after the primary publication and will remain accessible for 5 years. Access will be granted on a case-by-case basis following review of a research proposal and execution of a formal data-sharing agreement.

IPD Sharing Access Criteria

Access will be limited to qualified researchers who submit a request for a research project that has received prior ethical approval and who agree to comply with the study's confidentiality principles. Data access will be granted through a formal data-sharing agreement executed between the requesting researcher and the study sponsor or relevant institution. The agreement will specify the intended purpose of data use, the duration of access, and the confidentiality obligations. Shared data will consist of de-identified individual participant data (IPD), with all potentially identifying information removed. Supporting documents such as the study protocol, statistical analysis plan, and analytic code will also be provided to promote research transparency.

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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