VibrationSRMLNCT07253467
Load Dependent Modulation of Spinal Excitability: Linking H-Reflex Supression and Whole Body Vibration Induced Reflex Latency
A study testing Whole Body Vibration in people with Vibration and H-reflex, run by Istanbul Physical Medicine Rehabilitation Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
This study examines how different standing postures and whole-body vibration conditions affect spinal reflex activity. Participants will stand in various positions-with and without vibration of two amplitudes-and H-reflex responses from the soleus muscle will be recorded. Read more about this study
- Who is it for?
- Ages 25 to 50 yearsHealthy volunteers can take part
- What is being tested?
- Whole Body Vibration
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 21 Nov 2025to 30 Dec 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy adults between 25 and 50 years of age
- Individuals willing to participate and able to provide informed consent
- Individuals who can stand independently for at least 10 minutes
- Participants with no known neurological, orthopedic, or balance impairments
Who cannot join
- Individuals who can not tolerate WBV
- Individuals who can not tolerate electrical stimulation
- Pregnancy
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Istanbul Physical Medicine Rehabilitation Training and Research Hospital
Istanbul, Bahçelievler, 34158
About this study
This study examines how different standing postures and whole-body vibration conditions affect spinal reflex activity. Participants will stand in various positions-with and without vibration of two amplitudes-and H-reflex responses from the soleus muscle will be recorded. Additionally, vibration-induced reflex latency will be assessed across multiple vibration frequencies.
Read the detailed description
Participants will engage in a structured set of experimental tasks designed to evaluate the effects of postural mechanical loading, and whole-body vibration.
The protocol includes four primary standing conditions:
Quiet bipedal stance,
Single-leg stance on the left side,
Bipedal stance during whole-body vibration (WBV), and
Single-leg stance on the left side during WBV.
During all WBV conditions, two vibration amplitudes-2.2 mm and 1.2 mm-will be applied sequentially to assess amplitude-dependent modulation of reflex responses.
Throughout each condition, H-reflex recordings from the soleus muscle will be collected to quantify changes in spinal reflex excitability under varying postural and vibratory loads. In addition to these measurements, vibration-induced reflex latency will be evaluated by delivering vibratory stimuli at multiple frequencies (30, 32, 34, and 36 Hz) within the same experimental protocol. This approach allows for a comprehensive analysis of how both posture and vibratory parameters influence neuromuscular reflex pathways.
The investigators conducted an a priori power analysis for a repeated-measures ANOVA (within-subjects design) to determine the required sample size. The analysis was based on a medium expected effect size, specified as partial eta squared (ηₚ²) = 0.06, which corresponds to an effect size of f = 0.25. The investigators set the alpha error probability at 0.05 and the desired statistical power (1-β) at 0.80. The design included one group with five repeated measurements, assuming a correlation of 0.70 among repeated measures. Under these conditions, the critical F value was 2.5652405, with 4 numerator degrees of freedom and 48 denominator degrees of freedom. The power analysis indicated that a total sample size of 13 participants is required. The required sample size was calculated using G*Power version 3.1.9.4 (Franz Faul, University of Kiel, Germany).
- Being tested
- Whole Body Vibration
- Keywords
- H-Reflex, Whole Body Vibration, Bone Myoregulation Reflex, Reflex Latency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Whole Body VibrationOther
Whole Body Vibration (WBV) is a neuromuscular training modality in which patients stand, sit, or exercise on a platform that delivers mechanical oscillations (30-36 Hz, 1-2 mm amplitude). While WBV is applied H-Reflex tests are done.
| Study group | Role | What they receive |
|---|---|---|
| Healthy participants | Experimental | Participants will complete a series of experimental tasks involving postural mechanical and vibrational loading. The protocol consists of quiet standing on both feet, single-leg standing on the left side, standing during whole-body vibration (WBV), and single-leg standing on the left side during WBV. Vibration amplitudes of 2.2 mm and 1.2 mm will be applied in each condition. H-reflex measurements will be recorded from the soleus muscle throughout all tasks to evaluate alterations in spinal reflex excitability. Vibration induced reflex latency will be also measured with different vibration frequencies (30-32-34-36) also measured in the same protocol. Receives: Other: Whole Body Vibration |
What is being measured
The primary outcome is the main question the study is designed to answer.
Whole Body Vibration induced reflex latency
WBV induced reflex latency will be measured
Measured: Day 1 (single-session, during each experimental condition)
H-Reflex Size
Peak to peak amplitude of the H-Reflex will be measured
Measured: Day 1 (single-session, during each experimental condition)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Nov 2025
- Study start21 Nov 2025
- Primary completion8 Dec 2025
- Study completion30 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for VibrationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- Istanbul Physical Medicine Rehabilitation Training and Research Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, İsmet Alkım Özkan, Istanbul Physical Medicine Rehabilitation Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07253467
- Sponsor's protocol ID
- IstPRMTRH2A
- Acronym
- SRML
- Status last verified
- Mar 2026
- First submitted
- 19 Nov 2025
- Last updated
- 25 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 25 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Load Dependent Modulation of Spinal Excitability: Linking H-Reflex Supression and Whole Body Vibration Induced Reflex Latency
- ClinicalTrials.gov ID
- NCT07253467
- Acronym / sponsor ID
- SRML / IstPRMTRH2A
- Keywords
- H-Reflex, Whole Body Vibration, Bone Myoregulation Reflex, Reflex Latency
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- Istanbul Physical Medicine Rehabilitation Training and Research HospitalOther government
- Study start
- 21 Nov 2025 (actual)
- Primary completion
- 8 Dec 2025 (actual)
- Study completion
- 30 Dec 2025 (actual)
- First posted
- 28 Nov 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study examines how different standing postures and whole-body vibration conditions affect spinal reflex activity. Participants will stand in various positions-with and without vibration of two amplitudes-and H-reflex responses from the soleus muscle will be recorded. Additionally, vibration-induced reflex latency will be assessed across multiple vibration frequencies.
Detailed description
Participants will engage in a structured set of experimental tasks designed to evaluate the effects of postural mechanical loading, and whole-body vibration.
The protocol includes four primary standing conditions:
Quiet bipedal stance,
Single-leg stance on the left side,
Bipedal stance during whole-body vibration (WBV), and
Single-leg stance on the left side during WBV.
During all WBV conditions, two vibration amplitudes-2.2 mm and 1.2 mm-will be applied sequentially to assess amplitude-dependent modulation of reflex responses.
Throughout each condition, H-reflex recordings from the soleus muscle will be collected to quantify changes in spinal reflex excitability under varying postural and vibratory loads. In addition to these measurements, vibration-induced reflex latency will be evaluated by delivering vibratory stimuli at multiple frequencies (30, 32, 34, and 36 Hz) within the same experimental protocol. This approach allows for a comprehensive analysis of how both posture and vibratory parameters influence neuromuscular reflex pathways.
The investigators conducted an a priori power analysis for a repeated-measures ANOVA (within-subjects design) to determine the required sample size. The analysis was based on a medium expected effect size, specified as partial eta squared (ηₚ²) = 0.06, which corresponds to an effect size of f = 0.25. The investigators set the alpha error probability at 0.05 and the desired statistical power (1-β) at 0.80. The design included one group with five repeated measurements, assuming a correlation of 0.70 among repeated measures. Under these conditions, the critical F value was 2.5652405, with 4 numerator degrees of freedom and 48 denominator degrees of freedom. The power analysis indicated that a total sample size of 13 participants is required. The required sample size was calculated using G*Power version 3.1.9.4 (Franz Faul, University of Kiel, Germany).
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Healthy participants | Experimental | Other: Whole Body VibrationParticipants will complete a series of experimental tasks involving postural mechanical and vibrational loading. The protocol consists of quiet standing on both feet, single-leg standing on the left side, standing during whole-body vibration (WBV), and single-leg standing on the left side during WBV. Vibration amplitudes of 2.2 mm and 1.2 mm will be applied in each condition. H-reflex measurements will be recorded from the soleus muscle throughout all tasks to evaluate alterations in spinal reflex excitability. Vibration induced reflex latency will be also measured with different vibration frequencies (30-32-34-36) also measured in the same protocol. |
Who may qualify
- Ages
- 25 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Healthy adults between 25 and 50 years of age
- Individuals willing to participate and able to provide informed consent
- Individuals who can stand independently for at least 10 minutes
- Participants with no known neurological, orthopedic, or balance impairments
Key exclusion criteria (3 listed)
- Individuals who can not tolerate WBV
- Individuals who can not tolerate electrical stimulation
- Pregnancy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Whole Body VibrationWhole Body Vibration (WBV) is a neuromuscular training modality in which patients stand, sit, or exercise on a platform that delivers mechanical oscillations (30-36 Hz, 1-2 mm amplitude). While WBV is applied H-Reflex tests are done. | Other | Healthy participants |
Primary outcome
Whole Body Vibration induced reflex latency
Time frame: Day 1 (single-session, during each experimental condition)
WBV induced reflex latency will be measured
H-Reflex Size
Time frame: Day 1 (single-session, during each experimental condition)
Peak to peak amplitude of the H-Reflex will be measured
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Mar 2026.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Whole Body Vibration in people with Vibration and H-reflex, run by Istanbul Physical Medicine Rehabilitation Training and Research Hospital at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 25 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Whole Body Vibration induced reflex latency (time frame: Day 1 (single-session, during each experimental condition)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Mar 2026.