MedTrace Logo

Effect of Mechanical Loading and Bone Loss on Motor Neuron Activity-H-Reflex Relationship

NCT07253493 · Status: RECRUITING · Phase: NA · Type: INTERVENTIONAL · Enrollment: 24

Last updated 2025-11-28

No results posted yet for this study

Summary

Weight-bearing exercises (e.g., running, jumping, whole-body vibration) are widely practiced due to their beneficial effects on bone development and their role in the prevention and treatment of osteoporosis. However, the underlying neuroregulatory mechanisms responsible for these positive effects have not yet been fully understood. Two main neuromodulatory mechanisms have been proposed in the literature: (i) spinal reflexes originating from muscle spindles (stretch reflex, tonic vibration reflex), and (ii) the bone myoregulation reflex (BMR) based on load-sensitive osteocytes.

It is well established that increased voluntary contraction and the associated rise in background EMG activity, that is, motor neuron pool activity, enhance muscle spindle-based reflex responses (such as the H-reflex and tendon reflex). In contrast, it has been demonstrated that the H-reflex is suppressed during bone-loading activities such as single-leg stance, jumping, or whole-body vibration.

This study is based on two hypotheses:

* As mechanical loading increases, Ia inhibitory effects intensify, leading to greater H-reflex suppression.
* During whole-body vibration, the H-reflex is suppressed due to Ia inhibition.

If this inhibition originates from load-sensitive receptors-osteocytes-and thus from the BMR, then in osteoporosis, where osteocyte number and function are reduced, H-reflex suppression will be diminished.

The aim of this research is to test these hypotheses. Confirmation of these assumptions would suggest that reflex control during weight-bearing exercise occurs predominantly through osteocyte-mediated BMR mechanisms rather than muscle spindle-based mechanisms such as the stretch or tonic vibration reflex.

Conditions

  • Osteoporosis Postmenopausal

Interventions

DIAGNOSTIC_TEST

H-reflex

H-reflex will be measured during 5 different mechanical loads and whole body vibration.

DIAGNOSTIC_TEST

Bone myoregulation reflex

Bone myoregulation reflex will be measured by applying 10 seconds whole body vibration of 4 different frequencies.

Sponsors & Collaborators

  • Istanbul Physical Medicine Rehabilitation Training and Research Hospital

    lead OTHER_GOV

Principal Investigators

  • İlhan Karacan, Prof. Dr. · stanbul Physical Medicine Rehabilitation Training and Research Hospital

Study Design

Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Model
SINGLE_GROUP

Eligibility

Min Age
18 Years
Max Age
65 Years
Sex
FEMALE
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2025-11-18
Primary Completion
2026-03-31
Completion
2026-04-30

Countries

  • Turkey (Türkiye)

Study Locations

More Related Trials

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT07253493 on ClinicalTrials.gov