How mechanical loading and bone loss change motor neuron reflexes

The Effect of Mechanical Loading and Bone Loss on the Relationship Between Motor Neuron Pool Activity and H-Reflex Amplitude

Not applicable Interventional Istanbul Physical Medicine Rehabilitation Training and Research Hospital · NCT07253493

This study will test whether weight-bearing activities and whole-body vibration change spinal reflex (H-reflex) responses in postmenopausal women with and without osteoporosis.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment24 (estimated)
Ages18 Years to 65 Years
SexFemale
SponsorIstanbul Physical Medicine Rehabilitation Training and Research Hospital Government
Locations1 site (Bahçelievler, Istanbul)
Trial IDNCT07253493 on ClinicalTrials.gov

What this trial studies

Researchers will record soleus muscle EMG, platform acceleration, and heel force while participants stand on a vibration platform to measure changes in the H-reflex under different mechanical loading conditions. A stimulating electrode will be placed over the tibial nerve to elicit the H-reflex while data are sampled at 2 kHz and analyzed using Spike2 software. The trial compares postmenopausal women with femoral osteoporosis to age-matched controls without osteopenia, excluding those with neurologic, muscular, significant lower-extremity pain, cardiac arrhythmias, or current osteoporosis treatment. Data will test whether load-sensitive bone signaling and muscle spindle reflex mechanisms correspond with suppressed or enhanced H-reflex responses during bone-loading activities.

Who should consider this trial

Good fit: Ideal candidates are postmenopausal women under age 65 who either have femoral osteoporosis (T-score ≤ -2.5) or have normal bone density, who are not on osteoporosis treatment and have no neurologic, muscular, cardiac, or active painful lower-extremity conditions.

Not a fit: Patients with central or peripheral nervous system disorders, myopathies, active lower-extremity pain, cardiac arrhythmias, current osteoporosis therapy, skin lesions at electrode sites, or older than 65 are unlikely to benefit or be eligible.

Why it matters

Potential benefit: If successful, the results could help tailor weight-bearing or vibration-based exercise approaches to better protect bone health by clarifying the neural mechanisms involved.

How similar studies have performed: Prior studies have shown H-reflex suppression during bone-loading activities and have proposed a bone myoregulation reflex, but the precise neuroregulatory mechanisms remain incompletely established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Being in the postmenopausal period
* For the osteoporosis group: having femoral osteoporosis (femoral neck or total femur T-score ≤ -2.5)
* For the control group: having no osteoporosis or osteopenia (femoral neck and total femur T-scores \> -1, and L1-L4 and L2-L4 T-scores \> -1)
* Being a volunteer

Exclusion Criteria:

* Receiving osteoporosis treatment
* Having a peripheral or central nervous system disorder (e.g., stroke, polyneuropathy, radiculopathy, entrapment neuropathy, etc.)
* Having acquired or hereditary muscle diseases (myopathies)
* Having active painful lower extremity pathologies (e.g., osteoarthritis, inflammatory joint diseases, etc.)
* Having cardiac arrhythmias
* Having a history of other metabolic bone diseases
* Having skin lesions at the electrode placement sites on the lower extremities
* Being older than 65 years

Where this trial is running

Bahçelievler, Istanbul

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Osteoporosis PostmenopausalH-reflexosteoporosiswhole-body vibrationmechanical loadosteocytebone myoregulation reflexbackground EMG activity
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.