Non-invasive Vibratory Stimulation of the Knee Muscles for the Improvement of the Somatosensory Input and Motor Performance

NCT07424066 | Recruiting

• 1 other identifier: Prot. Nr. 138/25
• Study Type: interventional
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this interventional cross-sectional study is to evaluate motor responses to non-invasive vibratory stimulation applied to the hamstring muscle tendons in healthy individuals. Knee flexion and extension efforts, in both isometric and concentric contractions, will be tested. The investigators hypothesize that vibratory stimulation causes an increase in activity in the flexor muscles (hamstrings) and a decrease in the extensor muscles (quadriceps) of the knee in all motor tasks. It follows that during knee flexion (both concentric and isometric), vibratory stimulation should cause an increase in the distance between the angular trajectories of the knee obtained with and without vibratory stimulation (with a positive sign). The increased activity of the hamstring muscles would, in fact, contribute to increasing the velocity of the flexor movement. Conversely, during extensor movements (both concentric and isometric), vibratory stimulation should reduce the instantaneous velocity of the movement, therefore causing an increase in distance (with a negative sign) between the trajectories obtained with and without stimulation. Participants will be tested using an isokinetic dynamometer and they will be asked to perform the following motor tasks in a random order: concentric knee flexion, concentric knee extension, isometric knee flexion, and isometric knee extension. The dominant limb will be tested, only. The assessment will be performed one time.

Conditions

Vibration

Keywords

vibratory stimulation; muscle spindle; muscle contraction; spinal reflex; somatosensory system

Outcome Measures

Primary Outcomes (2)

• Knee angle

  Maximum distance (in degrees) between the knee trajectory obtained with and without vibratory stimulation.

  Day 1.

• Surface electromyography (sEMG)

  Difference in sEMG between the muscle activity with and without vibratory stimulation, for each muscle (i.e., Quadriceps, Hamstrings, and Plantarflexor muscles).

  Day 1.

Study Arms (1)

Healthy participants

EXPERIMENTAL

Healthy participants will perform motor tasks with the dominant lower limb, consisting in knee flexion and extension movements in isometric and concentric conditions. The motor tasks will be performed while a vibratory stimulation is applied to hamstring tendons (treatment) and without vibratory stimulation (control) to assess motor responses.

Device: Vibratory stimulation

Interventions

Vibratory stimulation DEVICE

A vibratory stimulator will be applied to the back of the dominant leg, at the level of the hamstring muscle tendons. The stimulator consists of two small vibrating boxes fixed to the leg by means of an elastic band.

Healthy participants

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age equal to or greater than 18 years.

You may not qualify if:

• Neurological disorders.
• Musculoskeletal injuries, including previous ones, that may compromise the execution of required movements.
• Cardiorespiratory disorders.

Sponsors & Collaborators

• University of Milano Bicocca: lead
• Istituto Auxologico Italiano: collaborator

Study Sites (1)

Istituto Auxologico Italiano, Clinica Capitanio

Milan, Milan, 20122, Italy

RECRUITING

Study Officials

• Cristiano Alessandro, Engineering

  University of Milano Bicocca

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Stefano Scarano, Medical Doctor

CONTACT

+3902619116717; s.scarano@auxologico.it

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 6, 2026
• First Posted: February 20, 2026
• Study Start: May 20, 2025
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: February 20, 2026

Record last verified: 2025-10

Locations

IT (1)