The Influence of Passive Local Muscle Vibration on Mechanical Power Output and Neuromuscular Activity During Counterbalanced RPE-clamped Cycling: A Randomized Controlled Trial

NCT07715292 | Enrolling By Invitation

• 1 other identifier: 28/12/KBPWr/EM_26/2024-2027
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to find out if applying mild mechanical vibration (100 Hz) to the the Achilles and patellar tendons before and during exercise can make cycling feel easier and help athletes generate more power. The researchers also want to test if a new, lightweight wearable sleeve called "Tendo" is just as effective at doing this as a stationary laboratory machine. The study will involve 40 healthy, active student-athletes aged 18 to 26. Each participant will attend three separate testing sessions in a laboratory, with at least 48 hours of rest between sessions. During each 85-minute session, participants will: Complete baseline resting measurements of their muscles and tendons. Ride a stationary exercise bicycle with a covered screen, adjusting their speed and pedaling based only on how hard they feel they are working, using a 0-100 effort scale called Borg CR100. Receive a 10-minute resting tendon vibration. Repeat the cycling test with a short "booster" vibration to see how their performance changes. To understand how the vibration works, the researchers will use harmless skin sensors to measure muscle activity (sEMG), a gentle tapping device to check tendon stiffness (MyotonPRO), and ultrasound imaging to look at tendon structure. Stationary Vibration: High-frequency (100 Hz) vibration from a fixed laboratory machine. Wearable Vibration: High-frequency (100 Hz) vibration from the portable Tendo sleeve. Sham Vibration: A low-frequency (15 Hz) vibration that does not trigger a physiological response, serving as a control to make sure the results are not just due to a placebo effect.

Conditions

Muscle Fatigue; Exertion, Perceived; Neuromuscular Activity; Athletic Performance

Keywords

Focal Muscle Vibration; Tendon Vibration; Rate of Perceived Exertion; BorgCR100; RPE-clamped; Cycling Performance; Tonic Vibration Reflex; Electromyography; Myotonometry; Wearable Technology; Sports Science; Neuromuscular Fatigue

Outcome Measures

Primary Outcomes (1)

• Mean Power Output

  The mean power output (measured in Watts) generated by the participant during the submaximal cycling task. The task is clamp-controlled based on a constant, pre-determined rate of perceived exertion (RPE) on the Borg CR100 scale. Since the perception of effort is kept constant (clamped), the changes in generated power output will reflect the actual physiological and performance efficacy of the focal muscle vibration compared to the sham condition.

  Continuous recording at 1 Hz, analyzed as the mean power output for each 3-minute block during the cycling task (specifically comparing blocks across the three experimental sessions).

Secondary Outcomes (2)

• Neuromuscular Activity

  Continuous recording during the cycling task, and static recordings with isometric contraction and with no contraction at baseline, immediately post-exercise, 15 minutes, and 30 minutes of recovery.

• Biomechanical and Viscoelastic Tissue Properties

  Recorded at baseline, immediately post-exercise, 15 minutes, and 30 minutes of recovery.

Other Outcomes (2)

• Tendon Morphological Structure (Ultrasound)

  Recorded at baseline, immediately post-exercise, 15 minutes, and 30 minutes of recovery.

• Physiological and Kinematic Strain

  Continuous recording during cycling task, recorded at baseline, immediately post-exercise, 15 minutes, and 30 minutes of recovery.

Study Arms (3)

Wearable Vibration

EXPERIMENTAL

Participants receive muscle vibration delivered via wearable Tendo device. The vibration is applied bilaterally to the Achilles and patellar tendons with a frequency of 100 Hz and an amplitude of 1 mm. This condition consists of a 10-minute resting pre-exercise stimulation followed by a 5-minute "booster" stimulation administered dynamically during movement midway through the cycling protocol to sustain the neurophysiological Tonic Vibration Reflex (TVR).

Device: Tendo device Vibrration; Device: Sham Muscle Vibration; Device: Laboratory control vibration

Laboratory Vibration (Active Control Reference)

ACTIVE COMPARATOR

Participants receive focal muscle vibration delivered via alabpooratory device. The vibration is applied bilaterally to the Achilles and patellar tendons with a frequency of 100 Hz and an amplitude of 1 mm. This condition consists of a 10-minute resting pre-exercise stimulation followed by a 5-minute resting "booster" stimulation administered midway through the cycling protocol to sustain the neurophysiological Tonic Vibration Reflex (TVR).

Device: Tendo device Vibrration; Device: Sham Muscle Vibration; Device: Laboratory control vibration

Sham Stimulation

SHAM COMPARATOR

Participants undergo an identical protocol but receive a low-frequency, non-therapeutic sham stimulation. The stimulation is applied bilaterally to the Achilles and patellar tendons via the Tendo device with a subminimal frequency of 15 Hz and an amplitude of 1 mm. This condition consists of a 10-minute resting pre-exercise sham stimulation followed by a 5-minute booster sham stimulation during the active cycling protocol to control for the acoustic noise, physical presence of the device, and potential placebo effects.

Device: Tendo device Vibrration; Device: Sham Muscle Vibration; Device: Laboratory control vibration

Interventions

Tendo device Vibrration DEVICE

Arm Description: Participants receive focal muscle vibration delivered via a lightweight, wearable Tendo system. The vibration is applied bilaterally to the Achilles and patellar tendons with a frequency of 100 Hz and an amplitude of 1 mm. This condition consists of a 10-minute resting pre-exercise stimulation followed by a 5-minute "booster" stimulation administered dynamically during movement midway through the cycling protocol to sustain the neurophysiological Tonic Vibration Reflex (TVR).

Laboratory Vibration (Active Control Reference); Sham Stimulation; Wearable Vibration

Sham Muscle Vibration DEVICE

Participants undergo an identical protocol but receive a low-frequency, non-therapeutic sham stimulation. The stimulation is applied bilaterally to the Achilles and patellar tendons via the Tendo sleeve with a subminimal frequency of 15 Hz and an amplitude of 1 mm. This condition consists of a 10-minute resting pre-exercise sham stimulation followed by a 5-minute booster sham stimulation during the active cycling protocol to control for the acoustic noise, physical presence of the device, and potential placebo effects.

Laboratory Vibration (Active Control Reference); Sham Stimulation; Wearable Vibration

Laboratory control vibration DEVICE

Participants receive focal muscle vibration delivered via a stationary laboratory device. The vibration is applied bilaterally to the Achilles and patellar tendons with a frequency of 100 Hz and an amplitude of 1 mm. This condition consists of a 10-minute resting pre-exercise stimulation followed by a 5-minute resting "booster" stimulation administered midway through the cycling protocol to sustain the neurophysiological Tonic Vibration Reflex (TVR).

Laboratory Vibration (Active Control Reference); Sham Stimulation; Wearable Vibration

Eligibility Criteria

• Age: 18 Years - 26 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age between 18 and 26 years
• Active student or doctoral student status at a higher education institution
• Active participation in sports training (endurance or mixed disciplines, e.g., cycling, running, triathlon, team sports) with a minimum frequency of 3 times per week, verified by a recruitment questionnaire.
• Good general health, with no medical contraindications to performing intense exercise testing on a cycle ergometer.
• Normal anatomical condition of the Achilles tendon and patellar ligament during baseline screening - no history of acute inflammation or ruptures.
• Provision of voluntary, written informed consent to participate in the study and for medical data processing.

You may not qualify if:

• Orthopedic and structural contraindications: Recent injuries in less than 6 months, joint ruptures, or surgical interventions in the lower limbs; chronic or acute inflammation of the Achilles tendon or patellar ligament; presence of metal implants or joint replacements in the stimulated limbs.
• Neurological contraindications: Diagnosed epilepsy or susceptibility to seizures, superficial or deep sensory impairment such as neuropathy, radiculopathy, that could impair stimulus evaluation or risk tissue damage.
• Cardiovascular contraindications: Diagnosed heart defects, unstable arterial hypertension, cardiac arrhythmias; presence of a pacemaker or implantable cardioverter-defibrillator, active thromboembolic diseases, deep vein thrombosis, or severe varicose veins of the lower limbs.
• General medical contraindications: Pregnancy; active oncological diseases; active infections or fever on the day of testing; dermatological changes, open wounds, or skin ulcers at the planned application sites of sEMG electrodes or Tendo vibration sleeves.
• Other: Regular intake of medications or substances that affect the threshold of pain or fatigue perception (e.g., strong analgesics, steroids, or pre-workout supplements containing high amounts of stimulants taken directly before the test).

Sponsors & Collaborators

• Wrocław University of Science and Technology: lead

Study Sites (1)

Medical Simulation Center, Faculty of Medicine, Wroclaw University of Science and Technology

Wroclaw, Lower Silesian Voivodeship, 50-370, Poland

Location

Related Publications (1)

• Marchand F, Pageaux B, Forestier N, Monjo F. Prolonged passive vibration of Achilles and patellar tendons decreases effort perception during subsequent cycling tasks. J Sport Health Sci. 2025 Dec;14:101061. doi: 10.1016/j.jshs.2025.101061. Epub 2025 May 24.

  PMID: 40419138 RESULT

Study Officials

• Szymon L Dragan, MD, PhD, Assoc. Prof.

  Faculty of Medicine, Wroclaw University of Science and Technology

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants are blinded to the specific intervention condition of each session (100 Hz active stationary vibration vs. 100 Hz active wearable vibration vs. 15 Hz subminimal sham stimulation). The sham stimulation is designed to mimic the acoustic noise and physical presence of the active wearable device but at a non-therapeutic frequency. Additionally, during all cycling blocks, the cycle ergometer monitor and feedback screens are covered. This ensures participants remain completely blinded to their real-time performance metrics (power output, cadence, and time), forcing them to regulate their effort solely based on internal, subjective perception (Borg CR100 scale). Complete investigator blinding is not possible due to the distinct physical setups of the stationary shaker and the wearable sleeve.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: dr hab. prof. uczelni Szymon Lukasz Dragan

Model Details: This is a randomized, counterbalanced, single-blind, three-arm crossover study. Each participant completes all three experimental conditions: 100 Hz stationary laboratory vibration, 100 Hz wearable vibration (Tendo sleeve), and 15 Hz subminimal sham stimulation. The order of the sessions is randomized for each participant prior to the first visit using a randomization generator sealedenvelope.com to eliminate systematic bias. A washout period of at least 48 hours is enforced between sessions to allow complete neuromuscular recovery and prevent any carryover effects.

Study Record Dates

• First Submitted: July 14, 2026
• First Posted: July 20, 2026
• Study Start: July 15, 2026
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): September 30, 2026
• Last Updated: July 20, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: The de-identified individual participant data and supporting documents (such as the study protocol and informed consent template) will become available immediately following the official publication of the primary manuscript in a peer-reviewed journal. These data will remain accessible for a period of 36 months (3 years) from the publication date.
• Access Criteria: Access will be restricted to qualified academic researchers and clinicians affiliated with recognized research institutions or universities who provide a methodologically sound research proposal. Approved applicants will receive access to the fully de-identified raw individual participant data including sEMG, MyotonPRO, and biomechanical parameters along with the blank informed consent form and study protocol. To request access, researchers must contact the corresponding author via their institutional email address. Requests will be evaluated by the study's scientific leadership. If approved, data will be shared via a secure, encrypted data transfer service after both parties sign a formal Data Use Agreement (DUA) to ensure participant confidentiality is strictly maintained.

Locations

PL (1)