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

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

Interventions

DEVICE

Tendo device Vibrration

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).

DEVICE

Sham Muscle Vibration

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.

DEVICE

Laboratory control vibration

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).

Sponsors & Collaborators

• Wrocław University of Science and Technology

  lead OTHER

Principal Investigators

• Szymon L Dragan, MD, PhD, Assoc. Prof. · Faculty of Medicine, Wroclaw University of Science and Technology

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

26 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-07-15

Primary Completion

2026-08-30

Completion

2026-09-30

Countries

• Poland

Study Locations