Project Tendura: The Impact of Blood Flow Restriction Resistance Training (BFR-RT) in Patients With Achilles Tendon Rupture (ATR) Repair

Summary

The goal of this clinical trial is to determine whether blood flow restriction resistance training (BFR-RT) improves postoperative muscle recovery and functional outcomes following primary surgical repair of acute Achilles tendon rupture (ATR) in adults undergoing standard rehabilitation. The main questions it aims to answer are:

Does patient-specific BFR-RT improve ankle plantarflexion strength recovery compared with sham BFR-RT or standard rehabilitation alone?

Does BFR-RT improve gastrocnemius-soleus muscle morphology and patient-reported functional outcomes following ATR repair?

Researchers will compare (1) BFR-RT combined with standard physical therapy, (2) sham BFR-RT combined with standard physical therapy, and (3) standard physical therapy alone to determine whether BFR-RT enhances muscle recovery, functional outcomes, and return-to-activity timelines following surgical ATR repair.

Participants will:

Be randomized to BFR-RT + standard physical therapy, sham BFR-RT + standard physical therapy, or standard physical therapy alone

Perform supervised rehabilitation exercises using a personalized tourniquet system calibrated to limb occlusion pressure (LOP) depending on group allocation

Undergo isometric ankle plantarflexion strength testing using the Fysiometer platform

Receive ultrasound imaging of the gastrocnemius-soleus complex to assess muscle cross-sectional area

Complete patient-reported outcome measures assessing pain and physical function

Attend follow-up evaluations at 6 weeks, 3 months, 4.5 months, 6 months, and 12 months postoperatively

Conditions

• Achilles Tendon Rupture
• Blood Flow Restriction Therapy
• Achilles Tendon Repairs/Reconstructions
• Dynamic Blood Flow Restriction

Interventions

DEVICE

Blood Flow Restriction Resistance Training (BFR-RT)

Blood flow restriction resistance training will be performed using the Delfi Personalized Tourniquet System applied to the affected limb during supervised rehabilitation exercises. The device automatically determines limb occlusion pressure (LOP) and applies 80% of LOP during low-load resistance exercises. This controlled vascular restriction produces metabolic stress intended to stimulate muscle hypertrophy and strength recovery while minimizing mechanical load on the healing Achilles tendon. Sessions are conducted under physiotherapist supervision within the standardized postoperative rehabilitation protocol.

DEVICE

Sham Blood Flow Restriction

Participants assigned to the sham group will wear the Delfi tourniquet cuff during rehabilitation sessions; however, cuff pressure will be inflated only to 20 mmHg, a level insufficient to induce vascular occlusion. This condition mimics the experience of the intervention device while avoiding physiologic blood flow restriction, thereby controlling for potential placebo effects associated with device use.

BEHAVIORAL

Standard Physical Therapy

Participants will undergo the standardized postoperative Achilles tendon rehabilitation program used at Massachusetts General Hospital. The protocol includes progressive weight-bearing, range-of-motion exercises, strengthening maneuvers, and return-to-sport progression phases supervised by trained physiotherapists.

Sponsors & Collaborators

• Massachusetts General Hospital

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-02-01

Primary Completion

2026-12-31

Completion

2027-02-01

FDA Device

Yes

Countries

• United States

Study Locations