BFRT for Subacromial Pain

Blood Flow Restriction Training for Subacromial Pain: A Pilot Randomized Controlled Trial

The goal of this pilot clinical trial is to learn if blood flow restriction training is safe and feasible in patients with subacromial pain. The main questions the investigators aim to answer are:

• What problems do participants with shoulder pain encounter when training with blood flow restriction?
• Is it feasible to apply blood flow restriction training as part of a physical therapy intervention?
• What are some preliminary effects of blood flow restriction training on the recovery of shoulder function and strength?

The investigators will compare active blood flow restriction training to sham (an inactive procedure designed to mimic the active training as closely as possible).

Participants will:

• Visit the clinic for physical therapy visits and exercise with blood flow restriction training for up to 8 weeks
• Visit the clinic for tests before starting the treatment, during the treatment (4 weeks), and after the end of the treatment (8 and 26 weeks).

Study Overview

• Status: Recruiting
• Conditions: Shoulder Pain
• Intervention / Treatment: Device: Active BFRT; Behavioral: Strengthening Exercises with BFRT; Behavioral: Skilled Physical Therapy Care; Device: Sham BFRT

• Study Type: Interventional
• Enrollment (Estimated): 36
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Federico Pozzi, PT, MA, PhD; Phone Number: (352) 273-6957; Email: fpozzi@phhp.ufl.edu

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32610
      • Recruiting
      • University of Florida
      • Contact: Shea Herlihy, MS; Phone Number: 352-273-7361; Email: herliso@ortho.ufl.edu
      • Principal Investigator: Federico Pozzi, PT, MA, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion criteria

• Between 18 and 50 years of age
• Unilateral pain in the anterolateral shoulder
• Self-reported shoulder function of ≤7 (10, full function)
• At least 90° of active shoulder elevation
• 3 out of 5 positive tests to define subacromial pain.

Exclusion Criteria (general):

• history of shoulder fracture, frozen shoulder, or shoulder surgery
• primary complaint of shoulder instability/dislocation
• history of cardiovascular, neurologic, and pulmonary conditions that would impair the subject's ability to participate in physical therapy
• active treatment for cancer
• uncontrolled diabetes
• uncontrolled high blood pressure
• corticosteroid injection at the shoulder within 6 weeks
• imaging evidence of rotator cuff tears
• pregnancy

Exclusion criteria (Blood flow restriction training specific)

• contraindications to BFRT (sickle cell anemia, deep vein thrombosis, peripheral circulatory diseases)
• taking anticoagulant or antiplatelet drugs

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active BFRT	Device: Active BFRT; The BFR device is applied unilaterally on participants involved upper extremity. The BFR device maintains 50% of participants limb occlusion pressure for the duration of each strengthening exercise.; Behavioral: Strengthening Exercises with BFRT; Participants perform 4 strengthening exercises while using the BFR device: seated scapular plane elevation, prone horizontal abduction, side-lying external rotation, and prone scapular plane elevation. Each exercise is performed unilaterally. Participants perform 1 set of 30 repetitions followed by 3 sets of 15 repetitions (4 total sets, 75 total repetitions). Participants are given 30 seconds rest between sets and 2 minutes of rest between strengthening exercises. Selected resistance for each strengthening exercise is equal to 20% of the participant's maximal force production as measured by handheld dynamometry. Resistance is adjusted weekly.; Behavioral: Skilled Physical Therapy Care; Participants perform non-strengthening interventions as part of skilled physical therapy care. Non-strengthening interventions include an upper arm ergometer for warm-up, active assisted range of motion of the shoulder, shoulder stretching, shoulder joint mobilizations, and cryotherapy. Non-strengthening interventions are prescribed at the discretion of the treating physical therapist. Participants are enrolled in physical therapy for a minimum of 4 weeks. After 4 weeks, the treating physical therapist can discharge a participant based on their progress in meeting their rehabilitation goals. Participants discharged from skilled physical therapy care will continue to complete strengthening exercises with BFRT until the end of the trial period (8 weeks).
Sham Comparator: Sham BFRT	Behavioral: Strengthening Exercises with BFRT; Participants perform 4 strengthening exercises while using the BFR device: seated scapular plane elevation, prone horizontal abduction, side-lying external rotation, and prone scapular plane elevation. Each exercise is performed unilaterally. Participants perform 1 set of 30 repetitions followed by 3 sets of 15 repetitions (4 total sets, 75 total repetitions). Participants are given 30 seconds rest between sets and 2 minutes of rest between strengthening exercises. Selected resistance for each strengthening exercise is equal to 20% of the participant's maximal force production as measured by handheld dynamometry. Resistance is adjusted weekly.; Behavioral: Skilled Physical Therapy Care; Participants perform non-strengthening interventions as part of skilled physical therapy care. Non-strengthening interventions include an upper arm ergometer for warm-up, active assisted range of motion of the shoulder, shoulder stretching, shoulder joint mobilizations, and cryotherapy. Non-strengthening interventions are prescribed at the discretion of the treating physical therapist. Participants are enrolled in physical therapy for a minimum of 4 weeks. After 4 weeks, the treating physical therapist can discharge a participant based on their progress in meeting their rehabilitation goals. Participants discharged from skilled physical therapy care will continue to complete strengthening exercises with BFRT until the end of the trial period (8 weeks).; Device: Sham BFRT; The BFR device is applied unilaterally on participants involved upper extremity. The BFR device maintains a pressure of 20mmHg for the duration of each strengthening exercise.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recruitment	Record the number of individuals a) approached, b) screened, c) qualified, and d) willing to participate. The reasons for participants who do not qualify or refuse to participate will be recorded.	Monthly report from beginning to completion of recruitment (anticipated 2 years)
Intervention feasibility	The interventionist team will complete standardized notes of the intervention, which will be reviewed weekly to document adherence and protocol fidelity and for early identification of intervention deviations. Outcomes include the number of patients a) completing at least 80% of the assigned BFRT visits, b) requesting to stop BFRT within a session, c) requesting to withdraw from the intervention, and d) requesting to switch intervention arms. The last number is a proxy for patients who do not accept randomization results.	Weekly record from enrollment to the end of treatment at 8 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Retention	Identify the number of dropouts and reasons impacting participation in follow-up visits.	Weekly record from enrollment to 26 weeks (end of the trial).
Intervention safety	Monitor the occurrance of severe adverse events and exercise-related adverse events.	Weekly record from enrollment to 26 weeks (end of the trial).
Participants masking feasibility	At the primary endpoint, participants will be asked to guess the treatment allocation to evaluate participant masking feasibility.	At 8 weeks
Patient acceptability	A guided interview using Likert scale-type and open-ended questions will be conducted to gather participant feedback on trial and intervention procedures. An electronic copy of this questionnaire will be sent to patients who withdraw/stop showing up to understand whether trial or intervention procedures impact patient retention.	At 8 weeks
Range of motion	The investigators will measure range of motion using an inclinometer or goniometer. The investigators will measure shoulder elevation in the scapular plane, external rotation, and internal rotation. The investigators will also measure coronal, axial, and sagittal rotation of the scapula during shoulder elevation in the scapular plane.	From enrollment to 4 weeks, 8 weeks and 6 months
Strength	The investigators will measure shoulder elevation in the scapular plane and external rotation strength using a handheld dynamometer.	From enrollment to 4 weeks, 8 weeks and 6 months
Timed Functional Arm and Shoulder Test (TFAST)	It includes three tasks: an internal/external rotation task (duration 30s), an outward circular motion task (duration 30s), and a gallon-lift task at the height of a standard counter (duration 30s). In each task, participants repeat movements as fast as possible.	From enrollment to 4 weeks, 8 weeks and 6 months
Supraspinatus and infraspinatus muscle cross-sectional area	The investigators will use ultrasound to take pictures of the supraspinatus and infraspinatus muscles. This outcome represents a marker of hypertrophy, a potential mechanism of strengthening.	From enrollment to 4 weeks, 8 weeks and 6 months
Supraspinatus tendon morphology	The investigators will use ultrasound to take pictures of the supraspinatus tendons. Established ultrasound procedures will be used to measure supraspinatus tendon thickness.	From enrollment to 4 weeks, 8 weeks and 6 months
Supraspinatus tendon elastography	Ultrasound will be used to take pictures of the supraspinatus tendons. The investigators will set the ultrasound parameters to elastography, allowing non-invasive measurement of tendon stiffness and elasticity.	From enrollment to 4 weeks, 8 weeks and 6 months
Pennsylvania Shoulder Score (PENN)	The PENN is a valid and reliable self-reported questionnaire for patients with shoulder pain.	From enrollment to 4 weeks, 8 weeks and 6 months
Global rating of change (GROC)	The GROC is a rating scale that quantifies participants' improvement or deterioration of symptoms over time. Changes will be measured using a 15-points Likert scale (-7, a very great deal worse to 7, a very great deal better, with 0 indicating no changes).	At 4 weeks, 8 weeks and 6 months
Patient specific functional scale (PSFS)	The PSFS asks patients to rate their difficulty performing three activities of their choice. It is advantageous because it asks patients to select the activities rather than providing pre-selected options.	From enrollment to 4 weeks, 8 weeks and 6 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Western Ontario Rotator Cuff Index (WORC)	The WORC is a valid and reliable tool to assess quality of life in patients with shoulder pain. The tool contains a total of 21 Likert-type questions in five different domains (Physical symptoms, Sports/Recreation/Work/Lifestyle/Emotions)	From enrollment to 4 weeks, 8 weeks and 6 months
Brief Pain Inventory (BPI)	The BPI is a reliable, primary pain recovery measure used in clinical trials of patients with shoulder pain. It measures pain across three domains (average, best, and worst).	From enrollment to 4 weeks, 8 weeks and 6 months
Patient Acceptable Symptoms State (PASS)	The PASS is a rating scale that quantifies participants' satisfaction with their current level of function in the context of clinical care.	At 8 weeks and 6 months
Pressure pain sensitivity	The investigators will apply pressure at a constant rate using a computerized pressure algometer with a 1 cm diameter rubber tip at the shoulder and the lower limb.	From enrollment to 4 weeks, 8 weeks and 6 months
Quick Disability of the Arm and Shoulder (Q-DASH)	The Q-DASH evaluates upper extremity disability while monitoring change or function over time. This assessment consists of 11 questions (3 items related to symptoms and 8 items related to functional tasks). Reliability and validity have been established for this scale.	From enrollment to 4 weeks, 8 weeks and 6 months
Infraspinatus tendon morphology	The investigators will use ultrasound to take pictures of the infraspinatus tendons. Established ultrasound procedures will be used to measure infraspinatus tendon thickness.	From enrollment to 4 weeks, 8 weeks and 6 months
Infraspinatus tendon elastography	Ultrasound will be used to take pictures of the infraspinatus tendons. The investigators will set the ultrasound parameters to elastography, allowing non-invasive measurement of tendon stiffness and elasticity.	From enrollment to 4 weeks, 8 weeks and 6 months
Optimal Screening for Prediction of Referral and Outcome (OSPRO)	The OSPRO is a concise, multidimensional 10-item yellow flag assessment tool that estimates 11 total questionnaire scores indicating elevated vulnerability and decreased resilience.	From enrollment to 4 weeks, 8 weeks and 6 months

Collaborators and Investigators

• Sponsor: University of Florida
• Collaborators: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

Study record dates

Study Major Dates

• Study Start (Actual): May 13, 2025
• Primary Completion (Estimated): March 31, 2027
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: March 3, 2025
• First Submitted That Met QC Criteria: March 11, 2025
• First Posted (Actual): March 12, 2025

Study Record Updates

• Last Update Posted (Estimated): July 8, 2025
• Last Update Submitted That Met QC Criteria: July 3, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: exercise; blood flow restriction training; subacromial impingement; rotator cuff tendinopathy; BFR; BFRT; subacromial pain; rotator cuff related shoulder pain
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Musculoskeletal Diseases; Joint Diseases; Arthralgia; Shoulder Pain
• Other Study ID Numbers: IRB202302184; R21AR082588-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Sharing Time Frame

Study protocol & statistical analysis plan: A manuscript describing the study protocol and statistical analysis plan will be submitted for publication within the first year of starting the clinical trial.

Clinical study report and analytic code: Individual data and analytic code will be made available after the publication of the primary results of this trial.

IPD Sharing Access Criteria

Study protocol and statistical analysis plan: The manuscript will be published as open access.

Clinical study report and analytic code: Data will be shared on NIH/NIAMS approvved data repository (i.e., Dataverse). Access will follow repository guidelines.

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No