Can Blood Flow Restriction Therapy Improve Strength and Cross-Sectional Area for Shoulder External Rotators Better Than Exercise Alone?

Not Applicable

• Conditions: Can Blood Flow Restriction Therapy Augments Strength Gains in the Rotator Cuff; Muscle Weakness
• Interventions: Other: Blood Flow Restriction Group (exercise with blood flow restriction using a Delfi unit)

• Registration Number: NCT04596020
• Lead Sponsor: George Fox University

Brief Summary

This 8-week study will investigate whether the application of blood flow restriction (BFR) therapy augments rotator cuff strength in untrained individuals. This is a RCT with subjects randomized to a BFR or non-BFR group. Both groups will do the same training program: 1) first sitting unilateral knee extension and standing unilateral knee curls (w/ or w/o BFR; 4 sets, 30/15/15/15 reps) and 2) scaption and sidelying external rotation (no BFR for either group; 3 sets x 15 reps each).

Detailed Description

This 8-week study will investigate whether the application of blood flow restriction (BFR) therapy augments rotator cuff strength in untrained individuals. This is a RCT with subjects randomized to a BFR or a non-BFR group. Both groups will perform the same training program 2 times a week over 8 weeks with one group performing the lower extremity exercises under occlusion (i.e., BFR applied to the proximal thigh of the dominant leg).

Prior to starting the study the subjects will have their strength assessed by a blinded physical therapist using a hand held dynamometer. The muscles assessed will be the: quadriceps, the hamstrings, the supraspinatus, and the external rotators of the shoulder. Another blinded physical therapist will assess the cross-sectional area of the quadriceps and the supraspinatus tendon using ultrasonography. These tests will be repeated at the conclusion of the study.

Subjects' training weight will be 30% of their 1 repetition max (1RM). 1RM will be determined using hand held dumbbells for the shoulder exercises and machines (knee extension, knee curl machines) for the lower extremity exercises.

Subjects will be randomized to either the BFR or non-BFR group. Subjects in the BFR group will perform the lower extremity exercises under occlusion (i.e., BFR applied to the proximal thigh of the dominant lower extremity). Both groups will perform 4 sets of each lower extremity exercise for 30/15/15/15 reps. After completing the lower extremity exercises the subjects will perform the shoulder exercises (scaption, sidelying external rotation) for 3 sets of 15 repetitions each. The shoulder exercises will not be performed with BFR in either group.

Study Timeline

• Status Verified: 2020-10
• Study First Submitted: 2020-10-08
• Study Start: 2020-10-10
• Study First Submitted QC: 2020-10-15
• Last Update Submitted: 2020-10-15
• Study First Posted: 2020-10-22
• Last Update Posted: 2020-10-22
• Primary Completion: 2020-12-07
• Study Completion: 2020-12-07

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

• Male or female subjects aged 18 and over

Exclusion Criteria

• Current neck, shoulder (or general upper extremity), and/or thoracic spine pathology;
• Shoulder surgery (or general upper extremity surgery) during the prior 6-month time period;
• Current lower extremity injury and/or having had a lower extremity surgery during the prior 6-month time period;
• Cervical/thoracic spine surgery during the prior 1-year;
• Subject having 1 or more contraindications for BFR training;
• Under the age of 18 years.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Blood Flow Restriction Group	Blood Flow Restriction Group (exercise with blood flow restriction using a Delfi unit)	This group will perform 2 lower extremity exercises (sitting unilateral knee extension, standing unilateral knee curl) under occlusion (i.e., BFR) for 4 sets (30/15/15/15 reps) each followed by 2 shoulder exercises (scaption and sidelying external rotation) 3 sets x 15 reps each. Exercises will be performed at 30% of 1RM.
Non-Blood Flow Restriction Group	Blood Flow Restriction Group (exercise with blood flow restriction using a Delfi unit)	This group will perform the same exercises for the same volume without the use of BFR.

Primary Outcome Measures

Name	Time	Method
Strength Assessment	Change in Baseline Strength (Newtons) at 8 weeks	Strength will be assessed using a hand held dynamometer and traditional manual muscle test positions
Ultrasonography	Change in Baseline Cross-Sectional Area of the Quadriceps (specifically Rectus Femoris) and the Supraspinatus tendon at 8 Weeks	Diagnostic ultrasound will be used to measure the cross-sectional area of the quadriceps (specifically the Rectus Femoris) and the tendon of the supraspinatus

Trial Locations

Locations (1)

George Fox University; 🇺🇸 Newberg, Oregon, United States