Effects of Blood Flow Restriction Training in Rotator Cuff Related Shoulder Pain

Study Overview
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Brief Summary
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Blood flow restriction training is widespread in sport performance areas, where it has proven to be beneficial in strength and hypertrophy development. However, there are only few studies related to its effects on subjects with pathology, and currently, there is no recent clinical trial evaluating its effects on patients with RCRSP. We are aiming to define the potential benefits, acute and short-term effects of adding blood flow restriction to a low-load exercise training for patients with RCRSP.

Official Title
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Effects of Blood Flow Restriction Training on Central Mechanisms of Pain Modulation in Subjects With Rotator Cuff Related Shoulder Pain: a Randomized Controlled Trial

Conditions
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Subacromial Pain Syndrome

Intervention / Treatment
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* Other: Side-lying external rotation exercise with a dumbbell
* Other: Side-lying external rotation exercise with a dumbbell with 40% arterial occlusion pressure blood flow restriction
* Other: Side-lying external rotation exercise with a dumbbell with 80% arterial occlusion pressure blood flow restriction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pain around the antero-lateral (deltoid area) region of the proximal shoulder during active movements in abduction and/or external rotation. 3/5 positive impingement tests: Neer, Hawkins-Kennedy, empty can, painful arc, and resisted external rotation or abduction. Pain at rest less than 3cm in a visual analogue scale (VAS). Exclusion Criteria: Previous shoulder surgery. Being treated with physical therapy or pharmacogical therapy for shoulder pain. External rotation range of motion less than 45º or 50% compared to the contralateral side. Suspected shoulder instability (previous dislocation/subluxation, sulcus sign, anterior drawer test, anterior/posterior aprehension test, relocation test). Suspected cervical radiculopathy (distraction, spurling, ULNT1, squeeze test, ipsilateral rotation less than 60º) Presence of neck pain. Suspected rotator cuff tears (drop arm test, external rotation lag sign, diagnostic imaging). Contraindications to blood flow restriction therapy.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Exercise without blood flow restriction<br>Side-lying external rotation exercise with a dumbbell (20-30% 1RM) without blood flow restriction. | Other: Side-lying external rotation exercise with a dumbbell<br>* Side-lying external rotation exercise with a dumbbell (20-30% 1RM). 2 times per week during 4 weeks.<br>|
| Experimental: Exercise with 40% of arterial occlusion pressure blood flow restriction<br>Side-lying external rotation exercise with a dumbbell (20-30% 1RM) with 40% of arterial occlusion pressure blood flow restriction. | Other: Side-lying external rotation exercise with a dumbbell with 40% arterial occlusion pressure blood flow restriction<br>* Side-lying external rotation exercise with a dumbbell (20-30% 1RM) with 40% arterial occlusion pressure blood flow restriction. 2 times per week during 4 weeks.<br>|
| Experimental: Exercise with 80% of arterial occlusion pressure blood flow restriction<br>Side-lying external rotation exercise with a dumbbell (20-30% 1RM) with 80% of arterial occlusion pressure blood flow restriction. | Other: Side-lying external rotation exercise with a dumbbell with 80% arterial occlusion pressure blood flow restriction<br>* Side-lying external rotation exercise with a dumbbell (20-30% 1RM) with 80% arterial occlusion pressure blood flow restriction. 2 times per week during 4 weeks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Conditioned Pain Modulation (CPM) | Conditioned pain modulation estimated using changes in pressure pain threshold measured with a manual algometer and a sphygmomanometer. | Baseline, immediately after the first treatment session, 1 month, and 2 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Shoulder pain and disability index (SPADI) | The SPADI ranges from 0% (no disability) to 100% (maximum degree of disability) | Baseline, 1 month, and 2 months | 
| Pain intensity | Mean pain intensity during last week measured with a visual analogue scale (VAS), ranging from 0cm (no pain) to 10cm (worst pain) | Baseline, 1 month, and 2 months | 
| Pain-free isometric strength | Pain-free isometric shoulder external rotation strength measured using a hand-held dynamometer | Baseline, immediately after the first treatment session, 1 month, and 2 months |