Blood Flow - an Underlying Mechanism Behind Clinical Improvements in Patients With Subacromial Pain Syndrome?

Study Overview
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Brief Summary
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The purpose of this randomized clinical trial is two-fold. Firstly to see if patients suffering Subacromial Pain Syndrome can improve blood flow in the supraspinatus muscle in their shoulder, and secondly to investigate how changes in this blood flow are related to pain experience and shoulder function.

Official Title
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Blood Flow - an Underlying Mechanism Behind Clinical Improvements in Patients With Subacromial Pain Syndrome?

Conditions
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Chronic Pain

Intervention / Treatment
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* Other: Exercise: local high intensity interval exercise
* Other: Exercise: best clinical practice


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: shoulder pain for longer than three months clinical findings indicative of subacromial pain syndrome (evaluated by Hawkins-Kennedy sign, Neers sign, painful arch and Yokum test) normal passive range of motion of the shoulder Exclusion Criteria: subjects unable to provide an informed consent lack of ability to complete the intervention full rupture of the tendon of m. supraspinatus planned shoulder surgery, or previous shoulder surgery on affected shoulder other musculoskeletal problem that could explain the symptoms adhesive capsulitis pregnancy rheumatoid arthritis symptomatic osteoarthritis of the shoulder/shoulder girdle glenohumeral instability widespread pain syndrome unstable underlying heart disease cortisone injections in the shoulder the last month allergies other serious mental or somatic disease (i.e. psychosis or active cancer disease).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention group<br>The subjects in this arm will receive four high intensity (80% of peak work rate) four-minute interval exercises for the abduction movement in the plane of the scapula (m. supraspinatus), supervised three times per week. In addition they will perform the exercise program described for the control group. | Other: Exercise: local high intensity interval exercise<br>* The subjects in this arm will receive four high intensity (80% of peak work rate) four-minute interval exercises for the abduction movement in the plane of the scapula (m. supraspinatus), supervised three times per week. In addition they will perform the exercise program described for the control group.<br>|
| Active Comparator: Control group<br>The control group will receive a best clinical practice home-exercise program, with regular follow-ups at the shoulder clinic every other week. The details are described in Granviken et al. (2015). | Other: Exercise: best clinical practice<br>* The control group will receive a best clinical practice home-exercise program, with regular follow-ups at the shoulder clinic every other week. The details are described in Granviken et al. (2015).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to exhaustion, incremental test | participants abduct their shoulder up to 90 degrees in scapula's plane (scapularization) at a frequency of 0,5 Hz. Every minute the load is increased with 250 grams. The test is stopped if participant fails to maintain pace or movement quality, or experiences increased pain. Time at failure is noted as the result. | Week 0 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SPADI questionnaire | Subjective pain and function outcomes (Likert scales) | Week 0 | 
| SPADI questionnaire | Subjective pain and function outcomes (Likert scales) | Pre+post-test (8 weeks in-between) | 
| Weight | Weight (kg) | Week 0 | 
| Height | Height (cm) | Week 0 | 
| Age | Age (years) | Week 0 | 
| Duration of symptoms | Duration of symptoms (months) | Week 0 | 
| Affected shoulder | What shoulder is affected (left/right) | Week 0 | 
| Socioeconomic status | The patient fills in a questionnaire stating number of children, marital status, welfare status and working situation | Week 0 | 
| 1 repetition maximum (1RM), bilateral shoulder test | After warmup: maximal strength was measured as the weight the subject could manage to lift once - usually achieved in 3-5 attempts. The movement conducted was the earlier described scapularization movement. | Week 0 | 
| 1 repetition maximum (1RM), bilateral shoulder test | After warmup: maximal strength was measured as the weight the subject could manage to lift once - usually achieved in 3-5 attempts. The movement conducted was the earlier described scapularization movement. | Week 8 | 
| Time to exhaustion, steady state | Subject abduct their shoulder up to 90 degrees in scapula's plane (scapularization) at a frequency of 0,5 Hz. The load is set to 80% of the incremental time to exhaustion test. The test is stopped if the fails to maintain pace or movement quality, or the subject experience increased pain. Time at failure is noted as the result. | Week 0 | 
| Time to exhaustion, steady state | Subject abduct their shoulder up to 90 degrees in scapula's plane (scapularization) at a frequency of 0,5 Hz. The load is set to 80% of the incremental time to exhaustion test. The test is stopped if the fails to maintain pace or movement quality, or the subject experience increased pain. Time at failure is noted as the result. | Week 8 | 
| Regional blood flow in m. supraspinatus, using contrast enhanced ultrasound (concentration of white analyzed as decibels in region of interest) | Baseline images will be taken with ultrasonic device to confirm an intact m. supraspinatus. An intravenous line will be inserted in the contralateral arm and the patient will be injected with a bolus of contrast dye (Optison, 3 ml bolus, 0.19 mg / mL perflutren). The injection is administered by a physician related to the research project. Measurements of regional blood flow at rest made are of the supraspinatus tendon. Then the participants perform a standardized training exercise to recruit the vasculature in m. supraspinatus (scapularization to 90 degrees, 80% of TTU weight (incremental), 3 minutes). Post-exercise images are taken immediately after this. | Week 0 | 
| Regional blood flow in m. supraspinatus, using contrast enhanced ultrasound (concentration of white analyzed as decibels in region of interest) | Baseline images will be taken with ultrasonic device to confirm an intact m. supraspinatus. An intravenous line will be inserted in the contralateral arm and the patient will be injected with a bolus of contrast dye (Optison, 3 ml bolus, 0.19 mg / mL perflutren). The injection is administered by a physician related to the research project. Measurements of regional blood flow at rest made are of the supraspinatus tendon. Then the participants perform a standardized training exercise to recruit the vasculature in m. supraspinatus (scapularization to 90 degrees, 80% of TTU weight (incremental), 3 minutes). Post-exercise images are taken immediately after this. | Week 8 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Shoulder, Exercise therapy