Neurophysiology of Weakness and Exercise in Rotator Cuff Tendinopathy

University of Oregon180 enrolled

Overview

The purpose of this study is to examine deficits in activation and motor patterns, as well as central drive in patients with rotator cuff tendinopathy. There are three specific aims: (1) determine the effect of acute pain relief on rotator cuff muscle activation in patients with rotator cuff tendinopathy, (2) determine the effect of exercise on rotator cuff muscle activation in patients with rotator cuff tendinopathy, and (3) compare rotator cuff muscle activation between patients with rotator cuff tendinopathy and healthy controls.

The long-term goal of our research agenda is to identify the mechanisms associated with rotator cuff tendinopathy (impingement syndrome) and subsequently evaluate novel treatment strategies that address these mechanisms. The objectives of this application are to study the muscle patterns in patients with rotator cuff tendinopathy as well as the effects of both pain and exercise on these patterns. Our first hypothesis is that pain relief from a shoulder injection will result in increased rotator cuff activity. Our second hypothesis is that patients with tendinopathy will demonstrate improved rotator cuff muscle activity following a six-week exercise program and that this improvement will be higher in patients that respond favorably to treatment. Our final hypothesis is that patients with cuff tendinopathy will show decreased rotator cuff activity compared to healthy subjects. The investigators plan on addressing these hypotheses using several novel techniques for muscle activity assessment.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

180

Conditions

Eligibility

Sex: ALLMin age: 21 YearsMax age: 45 YearsHealthy volunteers:

Medical Language ↔ Plain English

Patient Inclusion Criteria: * pain with passive provocative maneuvers (positive Hawkins or Neer test) * pain with active elevation (positive painful arc) * pain with isometric resisted movements (Jobe's "empty can" test or resisted shoulder external rotation with the arm at the side) * demonstrate weakness (\>10% force deficit in external rotation) Patient Exclusion Criteria: * shoulder surgery on the symptomatic side * positive Spurling test * traumatic shoulder dislocation or instability in the past 3 months * reproduction of shoulder pain with active or passive cervical range of motion * signs of rotator cuff tear (drop-arm test, lag signs, gross external rotation weakness, or positive image findings) * current musculoskeletal, neurologic or cardiovascular compromise Control Inclusion Criteria: * no current or previous shoulder injury * matched for age (within 5 years) and sex * meet Patient Exclusion Criteria (minus musculoskeletal, neurologic, or cardiovascular compromise) Control Exclusion Criteria: * pain with active arm elevation * positive Hawkins, Neer, or Jobe's test

Outcomes

Primary Outcomes

Rotator cuff activation after subacromial injection and exercise intervention, difference in rotator cuff voluntary activation between subjects and controls

Assessed using voluntary activation

Time frame: 6 weeks

Rotator cuff activation after subacromial injection and exercise intervention, difference in specific rotator cuff muscle activation between subjects and controls

Assessed using electromyography (EMG)

Time frame: 6 weeks

Secondary Outcomes

Rotator cuff voluntary activation after subacromial injection

Assessed using voluntary activation

Time frame: 2 hours

Rotator cuff muscle activation after subacromial injection

Assessed using EMG

Time frame: 2 hours

Rotator cuff voluntary activation correlations with pain levels

Assessed using voluntary activation relative to self-reported pain level

Time frame: 2 hours

Rotator cuff activation correlations with pain levels

Assessed using EMG relative to self-reported pain level

Time frame: 2 hours

Rotator cuff voluntary activation after 6-week exercise intervention and subacromial injection

Assessed using voluntary activation

Time frame: 6 weeks

Rotator cuff muscle activation after 6-week exercise intervention and subacromial injection

Assessed using EMG

Time frame: 6 weeks

Rotator cuff voluntary activation correlation with improvements in pain relief

Assessed using voluntary activation relative to self-reported pain relief

Time frame: 6 weeks

Rotator cuff voluntary activation correlation with improvements in clinical outcome measures

Assessed using voluntary activation relative to changes in questionnaire scores

Time frame: 6 weeks

Rotator cuff muscle activation correlation with improvements in pain relief

Assessed using EMG relative to self-reported pain relief

Time frame: 6 weeks

Rotator cuff muscle activation correlation with improvements in clinical outcome measures

Assessed using EMG relative to changes in questionnaire scores

Time frame: 6 weeks

Prior to treatment, rotator cuff voluntary activation in patients relative to healthy controls

Assessed using voluntary activation

Time frame: 6 weeks

Prior to treatment, rotator cuff muscle activation in patients relative to healthy controls

Assessed using EMG

Time frame: 6 weeks

After both a subacromial injection and a six-week exercise program, differences in rotator cuff voluntary activation between patients and healthy controls

Assessed using voluntary activation

Time frame: 6 weeks

After both a subacromial injection and a six-week exercise program, differences in rotator cuff muscle activation between patients and healthy controls

Assessed using EMG

Time frame: 6 weeks

Neurophysiology of Weakness and Exercise in Rotator Cuff Tendinopathy

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes