MedPath

Neurophysiology of Weakness and Exercise in Rotator Cuff Tendinopathy

Not Applicable
Completed
Conditions
Acute Pain
Atrophic
Infiltration
Muscle Weakness
Pathology
Goals
Impairment
Shoulder Pain
Tendinopathy
Syndrome
Interventions
Procedure: Subacromial injection
Other: Physical Therapy
Registration Number
NCT02971072
Lead Sponsor
University of Oregon
Brief Summary

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.

Detailed Description

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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
180
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
PatientsSubacromial injectionSubjects with shoulder tendinopathy who will undergo both a subacromial injection and physical therapy
PatientsPhysical TherapySubjects with shoulder tendinopathy who will undergo both a subacromial injection and physical therapy
Primary Outcome Measures
NameTimeMethod
Rotator cuff activation after subacromial injection and exercise intervention, difference in specific rotator cuff muscle activation between subjects and controls6 weeks

Assessed using electromyography (EMG)

Rotator cuff activation after subacromial injection and exercise intervention, difference in rotator cuff voluntary activation between subjects and controls6 weeks

Assessed using voluntary activation

Secondary Outcome Measures
NameTimeMethod
Rotator cuff voluntary activation after subacromial injection2 hours

Assessed using voluntary activation

Rotator cuff voluntary activation correlations with pain levels2 hours

Assessed using voluntary activation relative to self-reported pain level

Rotator cuff muscle activation correlation with improvements in clinical outcome measures6 weeks

Assessed using EMG relative to changes in questionnaire scores

After both a subacromial injection and a six-week exercise program, differences in rotator cuff voluntary activation between patients and healthy controls6 weeks

Assessed using voluntary activation

After both a subacromial injection and a six-week exercise program, differences in rotator cuff muscle activation between patients and healthy controls6 weeks

Assessed using EMG

Rotator cuff muscle activation after subacromial injection2 hours

Assessed using EMG

Rotator cuff voluntary activation after 6-week exercise intervention and subacromial injection6 weeks

Assessed using voluntary activation

Rotator cuff muscle activation after 6-week exercise intervention and subacromial injection6 weeks

Assessed using EMG

Prior to treatment, rotator cuff voluntary activation in patients relative to healthy controls6 weeks

Assessed using voluntary activation

Rotator cuff activation correlations with pain levels2 hours

Assessed using EMG relative to self-reported pain level

Rotator cuff muscle activation correlation with improvements in pain relief6 weeks

Assessed using EMG relative to self-reported pain relief

Rotator cuff voluntary activation correlation with improvements in pain relief6 weeks

Assessed using voluntary activation relative to self-reported pain relief

Rotator cuff voluntary activation correlation with improvements in clinical outcome measures6 weeks

Assessed using voluntary activation relative to changes in questionnaire scores

Prior to treatment, rotator cuff muscle activation in patients relative to healthy controls6 weeks

Assessed using EMG

Trial Locations

Locations (1)

University of Oregon

🇺🇸

Eugene, Oregon, United States

© Copyright 2025. All Rights Reserved by MedPath