Subacromial Impingement

Question 1

What is the most common condition of the shoulder that patients seek medical management for?

Answer 1

Rotator Cuff Disease

Question 2

What is the etiology of rotator cuff disease?

Answer 2

• Tendon degeneration-fibroblasts undergo senescence and apoptosis and there is swelling in the tendon
• Tear to avascular region (critical zone of the supraspinatus)- described as the region approx. 10mm from the distal attachment on the humerus, originally described by Codman and Mcnabb
• Impingement
• Trauma/instability

Question 3

What is primary Impingement?

What structures are involved and what causes this impingement?

Answer 3

Mechanical GH impingement w/ reduced subacromial space and associated AC joint problems

Structures-RC tendons, long head of biceps, GH joint capsule, subacromial bursa and arch

Causes-RC tendinopathy, posterior capsule tightness, morphology of acromion, postural dysfunction, hooked acromion

Question 4

What is secondary impingement?

Answer 4

impingement due to underlying instability

uncertain GH positioning mechanically and functional

Scapular dyskinesia

Question 5

What is internal Impingement?

What structures are involved and what causes this impingement?

Answer 5

undersurface impingement that occurs at or beyond 90 deg ER and 90 deg ABD as the inferior surface of supra/infraspinatus contact the glenoid rim and is common in throwing sports

structures include supra/infraspinatus, GH joint capsule, and subacromial bursa

Causes- capsular laxity, RC weakness, scapular dyskinesia, poor throwing mechanics

Question 6

How does a patient that has subacromial impingement usually present?

What is the test-item cluster for SIS?

What other special tests are there for SIS?

Answer 6

pain at night, pain w/ overhead activities, complaints of stiffness

• Hawkins-Kennedy Test
• Painful Arc Sign
• Infraspinatus Muscle Test

Neer test and empty can test

Question 7

What is the common patient presentation for pts. who have secondary SIS?

What are common objective findings?

Answer 7

young, history of instability, pain w/ overhead activities, general laxity, overhead reaching increases symptoms

objective findings:

• scapular dyskinesia
• weakness of scapular stabilizers
• hypermobility anterior capsule
• • instability tests

Question 8

What is the common patient presentation for pts. who have internal SIS?

What are common objective findings?

Answer 8

athlete, pain overhead reaching, pain throwing, aching posterior shoulder

Objective findings:

• • posterior impingement test
• • instability tests
• scapular dyskinesia
• weakness of scapular stabilizers
• hypermobility anterior capsule

Question 9

True or False: Surgery was found to be a better intervention for SIS than PT.

Answer 9

False, there was no difference in outcomes from PT and Surgery

Question 10

If there is unusually high activity of scapular motion (scapular dyskinesis) which muscle should be targeted w/ exercise?

What if there is low activity?

Answer 10

Upper Trap

Lower Trap/SA