Internal impingement of the shoulder

Heyworth BE, Williams RJ. Internal Impingement of the Shoulder. Am J Sports Med. 2009 May;37(5):1024–37:

A good academic article from a surgical perspective.

Excessive or repetitive contact of the greater tuberosity of the humeral head with the posterosuperior aspect of the glenoid when the arm is abducted and externally rotated ... [leading to] rotator cuff and glenoid labrum impingement.

Specifically:

Impingement of the undersurface (deep layer) of the posterior supraspinatus tendon and/or the anterior infraspinatus tendon by the posterosuperior glenoid margin ... which is distinct from subacromial impingement syndrome, [and] is known as internal impingement, or posterior glenoid impingement.

From 'Summary' at the end of the article:

Articular-sided, partial-thickness lesions at the musculotendinous junction of the infraspinatus tendon or at the distal insertion of the supraspinatus tendon, posterosuperior labral tears, and a loss of glenohumeral internal rotation are the hallmark findings of this condition.

GIRD = glenohumeral internal rotation deficit.

Credit in the figure legend

Chronic, diffuse posterior shoulder girdle pain is commonly the presenting complaint, but the pain may be localized to the joint line.

The posterior impingement sign:

deep posterior shoulder pain when the arm [is] brought into a position similar to that noted during the late cocking phase of throwing—abduction to 90° to 110°, extension to 10° to 15°, and maximal external rotation.

Posterior glenohumeral joint line tenderness, too (of course).

Non-operative management:

• Rest
• Ice
• Anti-inflammatories
• Physical therapy

Physical therapy focusing on:

• If GIRD -> posterior capsular stretching
• Strengthening of the periscapular musculature and rotator cuff

Physiopedia:

A lot of detail, not very concise.

Describes management in three detailed phases.

• Stretch posterior capsule
  • e.g. 'sleeper' stretch: passive internal rotation while lying on injured side, shoulder in 90° forward flexion, scapula retracted; and
  • 'cross-body' stretch (self-explanatory!)
• Pan-shoulder and -scapula strengthening

Manske RC, Grant-Nierman M, Lucas B. Shoulder posterior internal impingement in the overhead athlete. The International Journal of Sports Physical Therapy. 8(2):194–204:

Good detail on physical therapy protocol.

Interventions for:

1. GIRD – as already covered
2. Lack of rotator cuff and scapular strength and endurance – see article for progressions
3. Acquired glenohumeral anterior instability – essentially as for (2)

Other articles:

• Corpus KT, Camp CL, Dines DM, Altchek DW, Dines JS. Evaluation and treatment of internal impingement of the shoulder in overhead athletes. WJO. 2016;7(12):776.
• Jones G, Schoffl V, Johnson MI. Incidence, Diagnosis, and Management of Injury in Sport Climbing and Bouldering: A Critical Review. 2018;17(11).