Shoulder Impingement Syndrome

What is it?

• Pinching of the rotator cuff tendon(s) when there is narrowing of space in the top aspect of the shoulder (the arcomion & the coracoacromial ligament attaching to the coracoid process) (see highlighted areas in diagram below) (1, 2, 3, 4)
• Resulting in injury, loss in blood supply / circulation, swelling / inflammation causing further impingement
• Primarily affects the supraspinatus tendon but can also affect the infraspinatus of the rotator cuff tendons (1,2,3)

Causes of Impingement (1, 2, 3, 4)

Congenital ‘Hereditary’ Variations
• Size or shape of the bones in the shoulder area (acromial & coracoid processes)
• Thickness of shoulder ligaments & bursa (cushioning structures of shoulder)
• Degree of mid-back ‘thoracic’ curvature ‘Kyphosis’; excessive curve further facilitates rounding of the shoulder blade ’scapula’ thus causing impingement

Developmental or degenerative Factors
• Post traumatic / post surgical rotator cuff scarring
• Post trauma ’sprain’ of ‘A-C’ joint separation, loose ligaments
• Increased excess boney formation ‘osteophytes’
• Calcium deposit in rotator cuff tendon

Traumatic factors
• Ligament, cartilage and rotator cuff or biceps tendon injuries
• Shoulder subluxation / dislocation

Biomechanical factors
• Weakness of rotator cuff / shoulder blade muscles altering alignment / movement
• Mal-alignment of shoulder due to tight joint capsule from adhesions or scar tissue
• Adhesive capsulitis ‘frozen shoulder’

Classification of impingement in 3 stages (1,8)

Stage 1
• Any age: (usually under 30 years) repetitive shoulder use “overhead athletes”
• Reversible rotator cuff injury
• Local tenderness to palpation
• Restricted range of motion and weakness
• Tendinosis / tendinopathy of rotator cuff tendon which can become fibrotic

Stage 2
• Usually 30 to 40 years of age
• Pathology not reversible by time or / and modifying activity alone
• Local tenderness to palpation and with movement, crepitus with movement
• Loss of active & passive range of motion

Stage 3
• Usually greater than 40 years
• Some degree of irreversible pathology
• Continued increase pain on palpation and with movement
• Loss of active range of motion greater than passive motion
• Atrophy ‘loss in size’ of rotator cuff and shoulder musculature

Signs & Symptoms to look out for (1, 2, 3, 4,
• Pain in upper arm down to elbow, front, side and back of shoulder
• Can be from repetitive arm, shoulder use (athletics: tennis, swimming, throwing overhead, computer use, overhead motion)
• Inability to lower arm from 90 degrees slowly or smoothly with or without pain
• Painful arc: catching of swollen rotator cuff tendon(s) or bursa when raising arm

Other Possible Diagnosis… (1, 2, 3, 4)

• Torn labrum (cartilage)
• Instability (due to torn ligament)
• Tendonitis of structures in shoulder joint, Bursitis
• Cervical (neck) injury: herniated disc / pinched nerve
• Frozen Shoulder ‘Adhesive Capsulitis’

Treatment & Management

Treatments consisting of manual therapy to break up scar tissue & adhesions in the joint capsule, and specific prescribed Physiotherapy exercises are most effective for recovery versus strengthening exercises alone (3, 5, 6). Correcting muscle imbalances and movement & ‘proprioceptive’ awareness will also greatly help in restoring joint alignment and mobility (5, 6). Activity modification can also aid in the management and further prevention of the injury from reoccurring.

The use of anti-inflammatory medication & corticosteroid injections has a role in the treatment of inflammation and pain control (7).

When conservative treatment fails and the shoulder impingement is causing considerable pain & dysfunction, arthroscopic surgery followed by manual therapy and exercise has shown to be effective (8).

References:
1. Pyne. Diagnosis and Current Treatment Options of Shoulder Impingement. Current Sports Medicine Reports. 251 – 255, 2004 March.
2. Fu et al. Shoulder Impingement: A critical review. Clinical Orthopaedics and Related Research. 269: 162 – 173, 1991 August
3. Kamkar et al. Nonoperative Management of Secondary Impingement Syndrome. Journal of Orthopaedics and Sports Physical Therapy. 17(5): 212 – 224, 1993 May
4. Payne et al. The Combined Dynamic & Static Contributions to Subacromial Impingement: A Biomechanical Analysis. The American Journal of Sports Medicine. 25 (6): 801 – 808. 1997
5. Senbursa et al. Comparison of Conservative Treatment with & without Physical Therapy for patients with Impingement Syndrome: A prospective, randomized clinical trial. Knee Surgery, Sports Traumatology, Arthroscopy. 15(7): 915 – 921. 2007
6. Bang et al. Comparison of Supervised Exercise with & without Manual Physical Therapy for patients with Shoulder Impingement Syndrome. The Journal of Orthopaedic and Sports Physical Therapy. 30(3): 126 – 137. 2000
7. Akgun et al. Is Local Subacromial Corticosteroid Injection Beneficial in Subacromial Impingement Syndrome? Clinical Rheumatology. 23(6): 496 – 500. 2004
8. Brox et al. Arthroscopic Surgery versus Supervised Exercises in patients with rotator cuff disease (stage 2 impingement syndrome): A Prospective, randomized, controlled study in 125 patients with a 2-½ year follow-up. Journal of Shoulder and Elbow Surgery. 8(2): 102 – 111. 1999

More Images

Muscles of the shoulder