Conditions...

Shoulder Impingement Syndrome

Introduction

Shoulder impingement syndrome is considered to be one of the most common causes of shoulder pain.  It can have many different causes but is usually characterised by pain at the side or top of the shoulder and occurs most commonly during over head or hand – behind – back movements.

Causes

The shoulder joint itself is a ball and socket joint but is overlapped by numerous structures. There is tendons of a group of musles referred to as the rotator cuff (Supraspinatus, Infraspinatus, Teres Minor and Subscapularis), the long head of biceps tendon, 2 bursaes (fluid sacs within the shoulder to prevent friction) and the shoulder joint capsule (a series of ligaments holding the ball in the socket).  Pathology of any of these structures can cause impingement when the shoulder is abducted past 90 degrees (lifted out to the side beyond shoulder height) as the bony prominence on the head of the humerus (upper arm) bone compresses the rotator cuff tendons (mainly the Supraspinatus muscle) against the acromion (part of the shoulder blade). 

Other explanations have been offered when there is no history of muscle/soft tissue damage but impingement is still occurring such as: Mechanical or anatomical causes e.g the shape of the acromion, ligament length,  instability or hypermobility of the shoulder joint, joint capsule tightening and posture.

Signs and Symptoms

 Pain at the side or top of the shoulder joint mainly felt when trying to lift arm overhead.
 Loss of shoulder function with everyday and sporting activities
 Pain often radiates down the side of the upper arm
 Insidious onset (usually no specific mechanism of injury)
 May feel pain in the neck

Demographic

Impingement is more common in people who play sports involving frequent overhead activity (e.g. tennis, badminton, baseball), but it can be caused by frequent lifting of heavy objects by anyone. 

Differential Diagnosis

With a thorough history of injury and physical assessment using special diagnostic testing of the shoulder our physiotherapists can diagnose shoulder impingement syndrome.  An x-ray may be sought in order to discern the anatomy in the shoulder that is causing the impingement.  

Treatment

Physiotherapy treatment of shoulder impingement includes soft tissue manipulation, stretching exercises, ultrasound therapy, hot/cold therapy, joint mobilisation, strengthening exercises and postural education.  If the pain does not settle after a period of physiotherapy and the use of non-steroidal anti-inflammatory medication (if appropriate) it may be necessary to try a cortico-steroid injection into the shoulder joint. 

Surgical Implications

There is a very small amount of patients that may need to consider a surgical procedure to relieve their impingement (approximately 15-28% of all patients diagnosed) but this is very rare.  In most cases it will settle after a period of physiotherapy or, if necessary, an injection.

References

1. Bang, M.D. & Deyle, G.D, (2000) “Comparison of Supervised Exercise with and without Manual Physical Therapy for patients with shoulder Impingement Syndrome.” Journal of Orthopaedic & Sports physical Therapy 30(3):126-137

2. Dickens, V.A, et al. (2005). “Role of Physiotherapy in the Treatment of Subacromial Impingement Syndrome. A Prospective Study.” Physiotherapy 91:159-164

3. Lewis, J.S. et al (2001). “The Aetiology of Subacromial Impingement Syndrome.” Physiotherapy 87 (9). 485-469

4. Manske, R.C, et al. (2013). “Clinical Commentary: Shoulder posterior Internal Impingement in the Overhead Athlete.”  The International Journal of Sports Physical Therapy 8(2):194-204