Patient Information Sheet:
This information sheet is designed to give you a better understanding of shoulder subacromial impingement and the role of Physiotherapy treatment in managing this problem.
Symptoms: Shoulder pain and weakness due to subacromial impingement often comes on from repetitive overhead activities as an overuse problem or could possibly occur from a sudden jerking type movement or trauma.
Common symptoms are of lateral shoulder and referred upper arm pain with any of the following activities:
- Reaching overhead (ie hanging washing, swimming, throwing, reaching high)
- Washing your hair or reaching across to opposite shoulder
- Dressing (ie putting on a shirt, bra or belt)
- Night pain (especially in side lie positions)
Anatomy: The shoulder joint (glenohumeral joint) may be likened to a golf ball resting on a tee (see diagram below), and is inherently quite an unstable joint. It relies greatly on the rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis) and their tendon attachments to the capsule to provide support and control of shoulder movement. The area beneath the acromion of the shoulder blade contains the sub-acromial bursa, which helps protect and cushion the tendons as they passes through this space. This space is critical to tendon function as it is small and therefore leaves “little room for error” with functional shoulder movements.
Biomechanics: The rotator cuff and in particular supraspinatus acts to maintain stability of the glenohumeral joint and prevent unwanted or excessive translational movement (see diagram below). If the rotator cuff is inhibited by pain or a tear it may result in problematic increased upward movement of the ball in the socket. This movement may also occur in a shoulder with a tight posterior capsule, weak scapula movement control or with shoulders that are hypermobile with excessive movement translation.
Humeral head superior (upward) translation in the socket:
Primary Impingement: results from mechanical encroachment into the subacromial space usually by an acromial spur or hooked acromion. These patients are usually older and may also present with some degree of rotator cuff tendon tears.
Secondary Impingement: shoulder pain here often comes on from overuse and may also have a component of rotator cuff tendonitis, due to poor shoulder movement control and subtle/minor instability of the ball in socket.
Goals of Physiotherapy Treatment: The goal of Physiotherapy treatment is to reduce or eliminate inflammation of the bursa and surrounding soft tissues to effectively reduce shoulder pain and improve function.
- This may firstly involve providing advice regarding appropriate shoulder function and activity levels. This sometimes means you may need to reduce the amount of shoulder activity in elevated or overhead positions, as well as loaded or strenuous shoulder movements.
- Improve shoulder range of motion through the use of passive manual therapy techniques and instruction in specific assisted-active rehabilitation exercises.
- Reduce posterior capsule tightness with stretches to enable improved centring of the shoulder joint.
- Optimise rotator cuff control, endurance or strength by instruction in specific rotator cuff control exercises using resistive theratube / theraband and light- weights.
- Enhance scapula stability by re-education of optimal scapula muscle control through exercises and proprioceptive awareness movements.
- Correction of any neck or mid back problems which may occur from a painful/weak shoulder utilising “hands on” manual therapy techniques and postural awareness exercises.
Physiotherapy and specific exercises are often very effective at allowing your shoulder pain and condition to get better.
However, if you are one that does not improve sufficiently, then consideration could be given to having a cortisone injection to directly attempt to reduce local bursal inflammation. If you do already have a rotator cuff tear, then cortisone injections should possibly not be given as they could make your tear worse.
If injections do not help and all else fails, then you would need to consider an arthroscopic subacromial decompression (ie: surgery).
With the right attention and sometimes a little time and persistence your shoulder will improve.