HOW TO TREAT SUBACROMIAL BURSITIS Figure 1: Impingement of the subacromial bursa

to slide smoothly. However, the subacromial space is narrow, approximately 7-14 mm in depth, and it is occupied by several structures: ● Subacromial bursa ● Supraspinatus tendon ● Superior part of shoulder capsule ● Tendon of the long head of the biceps

The space restriction means these structures are tightly packed and constantly move in relation to each other.

This creates

potential for friction and consequent degeneration to develop. Inflammation or degeneration of the soft tissues, the shape of the acromion or degeneration of the acromioclavicular joint can all contribute to a reduction in the subacromial space.

The subacromial bursa (synonymous with subdeltoid bursa) plays a special role in the biomechanics of the shoulder joint and is a common cause of chronic shoulder pain. However, chronic sub- acromial bursitis is a challenge to diagnosis because of the mud- dled picture it presents on examination. The bursa’s intimate rela- tionship with the joint capsule, rotator cuff tendons and the biceps tendon makes it difficult to diagnose definitively and treat- ment

response can help to confirm or refute the diagnosis.

Lesions commonly coexist at the shoulder and a primary lesion in the subacromial bursa can indirectly affect other structures lying close to it and vice versa.

Anatomy The subacromial bursa is independent of the shoulder joint and normally does not communicate with it.

sac containing thin folds of tissue or plicae and is surrounded by fatty tissue.

Presentation ● The patient usually complains of a gradual onset of pain or ache, due to the microtrauma of overuse. bursitis due to a single traumatic incident.

Rarely is subacromial Sleeping on that

side may provoke the symptoms, acting as an indicator of the irritability of the lesion ● The symptoms are provoked by using the arm in the overhead position eg. racquet sports, throwing activities of all kinds and swimming

It is a smooth synovial The superficial layer of the bursa adheres to the

anterior two-thirds of the under surface of the acromion, falling away from the posterior third. Its deep layer lies directly over the rotator cuff tendons and medially it extends under the acromion as far as the acromioclavicular joint line. Laterally the bursa caps the greater tuberosity separating it from the overlying deltoid muscle.

The action of supraspinatus is to pull the greater tuberosity upwards and medially. As this occurs the walls of the subacromi- al bursa glide over one another allowing the head of the humerus

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Examination ● Unless a secondary capsulitis has developed, there is likely to

be a full range of passive movement present at the shoulder joint. The end of passive range may however provoke the pain eg. end range of full elevation. A painful arc may be present on active movement, particularly active abduction where pain pre- sents between 60 and 120 degrees. This is due to impingement in the subacromial space where the painful, inflamed structures catch under the coracoacromial arch. ● Pain may be provoked by resisting various movements of the

Altered joint mechanics, posture, incorrect training or over- training, and muscle imbalance which affects the steering mechanisms of the rotator cuff tendons, are all factors which may contribute to chronic subacromial bursitis.

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