Article > Shoulder > Subacromial Bursitis

Subacromial Bursitis

Bursae are small fluid-filled sacs that function to decrease the friction forces of one anatomical structure moving against another. They occur throughout our bodies in areas of high friction and are typically named according to their location. The subacromial bursa is situated beneath the acromion (part of the shoulder blade that juts out above the shoulder joint) and above the shoulder capsule (comprised of the shoulder ligaments and the rotator cuff muscle tendons). This bursa lessens the forces between the acromion and the shoulder capsule when the arm is moving and as it is raised overhead.

Subacromial bursitis results when the bursa becomes inflamed. This inflammation can occur as a result of overuse and impingement of the shoulder, but may also occur in association with other medical conditions, such as rheumatoid arthritis, polymayalgia and gout.

FACTORS

If shoulder impingement is the primary cause of the bursitis, moving into the position of impingement can further the injury. Impingement is reached while raising the arm above shoulder-height, to the side or forwards, combined with some inward turning of the arm. Avoidance of these positions may allow the injury to begin healing, but to properly treat this condition you need to understand the individual biomechanics. Together, this will rehabilitate the injury and prevent it from re-occurring.

The position of the scapula on the thorax (upper torso) through movement is quite variable from person to person. The state of the scapulothoracic joint will greatly affect the subacromial space during function. This scapulothoracic variation in biomechanics (including position, strength, movement, etc...) is very often the major factor in this injury. When properly assessed, these biomechanical factors can be targeted for change. Ultimately, this is the key to effective rehabilitation.

One somewhat uncontrollable factor in many cases of impingement is the physical structure of the acromion. Some may have an acromion that is angled downwards, thus reducing the available space under the acromion. This will result in less movement being required to reach a position of impingement, thereby making them more susceptible to injury.

PHYSIOTHERAPY TREATMENT

Most shoulder injuries occur in combination, such as those related by shoulder impingement. Proper assessment by a physiotherapist will help to isolate and differentiate these injuries from one another. As previously stated, these injuries may present itself in different ways, and thus treatment is quite variable and is based on a full assessment of the injury and the individual. This assessment will include a detailed history regarding both the injury and the individual, functional assessment of the affected areas, biomechanical analysis and screening for more serious pathology.

Some general points regarding treatment are as follows:

Initially, as per the guidelines, apply ice (not directly to the skin, use a towel for seperation) to the affected area for 10-15 minutes. Examination by a physiotherapist will help to determine the specific cause and biomechanics of the injury so that the appropriate structures can be targeted for therapy. To help control the inflammation and assist healing, physical modalities such as ultrasound and interferential may be used.

One of the most important aspects of treatment is activity modification. Avoidance of impinging positions is helpful in resting, as well as preventing, the injury. In many cases, simply allowing the bursa to rest for a few weeks (if done early enough) can alleviate the symptoms.

Once the inflammation has largely subsided, education regarding safe movement patterns may be carried out by a physiotherapist. Mobility exercises may also be increased to prevent any secondary stiffness that might be occurring.

To achieve any of the aforementioned goals the physiotherapist may employ a variety of treatment options. See the Rehabilitation section of the general Injury Care page to review these.

It is especially important to see your physician if the cause of the injury does not appear to be biomechanical. Your physiotherapist will know when to refer you onwards. Your physician may order blood tests to rule out inflammatory conditions, prescribe some anti-inflammatory medication, as well as provide some other options for treatment.