Bursa is a thin, lubricated cushion wedged between two surfaces to prevent friction between bone and surrounding soft tissues. The bursa sac is surrounded by synovial membrane that consist of synovial fluid. This synovial membrane is semi-permeable, that allows temporary blood flow to the bursa when injury occurs.
Bursitis occurs when the synovial membrane of the bursa gets inflamed. This inflamed synovium may thicken and secretes more synovial fluid causing the bursa to swell up. The inflammation might be due to:
- Injury/ trauma
- Repetitive movement (overuse)
- Degenerative changes (osteoarthritis/ bone spurs)
- Narrowing of the subacromial space (shoulder impingement – bursa / tendons)
Subacromiual bursitis is often accompanied by shoulder tendonitis or commonly known as inflammation of the shoulder tendons (supraspinatus or biceps tendon). Recurring micro strain of the tendon and attempts by the body to repair the tendon can lead to tendinosis also known as tendon degeneration. A degenerated tendon often appears to be thicker than a normal one. As the tendon continues to be subjected to trauma, tendon tear might happen eventually.
As a physiotherapist, we should be able to diagnose bursitis from either rotator cuff injury or shoulder osteoarthritis. However, for patient who suffers subacromial bursitis are likely to have frozen shoulder or shoulder tendinitis. If the pain in your shoulder is provoked while performing isometric test, it is highly because of the injury to the contractile structures (eg: muscles or tendons)
Management is to prevent pain and further injury, at the same time reducing the inflammation. Next, we will focus on restoring shoulder full ROM, scapula control (scapula-humeral rhythm), restore rotator cuff strength, and further training on the agility, proprioception to prepare patient to be able to get back to work functionally.
http://physioworks.com.au/injuries-conditions-1/bursitis_shoulder (Miller, 2017)
http://www.physio-pedia.com/Shoulder_Bursitis (Proost et al, n.d).
References:
Miller J. (2017) Bursitis Shoulder. [Online] Available at: http://physioworks.com.au/injuries-conditions-1/bursitis_shoulder. [Accessed on 16th March 2017]
Proost M. et al. (n.d) Shoulder bursitis. [Online] Available at: http://www.physio-pedia.com/Shoulder_Bursitis. [Accessed on 16th March]