Injuries and conditions

Shoulder Impingement

Shoulder Impingement

Shoulder impingement usually presents due to a combination of subacromial bursitis, shoulder spur and/or tendonitis. Patients typically report pain (and catching) over the side of the shoulder when the arm is raised over head. Hence they find difficulty undertaking tasks overhead and trouble sleeping on the affected side.

Shoulder impingement may occur with other conditions in the shoulder and therefore it requires careful workup and investigation to exclude subacromial bursitis, shoulder spurs, biceps tendonitis, biceps tendon tears, SLAP tears, supraspinatus and subscapularis tendon tears, and AC joint arthritis.

There are a number of areas that may be pain generators within your shoulder joint and subacromial space. A careful history, examination, and review of your imaging will identify the areas of concern.

  • Shoulder Impingement Syndrome: is usually caused by a bone spur and subacromial bursitis above your tendon and below the roof of the shoulder (acromion). In most cases it is a combination of a thickened bursa and a bone spur causing the problem; in some cases, it may be a calcium deposit in the tendon (calcific tendonitis) and associated bursitis.
  • Subacromial Spurs (Shoulder spurs) can cause impingement when your shoulder is elevated and this can lead to “pinching” of the tendon below, especially when the bursa is inflamed.
  • Subacromial bursitis: the bursa may become inflamed and swell with more fluid resulting in pain
  • Tendonitis: the above three issues may cause the tendon below to become irritated or damaged; this may lead to inflammation of the tendon and eventually even tearing.

Medical diagram showing the anatomy of shoulder and where a should shoulder impingement occurs

Medical diagram showing the anatomy of the shoulder and where Subacromial Bursitis and Acromion Bone Spurs occur to cause Should Impingement

Shoulder overload

  • Repeated motion, particular overhead, may lead to an overuse syndrome and result in inflammation of the bursa with eventual bone spur formation and rotator cuff tendonitis. The coracoacromial ligament thickens over time and places tension on the undersurface of the acromion. All of these changes increase the chances of shoulder impingement syndrome. Once a cycle of pain starts this leads to a decompensated shoulder with rotator cuff and scapular stabilising muscle dysfunction and weakness.
  • Workplace injury may also occur this way with manual occupations that involve heavy lifting and/or overhead work – such as painters, construction workers, electricians and carpenters.

Inflamed or Arthritic shoulder joint

  • When the entire shoulder joint is inflamed (such as with shoulder arthritis or gout) shoulder spurs may form within the shoulder joint and in the subacromial space (under the roof of the acromion). This can lead to shoulder impingement syndrome.

Internal impingement

This is a common cause of shoulder pain in throwing athletes caused by repetitive impingement between the undersurface of the rotator cuff and the back of the top of the socket (postero-superior glenoid).

Shoulder impingement commonly causes tenderness over the side of the shoulder. Patients often report pain, pinching, or stiffness when lifting their arms. There may also be pain when the arm is lowered from an elevated position.

Initially, the symptoms are often mild and tolerable – in such cases patients do not often seek treatment.

Common symptoms of shoulder impingement:

  • Pain that is present with activity and rest
  • Pain radiating from the top of the shoulder (either at the front or the side) down the side of the arm
  • Sudden pain with reaching or lifting movements
  • Overhead athletes may report pain with particular actions (such as a tennis serve or throwing a ball)

As the condition progresses the symptoms may worsen and not respond with periods of rest and activity modification:

  • Night pain (particularly waking you up at night)
  • Inability to lie on the affected side at all
  • Reduced strength and range of motion
  • Difficulty with activities that require the arm behind the back – such as button, zippering, putting on bra etc

When the symptoms persist and affect your quality of life then it is important to seek review.


A thorough examination of the shoulder is required, including checking areas of tenderness, range of motion, associated pathology (such as biceps tendon or rotator cuff tears) and then special impingement tests.


A plain X-ray will often show a spur under the acromion, and in some cases, there may be an exaggerated curve under the acromion (a type 2 or type 3 acromion). Patients with a type 2 or 3 acromion are at increased risk of shoulder impingement and tendon tears. The X-ray may also demonstrate a calcium deposit.

MRI scans will show the soft tissues in greater detail and demonstrate any fluid or inflammation in the bursa. It will also show the rotator cuff and biceps  – looking for any partial or complete tears.

A series of 3 medical diagrams supported by 3 xrays to show the difference between flat, curve and hook acromion

The goal of treatment is to reduce pain and restore function; in planning your treatment your age, activity level, occupation, and general health will be considered.

In most cases, the initial treatment for subacromial impingement is non-surgical; it may take weeks or months to notice gradual improvement and return to function. The principles around non-surgical treatment include rest, activity modification,non-steroidal anti-inflammatory drugs (NSAIDs), and physiotherapy. An ultrasound-guided cortisone injection is very effective with both diagnosis and treatment of shoulder impingement. Such injections may provide relief for anywhere between a few weeks to a few months. Generally, it is best not to have more than two injections per year as the cortisone may weaken the rotator cuff tendons and lead to tendon rupture.

If your condition does not improve with nonsurgical treatment, then surgery may be an option for you. Surgery may also be a better option if you have other associated shoulder problems, particularly those that are time urgent.

Surgery for shoulder impingement is performed arthroscopically (keyhole); this allows your surgeon to assess the condition of other structures in the shoulder, such as the biceps tendon, rotator cuff, and acromioclavicular joint. The goal of surgery is to remove the inflamed bursa (subacromial decompression), smooth out the bone spur (acromioplasty) and create more space for the rotator cuff. The surgery involves a few small keyhole incisions and can be done as a day procedure or with an overnight stay (depending on what else needs to be addressed in the shoulder).

A close up medical diagram showing the shoulder joint and Arthroscopic Bone Burr used to remove Acromion bone spurs

Shoulder Function

If you are unable to undertake basic tasks or to look after yourself, unable to drive, unable to get dressed, or have difficulty with hygiene and toileting.

Shoulder Pain

Pain with activity and even at rest
Night pain, especially if it wakes you from sleep
Unable to sleep on your affected shoulder
Increasing requirements of pain relief tablets
Multiple failed cortisone injections
Not responding to physiotherapy


If it is limiting your ability to work
Especially if you are in a manual job requiring repeated overhead activity


If you are unable (even after a period of rest and activity modification)  to participate in your chosen leisure activity or sport and you wish to continue to do so

Preventing further shoulder damage

There are certain conditions (such as subacromial bursitis with high-grade partial rotator cuff tears) where it may be better to decompress your shoulder and repair your rotator cuff before tears become full-thickness, retracted, or irreparable.
Dr Pant will carefully analyse your MRI scan and determine if this is the case for you (especially in younger patients).

Request a call back

Enquiries between 8am-6pm (Mon-Fri) will be responded to within 30-60 minutes.

"*" indicates required fields

Alternatively, if you have any further questions or would like a consultation with Dr Pant get in touch:

Medicare Card Help

1. Medicare Number
2. Position on card
3. Expiry Date

Request a call back