Impingement Syndrome (Swimmer's Shoulder)

Impingement Syndrome, which is sometimes called Swimmer’s shoulder or Thrower’s shoulder, is caused by the tendons of the rotator cuff (supraspinatus, infraspinatus, teres minor and subscapularis muscles) becoming 'impinged' as they pass through a narrow bony space called the Subacromial space – so called because it is under the arch of the acromion. With repetitive pinching, the tendon(s) become irritated and inflamed.

This can lead to thickening of the tendon which may cause further problems because there is very little free space, so as the tendons become larger, they are impinged further by the structures of the shoulder joint and the muscles themselves.

Impingement Syndrome in itself is not a diagnosis, it is a clinical sign.  There are at least NINE different diagnoses which can cause impingement syndrome. These include:
  • Bone spurs
  • Rotator cuff disease/injury
  • Labral injury
  • Shoulder instability
  • Biceps tendinopathy
  • Scapula (shoulder blade) movement dysfunctions
If left untreated, shoulder impingements can result in a rotator cuff tear.

Impingement Syndrome can be classified as:
1. External Impingement
2. Internal Impingement

External Impingement:
Which can be either primary or secondary:

  • Is usually due to bony abnormalities in the shape of the acromial arch.
  • Can sometimes be due to congenital abnormalities (known as os acromial), or due to degenerative changes, where small spurs of bone grow out from the arch with age, and impinge on the tendons.
  • Usually due to poor scapular (shoulder blade) stabilisation which alters the physical position of the acromion, hence causing impingement on the tendons.
  • Is often due to weak serratus anterior and tight pectoralis minor muscles
  • Other causes can include weakening of the rotator cuff tendons due to overuse (e.g. throwing and swimming) or muscular imbalance with the deltoid muscle and rotator cuff muscles.  
Internal Impingement:
  • Occurs predominantly in athletes where throwing is the main part of the sport (e.g. pitches in baseball)
  • The under side of the rotator cuff tendons are impinged against the glenoid labrum – this tends to cause pain at the back of the shoulder joint as well as sometimes at the front.
Symptoms Of Impingement Syndrome:
  • Shoulder pain comes on gradually over a long period.
  • Pain at the front and/or side of the shoulder joint with overhead activity such as throwing, front crawl swimming - most common in external impingements.
  • Pain at the back and/or front of the shoulder when the arm is held out to the side (abducted) and turned outwards (external rotation) - most common in internal impingements.
  • Pain when lifting the arm above 90 degrees.
  • Pain on internal (medial rotation) movements - for example reaching up behind your back.
  • Positive shoulder impingement tests.
The following examples are for information purposes only. We highly recommend seeing a sports injury professional or Doctor to receive a full assessment of your injury

Special Tests:
There are a range of tests which can be performed which are used to indicate certain injuries:
  • Empty Can Test
    You will be asked to put your arm out in front of you at a 45 degree angle to your body, with the thumb pointing to the floor (as if holding an empty can). The therapist will ask you to raise your arm whilst they resist your movement. This tests the supraspinatus tendon.

  • Neer’s Sign
    The therapist will position your arm with the thumb facing down and at a 45 degree angle to your body. They will then lift your arm up, above your head. If you experience pain or discomfort, you may have an impingement of supraspinatus.

  • Hawkins-Kennedy Test
    Your arm will be raised in front of you to 90° and the elbow bent. The therapist will then medially rotate (turn the wrist down and elbow up) the arm. If this causes pain you probably have an impingement of Supraspinatus.
            Impingement Syndrome Treatment
  • Rest
  • Apply ice or cold therapy to the painful area for 10-15 minutes per 2 hour period.  Remember to use an ice bag or a towel wrapped around the ice to protect against ice burn. 
  • Prescribe anti-inflammatory medication such as Ibuprofen or other NSAID's (non steroidal anti inflammatory drugs).
  • Advise on rehabilitation programme's to improve function and decrease pain.
  • Discuss the option of directly injected steroids into the subacromial space to reduce inflammation and reduce inflammation in the local area (this is not usually an early option).
  • Discuss the option of surgery in cases which have failed conservative rehabilitation efforts – this is usually after a period of at least 6-12 months.

       Impingement Syndrome Rehabilitation

Aims of rehabilitation
  • Reduce pain and inflammation.
  • Improve or maintain mobility of the shoulder joint.
  • Strengthen the shoulder.
  • Work on correcting any postural problems.
  • Get a coach or trainer to correct your technique.
  • Gradual return to full fitness.
Reducing pain and inflammation
  • Rest from all aggravating activities, especially those involving overhead movements. Every time you catch the tendons in the joint causing pain you may be making the condition worse. Maintain aerobic fitness on a stationary cycle.
  • NSAID's (Non Steroidal Anti-Inflammatory Drugs) e.g. Ibuprofen may be prescribed by a doctor. Athletes with asthma should not take Ibuprofen. The drugs may help in the early stages of rehabilitation (first few days) but longer term are unlikely to help as much.
  • Apply ice to the painful area for the first few days. 15 minutes at a time, every 2-3 hours.
  • This period of rest, icing and anti-inflammatory medication should last up to a week.
Mobility & Stretching Exercises:
  • Full mobility of the shoulder joint is key in rehabilitation of this injury. If there is insufficient mobility in the joint then the condition is likely to reoccur as the shoulder will not function correctly and allow enough space for the tendons to exist.
  • Mobility exercises should begin as soon as pain will allow and should avoid any areas of movement that do cause pain.
  • Generally any movements that involve lifting the arm out to the side (abduction) above horizontal should be done with the arm rotated outwards. The same applies to movements lifting the arm up forwards (flexion).
  • Stretching is also very important. Stretches should be held for 30 seconds at a time.
  • Massage can be used to help relax any tight muscles, such as the rotator cuff and upper back muscles.
  • These exercises can begin after 2-3 days, provided they are pain-free.
  • They should continue throughout the rehabilitation programme and beyond.
Simple Stretching Exercises Pictures ( Click on the picture to read description)

Strengthening Exercises
  • Strengthening the rotator cuff muscles is the key to strengthening the shoulder.
  • It is important to get an equal balance of strength between the external and internal rotators at the shoulder. It is thought that an imbalance of strength here will contribute to the likelihood of impingement.
  • Strengthening exercises can begin after a week or so's rest and mobility exercises, provided they are pain-free.
  • You should start with gentle rotator cuff strengthening exercises, with the arm by your side.
  • Strengthening should be progressed gradually throughout the programme as pain allows.
Muscle Energy Technique

The therapist rotates the arm in the direction of the white arrow as far as it will comfortably go.

The athlete then does a static contraction aiming to rotate the arm against the resistance of the therapist in the direction of the black arrow. Resistance should be enough so that the arm does not move.

Hold the contraction for only a couple of seconds at 50% of maximum effort. The therapist is then able to rotate the arm further in the direction of the white arrow again. This cycle is continued until no further improvement is made - usually 3 to 6 contractions.


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