Shoulder Impingement

Are you someone that gets pain when hanging the washing or putting a seatbelt on? Do find that you no longer have the right movement or strength to comfortably and painlessly reach overhead, particularly when doing these tasks repetitively or with a load? If yes, you may well have a shoulder impingement/Sub-Acromial Impingement (SAI)/Shoulder Impingement Syndrome.

The shoulder is an extremely versatile, functionally brilliant joint. To allow this functional versatility, the joint is shallow, therefore enabling very complex movements. This complexity does however mean that it’s more vulnerable to injury. Shoulder impingement is a very common injury associated with these complexities. It’s characterised generally by a painful arc of movement when the arm, at the shoulder joint, is raised between 80 and 110 degrees. In many instances, if the arm continues to be raised straight up in the air, the pain usually lessens and may not be painful when the arm is held well above the head. However, when the arm is brought back down again, the pain tends to come back in that same painful arc. Typically, it can be more painful when lifting an object with your arm raised at the shoulder, but this is generally because the muscular work of lifting puts extra strain on the tendon being impinged.

The pain is caused by compression or entrapment of the tendon within the shoulder joint between the bony top of the arm and the bony underside of the joint. The impingement is secondary to space narrowing and is caused by tendon inflammation and swelling, bone abnormalities, muscular and tendon tightness and poor joint mechanics (usually in a combination of these). The pain is commonly specific to the shoulder joint, but may extend down the arm. You may also find that neck pain or headaches begin to increase in regularity also.

Often, the type of injury will vary. Some people may find that impingement symptoms progressively worsen over a number of months or even years. Others may find that they twisted their arm the wrong way or lifted something above their head, which caused an immediate injury. Dependent on the cause of the impingement, the treatment and recovery will vary significantly.

Shoulder Impingement
A Picture of the shoulder joint, showing the Supraspinatus tendon and bursa being ‘Impinged’ or ‘Squashed’ as it passes under the acromion.

Risk factors include:
1. Age – the older we get the more the changes in joint mechanics and body structures has an impact. With age, we have a loss of strength and movement and therefore an increased risk of impingement. Furthermore, years of heavy lifting and overhead movement increase the risk again.
2. The sports we play – tennis, cricket, swimming, weightlifting, netball, basketball and cross-fit (pull-ups, push-ups and rope flicks). These types of sports require a lot of overhead, high velocity; weighted movements that place significant stress on the tendons and muscles that can get impinged.

3. Our everyday activities and work – lifting boxes, cleaning the freezer, helping a friend off a ladder and any other overhead activities, particularly repetitive or weighted activities, will place you at risk of impingement.

What can I do to help avoid impingement?
• Never strain to lift above your head

• Avoid activities that cause clicking, clunking or pain

• Never push through pain

• Know how to most efficiently carry out your activity – this may mean getting expert training for sport, or getting on the job training and advice for these activities at work or home

• Avoid as much as possible repetitive or heavy load activities when your arm, at the shoulder joint, is raised
What if long-term impingement is suspected?
• Consult your Physiotherapist – you may also need an ultrasound or MRI imaging depending on the severity and likely cause of the impingement

• Until you see your Physiotherapist, avoid the aggravating activity

• It is very important that you address your shoulder issue. Continued incorrect use can lead to worsening of symptoms as well as secondary injuries
What if an acute impingement injury is suspected?
• Rest with your arm by your side

• Avoid the aggravating activities

• Consult your Physiotherapist – because of the complex nature of the shoulder joint each individual will have a very specified treatment and rehabilitation program. Some general interventions may include appropriate strengthening exercises, soft tissue massage, electrotherapy, advice on activity modification and anti-inflammatory interventions, biomechanical corrections, joint mobilisation, stretches and a strategy for the graded return to activity.

Take home message:
There’re many reasons for why an impingement is occurring. The complex nature of the shoulder joint and the variations in impingement issues means that each patient needs their own rehabilitation program catered for them. In many instances, the outlook for rehabilitation is good, provided that the patient has good compliance with the exercises they’re given. But it should be remembered that the best results are found with those that adhere to the avoidance strategies.

Jonathon Entriken

Physiotherapist