Impingement syndrome is when the soft tissues in and around the shoulder joint are repeatedly jammed up by the bones around them. Typically, this occurs when the arm is about halfway to the overhead position. Impingement syndrome can limit your ability to lift the arm at all, or to use it with any force in that position, such as throwing a ball or writing on a whiteboard. Impingement syndrome usually involves inflammation of the rotator cuff tendons, in particular the supraspinatus tendon (supraspinatus tendinopathy or tendonitis), particularly in people over 40 years old. It can also involve inflammation of the subacromial bursa (subacromial bursitis) in people under 40 years old.
What causes impingement syndrome?
Shoulder impingement syndrome can come about for many different reasons.
One reason is when the space between the arch of the shoulder blade (acromion) and the shoulder bone (humerus) becomes narrower than it already is. This narrowing can result in irritation and damage to the cuff tendons, resulting in a painful response.
Narrowing of the space can be caused by changes in the bony structures, such as spurs from the AC (acromioclavicular) joint, or soft tissue changes, such as thickening of the subacromial bursa, or loss of muscle function of the rotator cuff or shoulder blade (scapular) muscles.
Poor posture: A habitual round-shouldered or slumped posture can result in poor functioning of the shoulder blade muscles, which may predispose you to impingement.
Change of activity: If you suddenly increase the amount of overhead activities you’re performing, this may predispose you to an impingement problem.
How do I know if I have impingement syndrome?
If you have shoulder impingement it will be painful to lift your arm, especially out to the side. The pain will be worse between 60o and 120o.
The pain of impingement syndrome can be worse at night, especially if you lie on your affected shoulder and therefore you might have difficulty sleeping. If you have injured your shoulder, the pain is acute and comes on quickly. If there was no injury, pain can come on gradually with repeated or sustained hand over head activities. You may also hear or feel a popping or grinding sensation when you move your shoulder. However, these feelings alone may not be a problem.
Your physiotherapist will perform a few tests to confirm the diagnosis. One is the ‘empty can test’, where you lift your arms out from your side, placing your arms out straight with thumbs facing the floor, and your physiotherapist applies resistance. If this test is painful, it indicates your supraspinatus is inflamed.
Another test, the Hawkins and Kennedy test, involves your physiotherapist applying a gentle passive movement downward to your forearm while your upper arm is supported out in front. If this causes pain then your physiotherapist will suspect that your bursa is inflamed.
It’s important to remember that no single test can give all of the answers. Your body’s response to a variety of clinical tests will assist your physiotherapist to provide the best treatment for you.
How can physiotherapy help with impingement syndrome?
Initially the goal of physiotherapy treatment is to reduce pain and inflammation, as well as to prevent further impingement and tissue damage. Your physiotherapist will most likely recommend modifying some of your activities, resting and icing the shoulder. To help with the pain, your physiotherapist may perform some massage to your muscles or mobilisation of your joints, to loosen your shoulder, neck or thoracic spine (the part of your spine that is between the shoulder blades).
In this acute phase, you may find ice or heat helpful. There is no evidence that either is superior to the other in the treatment of impingement syndrome, so personal preference will determine the effectiveness. Your physiotherapist may use low-level laser to reduce your pain and inflammation around the tendon
Changing posture or position
Often taping is useful to change your shoulder posture, allowing more space for the inflamed tendon and/or bursa. Your physiotherapist will give you simple strategies to change your posture so that your shoulder does not hurt so much. This will allow your shoulder blade (scapular) muscles to work better and improve the inflammation. Some strategies might be thinking about lifting your breast bone (sternum) up or imagining you are doing up a zipper from your belly button to the bottom of your ribs.
A complete rehabilitation program for the shoulder always includes some strengthening exercises. Your physiotherapist will give you an elasticised band for you to strengthen your shoulder blade and rotator cuff muscles. As your symptoms improve, your physiotherapist will progress the range of these exercises (how far you can move) and start adding resistance with different coloured bands, making the exercises more functional. All the exercises should be pain-free. Report to your physiotherapist if things don’t feel right.
If you play a sport involving overhead activities (such as tennis or volleyball), your physiotherapist may start you doing some strengthening for your gluteal (buttock) muscles as the stronger they are, the less force you need to generate from your shoulder muscles.
Your physiotherapist may use biofeedback (a machine that measures muscle activity) so you have more information about how your muscles are working and to help you increase the activity, particularly in your scapular muscles.
If you participate regularly in overhead athletic activities, your physiotherapist may video you throwing to analyse your technique, help minimise the potential impingement problem and hopefully improve your performance.
How effective is physiotherapy for impingement syndrome?
Physiotherapy has been shown to be effective for shoulder impingement syndrome. A 2014 study found that one year after a shoulder impingement injury, the patients who received physiotherapy had fewer episodes of shoulder impingement syndrome, requiring fewer visits to their GPs (37 per cent vs. 60 per cent) than the patients who had received initial corticosteroid injections. The patients who received injections often required additional injections as their impingement symptoms recurred.
In terms of specific treatments physiotherapists use, manual therapy is effective for relieving pain in shoulder impingement, but there is little evidence that electrotherapy, except for low-level laser, is effective in managing the condition. Doing exercises at home, with regular physiotherapist consultations, according to a program of progressive shoulder strengthening and stretching is effective in sustaining the improvements in the condition.
What can I do at home?
At home, you can make sure you sit and stand with a better posture. When standing, you can adopt a modified ballet third position making sure some part of your legs touch each other. This will stop you standing in a slumped position. Some people feel better with their shoulders held broad. Others find that if they lift their breast bone (sternum) up whenever they are lifting anything, their pain is improved.
A good range of motion exercise is placing your hands on your hips, then straight out in front, then placing your hands behind your head, taking your elbows back then straightening out your arms to the side and slowly lowering your arms down. Do this twice, two times a day. If straightening your arms out to the side is painful, don’t push your elbows back as far, as this exercise should be pain-free. Sometimes you are not aware that the muscles around your shoulder blades are working too much, so you can practise shrugging your shoulders up towards your ears with a breath in, then slowly letting the muscles go downwards with a breath out. This will decrease some of the tension around the neck and shoulders.
Overall the best home fix is an exercise program prescribed by your physiotherapist based on your individual condition and capacity.
How long until I feel better?
Shoulder impingement is due to inflammation of the tendon or the bursa, so you need to make sure you are not continually inflaming these structures.
If you keep a better posture and avoid using your arms repetitively above your chest, the shoulder impingement will settle relatively quickly (6–12 weeks).
If you are participating in overhead sporting activities it will take longer to settle, as often your technique may have to be corrected to make sure you are not continually re-inflaming the structures.