Shoulder Impingement - “My shoulder is sore to sleep on”

Shoulder Impingement - “My shoulder is sore to sleep on”

Tommy Conway, Director and Lead Physiotherapist at OneHEALTH

Do you have a shoulder that you can’t lie on at night? Do you wake in the morning with a painful shoulder? Does it even wake you up in the middle of the night if you spend 20 minutes lying on it. This can be a sign of a shoulder impingement which causes a lot of pain, starting with minor restrictions and then building up to a loss of movement and eventually unable to lift and hold objects like the kettle or a cup of tea. These restrictions can start with you being unable to reach for the seatbelt, unfasten your bra, tucking your shirt in can be restricted or even putting on your jacket can cause problems. All of these early restrictions are a warning sign to a shoulder impingement issue. When I usually see clients in my clinic with a shoulder impingement they have it a number of months, even a year. Believe me this condition does not improve with time and rest. The movement slowly gets worse and so does the pain. I will try to help you understand how to help your condition but first we need to learn about the condition.

What is a shoulder impingement?

A shoulder impingement is when the tendons of the shoulder muscles become pinched between the shoulder blade and the head of the humerus (Arm bone). If you are getting it hard to visualise see picture 1. In picture 1 you will see the round shaped upper arm bone is below the tendon (In orange) whilst the flat shaped shoulder blade is above the tendon. Because of where the tendons are positioned, they need a lot of space between the two bones to move freely. If there isn’t enough space the tendon can get pinched and start to swell, this further narrows the space for the tendons to move and starts the vicious circle of a shoulder impingement. This is when lifting your arm becomes painful and what we call a “painful arc”. The space between the shoulder blade and humerus is at its smallest at 80 degrees to 110 degrees, and this is when a lot of people will complain of pain. You might even be able to lift your arm all the way up but when you go up you will get pain at the arc (80-110 degrees) and when you go back down it can be worse at 80 - 110 degrees.

Why does it happen?

1: You lose movement of your arm bone (Humerus)

2: Control of your shoulder blade.

When the arm loses movement, there will not be enough space for your tendons to move freely within the joint This lack of space will give the tendons a lack of freedom to move and that’s when they start to get pinched. The muscles around the upper arm bone(Pic 2) need to stay flexible to allow the bone to rotate freely without pinching the tendon. This is why when you start struggling with the movements of tucking your shirt in and putting on your jacket, it is a good warning sign that you have lost some movement in the upper arm.

The next step is the compensation of the shoulder blade. If the movement in the arm is restricted the shoulder blade will move excessively to complete the task. This will result in the shoulder blade “winging” and tilting forward( See pic 3). This forward tilt again causes a narrowing of the space for the tendons. A clear indication of this problem is when you present with the painful arc as mentioned above. If your shoulder blade is tilted upwards when you start to lift your arm, the arm bone and shoulder blade meet too early and that's where you get the “PINCH” of your tendon.

Combine these two problems together and you have a very unhappy shoulder. That’s when you will present to me and say “My shoulder is sore to sleep on”. The reason it is sore to lie on is because your body will only rest in positions where it has no restrictions in movement. It will not allow you to put your body weight through a joint that does not have it’s full range of motion.

The warning signs you have is when you are trying to tuck in your shirt, Unfasten your bra, or putting on a jacket. This is when the problem can be rectified to 5- 6 sessions. Once the painful arc starts to present the shoulder has moved onto step 2 and this can take longer to rectify. I just want to clarify that exercises alone will not correct a shoulder impingement, that loss of movement at the upper arm has to be got back first. The only way to do that is through hands on treatment such as massage, mobilisations, dry needling etc. Once the therapist restores the movement then a strengthening programme can correct the unstable shoulder blade. It’s a step by step process that has good results, sometimes if not treated soon enough it can require surgery. This surgery requires making space for the tendon to move by shaving off some bone at the base of the shoulder blade. My only advice is the next time you wake up and say “My shoulder is sore to sleep on”, take the steps to getting it better now before it gets worse.

I hope this helps and any questions you can email me at [email protected]