Why does my shoulder hurt when I lift my arm?

Does your shoulder hurt when you lift your arm above your head?

You might feel a sharp, sudden pain in your shoulder when you try and do simple things like brushing your hair, reaching for something on a high shelf or fastening a zip at your back.

You might find that the pain is bad enough that you can’t do these things at all. If you can, it’ll take you much longer than usual.

When this happens, it’s probably due to an injury or weakening of your shoulder joint. Even a small injury can lead to serious pain and problems with movement in the shoulder’s finely-balanced joints.

The shoulder girdle

The shoulder girdle connects your arm to your body. It’s a complex system – unsurprising when you think of all the things that a healthy, pain-free shoulder can do. Even if you’re in a desk job, you use your shoulder girdle all day long simply to function normally. Every time you make a cup of tea, hang your coat up or press a lift button, you’ll use your shoulder girdle.

There are four shoulder joints: the Glenohumeral joint (the ball and socket), sternoclavicular joint, acromioclavicular joint and scapulothoracic joint.

Together, these four joints allow you to move your shoulder anywhere you like – up, down, across and round. But there is a price to pay for the range of movement you have in your shoulder – it’s naturally unstable.

Ligaments and muscles in the shoulder have the job of stabilising it, but sometimes, things go wrong.

The rotator cuff

The rotator cuff is the name for the group of muscles that stabilise your shoulder (the supraspinatus, infraspinatus, teres minor and subscapularis  muscles).

They run from your shoulder blade all the way down your arm. When you move your arm, they support the ball of the arm bone as it moves into the socket of your shoulder.

Without them, the ball would fall out of the socket and you wouldn’t be able to move your shoulder at all.

How rotator cuff injury causes your shoulder to hurt when you lift your arm…

The rotator cuff is notoriously prone to injury and is often the cause of pain. These might be vital muscles, but they can get lazy and begin to weaken (just like your glutes). A weak rotator cuff can’t do its job properly and you begin to experience shoulder pain when you lift your arm.

This often happens because of slouching and rounding your shoulders – as you probably do when you’re sitting at your desk.

Slouching means your rotator cuff doesn’t need to do anything to keep your shoulder in place. Muscles that aren’t being used inevitably weaken. Then, when you do try to use them (such as when you reach up to a high shelf), you get pain.

This pain happens because your shoulder joint can’t move through its usual range of movement without squashing parts of the joint, including the tendons. The joint becomes sore and inflamed, and even damaged. As this happens, there is swelling that reduces the amount of space in the joint and leads to even more pain and problems moving.

Find our more…

In this week’s injury rehab and prevention video series we will be sharing some tips to keep your shoulders strong and stable, and avoid any unwanted aches and pains. You can access the playlist here. If you find the content helpful, don’t forget to subscribe to our channel as we release a new series each week.

If your shoulder is sore, you can always book in for a physiotherapy assessment with one of our team. We will be able to assess your injury over video call and prescribe you with a home-based treatment plan that is completely tailored to your needs. If you’re in pain, don’t hesitate to get in touch, we’re here to help.