Shoulder Pain After Sleeping (and How to Prevent It)

The question of how to solve shoulder pain after sleeping is an important one to answer. Trying to sleep with shoulder pain can make life really tough, and hugely impact your sleep quality.

I remember nine months of not being able to sleep on one side after blowing my AC joint after a bad Aikido breakfall.

It’s an experience I never want to repeat, and in this article, I’ll give you some ideas on how to sleep with shoulder pain.

The best sleeping position for shoulder pain depends on what’s causing the pain in the first place.

For the most common cause of shoulder pain (impingement) the key is not to sleep on the side that’s sore. We’ll go into what impingement is, and what to do about it later, however, if you have this problem, sleeping on the sore shoulder will further irritate the joint.

Unfortunately, if you have a frozen shoulder (adhesive capsulitis) then no matter what position you take, it’s likely you’ll be in pain. However, this is a much rarer condition, so most people will be able to prevent sleeping with shoulder pain by staying on their good side or their back.

Avoiding Side Sleeper Shoulder Pain

Training yourself to sleep in a particular way comes down to habits. Before you had shoulder pain, you were either in the habit of lying on that sore shoulder or on both shoulders equally. Now, you need to train yourself to sleep in a different way until your shoulder heals.

Here are some techniques to train you to either sleep on your back, or on your good shoulder side:

  • Pack pillows on either side of you to prevent you rolling onto your sore side during the night
  • Start your night with a strong self-hypnosis suggestion that you will remain on your back / good side the whole night
  • Put a pillow under your lower legs, and sleep on your back with them slightly propped up. This will make it harder for you to roll over in your sleep
  • Sew a tennis ball into your sleeping Tshirt on the same side as your sore shoulder, around your tummy. Pressure on your abdomen will likely wake you before shoulder pain will, and it will encourage you not to roll in the first place

Training a new sleep position does take time. However, if the underlying problem is a rotator cuff problem, when you succeed in training this habit, you will tend to wake up without pain because you haven’t been irritating the joint during the night. 

Solutions to Shoulder Pain from Sleeping on Your Side

Once you’ve trained yourself to sleep either on your good side, or on your back, the next thing is to look at relieving the underlying cause of your shoulder pain.

The commonest cause of chronic pain of chronic shoulder pain is a damaged rotator cuff. The rotator cuff is made up of four muscles, all of which arise from your scapula: supraspinatus, teres minor, infraspinatus, and subscapularis.

These muscles come from the scapula and wrap around the head of the humerus. Their job is to balance the head of the humerus so that the stronger power muscles can move it.

If there’s damage to the rotator cuff, what happens is that instead of the head being balanced, the muscles will pull it in an asymmetric way and you will get impingement. 

Impingement occurs when the head of the humerus that rises up and digs into the overlying acromion, which is a shelf of bone over the top of the head of the humerus.

The shoulder joint, and where the head of the humerus impinges on the acromion, causing shoulder pain when you sleep on your side, or raise your arm out sideways

To avoid this happening, there needs to be a correct sequencing in the contraction of the shoulder joint muscles.

Because the shoulder is the most mobile joint in the animal kingdom, for that mobility to be maintained, all the rotator cuff muscles have to dance together perfectly to keep the head of the humerus within one or two millimeters of the head of the middle of the glenoid fossa (the cup the shoulder sits in.)

In other words, the cup of joint and the head of the humerus can only move a few millimeters away from the center of that cup. The cup is quite small, so the rotator cuff muscles have to be incredibly balanced to hold the head in balance.

How the supraspinatus needs to work in order to prevent shoulder impingement

The most important muscle of the rotator cuff is the supraspinatus muscle. It runs along the top of the head of the humerus and it needs to contract first as you lift your arm.

If it contracts first, it pulls the head of the humerus inwards and downwards. It pulls it into the joint cup. Once it’s pulled into the cup, then when the bigger power muscles like the deltoids contract to lift your arm, they will just rotate the head in the cup.

If, however, the supraspinatus doesn’t contract before the deltoids and other shoulder power muscles, then the head of the humerus is not pulled into the cup.

As the power muscles contract, they pull the humerus head upwards instead of rotating it. Once the head is pulled upwards, then the bursa, which sits above the head, gets squeezed, and the humerus digs into the acromion. This gives you the pain of the impingement. 

When you lie on your shoulder, the same thing happens. The head of the humerus gets pushed up into the chromium and squeezes the bursa and you get impingement pain. That’s the primary reason why a sore shoulder hurts when you lie on it.

If you want to impingement when you lift your arm, the sequence of muscles contracting has to be correct. It has to be supraspinatus first, then the deltoid and other power muscles. So that’s what you have to teach your shoulder.  

I’ve taught people how to do this, and even when they’ve had impingement pain for years, once they get the technique right, they’re often able to move their arm with much less pain, quite quickly.

There’s still a lot of retraining work to do, but that first initial training session is very rewarding for both of us.

One of the common causes of impingement is the supraspinatus muscle not working properly due to trigger points. Here’s where to find out more about treating triggers and relieving shoulder pain.