Got Shoulder impingement? What are you impinging on? - Be My Healer

Got Shoulder impingement? What are you impinging on?

You've been having shoulder pains for a while now, and it does not seem to get better. Then someone, like your doctor, suggested that you might have a impinged shoulder (or swimmer's shoulder). 

Impinged shoulder? Impinged on WHAT?​

Muscles? Nerves? Bones?

In this post, I will try to simply shoulder impingement for you.​

The short answer


The short answer is: the rotator cuff muscle.

However, this does not help you understand how and why you got here.

The rotator cuff muscle is not one muscle either. The so-called rotator cuff is made up of 4 small muscles surrounding your shoulder joint like 4 little fingers. They allow your shoulder to move in amazingly little restrictions.

The particular muscle that's been victimized here is the supraspinatus muscle, a small hard worker on the top of your shoulder joint.

supraspinatus muscle

supraspinatus muscle

The subacromial shoulder impingement syndrome

The subacromial shoulder impingement syndrome is the most common type of shoulder impingement.


subacromial space shoulder impingement

The subacromial space is describing the space between the head of the humerus bone and the "roof of the shoulder" bony acromion. This spacious area contains the subacromial bursa (the largest bursa in the human body) and the tendon of the supraspinatus muscle (part of the rotator cuff).


When shoulder function properly, the head of the humerus (the arm bone) rotates within the shoulder joint.

However in those with the subacromial shoulder impingement, the head of the humerus bone does not stay where it should be. During any form of upward, the head of the humerus bone move up into the subacromial space and collide with the bony acromion. 

subacromial shoulder impingement

When this happens, what's been squeezed between two pieces of bones are the supraspinatus muscle tendon and the subacromial bursa. Over time when this happen repetitively, inflammation and pain occur in the bursa and the muscle tendon. 

When you are feeling the pain in your shoulder, you are experiencing pain from either tendonitis or bursitis, or both, due to the impingement syndrome.


Frequently seen in clinical settings, those who have the subacromial shoulder impingement without trauma or previous shoulder injuries are in pain because of mechanical issues.

What mechanical issues? We are talking about muscle imbalance, such as the commonly tight upper trapezius muscle, pectoralis major and minor, as well as the weakened rotator cuff muscles and upper back muscles.​

What causes muscle imbalance? Poor posture is often to blame in lots of elderly population and office workers. Prolonged and repetitive overhead work in an occupation such as​ painter, gardener, chef, construction worker, machinist, and etc. 

For those with any past or recent injuries to your shoulder, neck and elbow are at high risk of developing chronic shoulder condition such as the subacromial shoulder impingement syndrome. Debilitating injuries often result in temporary muscle weakness, leaving rooms for bad muscle memory and compensation to become a habit. From there, you may develop shoulder impingement pain few month or a year after the initial injury.

Still not sure if you have the subacromial shoulder impingement syndrome? Do this simple test to find out if this is what you are suffering from.

With this said, I high recommend receiving proper treatment from a physical therapist whenever you (or family member) have sustained a major and debilitating injuries to prevent the development of chronic conditions or pains from the aftermath of the injury.​


  • Stretching or deep tissue massage to release the tight muscle groups
  • Targeted icing or therapeutic ultrasound treatment to control inflammation in the supraspinatus muscle tendon and subacromial bursa
  • Postural strengthening of the upper back to improve shoulder blade stabilization
  • Strengthening of the rotator cuff muscle in pain-free zone
  • Professional manual therapy from a physical therapist to improve shoulder joint glide (or learn to perform shoulder joint glide with a belt)

Chronic subacromial shoulder impingement left untreated may result in calcification of the rotator cuff muscle tendon involved, and partial or complete muscle tear may occur. At that time, surgeries and lengthy and painful rehabilitation process of minimum 6 months will be needed to regain function in the injured shoulder. 

The internal shoulder impingement syndrome

The other form of shoulder impingement is less common, and more of a problem for athletes. The internal shoulder impingement, or thrower's shoulder, is a problem for people having to doing lots of fast throwing and hitting overhead.

Where and how?

shoulder external rotation

This impingement occurs inside the shoulder joint. When the shoulder is pulled into terminal external rotation and forcefully reverse direction with high velocity, a piece of the supraspinatus tendon can get caught in the action and become impinged inside the shoulder joint itself.

With repetition, the impinged tendon can cause a lot of inflammation and pain within the joint capsule.​


This often happen because the patient has too much flexibility or availability in the external rotation motion. Athletes such as the base ball pitcher often has such flexibility due to repetitive stretching and practice. 


  • Targeted icing (with compression) or therapeutic ultrasound to calm down the pissed-off muscle tendon
  • Dynamic strengthening of the rotator cuff muscles to improve shoulder stabilization. 
  • Sports taping or kinesiotaping during practice and games to prevent further aggravation of injured tendon

There are other ways to impinge yourself with the shoulder joint, such as the impingement of the joint capsule or the joint labrum. However they are more rare and can only be diagnosed with advanced imaging technologies.

If neither of these two impingement scenarios describes your pain, please visit a physical therapist with a good review or referral for treatment.​

Thank you for reading, and I hope you find this post helpful.

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