As Sports Massage Therapists we will encounter patients who develop posterior shoulder pain or weakness. Both Winged Scapula – Serratus Anterior Palsy or Trapezius Palsy, become real possibilities due to trauma or impingement from sports.
Either one can cause shoulder weakness and pain.
How can the scapula’s position give us a clue as to what might be happening within the nervous system or in the surrounding muscular tissue? Before we address that lets look at the two conditions more closely.
First, Winged Scapula due to Serratus Anterior Palsy.
Injury to the Long Thoracic Nerve that innervates the Serratus Anterior muscle, is the most common reason for its dysfunction. Blunt force trauma, virus, or compression during activity are the most documented links to Winged Scapula.
What does the Serratus Anterior muscle do?
Its primary responsibility is to hold the scapula tightly to the ribs, Abduct the shoulder blade for protraction of the shoulder and assist in upward rotation.
If you throw a punch (like a boxer) this muscle moves the scapula in the direction of the punch.
Same if you perform a push-up. This muscle stabilizes the shoulder through concentric movement.
An athlete who develops this condition will have difficulty in pushing movements as well as reaching quickly overhead.
What are the visible signs of Serratus Anterior Palsy?
- A visible rise in the shoulder blade (scapula is elevated off the ribs) .
- Inferior border of scapula has moved in the vertebral (medial) direction.
- Shoulders are asymmetrical.
- Weakness is detected when patient is asked to protract arm forward.
- Spasms over pectoralis minor as it tries to compensate for weak protraction of S.A.
Now remember that one of the BIG visible signs is the medial deviation of the inferior border.
What if the inferior border is more axillary (lateral)?
That is more likely to be Trapezius Palsy.
Trapezius Palsy is caused by damage to the Spinal Accessory Nerve which innervates the Trapezius muscle.
Trapezius Palsy causes different signs than the Serratus injury. Some differences are:
- Scapular depression
- Weakness in scapular elevation (unable to shrug shoulders)
- Inferior border moves laterally towards axillary area which is the opposite of Serratus Palsy.
- Visible spasms over rhomboids and levator scapulae as they are overworked trying to compensate for T.P.
If I see any of the signs (Doug’s video above), I refer them to a doctor right away. Especially if they have pain.
A doctor can perform nerve tests and give a final diagnosis that will then help us to do our job more effectively.
One way would be if the doctor tells us that it is a simple impingement of the posterior triangle (corridor) of the neck.
We can then perform deep tissue massage to loosen hypertonic muscles that might be choking proper nerve innervation.
I will make another video soon on how I do just that!
Doug Holland, LMT