The Serratus Anterior Muscle - The Shoulder's Secret Weapon: Info & Tips On How To Keep It Healthy & Functioning Well
- Ben Elliot
- Apr 28
- 4 min read
The Serratus Anterior muscle is a bit of a secret workhorse when it comes to our upper back and shoulders. It's not frequently spoken about, but it wreaks havoc if it's not working properly, and quietly ensures all the big muscles of the shoulder and upper back are doing their jobs well if it is.
Where is the Serratus Anterior muscle and what does it do?
Attachments:
Origin: Outer surfaces of the upper 8 or 9 ribs.
Insertion: Underside of the Medial border of the scapula).
Actions:
Protracts the scapula - pulls it forward around the ribcage, away from the spine (think of a boxer’s punch. It's sometimes named the “boxer’s muscle”).
Upwardly rotates the scapula - needed for lifting the arms overhead.
Holds the scapula against the thoracic wall of the ribs — essential for stable shoulder movement.
Nerve Supply:
Long thoracic nerve (C5–C7 roots).
The nerve lies on top of the muscle, so it’s more vulnerable to injury from trauma, surgery or repetitive strain.
Damage to the nerve can create weakness or even paralysis of the serratus anterior.
Why is the Serratus Anterior so Important?
The serratus anterior is extremely important - it's one of those underrated muscles that doesn’t get much attention unless something goes wrong, but let's focus on the amazing things it does when it's working properly.
Shoulder Stability:
It plays a major role in holding the scapula (shoulder blade) flat against the rib cage. If weak or paralysed, the inferior angle of the scapula can wing out (called “scapular winging”), which compromises shoulder mechanics, stability and function. This leads to shoulder instability, limited overhead movement, poor posture, and potential pain in the neck/shoulder area.
Arm Elevation:
You can't lift your arm overhead properly without it. It works with the upper trapezius and lower trapezius to rotate the scapula upward, which is essential for overhead activities such as throwing, reaching, swimming and climbing.
Performance & Injury Prevention:
It’s crucial for athletes, especially in sports with lots of arm movement (tennis, boxing, CrossFit, etc.). A strong serratus anterior helps distribute load properly and prevents shoulder impingement, rotator cuff issues, and neck strain.
Breathing Support:
It also has a secondary role in assisting with breathing, especially during heavy exertion, by helping expand the ribcage.
What happens when the Serratus Anterior isn't working properly?
If the serratus anterior is weak or not firing properly, you’ll often see compensations elsewhere, like overworked traps, tight neck muscles, or shoulder impingement. Compensatory aspects such as these can cause pain anywhere around the upper back and shoulder, and affect posture, leading to rounded shoulders and a forward-shifted head.
These postural presentations are really common and are associated with neck pain, pain between the shoulder blades or at the top of the shoulders (see my post on Upper Cross Syndrome for more information on the mechanics of this posture).
If the serratus anterior is overly tightened, you can also have compensation from surrounding muscles, but mostly likely you would lack range of movement in the arm and potentially have pain around the sides of the ribs that can radiate to the front of the chest and front aspect of the arm.
How can we fix the Serratus Anterior?
The first task is to determine whether the muscle is weak or fatigued - or shortened and tight.
If it's weak we can use exercise to help strengthen or reactivate the muscle.
Strengthening Tips
Push-up plus (a push-up with extra scapular protraction at the top)
Wall Angels
Serratus punches with a resistance band
Dynamic bear crawls
These help activate and strengthen it in functional movement.
If it's tight, we can use stretch and manual release techniques to relax and loosen the muscle.
Lengthening Tips
Home Activity:
Foam roller release
Doorway Stretch
Practitioner Techniques:
Passive movement with static pressure over the ribcage
Acupuncture or dry needling on rib attachment area, or medial border of the scapula - note that deep needling across the anterior aspect of the scapula tends to be avoided due to risk of pneumothorax, but can be carried out with specialist training.
Treating the Serratus Anterior in isolation may provide some improvement, but the likelihood is that other areas will have compensated for the lack of support that the Serratus Anterior is supposed to give. It's crucial to relax tightness in surrounding areas and strengthen and lax or weak muscles. The usual compensatory pattern of muscle disharmony is...
Tight/Short:
Upper Trapezius
Levator Scapula
Pectoral Major & Minor
Infraspinatus
Teres Minor
Weak/Fatigued:
Rhomboids
Mid Trapezius
If these muscles aren't treated, the balance of the shoulder girdle will prevent the Serratus Anterior from recovering as it battles against this misalignment from the surrounding muscles pulling, or not pulling, structures in their intended direction. In particular, I can't emphasise enough how important a pectoral release is in resolving these types of issues.
So now you know how important our Serratus Anterior muscle is, and how to keep it healthy.
