Serratus Anterior Muscle – The Boxer’s Muscle!
The serratus anterior muscle is critical for shoulder stability. Its overall health is critical to shoulder health for yoga practitioners as it directly relates to postures that take our body weight into our hands and the ability of our rotator cuff muscles to function properly.
What does serratus anterior mean?
The serratus anterior muscle was named for its finger-like muscular origins that look serrated. “Serratus” comes from the Latin serrare meaning “to saw”.
Anterior refers to the muscle’s location on the front or anterior side of the body.
Serratus is known as the boxer’s muscle because it is the strongest protractor (sending it forward) of the scapula.
This anatomical movement is primarily what allows for the whole movement seen in a punch.
Where does the serratus anterior muscle attach?
- The upper 8 or 9 ribs
- The medial border or edge of the scapula
- There is a convergence of fibers on the inferior (bottom) angle of the scapula
What actions does the serratus anterior muscle do?
- Protraction of the scapula – It brings the scapula forward on the rib cage.
- Upward rotation of the scapula – It is used after the humerus abducts to ninety degrees.
- Stabilizes the scapula and prevents the inner edge from “winging”.
Postures where this muscle contracts:
I’ve also written more about how we use this muscle in yoga postures, especially in arm balances, in my book Functional Anatomy of Yoga.
Having said that, this muscle is a key stabilizer of the scapula and that is how it should be used in many yoga postures.
In utkatasana (below) this muscle upwardly rotates the scapula to get the arms over the head.
In bakasana (below) the serratus anterior muscle contracts to keep the chest from sinking through the shoulder blades.
Postures where this muscle lengthens:
In dhanurasana (below) the serratus anterior muscle is lengthened as the scapula retract (get pulled back and together).