GENERAL INFORMATION
The serratus anterior is a muscle that originates on the surface of the upper eight to nine ribs as well as inserts along the entire anterior length of the medial border of the scapula. This muscle is essential for scapular movement and also stabilisation.
ORIGIN
The serratus anterior muscle originates from the lateral aspect of the 1st to 8th as well as 9th ribs.
INSERTION POINT
The muscle inserts along the medial border of the scapula.
MAJOR ARTERIES
It is primarily supplied by the lateral thoracic artery, which ensures adequate blood flow for its functions.
NEURAL INNERVATION
The long thoracic nerve innervates the serratus anterior.
TRIGGER POINT
Trigger points can develop in various parts of the muscle, often resulting in pain on the side, back, and lower part of the scapula.
CONCENTRIC FUNCTION
This muscle is responsible for the protraction and upward rotation of the scapula, such as when throwing a punch (boxing) or pushing something.
ECCENTRIC FUNCTION
The serratus anterior helps control the deceleration of scapular retraction.
ISOMETRIC FUNCTION
Isometrically, it holds the scapula against the thoracic wall, also preventing it from winging.
RELATED MUSCLES (SCIENTIFIC NAMES)
- Pectoralis Major: A large muscle on the chest, essential for arm flexion, rotation, and adduction.
- Pectoralis Minor: A thin, triangular muscle beneath the pectoralis major, important for scapular movement and stability.
- Subclavius: A small muscle under the clavicle. It also helps in clavicle stabilisation.
- Trapezius: A large muscle extending over the back of the neck and shoulders, crucial for moving and stabilising the scapula.
ANTAGONISTS
- Rhomboids: Retract and rotate the scapula, opposing the protraction function of the serratus anterior.
- Trapezius: Specifically, the middle and lower fibres retract the scapula, countering the serratus anterior’s action.
- Levator Scapulae: Elevates the scapula, opposing the downward movement of the serratus anterior.
COMMON INJURIES
- Serratus anterior palsy: Occurs due to damage to the long thoracic nerve, also leading to muscle weakness.
- Winged scapula: The inner edge of the scapula protrudes backwards, often due to serratus anterior dysfunction.
EXERCISES
- Push-ups with a plus: At the end of a push-up, push further to protract your scapulas, engaging the serratus anterior.
- Serratus wall slides: Stand against a wall and slide your arms upward while pressing into the wall to engage it.
- Dumbbell punches: Hold dumbbells and punch forward, focusing on protracting the scapulas.
- Plank with shoulder protraction: Hold a plank position and push through the shoulders to protract the scapulas.
- Bear crawls: Move forward in a crawling position, keeping the scapulas protracted and stable.
STRETCHES
- Doorway stretch: Stand in a doorway with hands and elbows on the frame and also lean forward to stretch the serratus anterior.
- Reaching upward and leaning to the side: Extend one arm overhead and lean to the opposite side to stretch the muscle.
- Child’s pose with side reach: In the child’s pose, walk hands to one side to stretch the serratus anterior.
- Cross-body arm stretch: Pull one arm across the chest with the opposite hand, stretching the upper back and shoulders.
- Foam roller stretch: Lie on a foam roller placed vertically along the spine, extend arms out to the sides to stretch the chest and serratus anterior