Serratus Anterior Muscle: Functional Anatomy Guide
To build your muscles, you need to know your muscles! Athletes, trainers, bodybuilders and even regular gym-goers need to understand exactly how the muscles in their body function, so that they can work them properly to make them stronger and bigger.
In this post you will find out everything you need to know about the functional anatomy of the serratus anterior muscle – shape (appearance), function (muscle action), location, insertion, and origin.
Muscle Shape (Appearance) and Location
Just below the pectoralis major are the serratus anterior, named for their serrated (or saw-toothed) appearance as they cover a portion of the first eight ribs. Architecture is convergent, and fibers are diagonal.
Serratus anterior can be palpated by placing the fingers flat against the rib cage just lateral to the scapula and moving them up and down in a superior/inferior direction, then moving them around toward the front of the chest, stopping before one reaches the pectoral muscle.
In athletic bodies the muscle may be even visible to the naked eye along the ribs underneath the axilla.
Muscle Action (Main Functions of the Serratus Anterior Muscles)
The main function of the serratus anterior muscle is to help raise the shoulder blades, and stabilize the frontal and overhead motions. In other words, its role is to pull the scapula forward and around the rib cage, similar to the motion that occurs when throwing a punch. That’s why this muscle is sometimes referred as the “boxer’s muscle”. Because it is scapula forward, it works with the pectoralis minor to produce protraction. During breathing, the serratus anterior also assists in chest expansion. As such, the muscle is an antagonist to the rhomboids.
- anteversion of the arm;
- thoracic stabilization of the scapula;
- downward and lateral rotation (lower part);
- upward rotation (upper part);
- secondary elevation of the ribs (ancillary function in breathing);
Origin and Insertion of the Serratus Anteriod Muscle
The serratus anterior muscle originates on the surface of the upper ribs, as well as the side of the chest, and inserts along the entire length of the medial scapula (shoulder blade). If you place the palms of your hands up and near your armpits, and fan your fingers toward your breasts, you are on the top of the serratus anterior muscle.
Image credit: eHealthStar
Exercises for the Serratus Anterior
This muscle generally gets adequate stimulus during normal exercises for the chest, back, and shoulder. It works especially hard during the lockout phase of a push-up or bench press. But if it or the pectoralis minor is weak or injured, training it directly may be necessary. It can also be targeted during exercises that work the abdominal oblique muscles.
After bench press and pus-ups, one of the best exercises for working the serratus is the cross-bench dumbell pullover. Other great exercises include narrow reverse-grip pulldowns and chin-ups, and straight-arm pushdowns. But diet is just as important to the serratus as any exercise. This is one of those muscles that simply disappears under a layer of fat.
- Push away
- Pullover if finished in a protracted position
- Serratus cable pullover
Indication of Weakness
A possible sign of a weak serratus anterior is a winged scapula whereby the scapula sticks out in the back in anatomical position.
There are, in effect, three different chest muscles: the pectoralis major, pectoralis minor, and serratus anterior, or serratus magnus. Each of these must be fully stimulated as a result of your workouts if complete chest development is your goal.
As you can see from the images above, the serratus anterior is a medium-sized muscle that covers most of the ribs. It forms part of the sidewall of the chest. This muscle may be the sexiest muscle on the male physique and well-developed set of serratus can give your physique a truly polished look. This is the muscle group on the side of your rib cage that resembles shark gills when they’re well developed and you’re shredded. So it is visible only in the best-developed physiques. The serratus can normally be trained sufficiently via compound movements of the chest muscles using exercises like the “bench press.”