Muscle of the Month: Serratus Anterior
Our muscle of the month is the serratus anterior, a fan-shaped muscle that wraps around the rib cage on either side of the torso, running from the thorax to the scapula.
Named after the Latin for 'saw' due to its serrated edges, this broad muscle has an important part to play in arm movement, shoulder position and breathing. It’s often neglected in workouts and can be the source of pain and restricted movement if strained or injured.
Personal trainers and fitness class teachers should be aware of how the serratus anterior is employed in certain exercises, in particular lifting weights over the head and boxing. In fact, it is sometimes called the boxer’s muscle; dancers also tend to have well developed serratus anteriors.
The origin and insertion of the serratus anterior
A deep muscle located under the scapula and pecs, the serratus anterior is usually only visible in particularly athletic bodies.
The muscle originates from between the angles and costal cartilages of the ribs – from the first to the eighth or ninth rib. The digitations then pass over the posterior thorax before inserting into the medial border of the thorax, underneath the shoulder blades.
The superior section of the muscle runs from the first two ribs and fuses into the upper angle of the scapula; the intermediate section runs from the second and third rib to the medial border of the scapula; and the lower section runs from the fourth to the ninth rib up to the inferior angle of the scapula.
The action and basic functional movement of the serratus anterior
The action of the serratus anterior is largely connected to movement of the scapula, helping to stabilise it, abduct and rotate it, and draw it forward and upward.
Its functions include:
- Lifting the arms above the shoulders
- Moving the arms in different directions
- Aiding pulling and pushing
- Elongating the arm when punching
- Lifting weights or other items above the head
- Holding the shoulder blades in place during certain movements and exercises
- Spreading and supporting the ribs when inhaling
- Stabilising the area and improving posture
Common exercises for the serratus anterior
Most exercises for the serratus anterior involve the shoulders and some require a slight modification of a common exercise, for example a lean back push up.
Working under the direction of an experienced personal trainer will help you to develop the right kind of training schedule to improve your strength and fitness and meet your goals.
Exercises that will work the serratus anterior include:
- push ups and reverse push ups
- lean back push ups and scapular push ups
- wall presses
- shoulder blade protractions
- rhomboid pulls
- oblique punching
- straight arm push downs
Problems arising from weakness in the serratus anterior
If the serratus anterior muscles are not working as they should, it can lead to strain or injury, in particular:
- Shoulder, neck or back pain
- Rotator cuff problems
- Arm numbness
- Poor circulation in the armpit
Nerve or muscle damage to the serratus anterior can cause winging of the scapula, when one or both of the shoulder blades stick out instead of lying flat. If left untreated, it can cause pain the back, shoulders and neck and restrict the movement of the arms.
Although rare, Serratus Anterior Muscle Pain Syndrome (SAMPS) causes anterior chest pain through the fifth to the seventh ribs, sometimes moving outwards to the arms and the little finger and ring finger.
Though deeper than some other chest muscles, the serratus anterior should not be neglected in a work out. Keeping this muscle strong will help you avoid neck, shoulder and back pain, allow you to lift and move your arms in their full motion and help with your posture and breathing.