Meet Your Muscles: The Serratus Anterior

Where is it?

The serratus anterior is a lesser-known muscle that wraps around the sides of your ribcage, just under your armpits. If you’ve ever seen someone with very defined sides (especially in athletes), those zig-zag-looking muscles beneath the chest are the serratus anterior. It connects your upper ribs to the inside edge of your shoulder blade (scapula).

The name “serratus” comes from its saw-like shape. Think of it as a fan that spreads out across the ribs and helps anchor and guide your shoulder blades.

What does it do?

The serratus anterior plays a crucial role in moving and stabilizing your shoulder blades. It helps pull the shoulder blades forward and around the ribcage (like when you punch or reach forward), and it keeps them flat against your back during movement. This muscle also supports full overhead motion—so if you like to reach, lift, swim, or throw, your serratus is definitely involved. It even helps with breathing, especially during exertion, since it attaches to the ribs.

What makes it hurt?

When the serratus anterior is tight, weak, or irritated, it can cause discomfort in some surprising areas. Common issues include:

• Shoulder pain or feelings of instability

• Pain along the sides of the ribs, sometimes mistaken for intercostal or oblique pain

• “Winged scapula”, where the shoulder blade lifts off the back instead of lying flat

• Shallow or restricted breathing during stress or physical strain

Contributing factors can include poor posture, repetitive overhead movements, chest breathing, or stress-related tension. It’s often overlooked in shoulder issues—but it shouldn’t be.

How can massage help?

Massage therapy can help bring awareness and release to this tucked-away but hardworking muscle. It can be accessed by working along the ribcage, under the shoulder blade, and into the side body. It can be tender when massaged, especially if it’s tight. Releasing tension in the serratus anterior can improve shoulder mobility, help restore easier breathing, and reduce that annoying feeling of restriction in the upper torso.

What can I do besides massage to help it?

To support this muscle between sessions, you can:

• Stretch your side body: Try side bends or a yoga pose like “extended child’s pose with side reach”

• Work on posture: Keeping your shoulders open and upright reduces strain

• Breathe deeply: Belly breathing helps relax and engage the surrounding area

• Strengthen it: Wall push-ups or "plus" push-ups (with an extra push at the top) can gently activate the serratus

• Use a massage ball or foam roller: Gently roll out the upper side of the body under the armpits but above the ribs to keep that area from getting too tight and tender.