Why the Serratus Anterior Is the Posture Muscle You’re Forgetting (and How to Strengthen It)
Poor posture. Rounded shoulders. That familiar ache between your shoulder blades after nursing, carrying a baby, or sitting at a desk.
Sound familiar?
There’s a little-known muscle that could be the key to unlocking better posture, stronger shoulders, and even easier breathing: the serratus anterior.
Let’s talk about why this muscle matters—and how to wake it up with 4 simple exercises you can do anywhere.
What Is the Serratus Anterior?
The serratus anterior is a thin, fan-shaped muscle that sits along the side of your ribcage. It connects your ribs to your shoulder blades and plays a crucial role in how your shoulders and upper back move.
It’s often called the “boxer’s muscle” because it’s activated when throwing a punch. But don’t be fooled by the nickname—this muscle is just as important for postpartum moms and desk workers as it is for athletes.
👩⚕️ Dr. Piper Crossland, PT & mom of 4, explains:
“Your serratus anterior holds the shoulder blade flat against your ribcage. When it’s weak, the shoulder blade can ‘wing’ out or ‘tip’ forward, leading to poor posture, shoulder pain, and even neck tension.”
Why a Strong Serratus Anterior Matters for Posture
1. Scapular Stability
This muscle keeps your shoulder blades stable and flush with your ribcage. Weakness here can cause scapular winging or tipping, making your shoulders round forward.
2. Shoulder Mobility
Proper shoulder mechanics rely on your scapula rotating and gliding smoothly. Without this, overhead movements can strain your neck and upper back.
3. Breathing Support
Because it connects to the ribs, the serratus anterior assists in expanding your ribcage during deep breathing. This is key for core control and postpartum recovery.
4. Real-Life Benefits
Strengthening this muscle helps:
✅ Reduce neck and shoulder pain
✅ Improve posture during nursing or babywearing
✅ Support athletes in overhead sports
✅ Make daily movements feel easier
4 Serratus Anterior Exercises for Better Posture
These exercises activate and strengthen the serratus anterior. Start slow and focus on form.
⭐ 1. Serratus Stars
Why it works: Activates the serratus anterior while improving control of the shoulder blade through multiple directions.
How to do it:
1. Stand facing a wall with a resistance band looped around your wrists and your forearms pressing lightly against the wall.
2. Keeping slight tension in the band, move your right hand in a “star pattern”—reach up and out, straight out to the side, and down and out—returning to the starting position each time.
3. Repeat with the left hand.
4. Perform 2-3 rounds per side.
⬆️ 2. Serratus Wall Slides with Foam Roller
Why it works: Encourages scapular upward rotation and serratus engagement while adding dynamic movement.
How to do it:
1. Stand facing a wall with a resistance band looped around your wrists and your forearms and a foam roller pressed against the wall.
2. Lightly press into the roller to keep it in place as you roll it upward, extending your arms overhead.
3. Roll back down with control.
4. Repeat for 8-10 reps, keeping your core engaged and shoulder blades flush against your rib cage.
💪 3. Push-Up Plus (Protraction Holds)
Why it works: Strengthens the serratus anterior by focusing on scapular protraction.
How to do it:
1. Begin in a high plank or modified plank on your knees.
2. Keeping your elbows straight, push through your hands to spread your shoulder blades apart slightly (“round” your upper back).
3. Hold for 2-3 seconds, then return to start.
4. Repeat for 8-10 reps.
🥊 4. Serratus Punches (Supine)
Why it works: Activates the serratus in a functional, gravity-assisted position.
How to do it:
1. Lie on your back holding a light dumbbell in one hand, arm extended straight up toward the ceiling.
2. Without bending your elbow, “punch” the weight slightly higher by allowing your shoulder blade to lift off the floor.
3. Lower the shoulder blade back down with control.
4. Perform 10-12 reps per arm.
The Posture Connection (Why Moms Should Care)
Whether you’re holding a baby for hours or sitting at your laptop, posture plays a huge role in how you feel.
A weak serratus anterior can contribute to:
❌ Neck pain
❌ Shoulder injuries
❌ Tension headaches
❌ Poor breathing mechanics
But when it’s strong? You’ll feel more aligned, more confident, and better equipped to handle all the physical demands of motherhood.
💛 Think of it like K-tape you can put on yourself—with lasting results.
The Takeaway
The serratus anterior might not be a muscle you see in the mirror, but it’s one you’ll feel when it’s strong. Add these exercises to your routine and watch your posture (and comfort) improve.
Meet the Author
Piper is a pelvic health specialist passionate about helping women rebuild posture, core strength, and confidence through evidence-based movement and everyday strategies.
Disclaimer: This article is for educational purposes only and is not a substitute for medical advice. Always consult your healthcare provider or a qualified pelvic health professional before starting any new exercise or rehabilitation program, especially if you are pregnant or postpartum.