The Most Slept-On Muscle in Your Upper Body: The Serratus Anterior

If your shoulder always feels a bit off, whether that means stiff, painful, or just not right, there is a strong chance no one has ever taught you how to find your serratus anterior.

This isn’t some niche muscle for physios. It is one of the main reasons people get shoulder pain, bad posture, angry traps, tight pecs, and that constant sense of instability when they press, punch, or reach overhead.

What the serratus anterior actually does

It sits on the side of your ribs and connects to your shoulder blade. Its job is to keep your scapula moving smoothly. When it works, your shoulder blade glides. When it doesn’t, everything else tries to pick up the slack.

Your neck gets tight. Your traps switch on. Your pressing turns into shrugging. Your shoulder gets compressed. And eventually, pain becomes the default.

People think they have a rotator cuff problem. Sometimes they do. Most of the time the serratus just isn’t doing its job.

Why people miss it

Because no one teaches you to look for it. And when they do, the cues are terrible.

Keep your shoulders down.
Pull your shoulder blades back.
Brace your core.

All of these kill the serratus. They freeze the ribs and lock the scapula in place. The serratus needs movement to work. It needs reach. It needs breath. It needs your ribs to expand.

It is a coordination muscle, not a bodybuilding one. You do not feel a pump. You do not feel a burn. You feel a smooth shoulder. That is why it gets ignored.

What happens when it is weak

You become trap dominant.
You start compensating.
Your shoulder stops rotating properly.
Everything feels tight even when you stretch.

You can be strong, athletic, and mobile and still miss it. Your numbers don’t matter if your mechanics are off.

How to bring it back online

Go slow. Learn to breathe wide into your ribs. Reach without shrugging. Use light band work, wall slides, controlled push-up reaches, and hanging. Watch your neck. If it switches on, you are compensating.

Good serratus work looks boring from the outside. It feels subtle from the inside. But it changes how your whole upper body works.

When it clicks, your shoulder finally makes sense.

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