Why Your Shoulder Pain Might Actually Be a Mid-Back Problem

Have you ever felt a sharp pinch or a dull ache in your shoulder when reaching for something on a high shelf, putting on a jacket, or lifting weights at the gym?

If so, you might have been told you have "shoulder impingement"—a common term for when the tendons in your shoulder joint get pinched and inflamed.

When your shoulder hurts, your natural instinct is to stretch, rub, or strengthen the shoulder itself. But what if the real culprit isn't your shoulder at all? What if your shoulder pain is actually being caused by your mid-back?

Here is the surprising link between a rounded upper back and shoulder pain, backed by a landmark scientific study.

The "Narrow Hallway" Inside Your Shoulder

To understand why your back affects your shoulder, let’s look at a quick bit of anatomy.

Your shoulder joint is a ball-and-socket joint, and sitting right above it is a bony "roof" (which is actually part of your shoulder blade). The space between the ball of your arm bone and this bony roof is incredibly tight. We can think of it like a narrow hallway.

Inside this hallway run some very important structures, including your rotator cuff tendons and a small, fluid-filled cushion (bursa) that keeps things gliding smoothly.

• In a straight, upright spine: When you lift your arm, your shoulder blade naturally tilts backward (posterior tilt) and rotates upward. This clears the "hallway" so your arm can move freely without rubbing.

• In a rounded, slouched spine: When your mid-back rounds forward, your shoulder blades are forced to tilt forward and down. This physically lowers the "roof" of your shoulder joint, making that already narrow hallway even tighter.

Now, when you try to lift your arm, the bone of your upper arm gently compresses or pinches the sensitive tendons and cushions against that lowered roof. This is subacromial impingement.

What the Science Says: The 2014 Wake-Up Call

This connection isn’t just a theory—it was proven in a major 2014 study published by a team of medical researchers (Otoshi et al.).

The researchers wanted to see if there was a direct link between a person’s posture and their likelihood of having shoulder pain. They analysed a large group of individuals, measuring the curve of their upper backs and testing their shoulder health.

The results were eye-opening: people with a more rounded upper back (thoracic kyphosis) had a significantly higher rate of shoulder pain and limited range of motion.

The study proved that you cannot separate the shoulder from the spine. If your upper back is locked in a slouched position, your shoulder blade cannot move properly. This limits how high you can lift your arm and increases the likelihood of joint pinching and discomfort.

How to Fix Your Shoulder (By Fixing Your Back)

If you want to get rid of that shoulder pinch for good, you have to stop focusing only on where it hurts. You have to unlock your spine.

Here is a simple, three-step approach to get you started:

1. Mobilise Your Mid-Back

If your spine is stiff, your shoulders are trapped.

• What to do: Gently lean backward over a foam roller placed horizontally across your mid-back. Keep your lower ribs tucked down and support your head with your hands. Take deep breaths and let your mid-back drape over the roller to encourage extension.

2. Open Up Your Chest

Hours of sitting at a computer or driving pull our chest muscles into a tight, short position, which drags the shoulders forward.

• What to do: Perform a gentle doorway stretch. Place your forearms on either side of a door frame and gently step forward until you feel a comfortable stretch across your chest. Hold for 30 seconds while breathing deeply.

3. Wake Up Your Upper Back with the Prone Cobra

Once your spine can stand up straight and your chest is open, you need to strengthen the muscles that keep you there. One of the absolute best exercises to wake up these sleepy postural muscles is the Prone Floor Cobra.

• What to do: Lie face down on the floor. Lift your chest slightly off the ground by engaging your upper back, and rotate your thumbs up towards the ceiling. This externally rotates your arms, which naturally clears space in your shoulder joint so nothing gets pinched as you lift. Squeeze your shoulder blades together and down towards your back pockets. Hold this position for a few seconds, breathing naturally, and repeat.

• An advanced variation: If you want a slightly different challenge that also helps support optimal head and neck alignment, you can try performing the Prone Cobra while lying length-wise on a foam roller. This forces your core, upper back, and deep neck muscles to work together to keep you stable.

The Bottom Line

Your body is an interconnected web. If you try to fix a shoulder problem without addressing a slouched upper back, you are only treating the symptom, not the cause. By standing taller, rolling out your mid-back, and opening up your chest with exercises like the prone cobra, you'll give your shoulders the room they need to move freely and pain-free.