The 17 Muscles That Attach to Your Shoulder Blade (and What Each One Does)

If you want the wider picture first, start with our pillar guide, How the Shoulder Works. For the rotator cuff alone, read What Does the Rotator Cuff Actually Do?, and for the blade's movement, see Scapula 101.

Your shoulder blade is a flat, triangle-shaped bone on the upper back. It is not fixed to your ribs the way a skull sits on the spine. It floats on the back of the rib cage, held in place by muscle.

That design is useful. It lets your arm reach far in many directions. The socket where the arm bone (the humerus) meets the blade is shallow. So the blade has to tilt, slide and rotate to keep the ball of the joint in a good position as you move.

Physiotherapists often describe the blade as the base the arm works from. When the base moves well, the arm has a stable platform. This is a helpful way to think about it. It is still a model, and we do not know for certain how each person's pain connects to how their blade moves.

Muscles are easier to remember by their job than by their Latin names. The list below covers the major muscles that attach to the blade. Some textbooks include a few more, and the total of seventeen depends on how you count. Do not worry about memorizing every name.

• Trapezius (upper, middle and lower): a large, flat muscle across the upper back and neck. The upper part lifts the blade. The middle part pulls it toward the spine. The lower part pulls it down and helps the arm rise overhead.
• Rhomboids (major and minor): sit between the blade and the spine. They pull the blade back and toward the midline.
• Levator scapulae: runs from the side of the neck to the top inner corner of the blade. It lifts the blade and helps tilt the neck. Many people feel it after long hours at a screen.
• Supraspinatus: sits in the hollow above the spine of the blade. It helps start lifting the arm out to the side.
• Infraspinatus and teres minor: sit behind the blade. They turn the arm outward.
• Teres major: a small muscle on the lower outer edge of the blade. Sometimes called the "little lat," it helps bring the arm down and in.
• Deltoid (back fibres): the back part of the shoulder cap. It attaches to the spine and top of the blade, and helps move the arm backward.

• Subscapularis: the largest rotator cuff muscle, lying on the front surface of the blade. It turns the arm inward and helps keep the ball of the joint centred in its socket.
• Serratus anterior: a fan-shaped muscle that wraps around the side of the ribs. It pulls the blade forward around the rib cage and lifts it so the arm can reach overhead. Boxers use it when they punch forward, which is why it is nicknamed the "boxer's muscle."
• Pectoralis minor: a small chest muscle that attaches to a bony hook at the front of the blade. It pulls the blade forward and down.
• Coracobrachialis and the long heads of the biceps and triceps: arm muscles that start at the blade. They help move the arm forward, bend the elbow and steady the joint.

The rotator cuff is a group of four muscles: the supraspinatus, infraspinatus, teres minor and subscapularis. Their job is to keep the ball of the arm joint steady while the larger muscles move the arm. They sit on the top, back and front of the blade, so they overlap with the list above.

When people talk about "rotator cuff exercises," they usually mean exercises for these four muscles. Much of the blade work in this article is about the muscles that position the blade, which is a related but different job.

Most research looks at groups of muscles and whole movement programs, not at single muscles on their own. These points are the most useful:

• A 2025 review of specific exercise types found that scapular stabilization exercise, which trains the muscles that control the blade, was linked to better pain and function [R03].
• Shoulder problems often come with reduced joint position sense, which is the body's sense of where the joint is in space. Many rehab programs move in steps: range of motion first, then strength, then control and coordination [R16].
• In adults aged 60 and older, strength, mobility, body composition and posture are each linked to shoulder pain and disability. The evidence on forward head posture in older adults is limited and indirect [R28].
• Programs that focus on motor control may edge out generic exercise for disability in the short and medium term. The reason is not fully clear [R02].

None of these studies is about ShoulderBack Pro specifically. They describe exercise in general.

Start slowly. Stop if a movement causes sharp pain, and ask a clinician if pain lingers after you finish. Each of these steps has a seated option.

1. Find your blade. Sit tall in a chair with back support. Place your left hand on the top of your right shoulder blade. Slowly reach your right arm across your chest and feel the blade slide around the rib cage. Repeat three times, then switch sides. Standing works too.
2. Try a seated blade slide. Sit with your arms relaxed. Draw both shoulder blades gently down and back, as if sliding them into your back pockets. Hold for three seconds and release. Repeat eight times.
3. Notice the lift. Many people hold tension in the upper trapezius all day. Shrug your shoulders up only a little, then let them drop slowly. Do this five times, paying attention to how the release feels.
4. Draw your elbows back. Sit with elbows bent at your sides. Gently pull your elbows back, as if closing a drawer behind you. Keep your neck long. Hold briefly and return.
5. Build slowly. Use these movements on most days. If you feel fine the next day, add a repetition or two each week. If the next day is worse, go back to the last comfortable level.