Your shoulder joint is a complex system made up of five joints and three bones:
- clavicle, or collar bone
- scapula, your shoulder blade
- humerus, which is the long bone in your upper arm
This system of joints and bones allows your shoulder to move in different directions. Each movement has a different range of motion. The ability of your shoulders to move in a normal range depends on the health of your:
- individual joints
Your shoulders have the ability to move more than most joints. Your shoulder range of motion is, basically, how far you can move each shoulder in different directions without major joint pain or other issues.
Flexion is a movement that decreases the angle between the two parts that the joint is connecting. If you hold your arms straight and palms against your sides and raise your arms in front of your body to point your hands at something in front of you, you’re practicing flexion.
A normal range of motion for shoulder flexion is 180 degrees. This involves moving your arms from palms against the side of your body to the highest point you can raise your arms over your head.
Extension is a movement that increases the angle between the two parts that the joint is connecting. If you reach your hands behind you — think about putting something in your back pocket — you’re practicing extension.
A normal range of motion for shoulder extension to the highest point you can lift your arm behind your back — starting with your palms next to your body — is between 45 and 60 degrees.
Abduction occurs when you have arm movement away from the middle of your body. When you raise your arm out from the sides of your body, it’s an abduction of your shoulder.
A normal range for abduction, starting with your palms at your sides, is around 150 degrees in a healthy shoulder. This places your hands above your head with your arms straight.
Shoulder adduction occurs when you move your arms towards the middle of the body. If you hug yourself, your shoulders are adducting.
A normal range of movement for shoulder adduction is 30 to 50 degrees depending on flexibility and body composition. If your chest or biceps are particularly muscular, it may be difficult to move your arms inward.
With your arms at your sides, turn your palms towards your body and bend your elbows 90 degrees so your hands are pointing in front of you. Keep your elbows against your body and move your forearms towards your body.
Imagine your body is a cabinet, your arms are the cabinet doors and you’re shutting the doors. This is medial rotation — also referred to as internal rotation — and the normal range of motion for a healthy shoulder is 70 to 90 degrees.
With your arms at your sides, palms facing your body, bend your elbows 90 degrees. Keeping your elbows against your body swing your forearms away from your body. This is lateral rotation — also referred to as external rotation — and the normal range of motion for a healthy shoulder is 90 degrees.
Your shoulder is made up of many different moving parts. The ball of your upper arm fits into your shoulder socket. It’s held there with muscles, tendons, and ligaments. An issue with just one of these parts can affect your range of motion.
Common issues include:
Your doctor will diagnose a potential issue through a series of tests, which may include:
- physical exam
- CT scan
If you’re worried about the range of motion of your shoulder, you should mention the issue to your doctor.
A normal range of motion for your shoulder depends on your flexibility and the overall health of your shoulder.
If you’re concerned about the rotation or range of motion of your shoulder or you’re feeling pain during normal movement, you should consult with your doctor. They can help you find a treatment plan or recommend you to an orthopedist.