Shoulder Muscles: Anatomy, Function, and More

Have you ever wondered what's going on with your shoulder muscles? How does a simple twist of the arm enable you to lift heavy objects, or why does a sore neck make it hard to turn your head?

If so, then read on to learn more about how your shoulder muscles work. We'll also go over some stretches that can help relieve pain caused by tight shoulder muscles.

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Anatomy of Shoulder muscles

Shoulder muscles are the most complex and largest group of muscles in your body. They are responsible for stabilizing your shoulder joint, which is a ball-and-socket joint.

Shoulder muscles are divided into three groups: trapezius, deltoid, and rotator cuff. The trapezius muscle connects to your neck and back; it lifts your arm above your head when you reach up or move around in bed.

stabilizes your shoulder joint. (Image via Unsplash / Morrow Solutions)

The deltoid muscle is located on top of your shoulders and allows you to raise your arms out from their sides or make circles with them as if you were waving at someone or giving them a thumbs-up sign.

It also stabilizes the shoulder blade for movements such as throwing a ball or swinging an ax (or whatever else people do with axes). The rotator cuff is made up of four small but powerful muscles that work together to stabilize the shoulder joint while allowing it to rotate freely when needed.

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Function of Shoulder flexors

The muscles that bring your arm forward are known as the shoulder flexors. These are the muscles you use when you raise your arm in front of you, or flex it.

The most important muscle for this movement is not one of the shoulder flexors, however—it's a muscle called the pectoralis major, which forms most of your upper chest and abdomen from your clavicle (collar bone) to just below your navel (belly button).

pectoralis major is important for movements. (Image via Unsplash / Nigel Msipa)

This large muscle does most of its work when it contracts to pull your humerus forward and up towards where it would be if it were fully extended over your head.

The rest of the shoulder flexor group includes two small muscles called subclavius and serratus anterior that run parallel with the pectoralis major near their origins along each side of the clavicle.

Subclavius and serratus anterior are responsible for bringing small portions of the humerus closer together during shoulder flex movements, such as raising arms overhead while keeping elbows bent at 90-degree angles so they don't hit each other.

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Stretches for shoulder pain

If you suffer from shoulder pain, it can be difficult to find an exercise program that will help. Stretching and strengthening exercises for your shoulders should always include stretches for all of the muscles in your upper body. These are some of the most common shoulder muscle stretches for shoulder pain:

1) Chest stretch

• Lay on your back with arms outstretched above your head.
• Bend one knee and bring it towards your chest (while keeping the other leg flat on the floor).
• Pull gently on the leg being stretched until a good stretch is felt in that area.
• Repeat with opposite side.

2) Upper Trapezius stretch

• Sit upright with shoulders relaxed, hands at sides, elbows straight but not locked, and palms facing up or down (whichever feels more comfortable).
• Slowly turn the head so chin moves toward right shoulder until slight tension is felt between nose and earlobe; hold for 20 seconds before repeating on the opposite side.

simple shoulder muscle stretching exercises can help in alleviating the pain. (Image via Unsplash / Alora Griffiths)

3) Lower trapezius stretch

• Stand upright holding hands behind back at waist level with fingers interlaced (thumbs touching each other).
• Squeeze shoulder blades together as if trying to lift them up under armpits then relax them down again.

4) Knees-to-chest lift

• Lie supine on a mat while extending both legs straight up into air; bend knees so they point towards the ceiling.
• Clasp hands around shins just below knee caps then slowly lower them towards stomach until stretched out the torso off floor by less than halfway down leg length from knee caps.

Stretching your shoulder muscles helps prevent injury. If you're experiencing shoulder pain, try these stretches for relief.

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The physiology of the shoulder muscles can help you understand how it works and how injuries and pain affect your daily life. You can also learn about common symptoms, diagnosis, and treatment for shoulder pain.

Prevention is key, so be sure to include exercises in your routine that stretch and strengthen the muscles of the shoulder region.