Your shoulder muscles stabilize your shoulder joint and help you move your arm in many directions. Shoulder muscle injuries are common in people who use their shoulders a lot for overhead motions, such as pitchers or swimmers.
Your shoulder is a ball-and-socket joint that allows you to perform a wide range of movements. You use these muscles for actions from throwing a ball to reaching an item on a shelf. Also called the glenohumeral joint, it has more range of motion than any other joint in your body. There are about eight muscles in your shoulder that support this joint. They give it strength, stability and shape.
Your shoulder muscles are skeletal muscles. Tendons attach them to bones. They’re voluntary muscles, meaning you control how they move and work. Some other muscles in your body, such as those in your heart, are involuntary. This means they work without you having to think about it.
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The shoulder muscles serve a variety of functions, including:
Your shoulder muscles surround the top of your arm where it connects to your body’s trunk. Tendons connect your shoulder muscles to bones. These bones include your scapula (shoulder blade), humerus (bone between your shoulder and elbow) and clavicle (collarbone).
The most important muscles in your shoulder are the four rotator cuff muscles. Together with tendons, they cup the front of your shoulder and:
The rotator cuff muscles include:
Other muscles that support your shoulder include:
Like other muscles in your body, shoulder muscles contain lots of elastic fibers. These fibers give them flexibility and allow them to contract (tighten). They are red and white, so they look striated (striped or streaked).
The shoulder joint is extremely flexible, so the muscles and other soft tissues around it undergo a lot of wear and tear. This makes the shoulder muscles susceptible to injuries and degenerative conditions, including:
Shoulder muscle conditions are common. In 2006, more than 7 million people saw their healthcare provider for a shoulder problem. Approximately two to four million of these shoulder issues involved the rotator cuff.
Take care of your shoulder muscles by:
Contact your doctor right away if you:
A note from Cleveland Clinic
Your shoulder muscles support and stabilize the most flexible joint in your body. They help you perform a wide range of movements, from brushing your hair to throwing a ball. Since we use our shoulder muscles so much, they’re prone to injuries. You can prevent most shoulder pain by resting your muscles when they feel tired and keeping them strong and conditioned.
Last reviewed by a Cleveland Clinic medical professional on 08/24/2021.
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