Shoulder

:This article is about the body part. See hard shoulder for the road segment.

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In human anatomy, the shoulder joint is composed of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone). Two joints facilitate shoulder movement. The acromioclavicular (AC) joint is located between the acromion (part of the scapula that forms the highest point of the shoulder) and the clavicle. The glenohumeral joint, to which the generic term "shoulder joint" usually refers, is a ball-and-socket joint that allows the arm to rotate in a circular fashion or to hinge out and up away from the body. (The "ball" is the top, rounded portion of the upper arm bone or humerus; the "socket," or glenoid, is a dish-shaped part of the outer edge of the scapula into which the ball fits.) Arm movement is further facilitated by the ability of the scapula to slide both laterally and vertically along the rib cage. The capsule is a soft tissue envelope that encircles the glenohumeral joint. It is lined by a thin, smooth synovial membrane.

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The bones of the shoulder are held in place by muscles, tendons, and ligaments. Tendons are tough cords of tissue that attach the shoulder muscles to bone and assist the muscles in moving the shoulder. Ligaments attach shoulder bones to each other, providing stability. For example, the front of the joint capsule is anchored by three glenohumeral ligaments.

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The rotator cuff is a structure composed of tendons that, with associated muscles, holds the ball at the top of the humerus in the glenoid socket and provides mobility and strength to the shoulder joint.

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Two filmy sac-like structures called bursae permit smooth gliding between bone, muscle, and tendon. They cushion and protect the rotator cuff from the bony arch of the acromion.

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Human anatomy: Human anatomy or anthropotomy is a special field within anatomy. It studies organs and organ systems of the human body, leaving the study of tissues to histology and cells to cytology....

Clavicle: "this article uses a few professional terms to explain certain anatomical details. These words apply only when the body is in the anatomical position, i.e., standing up with hands facing forward. These terms are:...

Scapula: In anatomy, the scapula, or shoulder blade, is the bone that connects the humerus (arm bone) with the clavicle (collar bone)....

Shoulder related Images and Photos (experimental)

Gadget Shoulder Holster	A Perfect Circle - Shoulder Logo	Angel on My Shoulder Paul Muni 1946	I Love Lucy Diva Shoulder Tote
I Love Lucy Diva Shoulder Tote	I Love Lucy Heart Shoulder Tote	England adidas Messenger Shoulder Bag	I Love Lucy Heart Shoulder Tote
I Love Lucy Sweetheart Shoulder Bag	I Love Lucy Sweetheart Shoulder Bag	Surgery of the Shoulder	Reaper Carrying a Scythe on His Shoulder Back View