Orthopedics Orthopedic Surgery Home Office Ergonomics Guide Home Office Ergonomics Guide Overview Your Back Back Pain Exercises Anatomy General Tips Products Holistic Help Your Neck Neck Pain Exercises Anatomy General Tips Products Holistic Help Your Eyes Eye Strain Exercises Anatomy General Tips Products Your Shoulders Shoulder Pain Exercises Anatomy General Tips Products Your Wrists Wrist Pain Exercises Anatomy General Tips Products Your Hands Hand Pain Exercises Anatomy General Tips Products Your Hips Hip Pain Exercises Anatomy General Tips Products Your Knees Knee Pain Exercises Anatomy General Tips Products Anatomy of the Human Shoulder Joint By Jonathan Cluett, MD Jonathan Cluett, MD LinkedIn Twitter Jonathan Cluett, MD, is a board-certified orthopedic surgeon with subspecialty training in sports medicine and arthroscopic surgery. Learn about our editorial process Updated on May 25, 2022 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Stuart Hershman, MD Medically reviewed by Stuart Hershman, MD LinkedIn Stuart Hershman, MD, is board-certified in orthopaedic surgery. He is the director of adult spinal deformity & complex spinal reconstruction at Massachusetts General Hospital and is on the faculty at Harvard Medical School. Learn about our Medical Expert Board Fact checked Verywell Health content is rigorously reviewed by a team of qualified and experienced fact checkers. Fact checkers review articles for factual accuracy, relevance, and timeliness. We rely on the most current and reputable sources, which are cited in the text and listed at the bottom of each article. Content is fact checked after it has been edited and before publication. Learn more. by Angela Underwood Fact checked by Angela Underwood LinkedIn Angela Underwood's extensive local, state, and federal healthcare and environmental news coverage includes 911 first-responder compensation policy to the Ciba-Geigy water contamination case in Toms River, NJ. Her additional health-related coverage includes death and dying, skin care, and autism spectrum disorder. Learn about our editorial process Print Table of Contents View All Table of Contents Shoulder Bones Shoulder Muscles Shoulder Capsule Shoulder Labrum Next in Home Office Ergonomics Guide Non Surgical Treatments for Shoulder Bursitis The shoulder joint is the junction between the chest and the arm. The range of movements and the strength of the muscles around the shoulder depend on two shoulder joints, many muscles, tendons, and bones of the upper arm and the upper back. There are two joints at the shoulder. The glenohumeral joint: The ball-and-socket junction of the top of the arm bone and the socket of the shoulder bladeAcromioclavicular joint: The junction of the collar bone with the shoulder blade Most shoulder motion occurs at the ball-and-socket glenohumeral joint, but for full motion of the shoulder, the acromioclavicular joint must also be functioning normally. Shoulder Bones The three bones of the shoulder are the: Humerus (arm bone) Scapula (shoulder blade) Clavicle (collarbone) The scapula has one part that forms a socket for the ball-and-socket shoulder joint; this is called the glenoid. The glenoid is covered with smooth cartilage. The rounded top of the arm bone (humerus) contacts the shoulder blade at the glenohumeral joint. The acromioclavicular joint is where a different part of the shoulder blade, the acromion, connects to the collarbone. The socket of the shoulder joint is part of the scapula, and if scapular movement is not normal, then shoulder function cannot be normal. Many people with shoulder pain, weakness, and instability often need to focus on improvements in their scapular function to help improve their shoulder mechanics. Shoulder Muscles There are 17 muscles that cross the shoulder joint. The periscapular muscles help to control the movements of the shoulder blade. This movement is critical to normal shoulder function. Rotator Cuff The rotator cuff is a group of four muscles and tendons that surround the glenohumeral joint. The rotator cuff muscles are important for the movements of this joint. The rotator cuff is important in many routine activities, and when it's injured, it can cause severe pain. When the rotator cuff is inflamed or irritated, this is referred to as rotator cuff tendonitis. When the tendons of the rotator cuff have torn, this is called a rotator cuff tear. Verywell / Alexandra Gordon What Is a Rotator Cuff Tear? Shoulder Capsule The shoulder capsule surrounds the ball-and-socket part of the shoulder joint. The capsule separates the joint from the rest of the body and contains the joint fluid. Several ligaments make up parts of the joint capsule, and these ligaments are important in keeping the shoulder joint in the proper position. When the shoulder dislocates, the ligaments of the shoulder capsule can be torn. The tension of the shoulder capsule is important: If the capsule is too loose, the condition is called multidirectional instability. When the shoulder capsule is too tight, the condition is called a frozen shoulder (adhesvie capsulitis). Frozen Shoulder Shoulder Labrum The labrum is a rim of cartilage that surrounds the socket of the shoulder joint. The socket of the shoulder joint is shallow, and the labrum gives the socket more depth, and thus more stability. The labrum also serves as the attachment of a major tendon in the shoulder, the biceps tendon. Labral tears in the shoulder can cause pain, instability of the joint, or both. Labral tears are usually classified based on their location. The most common labral tears are those associated with a shoulder dislocation, called a Bankart tear, and those associated with biceps tendon problems, called SLAP tears. Non Surgical Treatments for Shoulder Bursitis 5 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Crowe MM, Elhassan BT. Scapular and shoulder girdle muscular anatomy: Its role in periscapular tendon transfers. J Hand Surg Am. 2016;41(2):306-315. doi:10.1016/j.jhsa.2015.06.123 Ryan V, Brown H, Minns lowe CJ, Lewis JS. The pathophysiology associated with primary (idiopathic) frozen shoulder: A systematic review. BMC Musculoskelet Disord. 2016;17(1):340. doi:10.1186/s12891-016-1190-9 Hospital for Special Surgery. Shoulder Labrum Tears: An Overview. Olds M, Ellis R, Donaldson K, Parmar P, Kersten P. Risk factors which predispose first-time traumatic anterior shoulder dislocations to recurrent instability in adults: a systematic review and meta-analysis. Br J Sports Med. 2015;49(14):913-922. doi: 10.1136/bjsports-2014-094342 Simoni P, Scarciolla L, Kreutz J, Meunier B, Beomonte Zobel B. Imaging of superior labral anterior to posterior (Slap) tears of the shoulder. J Sports Med Phys Fitness. 2012;52(6):622-630. PMID: 23187325 By Jonathan Cluett, MD Jonathan Cluett, MD, is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the United States men's and women's national soccer teams. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit