Musculoskeletal system
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha in Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
The shoulder joint is a synovial ball-and-socket joint formed between the head of the humerus and the glenoid cavity of the scapula (Fig. 3.18a). The glenoid cavity is shallow, which makes the joint unstable. It has a wide range of movements and relies on muscle support for stability. The joint capsule is lax to permit the wide range of movements available at the joint. It attaches close to the margin of the head of humerus, except inferiorly where it attaches 2–3 cm distally. The capsule is strengthened by four muscles, subscapularis, supraspinatus, infraspinatus and teres minor, which are known collectively as the rotator cuff. Subscapularis originates on the anterior aspect of the scapula and inserts into the lesser tuberosity of the humerus. Supraspinatus originates from the supraspinous fossa of the scapula and inserts into the superior aspect of the greater tuberosity of the humerus. Infraspinatus originates from the infraspinous fossa on the scapula and inserts into the middle portion of the greater tuberosity. Teres minor originates from the upper two-thirds of the axillary border of the scapula (posterior surface) and inserts into the inferior aspect of the greater tuberosity.
A to Z Entries
Clare E. Milner in Functional Anatomy for Sport and Exercise, 2019
The glenohumeral joint relies heavily on its soft tissues to stabilize it because the glenoid fossa of the scapula provides only a shallow socket in which the head of the humerus sits (see shoulder complex – joints). Stability of the joint is achieved passively by the ligaments that span the joint and functionally by the muscles surrounding the joint. Muscles are responsible for both joint rotation movements and drawing the bones together to strengthen the joint and maintain its integrity. The major role of the infraspinatus, supraspinatus, subscapularis, and teres minor muscles – the rotator cuff – is strengthening and stabilizing the shoulder joint by drawing the humerus into the glenoid fossa. The glenoid fossa is shallow and almost vertical in orientation, therefore, the supraspinatus plays a major role in preventing downward dislocation of the humerus when carrying heavy weights in the hand. The infraspinatus and teres minor muscles also play a role in externally rotating the arm. Subscapularis internally rotates the arm and supraspinatus abducts the arm.
The shoulder
David Silver in Silver's Joint and Soft Tissue Injection, 2018
The glenohumeral joint consists of the head of the humerus articulating with the glenoid fossa of the scapula. This shallow joint space is no more than 1.5 inches (3.8 cm) in length. The joint is held together by a rather loosely-applied voluminous capsule of fibrous tissue, which is considerably strengthened by the three tendons of the rotator cuff that blend with it anteriorly, posteriorly and superiorly, respectively, from the subscapularis, the infraspinatus together with teres minor, and the supraspinatus. The long head of the biceps tendon arises on the superior glenoid tubercle within the capsule of the joint and becomes covered by its own synovial sheath as it lies superiorly in the capsule. It leaves the joint space through an opening in the capsule, passing over the bicipital groove, which lies on the anterolateral surface of the head of the humerus, to join the short head of the biceps muscle anteriorly over the upper arm.
Convolutional LSTM: a deep learning approach to predict shoulder joint reaction forces
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
S. T. Mubarrat, S. Chowdhury
According to the Global Burden of Diseases (GBD) 2010 study, the musculoskeletal disorders (MSDs) are the second most common cause of disability globally (Vos et al. 2012). The GBD 2010 study also listed occupational risk factors to be one of the top three major contributors to MSD-caused years-lived-with-disability (Vos et al. 2012). Among work-related MSDs, the shoulder MSDs (accounted for 16.6% of all MSD cases) are the costliest— $28,288 per claim—and severe type of days-away-from-work (DAFW) injury in the United States, requiring 28.3 median days to recover before returning to work (Bureau of Labor Statistics 2019). The vulnerability of the shoulder complex to injuries is because the main joint in the shoulder complex, the glenohumeral joint, is highly unstable (Andrews et al. 2008), which arises due to the loose-fitting of the humeral head into the glenoid cavity—only 30% of humeral head is in contact with the glenoid cavity—at any given shoulder position (Soslowsky et al. 1992). The stability of the glenohumeral joint, also known as the shoulder joint, is primarily ensured by the coordinated action of the surrounding shoulder muscles to produce net internal joint reaction forces to counteract translational (shear) forces produced by the external loading (Lippitt and Matsen 1993). Therefore, an efficient and feasible estimation method of the shoulder joint reaction forces can contribute to identifying exertions that lead to injury and disability, aiding rehabilitation planning, and improving the product design (e.g., implant, exoskeleton, and soft robotics).
Longitudinal assessments of strength and dynamic balance from pre-injury baseline to 3 and 4 months after labrum repairs in collegiate athletes
Published in Physiotherapy Theory and Practice, 2022
Ling Li, Brenna K. McGuinness, Jacob S. Layer, Yu Song, Megan A. Jensen, Boyi Dai
The glenoid labrum is a fibrous rim that surrounds the glenoid cavity to stabilize the glenohumeral joint. Certain labrum injuries may require surgical repairs for specific populations (Dodson and Altchek, 2009). In the general population, the superior labrum from anterior to posterior (SLAP) repairs represent approximately 9.4% of total shoulder surgeries (Weber, Martin, Seiler, and Harrast, 2012). In National Collegiate Athletics Association (NCAA) athletes, SLAP tears and other non-SLAP labrum tears are the two upper extremity injuries mostly requiring surgical treatment (Gil, Goodman, DeFroda, and Owens, 2018). SLAP tears comprise over 17% of shoulder surgeries, while non-SLAP labrum tears are a portion of surgical treatment to shoulder instability that makes up more than 60% of shoulder surgeries (Gil, Goodman, DeFroda, and Owens, 2018).
Comparison of low level and high power laser combined with kinesiology taping on shoulder function and musculoskeletal sonography parameters in subacromial impingement syndrome: a Randomized placebo-controlled trial
Published in Physiotherapy Theory and Practice, 2022
Zohreh Zaki, Roya Ravanbod, Marc Schmitz, Kambiz Abbasi
Lifetime prevalence of the shoulder pain ranges from 6.7 to 66.7% and overall prevalence of the rotator cuff abnormalities ranges from 9.7 to 62% and increased in an age-dependent manner (Ghosh, 2012; Teunis, Lubberts, Reilly, and Ring, 2014). Structures in the subacromial space impinge against the coracoacromial arch in the subacromial impingement syndrome (SAIS) (Mackenzie, Herrington, Horlsey, and Cools, 2015; Neer, 1972). Various factors may influence on the existing structures in the subacromial space. Impaired muscle function of the shoulder girdle including supraspinatus and deltoid could be a leading cause of SAIS (Graichen et al., 1999b; Kase, Wallis, and Kase, 2013). Biomechanically, during shoulder abduction deltoid roles up the humeral head while rotator cuff muscles glide the head down to keep it centered in the glenoid cavity. Narrowing of the subacromial space inevitably occurs when deltoid momentum excels and increases upward translation of the humeral head, simultaneously with rotator cuff impairment (Graichen et al., 1999a).
Related Knowledge Centers
- Shoulder Joint
- Supraspinatus Muscle
- Synovial Joint
- Joint
- Scapula
- Rotator Cuff
- Humerus
- Shoulder
- Ball-and-Socket Joint
- Biceps