Sternoclavicular articulation
Encyclopedia
The sternoclavicular articulation is a synovial double-plane joint composed of two portions separated by an articular disc. The parts entering into its formation are the sternal end of the clavicle
, the upper and lateral part of the manubrium sterni (clavicular notch of the manubrium sterni), and the cartilage of the first rib
, visible from the outside as the suprasternal notch
. The articular surface of the clavicle is much larger than that of the sternum, and is invested with a layer of cartilage, which is considerably thicker than that on the latter bone.
in three planes, predominantly in the anteroposterior & vertical planes, although some rotation also occurs. Muscles don't directly act on this joint, although all almost all actions of the shoulder girdle or the scapula will cause some motion at this articulation.
The unique double-hinged articular disk found at the junction of the clavicular head and manubrium
allows for movement between the clavicle and the disk during elevation and depression of the scapula. This disk also allows motion between the sternum (manubrium) and itself during protraction
and retraction
of the scapula.
Clavicle
In human anatomy, the clavicle or collar bone is a long bone of short length that serves as a strut between the scapula and the sternum. It is the only long bone in body that lies horizontally...
, the upper and lateral part of the manubrium sterni (clavicular notch of the manubrium sterni), and the cartilage of the first rib
First rib
The first rib is the most curved and usually the shortest of all the ribs; it is broad and flat, its surfaces looking upward and downward, and its borders inward and outward....
, visible from the outside as the suprasternal notch
Suprasternal notch
The suprasternal notch , also known as the jugular notch, is part of human anatomy. It is a large, visible dip.-Anatomical location:...
. The articular surface of the clavicle is much larger than that of the sternum, and is invested with a layer of cartilage, which is considerably thicker than that on the latter bone.
Movement
The sternoclavicular joint allows movement of the clavicleClavicle
In human anatomy, the clavicle or collar bone is a long bone of short length that serves as a strut between the scapula and the sternum. It is the only long bone in body that lies horizontally...
in three planes, predominantly in the anteroposterior & vertical planes, although some rotation also occurs. Muscles don't directly act on this joint, although all almost all actions of the shoulder girdle or the scapula will cause some motion at this articulation.
The unique double-hinged articular disk found at the junction of the clavicular head and manubrium
Manubrium
The manubrium or manubrium sterni is the broad, upper part of the sternum. Located ventrally with a quadrangular shape, wider superiorly and narrower inferiorly, it articulates with the clavicles and the first two ribs.-Borders:The superior border is the thickest and presents at its center the...
allows for movement between the clavicle and the disk during elevation and depression of the scapula. This disk also allows motion between the sternum (manubrium) and itself during protraction
Protraction
Protraction is the anatomical term of motion for anterior movement of an anatomical part of the body forward . This can include the shoulders, jaw, pelvis, etc.It is the opposite of retraction....
and retraction
Retraction
A retraction is a public statement, by the author of an earlier statement, that withdraws, cancels, refutes, diametrically reverses the original statement or ceases and desists from publishing the original statement...
of the scapula.
Ligaments
- Anterior sternoclavicular ligamentAnterior sternoclavicular ligamentThe anterior sternoclavicular ligament is a broad band of fibers, covering the anterior surface of the articulation; it is attached above to the upper and front part of the sternal end of the clavicle, and, passing obliquely downward and medialward, is attached below to the front of the upper part...
- Articular capsule
- Articular diskArticular diskThe articular disk is a thin, oval plate of fibrocartilage present in several joints which separates synovial cavities. This separation of the cavity space allows for separate movements to occur in each space....
- Costoclavicular ligamentCostoclavicular ligamentThe costoclavicular ligament , is the anatomical name of a ligament that is short, flat, strong, and rhomboid in form....
- Interclavicular ligamentInterclavicular ligamentThe interclavicular ligament is a flattened band, which varies considerably in form and size in different individuals, it passes in a curved direction from the upper part of the sternal end of one clavicle to that of the other, and is also attached to the upper margin of the sternum.It is in...
- Posterior sternoclavicular ligamentPosterior sternoclavicular ligamentThe posterior sternoclavicular ligament is a band of fibers, covering the posterior surface of the sternoclavicular joint. It is attached above to the upper and back part of the sternal end of the clavicle, and, passing obliquely downward and medialward, is fixed below to the back of the upper...
See also
- Acromioclavicular jointAcromioclavicular jointThe acromioclavicular joint, or AC joint, is a joint at the top of the shoulder. It is the junction between the acromion and the clavicle. -Function:...
- ShoulderShoulderThe human shoulder is made up of three bones: the clavicle , the scapula , and the humerus as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The major joint of the shoulder is the glenohumeral joint, which...
- Shoulder girdle (Pectoral girdle)
- Glenohumeral jointGlenohumeral jointThe glenohumeral joint, or shoulder joint, is a multiaxial synovial ball and socket joint and involves articulation between the glenoid fossa of the scapula and the head of the humerus...
(Shoulder joint)