Elbow-joint
Elbow
Left elbow-joint, showing anterior and ulnar collateral ligaments.
Latin	articulatio cubiti
Gray's	subject #84 321
MeSH	Elbow+joint
Dorlands/Elsevier	a_64/12161185

The elbow-joint is a ginglymus or hinge joint. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Introduction ( Joints or Articulations Sutural ligament Fibrocartilages Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Elsevier, the world's largest Publisher of Medical and Scientific literature, forms part of the Reed Elsevier group In the hinge joint ( ginglymus) the articular surfaces are moulded to each other in such a manner as to permit motion only in one plane forward and backward the extent of motion Three bones form the elbow joint: the humerus of the upper arm, and the paired radius and ulna of the forearm. The humerus is a Long bone in the Arm or Forelimb that runs from the Shoulder to the Elbow. The radius is the Bone of the Forearm that extends from the lateral side of the elbow to the Thumb side of the Wrist. The ulna ( elbow bone) is a long bone prismatic in form placed at the medial side of the Forearm, parallel with the radius. ^[1]

The elbow is the region surrounding the elbow-joint. ^[2]

The bony prominence at the very tip of the elbow is the olecranon process of the ulna, and the inner aspect of the elbow is called the antecubital fossa. The olecranon is a large thick curved eminence situated proximal end of the Ulna in the Forearm. The cubital fossa is the triangular area on the anterior view of the Elbow joint of the Arm.

Movements

Two main movements are possible at the elbow:

• The hinge-like bending and straightening of the elbow (flexion and extension) happens at the articulation ("joint") between the humerus and the ulna. The movement of body structures is accomplished by the contraction of Muscles Muscles may move parts of the skeleton relatively to each other or may move parts of internal organs relatively
• The complex action of turning the forearm over (pronation or supination) happens at the articulation between the radius and the ulna (this movement also occurs at the wrist joint). In Anatomy, pronation is a rotational movement of the forearm (at the radioulnar joint or foot (at the subtalar and talocalcaneonavicular joints Supination is a position of either the Forearm or foot in the forearm when the palm faces anteriorly or faces up (when the arms are unbent and at the sides

In the anatomical position (with the forearm supine), the radius and ulna lie parallel to each other. During pronation, the ulna remains fixed, and the radius rolls around it at both the wrist and the elbow joints. In the prone position, the radius and ulna appear crossed.

Most of the force through the elbow joint is transferred between the humerus and the ulna. Very little force is transmitted between the humerus and the radius. (By contrast, at the wrist joint, most of the force is transferred between the radius and the carpus, with the ulna taking very little part in the wrist joint). In Human anatomy, the wrist is the flexible and narrower connection between the Forearm and the palm. In Tetrapods the carpus is the sole cluster of the Bones in the Wrist between the radius and Ulna and the Metacarpus

Muscles, arteries, and nerves

The muscles in relation with the joint are:

• in front, the Brachialis
• behind, the Triceps brachii and Anconæus
• laterally, the Supinator, and the common tendon of origin of the Extensor muscles
• medially, the common tendon of origin of the Flexor muscles, and the Flexor carpi ulnaris

The arteries supplying the joint are derived from the anastomosis between the profunda and the superior and inferior ulnar collateral branches of the brachial, with the anterior, posterior, and interosseous recurrent branches of the ulnar, and the recurrent branch of the radial. Muscle (from Latin musculus, diminutive of mus "mouse" is contractile tissue of the body and is derived from the The brachialis ( brachialis anticus) is a Muscle in the upper Arm that flexes the elbow joint. The triceps brachii ( Latin for "three-headed" of the arm is the large muscle on the back of the human Upper limb. The anconeus muscle is a small Muscle on the posterior aspect of the elbow joint The supinator is a broad muscle curved around the upper third of the radius. The flexor carpi ulnaris muscle (FCU is a muscle of the human forearm that acts to flex and adduct the hand Arteries are Blood vessels that carry blood away from the Heart. The inferior ulnar collateral artery (anastomotica magna artery arises about 5 cm The brachial artery is the major Blood vessel of the upper arm The radial recurrent artery arises from the Radial artery immediately below the elbow. These vessels form a complete anastomotic network around the joint. An anastomosis (plural anastomoses, from gr ἀναστόμωσις communicating opening) is a Network of streams that both branch out and reconnect

The nerves of the joint are a twig from the ulnar, as it passes between the medial condyle and the olecranon; a filament from the musculocutaneous, and two from the median. A nerve is an enclosed cable-like bundle of peripheral Axons (the long slender projections of Neurons. The olecranon is a large thick curved eminence situated proximal end of the Ulna in the Forearm. The musculocutaneous nerve arises from the Lateral cord of the Brachial plexus, opposite the lower border of the Pectoralis minor, its fibers being derived The median nerve is a Nerve that runs down the Arm and Forearm.

Portions of joint

The elbow-joint comprises three different portions. All these articular surfaces are enveloped by a common synovial membrane, and the movements of the whole joint should be studied together.

The combination of the movements of flexion and extension of the forearm with those of pronation and supination of the hand, which is ensured by the two being performed at the same joint, is essential to the accuracy of the various minute movements of the hand.

The hand is only directly articulated to the distal surface of the radius, and the ulnar notch on the lower end of the radius travels around the lower end of the ulna. The ulna is excluded from the wrist-joint by the articular disk. The articular disk (or disc) is a thin oval plate of Fibrocartilage present in several Joints which separates synovial cavities

Thus, rotation of the head of the radius around an axis passing through the center of the radial head of the humerus imparts circular movement to the hand through a very considerable arc.

Ligaments

The trochlea of the humerus is received into the semilunar notch of the ulna, and the capitulum of the humerus articulates with the fovea on the head of the radius. The humerus is a Long bone in the Arm or Forelimb that runs from the Shoulder to the Elbow. The ulna ( elbow bone) is a long bone prismatic in form placed at the medial side of the Forearm, parallel with the radius. The radius is the Bone of the Forearm that extends from the lateral side of the elbow to the Thumb side of the Wrist. The articular surfaces are connected together by a capsule, which is thickened medially and laterally, and, to a less extent, in front and behind. These thickened portions are usually described as distinct ligaments.

The major ligaments are the ulnar collateral ligament, radial collateral ligament, and annular ligament. The ulnar collateral ligament ( internal lateral ligament) is a thick triangular band consisting of two portions an anterior and posterior united by a thinner intermediate portion The radial collateral ligament ( external lateral ligament) is a short and narrow fibrous band less distinct than the Ulnar collateral, attached above to a depression The Annular Ligament ( orbicular ligament) is a strong band of fibers which encircles the head of the Radius, and retains it in contact with the Radial notch

Synovial membrane

The synovial membrane is very extensive. Synovial membrane (or synovium) is the soft tissue that lines the non- cartilaginous surfaces within Joints with cavities ( Synovial joints It extends from the margin of the articular surface of the humerus, and lines the coronoid, radial and olecranon fossæ on that bone; it is reflected over the deep surface of the capsule and forms a pouch between the radial notch, the deep surface of the annular ligament, and the circumference of the head of the radius. Projecting between the radius and ulna into the cavity is a crescentic fold of synovial membrane, suggesting the division of the joint into two; one the humeroradial, the other the humeroulnar.

Between the capsule and the synovial membrane are three masses of fat:

• the largest, over the olecranon fossa, is pressed into the fossa by the Triceps brachii during the flexion;
• the second, over the coronoid fossa,
• and the third, over the radial fossa, are pressed by the Brachialis into their respective fossæ during extension.

Terminology: "Elbow" and "Ell"

The now obsolete length unit ell relates closely to the elbow. An ell (from Proto-Indo-European *el- "elbow forearm" is a unit of measurement approximating the distance from the elbow to the wrist This becomes especially visible when considering the Germanic origins of both words, Elle (ell, defined as the length of an arm from shoulder to fingertips) and Ellbogen (elbow).

It is unknown when or why the second "l" was dropped from English usage of the word, but a more precise suggested spelling would be "ellbow" for the joint and "ellbone" for the ulna, the etymological originator of both unit and joint.

Carrying angle

Normal radiograph; right picture of the straightened arm shows the carrying angle of the elbow

When the arm is extended, with the palm facing forward or up, the bones of the humerus and forearm are not perfectly aligned. Extension is a movement of a joint that results in increased angle between two bones or body surfaces at a joint The humerus is a Long bone in the Arm or Forelimb that runs from the Shoulder to the Elbow. The forearm is the structure on the Upper limb, between the elbow and the Wrist. The deviation from a straight line (generally on the order of 5-10°-men, 10-25°-women) occurs in the direction of the thumb, and is referred to as the carrying angle (visible in the right half of the picture, right). In females the carrying angle is greater than in males. ^[3]

Carrying angle is typically larger in women than in men, due to the wider pelvic girdle exhibited in women.

The carrying angle can influence how objects are held by individuals - those with a more extreme carrying angle may be more likely to supinate the forearm when holding objects in the hand to keep the elbow closer to the body. Supination is a position of either the Forearm or foot in the forearm when the palm faces anteriorly or faces up (when the arms are unbent and at the sides

Elbow arthritis

Elbow arthritis is usually seen in individuals with rheumatoid arthritis or after severe articular fractures. When the damage to the joint is severe, fascial arthroplasty or elbow joint replacement may be considered. ^[4]

Additional images

Medial Humerus Radius Ulna Articulated	Left Human Posterior Distal Humerus Extended	Left Human Posterior Distal Humerus Flexed	Left elbow-joint, showing posterior and radial collateral ligaments.
Capsule of elbow-joint (distended). Anterior aspect.	Capsule of elbow-joint (distended). Posterior aspect.	The Supinator. Posterior view.	Diagram of the anastomosis around the elbow-joint.
Back of right upper extremity.	Close-up radiograph, right elbow-joint	Left male elbow	Pathological fusion of three bones at elbow.

References

1. ^ eMedicine/Stedman Medical Dictionary Lookup!
2. ^ eMedicine/Stedman Medical Dictionary Lookup!
3. ^ Steel, F; Tomlinson J (1958). "The carrying angle in man.". Journal of Anatomy 92 (2): 315-7. PMID 13525245.  
4. ^ Summary - Total elbow joint replacement for elbow arthritis: Surgery with a dependable, time-tested prosthesis can lessen pain and improve function in elbows, especially those with rheumatoid arthritis

This article was originally based on an entry from a public domain edition of Gray's Anatomy. The public domain is a range of abstract materials &ndash commonly referred to as Intellectual property &ndash which are not owned or controlled by anyone Henry Gray's Anatomy of the Human Body (or Gray's Anatomy as it has commonly been shortened is an English-language Human anatomy Textbook As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.