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Metacarpophalangeal
The metacarpophalangeal joints (MCP) are situated between the metacarpal bones and the proximal phalanges of the fingers. These joints are of the condyloid kind, formed by the reception of the rounded heads of the metacarpal bones into shallow cavities on the proximal ends of the proximal phalanges. Being condyloid, they allow the movements of flexion, extension, abduction, adduction and circumduction at the joint. Structure Ligaments Each joint has: * palmar ligaments of metacarpophalangeal articulations * collateral ligaments of metacarpophalangeal articulations Dorsal surfaces The dorsal surfaces of these joints are covered by the expansions of the Extensor tendons, together with some loose areolar tissue which connects the deep surfaces of the tendons to the bones. Function The movements which occur in these joints are flexion, extension, adduction, abduction, and circumduction; the movements of abduction and adduction are very limited, and cannot be performed while th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbricals Of The Hand
The lumbricals are intrinsic muscles of the hand that flex the metacarpophalangeal joints, and extend the interphalangeal joints. p. 97 The lumbrical muscles of the foot also have a similar action, though they are of less clinical concern. Structure The lumbricals are four, small, worm-like muscles on each hand. These muscles are unusual in that they do not attach to bone. Instead, they attach proximally to the tendons of flexor digitorum profundus, and distally to the extensor expansions. The first and second lumbricals are unipennate, while the third and fourth lumbricals are bipennate. Nerve supply The first and second lumbricals (the most radial two) are innervated by the median nerve. The third and fourth lumbricals (most ulnar two) are innervated by the deep branch of ulnar nerve. This is the usual innervation of the lumbricals (occurring in 60% of individuals). However 1:3 (median:ulnar - 20% of individuals) and 3:1 (median:ulnar - 20% of individuals) also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metacarpal
In human anatomy, the metacarpal bones or metacarpus form the intermediate part of the skeletal hand located between the phalanges of the fingers and the carpal bones of the wrist, which forms the connection to the forearm. The metacarpal bones are analogous to the metatarsal bones in the foot. Structure The metacarpals form a transverse arch to which the rigid row of distal carpal bones are fixed. The peripheral metacarpals (those of the thumb and little finger) form the sides of the cup of the palmar gutter and as they are brought together they deepen this concavity. The index metacarpal is the most firmly fixed, while the thumb metacarpal articulates with the trapezium and acts independently from the others. The middle metacarpals are tightly united to the carpus by intrinsic interlocking bone elements at their bases. The ring metacarpal is somewhat more mobile while the fifth metacarpal is semi-independent.Tubiana ''et al'' 1998, p 11 Each metacarpal bone consists of a bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheumatoid Arthritis
Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects synovial joint, joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involved, with the same joints typically involved on both sides of the body. The disease may also affect other parts of the body, including skin, eyes, lungs, heart, nerves and blood. This may result in a anemia, low red blood cell count, pleurisy, inflammation around the lungs, and pericarditis, inflammation around the heart. Fever and low energy may also be present. Often, symptoms come on gradually over weeks to months. While the cause of rheumatoid arthritis is not clear, it is believed to involve a combination of genetics, genetic and environmental factors. The underlying mechanism involves the body's immune system attacking the joints. This results in inflammation and thickening of the synovium, joint capsule. It also affec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palmar Ligaments Of Metacarpophalangeal Articulations
In the human hand, palmar or volar plates (also referred to as palmar or volar ligaments) are found in the metacarpophalangeal (MCP) and interphalangeal (IP) joints, where they reinforce the joint capsules, enhance joint stability, and limit hyperextension. The plates of the MCP and IP joints are structurally and functionally similar, except that in the MCP joints they are interconnected by a deep transverse ligament. In the MCP joints, they also indirectly provide stability to the longitudinal palmar arches of the hand. (MCP joints) (IP joints) The volar plate of the thumb MCP joint has a transverse longitudinal rectangular shape, shorter than those in the fingers. Structure This fibrocartilaginous structure is attached to the volar base of the phalanx distal to the joint. From there, it forms a palmar continuation of the articular surface of the phalanx bone and its inner surface thus adds to the articular surface during extension. In its proximal end, the volar pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extensor Pollicis Longus Muscle
In human anatomy, the extensor pollicis longus muscle (EPL) is a skeletal muscle located dorsally on the forearm. It is much larger than the extensor pollicis brevis, the origin of which it partly covers and acts to stretch the thumb together with this muscle. Structure The extensor pollicis longus arises from the dorsal surface of the ulna and from the interosseous membrane, next to the origins of abductor pollicis longus and extensor pollicis brevis. Passing through the third tendon compartment, lying in a narrow, oblique groove on the back of the lower end of the radius,'' Gray's Anatomy'' 1918, see infobox it crosses the wrist close to the dorsal midline before turning towards the thumb using Lister's tubercle on the distal end of the radius as a pulley. It obliquely crosses the tendons of the extensores carpi radialis longus and brevis, and is separated from the extensor pollicis brevis by a triangular interval, the anatomical snuff box in which the radial artery i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexor Digitorum Profundus
The flexor digitorum profundus is a muscle in the forearm of humans that flexes the fingers (also known as digits). It is considered an extrinsic hand muscle because it acts on the hand while its muscle belly is located in the forearm. Together the flexor pollicis longus, pronator quadratus, and flexor digitorum profundus form the deep layer of ventral forearm muscles.Platzer 2004, p 162 The muscle is named . Structure Flexor digitorum profundus originates in the upper 3/4 of the anterior and medial surfaces of the ulna, interosseous membrane and deep fascia of the forearm. The muscle fans out into four tendons (one to each of the second to fifth fingers) to the palmar base of the distal phalanx. Along with the flexor digitorum superficialis, it has long tendons that run down the arm and through the carpal tunnel and attach to the palmar side of the phalanges of the fingers. Flexor digitorum profundus lies deep to the superficialis, but it attaches more distally. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interphalangeal Articulations Of Hand
The interphalangeal joints of the hand are the hinge joints between the phalanges of the fingers that provide flexion towards the palm of the hand. There are two sets in each finger (except in the thumb, which has only one joint): * "proximal interphalangeal joints" (PIJ or PIP), those between the first (also called proximal) and second (intermediate) phalanges * "distal interphalangeal joints" (DIJ or DIP), those between the second (intermediate) and third (distal) phalanges Anatomically, the proximal and distal interphalangeal joints are very similar. There are some minor differences in how the palmar plates are attached proximally and in the segmentation of the flexor tendon sheath, but the major differences are the smaller dimension and reduced mobility of the distal joint. Joint structure The PIP joint exhibits great lateral stability. Its transverse diameter is greater than its antero-posterior diameter and its thick collateral ligaments are tight in all positions duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extensor Pollicis Brevis Muscle
In human anatomy, the extensor pollicis brevis is a skeletal muscle on the dorsal side of the forearm. It lies on the medial side of, and is closely connected with, the abductor pollicis longus. The extensor pollicis brevis (EPB) belongs to the deep group of the posterior fascial compartment of the forearm. It is a part of the lateral border of the anatomical snuffbox. Structure The extensor pollicis brevis arises from the ulna distal to the abductor pollicis longus, from the interosseous membrane, and from the dorsal surface of the radius. Its direction is similar to that of the abductor pollicis longus, its tendon passing the same groove on the lateral side of the lower end of the radius, to be inserted into the base of the first phalanx of the thumb. Variation Absence; fusion of tendon with that of the extensor pollicis longus or abductor pollicis longus muscle. Function In a close relationship to the abductor pollicis longus, the extensor pollicis brevis both exten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexor Pollicis Brevis Muscle
The flexor pollicis brevis is a muscle in the hand that flexes the thumb. It is one of three thenar muscles. It has both a superficial part and a deep part. Origin and insertion The muscle's superficial head arises from the distal edge of the flexor retinaculum and the tubercle of the trapezium, the most lateral bone in the distal row of carpal bones. It passes along the radial side of the tendon of the flexor pollicis longus. The deeper (and medial) head "varies in size and may be absent." It arises from the trapezoid and capitate bones on the floor of the carpal tunnel, as well as the ligaments of the distal carpal row. Both heads become tendinous and insert together into the radial side of the base of the proximal phalanx of the thumb; at the junction between the tendinous heads there is a sesamoid bone.'' Gray's Anatomy'' 1918, see infobox Innervation The superficial head is usually innervated by the lateral terminal branch of the median nerve. The deep part is often in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extensor Digitorum Communis
The extensor digitorum muscle (also known as extensor digitorum communis) is a muscle of the posterior forearm present in humans and other animals. It extends the medial four digits of the hand. Extensor digitorum is innervated by the posterior interosseous nerve, which is a branch of the radial nerve. Structure The extensor digitorum muscle arises from the lateral epicondyle of the humerus, by the common tendon; from the intermuscular septa between it and the adjacent muscles, and from the antebrachial fascia. It divides below into four tendons, which pass, together with that of the extensor indicis proprius, through a separate compartment of the dorsal carpal ligament, within a mucous sheath. The tendons then diverge on the back of the hand, and are inserted into the middle and distal phalanges of the fingers in the following manner.'' Gray's anatomy'' (1918), see infobox Opposite the metacarpophalangeal articulation each tendon is bound by fasciculi to the collateral ligame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexor Digiti Minimi Brevis (hand)
The flexor digiti minimi brevis is a hypothenar muscle in the hand that flexes the little finger (digit V) at the metacarpophalangeal joint. It lies lateral to the abductor digiti minimi when the hand is in anatomical position. Structure The flexor digiti minimi brevis arises from the hamulus of the hamate bone and the palmar surface of the flexor retinaculum of the hand. It is inserted into the medial side of the base of the proximal phalanx of digit V. It is separated from the abductor digiti minimi, at its origin, by the deep branches of the ulnar artery and the ulnar nerve. The flexor digiti minimi brevis is sometimes not present; in these cases, the abductor digiti minimi is usually larger than normal. The flexor digiti minimi brevis is one of three muscles in the hypothenar muscle group. These three muscles form the fleshy mass at the base of the little finger, and are solely concerned with the movement of digit V. The other two muscles that make up the hypothenar m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interphalangeal Joints Of The Hand
The interphalangeal joints of the hand are the hinge joints between the phalanges of the fingers that provide flexion towards the palm of the hand. There are two sets in each finger (except in the thumb, which has only one joint): * "proximal interphalangeal joints" (PIJ or PIP), those between the first (also called proximal) and second (intermediate) phalanges * "distal interphalangeal joints" (DIJ or DIP), those between the second (intermediate) and third (distal) phalanges Anatomically, the proximal and distal interphalangeal joints are very similar. There are some minor differences in how the palmar plates are attached proximally and in the segmentation of the flexor tendon sheath, but the major differences are the smaller dimension and reduced mobility of the distal joint. Joint structure The PIP joint exhibits great lateral stability. Its transverse diameter is greater than its antero-posterior diameter and its thick collateral ligaments are tight in all positions duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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