Search results
Results from the WOW.Com Content Network
The carpometacarpal (CMC) joints are five joints in the wrist that articulate the distal row of carpal bones and the proximal bases of the five metacarpal bones.. The CMC joint of the thumb or the first CMC joint, also known as the trapeziometacarpal (TMC) joint, differs significantly from the other four CMC joints and is therefore described separately.
The first metacarpal bone is short and thick with a shaft thicker and broader than those of the other metacarpal bones. Its narrow shaft connects its widened base and rounded head; the former consisting of a thick cortical bone surrounding the open medullary canal; the latter two consisting of cancellous bone surrounded by a thin cortical shell.
Besides the metacarpophalangeal joints, the metacarpal bones articulate by carpometacarpal joints as follows: the first with the trapezium; the second with the trapezium, trapezoid, capitate and third metacarpal; the third with the capitate and second and fourth metacarpals; the fourth with the capitate, hamate, and third and fifth metacarpals;
In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; [1] [2] (2) the wrist joint or radiocarpal joint, the joint between the radius and the carpus [2] and; (3) the anatomical region surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of ...
Joints of the hand, X-ray. The bones in each carpal row interlock with each other and each row can therefore be considered a single joint. In the proximal row a limited degree of mobility is possible, but the bones of the distal row are connected to each other and to the metacarpal bones by strong ligaments that make this row and the metacarpus a functional entity.
The carpometacarpal joint connects the carpal bones to the metacarpus or metacarpal bones which are joined at the intermetacarpal articulations. In the fingers, finally, are the metacarpophalangeal joints (including the knuckles ) between the metacarpal bones and the phalanges or finger bones which are interconnected by the interphalangeal joints .
In human anatomy, the main role of the carpal bones is to articulate with the radial and ulnar heads to form a highly mobile condyloid joint (i.e. wrist joint), [1] to provide attachments for thenar and hypothenar muscles, and to form part of the rigid carpal tunnel which allows the median nerve and tendons of the anterior forearm muscles to be ...
A real differentiation appeared an estimated 70 mya in early primates, while the shape of the human thumb CMC finally appears about 5 mya. The result of this evolutionary process is a human CMC joint positioned at 80° of pronation, 40 of abduction, and 50° of flexion in relation to an axis passing through the second and third CMC joints. [40]