Search results
Results From The WOW.Com Content Network
A multiaxial joint (polyaxial joint or triaxial joint) is a synovial joint that allows for several directions of movement. [9] In the human body, the shoulder and hip joints are multiaxial joints. [10] They allow the upper or lower limb to move in an anterior-posterior direction and a medial-lateral direction.
RS3PE typically involves the joints of the extremities, specifically the metacarpophalangeal and proximal interphalangeal joints, wrists, shoulders, elbows, knees and ankles. [4] It is more common in older adults, with the mean age between 70 and 80 years in most studies. [4] [5] It occurs more often in men than in women with a 2:1 ratio.
Synovial joints, joints that are not directly joined, are lubricated by a solution called synovial fluid that is produced by the synovial membranes. This fluid lowers the friction between the articular surfaces and is kept within an articular capsule , binding the joint with its taut tissue.
The presence of an articular disk also permits a more even distribution of forces between the articulating surfaces of bones, increases the stability of the joint, and aids in directing the flow of synovial fluid to areas of the articular cartilage that experience the most friction. The term "meniscus" has a very similar meaning. [1]
Histology of a synovial membrane. H&E stain. The synovial membrane is variable but often has two layers: [4] The outer layer, or subintima, can be of almost any type of connective tissue – fibrous (dense collagenous type), adipose (fatty; e.g. in intra-articular fat pads) or areolar (loose collagenous type).
The English word joint is a past participle of the verb join, and can be read as joined. [21] Joint is derived from Latin iunctus, [21] past participle of the Latin verb iungere, join, unite, connect, attach. [22] The English term articulation is derived from Latin articulatio. [21]
Finally, the joint capsule matures and forms a cavity, with a central meniscus, and an encasement of synovium. [9] This final structure will form several distinct layers of the articular cartilage found in all synovial joints including the Deep Zone (closest to the bone), Middle Zone, and Superficial Zone (closest to the synovial fluid).
The joint is strong, supporting the entire weight of the upper body. It is a synovial plane joint with irregular elevations and depressions that produce interlocking of the two bones. [1] The human body has two sacroiliac joints, one on the left and one on the right, that often match each other but are highly variable from person to person. [1]