In human anatomythe annular ligaments of the fingersoften referred to as A pulleysare the annular part of the fibrous sheathes of the fingers. Four or five such annular pulleys, together with three cruciate pulleysform a fibro-osseous tunnel on the palmar aspect of the hand through which passes the deep and superficial flexor tendons. The annular and cruciate ligaments serve to govern the flexor mechanism of the hand and wrist, providing critical constraints to the flexor tendons to prevent bowstringing upon contraction and excursion of extrinsic flexor musculo-tendinous units.
The hand and wrist are made up of many different bones, muscles and ligaments that enable a wide range of movements. The wrist is formed where the two bones of the forearm — the radius the larger bone on the thumb side of the arm and the ulna the smaller bone on the pinky side — meet the carpus. Rather than a single joint, the wrist is actually made up of multiple joints where the bones of the arm and hand meet to allow movement.
The joints in our hands are made up of cartilage surfaces that cap the bones. Cartilage is a smooth surface that allows for gliding. When cartilage is healthy, there is a cushioning effect of the cartilage that absorbs and evens out the forces across the joint.
Did you know that the tendons attached to your thumb run all the way up your forearm? There are four thumb tendons:. Learn more about anatomy of the fingers, hand, wrist, arm and shoulder at www.
Texting, typing, gaming … Such activities pervade our lives. More specifically these painful or irritating conditions are repetitive stress injuries that fall under the more scientific categories of tendinitis, tendinosis, carpal tunnel syndrome, osteoarthritis, carpometacarpal joint irritation, collateral ligament injury, etc. As I alluded to, we use our thumbs frequently throughout the day for technology use and otherwise.
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 carpometacarpal joint of the thumb pollexalso known as the first carpometacarpal joint, or the trapeziometacarpal joint TMC because it connects the trapezium to the first metacarpal bone, plays an irreplaceable role in the normal functioning of the thumb. The most important joint connecting the wrist to the metacarpus, osteoarthritis of the TMC is a severely disabling condition; up to twenty times more common among elderly women than in average.
The wrist and hand form a continuum with the upper extremities and allow the body to reach out to perform a vast number of functions exclusive to primates and humans. The wrist acts as a hinge that articulates the forearm with the hand, and the hand with fingers. Together wrist, hand and fingers are responsible for fine movements and grasping.
The joint capsule of the thumb is fibrous and durable, and allows for great mobility. There are nine interphalangeal joints in each hand, two on each finger and one in the thumb. The thumb joint has two collateral ligaments as well as the capsule, which is lined by a synovial membrane.
The first carpometacarpal joint is formed by the proximal joint facet of the first metacarpal and the distal joint on the trapezium. The morphologic features of these facets, together with a lax but strong joint capsule, give the thumb great mobility and play a major role in the opposition of the thumb. Based on the kinematic behavior of the joint, it was given the functional status of a ball-and-socket joint.