بایگانی برچسب برای: Hand and Wrist

Hand.and.Wrist.Anatomy.and.Biomechanics.[taliem.ir]

Hand and Wrist Anatomy and Biomechanics

In their biological taxonomy and status as “higher-level mammal—homo sapiens,” humans owe their distinction from primates to the miraculous structure of the hand. With its 19 degrees of freedom and its opposing thumb, the hand is a highly developed and complex grasping organ. This enables a wide range of movement combinations while simultaneously allowing adaptation of force, speed, and facileness. Moreover, the hand also features a highly specific sensory and tactile organ that human beings use to perceive and assess themselves and their surroundings. Owing to its capacity for making gestures, the hand plays an important role in interpersonal communication. In writing, music, and the visual arts, the hand acts as a means of expression for the human mind.229 These gross and fine motor skills, along with sensory capacities, enable humans to take care of and nourish their bodies, as well as communicate and shape their environment. With all these possibilities, the hand also plays a major role in self-expression and in developing the human mind, and significantly contributes to modifying human motor capacities.202 The mobilizing of this functionality requires exceptional interaction between the central control system and anatomical structures such as bones and joints, muscles and tendons, nerves and blood vessels, making the hand an extremely complex organ. The distal area of the lower arm consists of the distal radioulnar joint, the thumb and finger carpometacarpal (CMC) joints, the palm, and the fingers. In total, there are 27 bones with 36 articulations and 39 active muscles. In order for the hand to translate its wide range of fine and gross motor capabilities into its complex range of motion, these structures must all be coordinated.