1.Wrist not a single joint – made up of articulations between carpal bones and radio-carpal joint of forearm
2.Functionally wrist and hand are interdependent; all movements of hand are accompanied by movements of radiocarpal and intercarpal joints
3.The wrist complex alone can move in two directions, but combined with pronation and supination of forearm, the hand gives the appearance of being connected to the forearm by a ‘ball and socket’ joint, with intrinsic stability
4.The radial styloid process extends further, distally, than the ulnar styloid process so the ROM for radiocarpal wrist abduction is 7º, and for adduction 30º. When midcarpal ROM is added to this, the total ROM at the wrist for abduction is 15º and for adduction 45º.
5.The range of motion for wrist flexion and for wrist extension is 85º each.
6.When powerful finger movements required, both wrist flexors and extensors contract simultaneously. This helps to prevent too much wrist flexion (which would lead to active insufficiency of bi-articular muscles), to aid powerful finger flexion for gripping
7.Prehension = Grip. Type of grips -precision (for small objects) and power (when considerable force required and the hand is used). Of TWO power grips ‘palmar’ is most powerful with long axis of object lying along palmar gutter. In ‘hook’ grip, object is held between palm and flexed fingers. Grip secure in direction of fingers, used to carry bags