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Explore the intricate structure of the wrist and hand, detailing joints, ligaments, movements, and muscles involved. Learn about carpal tunnel, thumb and finger actions, and how to optimize hand function for various grips and precision tasks.
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The Wrist and Hand Great Mobility = Many Joints
The Wrist and Hand • Radiocarpal • wrist joint • condyloidjoint • Carpals • two rows of four bones • carpal joints • gliding joints
Metacarpals carpometacarpaljoint intermetacarpaljoints metacarpal-phalangealjoints interphalangeal joints The Wrist and Hand
Ligaments of the wrist(radiocarpal joint) • volar (palmar) radiocarpal • volar (palmar) ulnarcarpal • ulnar collateral • dorsal radiocarpal • dorsal ulnarcarpal • radial collateral
Movements of theHand at the Wrist Joint • Flexion • Extension • Hyperextension • Radial flexion (abduction) • Ulnarflexion (adduction) • Circumduction • Carpal Tunnel – finger flexors and median nerve pass through it – overuse my result in pain caused by nerve compression and numbing of the fingers caused by blood vessel involvement.
Movements of the Thumb(saddle joint) • Abduction • Adduction • Flexion • Extension • Circumduction • Opposition
Movements of the Fingers(Hinge joints) • Flexion • Extension • Abduction • Adduction • Circumduction
Muscles of the Wrist and Hand • Of the 19 muscles that move the fingers and thumb 10 are located entirely in the hand – called intrinsics • Those located outside the hand on the forearm but with tendon attachments on the thumb or fingers are extrinsic muscles
Muscles of the Wrist and Hand • Wrist Flexors (proximal attachment) – medial epicondyle
Muscles of the Wrist and Hand • Wrist Extensors (proximal attachment) – lateral epicondyle • These attachments allow these muscles to remain effective across the wrist joint regardless of the position of the forearm – they also contribute to the stabilization of the elbow • Disadvantage is the limiting ROM when there is simultaneous movement across all joints
Cooperative Action of theWrist and Digits • The length of the long finger muscles is relative to the ROM in the wrist and fingers • Long finger muscles do not have sufficient length to permit the full range of motion in the joints of the fingers and wrist at the same time. • Try and flex the wrist and fingers at the same time • Try and extend the wrist and fingers at the same time
Using the Hands for Grasping (Prehension) • Power grip • flexion of all fingers • thumb being primarily a stabilizer • palm is not involved • depends on size and shape of object • uses more extrinsic muscles
Precision handling – involves the use of the thumb and one or two fingers in various positions in order to accommodate a variety of grasping functions • great variability in pressure and fine motor control • more intrinsic muscles being used