CHAPTER 7 Wrist and Hand

Wrist Functional classification: condyloid Radius and ulna articulate with carpals… But unlike the elbow where the ulna is the more important part… At the wrist it is the radius which is more important

Bones—Hand Carpals Metacarpals Short bones Arranged in 2 rows Base articulates with carpal bones and adjacent metacarpals. The head articulates with the base of proximal phalanx.

Bones—Hand Phalanges Thumb—two: proximal and distal Digits 2–5—three: proximal, middle, and distal

Thumb: first digit carpometacarpal joint Joints—Hand Thumb: first digit carpometacarpal joint Saddle Motions include: Flexion/extension Abduction/adduction Opposition/reposition Recommend inserting Figures 7-8A, B, C

Metacarpophalangeal joints Joints—Fingers Metacarpophalangeal joints Condyloid with two degrees of freedom Flexion/extension; abduction/adduction

Interphalangeal joints Joints—Fingers Interphalangeal joints Digits 2–5—proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints Thumb—one interphalangeal joint Hinges—one degree of freedom Flexion/extension

Joints—Soft Tissue Supporting Structures Ligaments of the wrist Extrinsic—radius, ulna, or metacarpals to carpals Flexor and extensor retinacula—Carpal Tunnel Syndrome on flexor side

Muscles Wrist extensors Primary wrist extensors: Extensor digitorum Extensor carpi radialis brevis (ECRB)—extensor carpi radialis longus (ECRL)—extensor carpi ulnaris (ECU) Extensor digitorum Wrist extension when fingers extended

Muscles Wrist flexors Primary muscles Flexor carpi radialis (FCR)—FCU—flexor digitorum superficialis (FDS)—flexor digitorum profundus (FDP)—Palmaris Longus (PL)—FPL—APL

Radial/ulnar deviation Muscles Radial/ulnar deviation Aka abduction and adduction Deviation occurs in frontal plane about an A-P axis.