Chapter 13 Hand

Joints and Motions of the Thumb Carpometacarpal (CMC) Flexion and extension Abduction and adduction Opposition and reposition Metacarpophalangeal (MCP) Interphalangeal (IP) CMC – trapezium & base of 1st metacarpal; saddle joint; rotation is a passive accessory motion of thumb Modified biaxial joint MCP – uniaxial IP - uniaxial

Joints and Motions of the Fingers Carpometacarpal (CMC) Accessory motion, minimal opposition Metacarpophalangeal (MCP) Flexion/extension/hyperextension Abduction/adduction Proximal interphalangeal (PIP) and distal interphalangeal (DIP) Flexion/extension CMC – nonaxial; plane joints

Bones and Landmarks Metacarpals (5) Base Head Phalanges (14)

Ligaments and Other Structures Flexor retinaculum Palmar carpal ligament Transverse carpal ligament Extensor retinaculum Extensor expansion ligament (extensor hood)

Ligaments and Other Structures Palmar arches Proximal carpal arch Distal carpal arch Longitudinal arch

Extrinsic Muscles of the Thumb and Fingers Anterior Flexor digitorum superficialis Flexor digitorum profundus Flexor pollicis longus FDS – middle phalanx FDP – distal phalanx (not a muscle card)

Extrinsic Muscles of the Thumb and Fingers Posterior Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis Extensor digitorum Extensor indicis Extensor digiti minimi

Intrinsic Muscles of the Thumb and Fingers Thenar (thenar eminence) Flexor pollicis brevis Abductor pollicis brevis Opponens pollicis

Intrinsic Muscles of the Thumb and Fingers Deep palm Adductor pollicis Dorsal and palmar interossei Lumbricales No muscle cards on these

Intrinsic Muscles of the Thumb and Fingers Hypothenar (hypothenar eminence) Flexor digiti minimi Abductor digiti minimi Opponens digiti minimi

Hand Description of anatomical relationships Summary of muscle actions Summary of muscle innervation Summary of muscle actions – Table 13.4 page 187 Summary of Muscle Innervations – Table 13.5 & 13.6 page 188

Common Wrist and Hand Pathologies Wrist fracture de Quervain’s disease Dupuytren’s contracture Wrist Fractures - Colles – transverse fracture of distal radius with posterior displacement of distal fragment - Smith’s – distal fragment displaces anteriorly - greenstick fracture

Hand Function Functional position Grasps Power grip Precision grip Functional Position – wrist slightly extended; MCP & PIP slightly flexed; thumb in opposition Power Grip – holds forcibly while being moved; Precision Grip – aka precision prehension grip; manipulating objects with finer type movement Power Grips Cylindrical – holding a hammer Spherical – doorknobs Hook – holding a handle Precision Grips Pad to Pad Pinch grip Three Jaw chuck – holding a pen Tip to Tip – pincer grip Pad to side – lateral prehension – key Side to side - cigarette