Hand Muscles Cheat Sheet (DRAFT) by Siffi

Origin: Posterior surface of the shaft of the ulna + middle 1/3rd of posterior surface of the radius
Insertion: Radial side of the 1st metacarpal base + trapezium
Nerve: Posterior intero­sseous Nerve (radial) - (C7-8)
Action: Abducts the wrist joint and assists in abducting the thumb - extends the thumb with pollicis extensors at the carpom­eta­carpal joint

- Can mimic deQuer­vain's tenosy­novitis and superf­icial radial nerve irritation

Origin: Proxim­ola­teral part of the thenar eminence + flexor retina­culum, scaphoid bone and trapezium
Insertion:
Medial fibres: Radial side of the base of the proximal phalanx of the thumb
Lateral Fibres: Dorsal digital expansion of the thumb
Nerve: Lateral Terminal branches of the median nerve (C8-T1)
Action: Draws thumb in

Origin: Superf­icial: Distal border of the flexor retina­culum & distal tubercle of the trapezium Deep: Trapezoid & capitate & palmar ligaments of the distal row of carpal bones
Insertion: Superf­icial: Radial sides of the base of the proximal phalanx of the thumb Deep: Sesamoid bone and base of the 1st phalanx
Nerve: Superf­icial: Lateral terminal branch of the median nerve Deep: Deep branch of the ulnar nerve (C8-T1)
Action: Flexes the MCP Joint

Origin: Tubercle of the trapezium and flexor retina­culum
Insertion: Lateral border and adjoining lateral half of the palmar surface of the metacarpal bone of the thumb
Nerve: Lateral Terminal Branch of the median nerve C8-T1 + Branch of the deep terminal branch of the ulnar nerve
Action: Flexes the metacarpal joint of the thumb and assists in opposition

Origin:
Oblique: Capitate, bases of 2nd and 3rd metaca­rpal, palmar ligaments of the carpus and sheath of the tendon of FCR
Transv­erse: Anterior body of the 3rd metacarpal
Insertion: Medial side of the base of the proximal phalanx of the thumb + ulnar sesamoid
Nerve: Deep branch of the ulnar nerve (T1)
Action: Adduct thumb at CMC Joint

- Weeders are suscep­tible - TrPs in APB, FPB + OP
- Deep tenderness in the web of the thumb could be from scalenes, brachi­alis, ECRB or Brachi­ora­dialis

Origin: Pisiform, tendon of FCU + pisohamate ligament
Insertion: Ulnar side of the base of the proximal phalanx of the little finger, ulnar border of dorsal digital expansion of EDM
Nerve: Deep branch of ulnar nerve (C8-T1)
Action: Abduction of the 5th digit from the 4th

Origin: Convex surface of the hook of the hamate + palmar surface of the flexor retina­culum
Insertion: Ulnar side of the base of the proximal phalanx of the little finger
Nerve: Deep branch of ulnar nerve (C8-T1)
Action: Flexion of the little finger at the MCP Joint

Origin: Convexity of the hook of the hamate + flexor retina­culum
Insertion: Whole length of ulnar margin of the 5th metacarpal bone and adjacent palmar surface
Nerve: Deep branch of the ulnar nerve (C8-T1)
Action: Flexion of the 5th metacarpal + assists in opposition

Origin: Palmar surfaces of metacarpal bones
Insertion: Bases of proximal phalanges
Nerve: Deep branch of the ulnar nerve (C8-T1)
Action: Adduction of the fingers - grip

Origin: Metaca­rpals
Insertion: Proximal phalanges + extensor expansion
Nerve: Deep branch of ulnar nerve C8-T1
Action: Abduction of the fingers - grip

Origin: Flexor digitorum profundus (radial side)
Insertion: Extensor expansion
Nerve: 1st and 2nd - median nerve (C8-T1), 3rd and 4th - Deep terminal branch of the ulnar nerve (C8-T1)
Action: Flexion of MCP joints while extending both interp­hal­angeal joints of the digit - upstroke in writing