(Preview) Forearm&Hand Muscles

ulna osteology

-semilunar notch: articulates w/ trochlea of humerus

-olecranon process: most superior part of ulna

-radial notch: articulates with head of radius

-styloid process: distal

radius osteology

*mobile during pronation/supination

-radial tuberosity: insertion biceps brachii

-head: articulates with radial notch of ulna

-neck

-ulnar notch: articulates w/ distal ulna

-styloid process

radioulnar ligaments

1.Radial collateral l.

2.Annular l. (*holds head of radius against ulna)

3.Ulnar collateral l.

4.Interosseous membrane

5.Radioulnar l. (dorsal)

*tendons pass over dorsal tubercle

generel anterior forearm origin, insertion, innervations, and blood supply

•Origin of muscles: medial epicondyle of humerus (mostly)

•Insertion of muscles: look at the name of the muscle for a hint

•Innervation: Median n. (mostly) / Ulnar n.

•Blood supply: Ulnar a. / Anterior Interossesous a. / Radial a.

anterior forearm: layer 1

“Purple Frogs Play Ultimate Sports”

anteriore forearm: layer 2

anterior forearm: layer 3

Palmar Hand: Flexor Digitorum Superficialis and Profundus

-FDP and FDS have different insertions that alter their function

-FDP:

• i: distal phalanx 2,3,4,5

• act: flex DIP and PIP

-FDS:

• i: middle phalanx

• act: flex PIP

generel posterior forearm origin, insertion, innervation, and blood supply

•Origin of muscles: lateral epicondyle of humerus (mostly)

•Insertion of muscles: look at the name of the muscle for a hint

•Innervation: Radial n.

•Blood supply: Posterior Interossesous a. / Interosseous recurrent a.

posterior forearm: layer 1

“Bad children certainly do make us angry”

posterior forearm: layer 2

“Some adults beleive love infects”

what happens if either FCU or FCR were severely weakened or paralyzed?

-both need to contract at the same time to flex normally

-if one doesn’t work will deviate to the other side

• bc have different innervations

intrinsic hand muscles

+adductor pollicis

lumbricals muscle table

-Origin: tendons of flexor digitorum profundus muscle in palm

-Insertion: extensor expansion of 1st phalanx (fingers 2 - 5)

-Innervation

• median nerve (lateral 2) 

• ulnar nerve (medial 2)

-Action: flex fingers at metacarpophalangeal joints and extend fingers at interphalangeal joint

palmar interosseous muscle table

-Origin: mid-axis side of metacarpals 2, 4, 5

-Insertion: extensor expansion on 1st phalanx of corresponding digit

-Innervation: ulnar nerve

-Action: adduct fingers toward 3rd finger

dorsal interosseous muscle table

-Origin: sides of metacarpals

-Insertion: extensor expansion over proximal phalanx of fingers 2-4

-Innervation: deep branch of ulnar nerve

-Action: abduct the fingers

palmar vs dorsal interossei actions

•“DAB with the PAD”

–Dorsal interossei ABduct

–Palmal interossei ADduct

hypothenar muscels

-act on 5th digit

-Flexor digiti minimi brevis; abductor digiti minimi; opponens digiti minimi

thenar muscles

-act on the thumb

-in=median nerve/recurrent median nerve

•Flexor pollicis brevis

•Abductor pollicis brevis

•Opponens pollicis

actions of the pollex

muscels of the thumb + innervation