The Foot Flashcards
What are the 4 layers of the foot?
layer #1: superficial muscles
layer #2: long flexor tendons and associated muscles
layer #3: deep intrinsic muscles
layer #4: deep tendons and the interossei
What 3 muscles make up LAYER 1 - SUPERFICIAL MUSCLES?
- abductor hallucis
- flexor digitorum brevis
- abductor digiti minimi
Abductor hallucis (O.I.A.I)
origin: under the calcaneus
insertion: side of proximal phalanx of toe #1
action: flex and abduct big toe
innervation: medial plantar nerve
Flexor digitorum brevis (O.I.A.I)
origin: under the calcaneus
insertion: middle phalanges of the 4 lateral toes
action: flex the toes
innervation: medial plantar nerve
Abductor digiti minimi (O.I.A.I)
origin: under the calcaneus
insertion: side of proximal phalanx of toes #5
action: abducts toe #5
innervation: lateral plantar nerve
What 2 muscles make up LAYER 2 - LONG FLEXOR TENDONS AND ASSOCIATED MUSCLES?
- quadrates plantae
- the lumbricals
Quadrates plantae (O.I.A.I)
origin: one head on each side of the calcaneus
insertion: tendon of the flexor digitorum longus
action: flex the toes
innervation: lateral plantar nerve
Lumbricals (O.I.A.I)
origin: flexor digitorum longus
insertion: extensor expansion of phalanges 2-5
action: flexes the phalange metatarsal joint, extends the inter phalanges joints
innervation: medial plantar nerve on phalanges 2, lateral plantar nerve on the rest
What 3 muscles make up LAYER 3 - DEEP INTRINSIC MUSCLES?
- flexor hallucis brevis
- adductor hallucis
- flexor digiti minimi brevis
Flexor hallucis brevis (O.I.A.I)
origin: two bellies originate side by side on cuneiforms #1 and #2
insertion: proximal phalanx
action: flex big toe
innervation: medial plantar nerve
Adductor hallucis (O.I.A.I)
oblique head origin: base of metatarsals 2,3,4
transverse head origin: capsules of the metatarsal phalangeal joints
insertion: lateral sesamoid bone
action: adducts big toe
innervation: lateral plantar nerve
Flexor digiti minimi brevis (O.I.A.I)
origin: metatarsal #5
insertion: proximal phalanx
action: flexes pinky toe
innervation: lateral plantar nerve
What are the 2 muscles that make up LAYER 4 - THE INTEROSSEI AND THE PERONEUS LONGUS TENDON?
- plantar interossei (3)
- dorsal interoseei (4)
Plantar inerossei (O.I.A.I)
origin: medial side of metatarsal 3,4,5
insertion: medial sides of their own extensor expansions
action: adductors of the digits
innervation: lateral plantar nerve
Dorsal interossei (O.I.A.I)
origin: between metatarsals
insertion: extensor expansion of toe close to the axis (phalanx 2)
action: abductor of the digits
innervation: lateral plantar nerve
