Part 10: Sole of the Foot Flashcards
What is the cutaneous innervation of the sole?
Heel: medial calcaneal branches of tibial
Sole is supplied by medial and lateral plantar nerves in similar fashion to palm of hand (medial 3.5 toes, lateral 1.5 toes)
What is the role of plantar aponeurosis?
Covers length of sole from medial and lateral tubercles of calcaneus inserted into 5 slips, 1 to each toe. Skin is anchored to aponeurosis via subcut fibrous septa. This improves grip of sole.
How are the muscle layers of the sole arranged?
4 layers are described:
As tendons pass to toes muscles generally get shorter in deeper layers.
1st: FDB, Abductor H, Abductor digiti minimi
2nd: Tendons of FHL + FDP, flexor accessorius muscle, lumbricals
3rd: FHB, Adductor H, Flexor digiti minimi
4th: Interossei, Tendon peroneus longus and Tibialis post
What is the origin, insertion, action and innervation of flexor digitorum brevis?
O: Medial tubercle calcaneus
I: 4 tendons to lateral 4 toes, insert to side middle phalanx
A: flexes middle phalanx in any position of ankle
N: Medial plantar (S2,3)
What is the origin, insertion, action and innervation of Abductor hallucis?
O: Medial tubercle calcaneus
I: Medial side proximal phalanx great toe
A: Abbduction great toe
N: Medial plantar (S2,3)
What is the origin, insertion, action and innervation of Abductor digiti minimi?
O: Both medial and lateral tubercles calcaneus
I: lateral side proximal phalanx small toe
A: Abduct small toe
N: Lateral plantar nerve (S2,3)
What is the origin, insertion, action and innervation of Flexor accessorius muscle?
O: Medial fleshy head (medial tubercle calcaneus) tendinous lateral head (lateral tubercle calcaneus)
I: Inserts into tendon of FDL at point of division into 4 tendons
A: Flexes toes in any ankle position
N: Lateral plantar nerve (S2,3)
What is the origin, insertion, action and innervation of lumbrical muscles?
O: Arise from FDL tendons, pass forward on medial side of tendons
I: Extensor expansions of lateral 4 toes
A: maintain extension of interphalangeal joints while FDL flexes toes to prevent toes buckling under when walking etc
N: 1st - medial plantar nerve, 2nd, 3rd + 4th are lateral plantar nerve
What is the origin, insertion, action and innervation of flexor hallucis brevis
O: Undersurface of cuboid and undersurface of all cuneiforms
I: Inserted into medial and lateral sides base of proximal phalanx great toe via sesamoid bones.
A: Flexion of proximal phalanx great toe
N: Medial plantar (S2,3)
What is the origin, insertion, action and innervation of adductor hallucis?
O: Large oblique head anterior to FHB base of 2-4 MT bones. Transverse head from deep transverse ligament
I: Lateral side proximal phalanx great toe
A: Adducts great toe, assists in maintaining transverse arch.
N: Lateral plantar (S2,3)
What is the origin, insertion, action and innervation of flexor digiti minimi?
O: base of 5th MT
I: Proximal phalanx little toe
A: assists in flexion of little toe
N: Lateral peroneal nerve
Where do the plantar interossei arise?
MT bone of own toe
Where do dorsal interossei arise?
2 head from the 2 MT either side of toe
Where is the longitudinal axis of the foot?
The second toe (ie abduction is away from 2nd toe)
How many plantar interossei muscles are there?
3 - only the 3 lateral toes require them as big toe has its own adductor and 2nd toe can not be adducted as it is the longitudinal axis
