The Foot Flashcards
7 tarsals
talus calcaneus cuboid navicular 3 cuneiform
talus, different parts
almost totally covered by articular cartilage, no muscles attach
trochlea- articular surface
head-articulates w/ navicular
neck-entrance for arteries
posterior tubercles- groove for flexor hallucis longus
most common fractured tarsal
talus- often from forced dorsiflexion as in MVA
fractures thru neck can disrupt vascular supply, lead to AVN
calcaneus
heel bone- articulates w/ talus superiorly at subtalar joint, w/ cuboid anteriorly
achilles tendon inserts onto posterior aspect
significant aspects of calcaneus
calcaneal tuberosity- what you stand on
sustentaculum tali- projecting bony shelf, supports head of talus, FHL tendon passes beneath this and inserts on hallux
calcaneal fracture
often from fall from higher heights, can fracture into multiple pieces (comminuted)
w/ calcaneal fracture, what else needs to be considered
must rule out fractures of spine given the high axial load
involving Subtalar joint can have arthritis long term
insertion of fibularis brevis
tuberosity of the 5th metatarsal
metatarsal w/ sesamoid bones
first metatarsal
metatarsal fractures
direct trauma often from kicking
5th metatarsal fractures are common, esp w/ rolling ankle inversion
brevis tendon pulls reflexively and can pull off 5th tuberosity
plantar aponeurosis, fn
thick central portion of plantar fascia, continuous w/ crural fascia
protect underlying structure, support longitudinal arches, compartmentalize the foot
4 compartments of foot
medial
lateral
central
interosseus
more important to organize in layers
1st layer of plantar muscles
intrinsic muscles
abductor hallucis- abducts big toe
flexor digitorum brevis- muscle belly gives 4 tendons, flexes toes 2-5
abductor digiti minimi- abducts 5th toe
second layer of plantar muscles
extrinsic tendons- FDL,, FHL
intrinsic- quadratus plantae assists FDL
lumbrical muscles (4) flex toes, arise from FDL tendons
what else in second plantar layer
neurovascular structures enter foot in this layer
third plantar layer
flexor digiti minimi brevis
adductor hallucis
flexor hallucis brevis
intrinsic
4th layer of plantar muscles
3 plantar -adduct
4 dorsal- abduct
extensor expansion
site of insertion for interossei and lumbricals, just like hands
dorsal phalanges
innervation of plantar intrinsic muscles
lateral plantar nerve innervates 14 muscles
medial plantar innervates 4: flexor digitorum brevis, abductor hallucis, flexor hallucis brevis, 1st medial lumbrical
all from S2/S3 (play footsie with me)
order of structures in tarsal tunnel
Tall Dark ANd Handsome
tibialis posterior digitorum longus posterior tibial Artery tibial Nerve Hallucis longus
medial plantar nerve
terminal branch of tibial nerve
innervates 4 plantar muscles, cutaneous to 3.5 digits (like median nerve) and medial aspect of foot
lateral plantar nerve
other terminal branch of tibial nerve
superficial and deep branch- deep innervates rest of intrinsic foot muscles, superficial sensation to 1/5 lateral digits (like ulnar) and lateral aspect of foot
two branches of posterior tibial artery
medial plantar artery- small superficial and deep branches, mainly muscles of great toe
lateral plantar- workhorse, forms deep plantar arch (w/ deep branch of dorsalis pedis artery, anastamosis)
-deep arch gives off plantar metatarsal arteries
subtalar joint, ligaments
aka talocalcaneal joint
plane synovial joint- permits inversion and eversion
main ligament is interosseus talocalcaneal ligament
helped by transverse tarsal joints
