MSK foot and ankle Flashcards
(258 cards)
how many bones are in the foot and ankle?
28
what is the shank?
the tibia and fibula
medially rotated the rearfoot with pronation
syndesmotic joint
how much of body weight goes through the tibia?
70-90%
what is the mortise?
space created by tibia and fibula where talus articulates
very important for stability
open chain DF vs closed chain DF glides at the mortise
open chain: talus glides posterior on a fixed tibia
used post glide
closed chain: tibia glides anterior on a fixed talus
use ant glide
describe the talocrural joint
artic of the talus and mortise
primary function is PF and DF
wedge shape
greater stability in DF
what muscles attach on the talus?
none
what does the interosseous ligament do?
transfers some WB force to the fibula
injured with rotation
what do the tibiofibular ligaments do?
prevent excessive displacement of the fibula
what is the deltoid ligament for?
restrains eversion
what are the ant/post talofibular and calcaneofibular ligaments for?
restrain inversion
describe the subtalar joint
artic of talus and calcaneus
“bridge between the foot and ankle”
mobile yet stable
mvmts of supination and pronation
what is the sinus tarsi?
area of nerves for proprioception
between the two artics of the subtalar joint
what are the two subtalar joint axis?
superior view: 23 deg +/- 11 (towards big toe)
medial view: 41 deg +/- 9 (anterior is up)
midtarsal joint
chopart joint
talonavicular is more mobile
calcaneocuboid
mvmts of eversion/inversion and PF/DF
tarsometatarsal joint
lisfranc joint
cuneiforms and MT 1-3, cuboid and MT 4-5
very little motion in 1-3 (like the hand)
lisfranc injury most common at 3 MT
where is the lisfranc ligament?
medial cuneiform to 2 MT
1st MTP joint
transmits lots of force
80% during walking
200% during athletic activities
800% during jumping
where are the two sesamoids of the foot?
near 1st MTP
how much mobility is needed at 1st MTP?
60-75 deg
describe the plantar fascia
type I collagen
prevents collapse of longitudinal arch
when is tension in plantar fascia highest?
between initial contact and loading response
what are some potential causes of heel pain?
subcutaneous calcaneal bursa - tight shoes
retrocalcaneal bursa - between achilles/calc
calcaneal fat pad - 2nd leading cause
what are the muscles of the anterior compartment?
anterior tibialis:
primary DF/inverter in OC
stab talocrural and midfoot in CC
extensor hallucis longus:
extends great toe and stab midfoot
extensor digitorum longus:
extends 2-5 and stab midfoot
peroneus tertius:
assists in DF/eversion
synergist with per brevis