Lower Leg iRA Flashcards
why is it beneficial for the distal tibia to be wider anteriorly than posteriorly?
aids in bony approximation when in full DF (wedging effect)
in the sagittal plane, is the distal tibia concave or convex?
concave
in the transverse plane, is the distal tibia concave or convex?
convex
what is the orientation of the proximal navicular?
oval, concave
what is the orientation of the distal navicular?
convex with 3 facets
what is the orientation of the lateral navicular?
irregular
what muscle is the navicular tuberosity a primary attachment for?
tibialis posterior
what bones does the cuboid articulate with?
- 4th and 5th metatarsals
- calcaneus
what bones do the cuneiforms articulate with?
- navicular
- metatarsals 1-3
- cuboid
which cuneiform is the largest?
medial
what muscle is the medial cuneiform a primary attachment for?
tibialis anterior
what other muscles attach to the medial cuneiform?
- tibialis posterior
- fibularis longus
the intermediate cuneiform is a partial attachment for what muscle?
tibialis posterior
the lateral cuneiform is a partial attachment for what muscle?
tibialis posterior
metatarsals 1-3 articulate with ____
cuneiforms
metatarsals 4-5 articulate with ____
cuboid
which metatarsal is the longest?
2nd
which metatarsal has a styloid process?
5th
which MTP joint has medial and lateral sesamoids?
1st
what muscle are the medial and lateral sesamoids embedded in?
flexor hallucis brevis
what 5 features of the ankle make it a rigid joint?
- joint congruency
- capsular support
- ligamentous support
- muscular stability
- interaction of joint angles at varied positions (perpendicular for stable platform)
what makes the ankle a flexible joint?
interaction of joint angles at varied positions (parallel for load acceptance)
attachments of the deltoid ligament
medial malleolus to navicular tuberosity, sustentaculum tali, and medial talus
what motion does the anterior talofibular ligament restrict?
anterior translation of the foot
what muscles are in the anterior compartment of the lower leg? (hint: TEEF)
- tib anterior
- extensor hallucis longus
- EDL
- fibularis tertius
what muscles are in the lateral compartment of the lower leg?
fibularis longus and brevis
what are the superficial flexors in the posterior compartment?
gastroc, soleus, plantaris
what are the deep flexors in the posterior compartment? (hint: FFPT)
- FDL
- FHL
- popliteus
- tib posterior
what muscles are in the 1st layer of intrinsics? (hint: AFA)
- abductor hallucis
- FDB
- abductor digiti minimi
what muscles are in the 2nd layer of intrinsics?
- flexor digitorum accessorius (quadratus plantae)
- lumbricals
what muscles are in the 3rd layer of intrinsics? (hint: FAF)
- FHB
- adductor hallucis
- flexor digiti minimi brevis
what muscles are in the 4th layer of intrinsics?
dorsal and plantar interossei
what nerve is being compressed in tarsal tunnel syndrome?
posterior tibial nerve
what nerve can be impacted by an inversion injury?
superficial fibular nerve
what structures make up the mortise?
- inferior tibia
- medial and lateral malleoli
- inferior transverse talofibular ligament
what happens at the navicular and cuboid during pronation?
- navicular depression
- cuboid ABD
subtalar supination: slight depression causes slight ____ of the foot
extension (aka PF)
subtalar supination: medial displacement causes ____ of the foot
ADD
subtalar supination: rotation as calcaneus lies down flat on lateral surface with ____ of the foot
inversion
metatarsals and phalanges are ____ proximally and ____ distally
concave, convex
DF/PF are sagittal movements that primarily occur at what 3 joints?
talocrural, MTP, IP
inversion/eversion = tilting of the plantar surface of the foot towards/away from midline in the ____ plane at what 2 joints?
- coronal plane
- subtalar and transverse tarsal joints
ABD of the foot primarily occurs at what joints?
transverse tarsal joints
how much DF is needed to walk?
10 degrees
how much DF is needed to stand up from a chair?
17-20 degrees
how much DF is needed to descend stairs?
20 degrees
what bony factors limit DF?
- superior surface of talar neck hits anterior margin of tibia
- mortise
what capsuloligamentous factors limit DF?
- posterior capsule
- posterior fibers of collateral ligaments
what muscular factors limit DF?
triceps surae
medial arch
- calcaneus
- talar head
- navicular
- mets 1-3
lateral arch
- calcaneus
- cuboid
- mets 4-5
transverse arch
- bases of mets
- cuboid
- cuneiforms
windlass effect
- plantar fascia resists flattening of the longitudinal arch
- energy is stored for propulsion
