Ankle and Foot Kinesiology

function of the anterior talofibular ligament

resists plantar flexion, adduction, and inversion

function of the posterior talofibular ligament

resists inversion

function of the calcaneofibular ligament

resists dorsiflexion and inversion

function of the deltoid ligament

resists eversion

main cause of medial malleoli avulsion fractures

during extreme eversion when the deltoid ligament is put under high tension

tibial torsion

twisting of the tibia, measured as the angle between the line of the tibial plateau and line through the malleoli

normal angle of tibial torsion

20-30 degrees of ER

main causes of tibial torsion

normal bone development, misaligned tibial fractures

compensatory strategy for excessive tibial torsion

internally rotating the hip

pronation of the ankle/foot

a combination of eversion, abduction, and dorsiflexion

supination of the ankle/foot

a combination of inversion, adduction, and plantar flexion

talocrucal joint axis orientation

10 degrees superior of transverse plane medially and 6 degrees anteriorly of frontal plane medially

main component of pronation at the talocrural joint

dorsiflexion

main component of supination at the talocrural joint

plantar flexion

tibial and fibular movement during talocrural joint dorsiflexion

tibia and fibula spread apart because of the widening of the trochlea of the talus

ligaments put under tension during talocrural joint dorsiflexion

anterior tibiofibular ligament and calcaneofibular ligament

talocrural joint arthrokinematics during open-chain dorsiflexion

convex on concave, roll into dorsiflexion, and posterior slide

talocrural joint arthokinematics during closed-chain dorsiflexion

concave on convex, anterior roll and anterior slide

talocrural joint arthokinematics during open-chain plantar flexion

convex on concave, roll into plantar flexion and anterior slide

talocrural joint arthokinematics during closed-chain plantar flexion

concave on convex, posterior roll and posterior slide

ligaments of the subtalar joint

interosseous talocalcaneal ligament and plantar calcaneonavicular ligament

subtalar joint axis orientation

42 degrees superior to the transverse plane and 16 degrees medial to the sagittal plane

primary components of pronation at the subtalar joint

eversion and abduction

primary components of supination at the subtalar joint

inversion and adduction

subtalar joint motion during weight-bearing pronation

calcaneal eversion and talar head adduction/plantarflexion

subtalar joint motion during weight-bearing supination

calcaneal inversion and talar head abduction and dorsiflexion

result of tibial IR during pronation

forces the talus to adduct and plantarflex, flattening the foot in order to conform to the ground surface

result of tibial ER during supination

forces the talus to abduct and dorsiflex, arching the foot in order to form a rigid lever

pes planus

flat foot

pes cavus

arched foot

function of the transverse tarsal joint

adds supination/pronation motions, allows mid/forefoot to adapt to varied ground contours

transverse tarsal joint oblique axis orientation

52 degrees superior to transverse plane and 57 degrees medial of sagittal plane

main components of pronation at transverse tarsal joint oblique axis

abduction and dorsiflexion

main components of supination at transverse tarsal joint oblique axis

adduction and plantar flexion

transverse tarsal joint longitudinal axis orientation

15 degrees superior of transverse axis and 9 degrees medial of sagittal axis

main components of supination at transverse tarsal joint longitudinal axis

inversion

main components of pronation at transverse tarsal joint longitudinal axis

eversion

function of transverse tarsal joint supination during subtala joint pornation

helps to adjust to terrain and keep forefoot flat on the ground

function of transverse tarsal joint pronation during subtalar pronation

create a mobile foot for force absorption

determining factors of transverse tarsal joint movement

surface someone is standing on and whether you need a flat arch or a level to push off

relationship between transverse tarsal joint and hindfoot joints

transverse tarsal joint movement is separate from hindfoot joints

function of transverse tarsal joint supination during subtalar joint supination

helps to make the foot a rigid level to push off of

function of the transverse tarsal joint pronation during subtalar joint supination

helps to keep the foot flat on the ground

function of the tarsometatarsal joints

keeping the foot in contact with the ground, kicking in during extreme pronation/supination

supination twist

supination at the tarsometatarsal joint when hind foot is in extreme pronation

pronation twist

pronation at the tarsometatarsal joint when the hind foot is in extreme supination

function of supination/pronation twist at tarsometatarsal joint

keeps foot in contact with the ground and transfers forces between medial/lateral sides of the feet

metatarsal break

MTP extension that allows the weight-bearing foot to rotate over the toes and push off the ground

Windlass effect

extension at the metatarsal break helps put tension on the plantar aponeurosis, creating a rigid lever that arches the foot

mechanism of lateral ankle sprain

plantar flexion and inversion

anterior drawer ankle test

tests forstability of the ATFL

Feiss line

a line running from the medial malleolus to the plantar aspect of the first metatarsophalangeal joint

foot pronation assessments

vertical navicular height, navicular drfit/drop, longitudinal arch angle, Feiss line

mechanical changes of lower extremity when foot is planted and hip is in full IR

subtalar pronation, lowering of medial arch, valgus stress on knee, forefoot/midfoot inversion, flexion/adduction at hip

mechanical changes of lower extremity when foot is planted and hip is in full ER

subtalar supination, raising of medial arch, forefoot/midfoot eversion

subtalar joint neutral

position from which the STJ can be maximally supinated/pronated

rearfoot varus

rearfoot valgus

forefoot varus

forefoot valgus