Biomechanics Foot

Question 1

foot functioins

Answer 1

provide a stable base of support
-critical for bi-ped transition
-to permit energy efficient walking pattern
allow transverse plane rotation of LE with foot fixed to supporting surface
shock attenuation

Question 2

what foot motion occurs during
-initial contact
-terminal stance
result

Answer 2

initial contact
-pronation
-causes increased foot mobility
terminal stance
-supination
-causes increased foot stability

Question 3

how is shock attenuation created in the foot

Answer 3

created by controlled elongation of arches

• foot pronation causes foot elongation
• elongation created by elasticity of ligaments and fascia
• eccentric contraction of intrinsic foot muscles

Question 4

transfer of thigh and leg rotation initiated by _____ via _____
-causes movement of the _____ that generates _____

Answer 4

initiated by pelvic rotation via talocrural joint coupling

causes movement of the talus that generates foot motion

Question 5

motion in cardinal planes during foot pronation

Answer 5

transverse
-adduction of talus
sagittal
-plantarflexion of talus
frontal
-eversion of calcaneus

Question 6

motion in cardinal planes during foot supination

Answer 6

abduction of talus
dorsiflexion of talus
inversion of calcaneus

Question 7

rank the regions of greatest movement during foot pronation and supination

• rearfoot
• midfoot
• forefoot

Answer 7

#1: midfoot
#2: rearfoot
#3: forefoot
all 3 regions necessary for foot pronation and supination

Question 8

total foot motion

• greatest sagittal plane movement is between which bones?
• is talonavicular joint motion > or < than talocalcaneal joint motion
• motion between medial cuneiform and navicular is > or < than expected

Answer 8

greatest sagittal plane movement between tibia and talus
talonavicular joint motion > than talocalcaneal joint
motion between medial cuneiform and navicular > than expected

Question 9

what types of movement can you have between the rearfoot and midfoot

Answer 9

grouped movement
-rearfoot and midfoot move in same direction
independent movement
-motion occurs in opposite directions
-occurs about longitudinal axis of midfoot

Question 10

foot mechanism model

• what are the individual mechanisms?
• which are constrained vs. non-constrained

Answer 10

tarsal mechanism
-constrained
tarsometatarsal mechanism
-non-constrained
metatarsophalangeal mechanism
-non-constrained

Question 11

joints involved in the tarsal mechanism

Answer 11

subtalar (tibia and calcaneus)
talocalcaneonavicular
calcaneocuboid

Question 12

major ligaments of the tarsal mechanism

Answer 12

interosseous talocalcaneal ligament
cervical ligament
-subtalar joint
bifurcated ligament
-"Y" band
-calcaneocuboid and calcaneonavicular portions

Question 13

tarsal mechanism is constrained

• what does constrained mean?
• purpose

Answer 13

all parts of the system are interrelated
well suited to transmit motions and modify motions during transmission
example
-gears of a clock
if one part of the system breaks down, the whole system shuts down

Question 14

osseous components of tarsometatarsal mechanism

Answer 14

Chopart's Joint
-proximal aspect: talus and calcaneus
-distal aspect: navicular and cuboid
LisFranc's Joint
-between distal tarsals and metatarsals

Question 15

components of medial and lateral column of tarsometatarsal mechanism

Answer 15

medial column
-cuneiforms
-navicular
-1st - 3rd ray
lateral column
-cuboid
-4th and 5th ray

Question 16

ligaments of the tarsometatarsal mechanism

Answer 16

long plantar ligament
peroneus longus tendon
short plantar ligament
-below long plantar
spring ligament

Question 17

functional characterisitics of the tarsometatarsal mechanism

-important rays

Answer 17

first ray
fifth ray
-most mobile
second ray
-most stable

Question 18

functional characteristics of the tarsometatarsal mechanism

-purpose of counter or opposite rotation of midfoot with respect to rearfoot

Answer 18

maintains a plantargrade position of the foot during stance phase in walking

Question 19

tarsometatarsal mechanism

-what actions occur during loading response of gait (initial contact)

Answer 19

RF everts

FF inverts

Question 20

tarsometatarsal mechanism

-what actions occur during terminal stance

Answer 20

RF inverts

FF everts

Question 21

foot pronation

-during initial contact… (5 items)

Answer 21

internal tibial rotation causes
-talus to glide inward and downward
simultaneous eversion of calcaneus
movement of talocalcaneonavicular and calcaneocuboid joint to be positioned side-by-side
pronation of rearfoot causes increased mobility in the midfoot and forefoot
this is the “loose pack position”

Question 22

in closed kinetic chain, independent movement between RF and MF during foot pronation causes what to occur
-results in…

Answer 22

causes an “un-winding” of the foot ligaments

-loose pack position

Question 23

foot supination

-during terminal stance… (5 items)

Answer 23

external tibial rotation causes
-talus to glide outward and upward
simultaneous inversion of the calcaneus
movement of the talocalcaneonavicular and calcaneocuboid joints to be positioned on top of one another
supination of RF causes increased stability in the MF and FF
this is the closed pack position

Question 24

in closed kinetic chain, independent movement between RF and MF during foot supination causes…

Answer 24

winding of the foot ligaments

Question 25

plantar fascia

-names of bands

Answer 25

lateral
central
medial

Question 26

central band of plantar fascia divided into…

-each of these divides…

Answer 26

divided into 5 slips

each slip divides superficial and deep tract

Question 27

windlass mechanism

• part of which mechanism of the foot
• what is it?
• function

Answer 27

part of metatarsophalangeal mechanism
plantar fascia
-medial tubercle of the calcaneus to the proximal phalanges
-bowstrings all three foot mechanisms
-becomes taut with toe extension
can assist in re-supinating the foot during mid to late stance