foot and ankle anatomy

proximal tibiofibular joint
type

plane gliding synovial joint surrounded by capsular ligament

distal tibiofibular joint
type

syndesmosis/ fibrous joint

syndesmosis defintion

2 bones held together by interosseous ligament

distal tibiofibular joint
importance

stability of ankle reliant on the gripping of the talus by 2 malleoli

distal tibiofibular joint
talus socket area

the lower most part of the later deepens the tibial articular surface thus the socket for the talus

distal tibiofibular joint
shafts held together by

interosseous membrane

what happens to fibula during dorsiflexion ?

slight lateral displacement due to wider anterior talus

tibia
weight bearing

main weight bearing bone

tibia
interior surface texture and why

smooth for articulation with the superior surface of the body of the talus

fibula
weight-bearing %

17%

lateral malleolus (fibula)
function

serves as a site for ligament and muscle attachment
articulates with the tibia superiorly (superior tibiofibular joint) and inferiorly ( inferior tibiofibular joint)

lateral malleolus (fibula)
palpation

easily palpated

ankle joint (talo-crural joint)
components

tibia
fibula
talus

ankle joint (talo-crural joint)
tendon resembles

mortise and tenon

ankle joint (talo-crural joint)
importance of mortise and tenon structure

to prevent lateral or angular displacement due to medial and lateral malleoli

ankle joint (talo-crural joint)
type

synovial hinge joint

boney points of ankle and foot

lateral ligaments

anterior talo fibular ligament (ATFL)
calcaneo fibular ligament (down and back) (CFL)
posterior talo fibular ligament (PTFL)

medial (deltoid) leigaments

posterior tibio talar ligament
anterior tibio talar ligament (forward and down)
tibio calcaneal ligament (down to sustentaculum tali)
tibio navicular ligament (down and forward)

the ankle joint
surface covered in

hyaline cartilage

the ankle joint
function of hyaline cartilage

shock absorbing
lowers friction
hard wearing

the ankle joint
synovial fluid function

allows for smooth movement
provides nutrition

the ankle joint
stability dependant on

joint surface congruency
joint capsule and supporting ligaments
muscles around the joint
bony contours (concave surface of tib + convex surface of fib)

movements of the ankle joint

dorsiflexion
plantar flexion

dorsi flexors

tibialis anterior
extensor digitorum longum
extensor hallucis longus

plantar flexion

gastrocnemius
soleus
plantaris
flexor digitorum longus
flexor hallucis longus
tibialis posterior

talus
attachments

no muscle attachments

talus
position

between the malleoli of tibia and fibula

talus
articulation

with lower surface of tibia and fibula

sinus tarsi
what is it?

a tunnel between talus and the calcaneus that contains structures that contribute to the stability of the ankle and to its propriocpetion

sinus tarsi
contains

blood vessels
nerves
fat
ligamentous complex

calcaneus
size comparison

largest of tarsal bones

calcaneus
attachment

posterior surface is the attachment for the achilles tendon

sustentaculum tali
what is it ?

a horizontal shelf that arises from the anteromedial portion of the calcaneus.

sustentaculum tali
superior surface shape and articulation

concave
articulates with the middle calcaneal surface of the talus

sustentaculum tali
inferior surface groove purpose

intended for tendon of flexor hallucis longus

navicular
location

medial side of foot

navicular
articulation (proximally, distally, and laterally )

proximally with the talus
distally with the 3 cuneiform bones
laterally with the cuboid

metatarsal phalangeal joints
type and description

condyloid joints
elliptical/round

interphalangeal joints
type

hinge joints

interphalangeal joints
great toe

only 1 interphalangeal joint

interphalangeal joints
4 lateral toes

distal and proximal interphalangeal joints each

plantar calcaeonavicular ligament
type

spring ligament

plantar calcaeonavicular ligament
what and where

thick, broad fibrous band that is located on the bottom portion of the foot

plantar calcaeonavicular ligament
functions

connects navicular bone's plantar surface with the sustentaculum of the calcaneus.
provides support to the head of talus
bears significant amount of body weight

subtalar joint
importance

maintain rear foot arthrokinematics
foot function in weight bearing particularly

subtalar joint
type

synovial joint

subtalar joint
formed by

body of talus superiorly and body of calcaneus inferiorly

subtalar joint
communication

doesnt communicate with any other and is surrounded by capsular ligament

subtalar joint
held by

medial and lateral talocalcaneal ligaments
interosseous talocalcaneal ligament occupying sinus tarsi
cervical ligament attaching to neck of talus to upper surface of calcaneus

subtalar joint
movements

inversion
eversion

subtalar joint
inversion muscles

tibialis anterior
tibialis posterior
flexor digitorum longus
flexor hallucis longus
extensor hallucis longus

subtalar joint
inversion degrees of movement

20 degrees

subtalar joint
eversion muscles

peroneus longus
peroneus brevis
extensor digitorum longus

subtalar joint
eversion degrees of movement

10 degrees

subtalar joint
nerve supply

branches of medial and lateral plantar nerves

transverse (mid-tarsal) joints

talo-navicular
calcaneo-cuboid

talo navicular joint
type

ball and socket

calcaneo cuboid joint
type

saddle shaped synovial joint

transverse (mid-tarsal) joints
movements

inversion and eversion

gastrocnemius
origin

2 heads originate from the posterior surface of the medial and lateral condyles of femur

gastrocnemius
insertion

fuse together to insert into Achilles tendon which inserts into the posterior portion of the calcaneus

gastrocnemius
action

powerful plantar flexor of foot

soleus
origin

2 heads originate form the proximal tibia and fibula

soleus
insertion

achilles tendon

soleus
actions

powerful plantar flexor of foot
main role is postural

achilles tendon
what is it

the tendon through which gastrocnemius and soleus exert their force on the foot during the propulsive phase of walking, running, or jumping

achilles tendon
strength

strongest tendon in the body

plantaris
origin

lateral supracondylar line of the femur at a position slightly superior to the origin of the lateral head of gastrocnemius

plantaris
insertion

achilles tendon

plantaris
actions

plantar flexion

flexor digitorum longus
origin

arises back of the tibia below popliteus and medial to tib posterior

flexor digitorum longus
insertion

splits into 4 tendon attaches to tendon sheaths of the 4 toes

flexor digitorum longus
action

flexes the toes particularly distal phalanges

flexor digitorum brevis
origin

calcaneal tuberosity
4 tendons perforated by flexor digitorum longus

flexor digitorum brevis
insertion

side middle phalanx of 4 toes

flexor digitorum brevis
action

flexion of the toes

flexor hallucis longus
origin

shaft of fibular below attachment of soleus
passes under sustentaculum tali
passes between 2 sesamoid bones of the head of 1st metatarsal

flexor hallucis longus
insertion

base distal phalanx great toe

flexor hallucis longus
action

flexor of great toe

flexor hallucis brevis
origin

plantar surface lateral cuneiform/cuboid

flexor hallucis brevis
insertion

2 tendons into the proximal phalanx of the great toe

tibialis posterior
origin

inner posterior borders of tibia and fibula
also attached to the interosseous membrane, which attaches to the tibia and fibula

tibialis posterior
insertion

main portion inserts into the tuberosity of the navicular and the plantar surface of the medial cuneiform
pantar portion inserts into the bases of 2nd, 3rd, and 4th metatarsals , the intermediate and lateral cuneiforms, and the cuboid

tibialis posterior
actions

inversion
assists in plantar flexion
supports medial longitudinal arch

tibialis anterior
origin

upper 2/3rds of anterior lateral tibia

tibialis anterior
insertion

medial cuneiform base of 1st metatarsal

tibialis anterior
actions

dorsiflexion
inversion
balance
controls placement of foot on the ground

toe extensors

extensor digitorum longus
extensor digitorum brevis

toe extensors
importance

in running to ensure that great toe and foot clears the ground ready for the heel to be placed on the ground

extensor digitorum longus
origin

arises upper 3/4s shaft of fibula
passes deep to extensor retinacula splits into 4 tendons

extensor digitorum longus
insertion

each tendon divides int o3, the central slip attaching base middle phalanx, other 2 unite to insert to base distal phalanx

extensor digitorum longus
action

toe extension

extensor hallucis longus
origin

middle third shaft of fibula
tendon passes deep to extensor retinacula, traverses foot

extensor hallucis longus
insertion

base distal phalanx

extensor hallucis longus
action

great toe extensor

peroneus longus
origin

proximal 2/3 lateral aspect of fibula

peroneus longus
insertion

base of 1st metatarsal and medial cuneiform

peroneus longus
nerve supply

superior peroneal

peroneus brevis
origin

distal 2/3 lateral fibula