Foot and Ankle Flashcards
What is the ankle joint?
Talocrural
What is the foot?
All tarsal bones and joints distal to TC
What comprises rearfoot?
Talus, calcaneus, subtalar joint
What comprises midfoot?
Five tarsal bones
What comprises forefoot?
Metatarsals, phalanges
Describe distal tibia…
Torsion of long axis of tibia 20-30 degrees*
What forms ankle mortis?
Malleoli
what creates toe out
tibial and femoral torsion
Hip anteversion causes the foot to..
Toe in
Hip retroversion causes the foot to…
Toe out
Which bone joins the foot to the leg?
Talus–no muscular attachments, mainly covered in articular cartilage
All motion in the talus is…
Passive
Talus articulates with _____ inferiorly and _____ superiorly
Superior: Ankle Mortis
Inferior: Calcaneus
Attachment point for posterior tib
Navicular
Important bone to assess bilaterally for differences (foot)
Cuboid
Metatarsals have ____ base and ______ head
Concave base, convex head
Why are metatarsals arched?
To support more weight, provide space for muscles and tendons
Dorsi/P F
- plane
- AOR
sagittal plane
med-lat AOR
inv/ev
- plane
- AOR
frontal plane
ant-post AOR
abd/add
- plane
- AOR
transverse plane
vertical AOR
Pronation AOR, motion combo
- oblique AOR
- dorsiflexion, eversion, abduction
Supination AOR, motion combo
- oblique AOR
- plantarflexion, inversion, adduction
What type of joint is proximal TF?
Synovial- but firm to transfer biceps fem and LCL force
What type of joint is distal TF?
Syndesmosis
-ligaments limit motion
Why is eversion harder than inversion?
Because fibula projects more inferiorly- lateral malleolus blocks to movement
90-95 percent of compressive forces pass thru
talus and tibia
Function of deltoid ligament
limits excessive eversion – reason it’s less commonly sprained than LCL
Open chain AK at TC joint
Convex talus on concave mortis–roll and glide in opposite directions
AK of dorsiflexion
posterior glide, anterior roll
AK of plantarflexion
anterior glide, posterior roll
Lateral Collateral Ligaments ankle
Ant/Post talofibular
Calcaneofibular
LCL (ankle) function
Controls varus stress (inversion)
ATFL checks
inversion w/pf
CFL checks
inversion with df
PTFL function
stabilized tals in mortise
TC joint
DoF
Axis
What is close-packed?
one DoF– df/pf
oblique axis
cp = df
Dorsiflexion:
- Occurs with
- Min necessary for normal function
- Slight abd/ev
- 10 degrees
Plantarflexion:
- Occurs with
- Normal range
- Slight add/inv
- Normal range 20-50
abduction/adduction axis
vertical
dorsiflexion/plantarflexion axis
medial-lateral
Subtalar joint formed by
posterior, middle, anterior facets of calcaneus and talus
close packed position for subtalar joint
supination
inv/ev axis
atero-posterior
Talonavicular joint function
mobility- twisting of midfoot relative to rearfoot
what conv/concavv=e structures in TN joint?
convex talus with concave navicular
Does calcaneocuboid joint allow more or less motion than talonavicular?
less
When do we utilize the spring ligament of the talonavicular joint?
when walking on unstable surfaces
Which joint transitions hindfoot and forefoot?
Transverse Tarsal (Midtarsal) Joint
Purpose of TT joint
adds to overall ROM of supination/pronation
What is the main function of Lisfranc’s joint?
TMT joint– position metatarsals and phalanges relative to weight bearing surface
How do metatarsal movements become oppsoite of ankle?
at midfoot joint, df causes inversion, plantarflexion causes eversion
Which toe digit is used to reference abduction/adduction?
Second digit
What is hallux rigidis?
Limited first mtp extension which is important for gait so must be treated!
Most important aspect of mtp joint in gait
Need extension in first mtp for toe off in gait!
Functions of IP joints
Smooth the weight shift to the opposite foot during gait
Maintain stability
Function of Medial Longitudinal Arch
Loadbearing/shock absorbing
What is the medial longitudinal arch formed by?
Calcaneus Talus Navicular Cuneiforms 3 Metatarsals (middle three)
Plantar aponeurosis orig/ins
From calcaneus to proximal phalanx of each toe
How to increase tension in plantar fascia? Function of PF?
- Increase tension: active/passive toe extension
- Function = support MLA
Rearfoot shock absorption function of MLL
WB depresses talus inferiorly which flattens MLA–rearfoot pronation
What occurs in an abnormally dropped medial longitudinal arch?
Plantar fascia becomes overstretched and weakened so it cannot dissipate or accept body weight
What is the transverse arch formed by?
Intercuneiform and cuneocuboid joint complex
What happens to the transverse arch during WB and why?
It flattens during WB which allows weight distribution across all five metatarsal heads.
What is coupled with rear foot inversion?
Tibial external rotation
What is coupled with rearfoot eversion?
Tibial internal rotation
Superficial ankle plantarflexors and supinators
Gastroc, soleus, plantaris
Deep ankle plantarflexors and supinators
Tibialis posterior, FDL, FHL
Roles ofa nkle plantarflexors adn supinators in gait
Decelerate forward tibial translation (eccentric)
Accelerate body fwd/upwards (conc)
Stabilize knee extension
Ankle dorsiflexors
Tibialis anterior, EHL, EDL, peroneals
Peroneus longus and brevis are primary…
everters– decelerate rate/extent of supination at subtalar jt
When are peroneals most active?
Mid to late stance
Common pathologies at foot
plantar fasciitis, heel spurs, hallux valgus/varus, hallux rigidus, pes planus/cavus, lateral ankle sprain/chronic ankle instability
What is hallux valgus?
bunion– lateral deviation of big toe relative to midline
