Ankle & Foot Flashcards
3 major joints of the ankle and foot
talocrural
subtalar
transverse tarsal
Which tarsal bone is of the most importance clinically?
talus
What percent of the talus’ surface is covered with articular cartilage?
70%
Most movements of the ankle move about what kind of axis?
oblique
Pronation is the combined motion of what 3 movements?
eversion, abduction, and dorsiflexion
Supination is the combined motion of what 3 movements?
inversion, adduction, and plantar flexion
The articulation of the talus with the distal end of the tibia and both malleoli is called what?
Talocrural joint
The talocrural joint is often referred to as the ____ joint
mortise
The proximal portion of the talocrural joint is con___.
concave
Approximately __% to __% of the compressive forces pass through the talus and tibia; the remaining _% to __% pass through the lateral region of the talus and the fibula
90-95
5-10
What characteristic of the talocural joint protects the subchondral bone from damaging stress?
The 3mm of articular cartilage that line the joint
3 lateral collateral ligaments
anterior and posterior talofibular and the calcaneofibular ligaments
Which lateral ligament is the most frequently injured?
The anterior talofibular ligament
During dorsiflexion at the talocrural joint the talus rolls ____ and slides _____.
anteriorly
posteriorly
During plantarflexion at the talocrural joint the talus rolls ____ and slides _____.
posteriorly
anteriorly
Is the talocrural joint more stabledully dorsiflexed or plantarflexed?
dorsiflexed
Extreme and violent dorsiflexion of the ankle can cause what?
Damage to the ankle mortise called a high ankle sprain
Which motion is most important to train/rehab in?
Dorsiflexion
Which motion is most important to restore in an injury?
dorsiflexion
The subtalar joint is an articulation between what 2 bones?
talus and calcaneus
What movements occur at the subtalar joint?
Pronation and supination
What aspect of the subtalar articulation is the most prominent?
The posterior articulation of the subtalar joint occupies about 70% of the total articular surface area
What 2 ligaments provide the most stability to the subtalar joint?
- interosseous (talocalcaneal)
- cervical
What motion do the interosseous (talocalcaneal) and cervical ligaments limit the most?
inversion
Although they limit the extremes of all motions
What is the primary function of the calcaneofibular ligament at the subtalar joint?
Limits excessive inversion
What is the primary function of the tibiocalcaneal fibers of the deltoid ligament at the subtalar joint?
Limits excessive inversion
The subtalar axis of rotation is positioned __ degrees from the horizontal plane and __ degrees from the sagittal plane
42
16
Pronation and supination of the subtalar joint occur as the _____ moves relative to the ____.
calcaneus
talus
Does more movement occur at the subtalar or talocrural joint?
subtalar
How much inversion and eversion occur at the subtalar joint?
- inversion = 22.6 degrees
- eversion = 12.5 degrees
Why is inversion so much greater than eversion?
The lateral malleolus and the relatively thick deltoid ligament naturally limit eversion
The transverse tarsal joint consists of what 2 distinct articulations?
- talonavicular joint
- calcaneocuboid joint
What joints connect the rearfoot with the midfoot?
the 2 midtarsal (transverse tarsal) joints
What is the main function of the transverse tarsal joint?
Works cooperatively with the subtalar joint to control most of the pronation and supination posturing of the entire foot
What motions occur at the talonavicular joint?
twisting (inverting and everting) of the midfoot relative to the rearfoot
What are the 3 components of the talonavicular joint?
- Talus
- Navicular
- Spring Ligament
What component of the talonavicular joint forms the floor and medial wall?
spring ligament
The calcaneocuboid joint composes the ____ component of the transverse tarsal joint.
lateral
What forms the calcaneocuboid joint?
the anterior (distal) surface of the calcaneus and the proximal surface of the cuboid
The amount of pure inversion and eversion of the midfoot is about __ to __ degrees of inversion and __ to __ degrees of eversion
20 - 25
10 - 15
Which arch of the foot is the primary load-bearing and shock absorber
Medial Longitudinal Arch
What bones form the medial arch of the medial longitudinal arch?
- calcaneus
- talus
- navicular
- cuneiforms
- associated three medial metatarsals
What is the main structure that maintains the height of the medial longitudinal arch?
the deep plantar fascia
What is pes planus?
a flattening of the arch during weight bearing activities
What is rigid pes planus?
a dropped arch even in non-weight bearing positions
Flexible pes planus is associated with dysfunction of what muscle?
the tibialis posterior muscle
What is pes cavus?
An abnormally raised medial longitudinal arch
Exaggerated pronation at the subtalar joint leads to what actions at the hip?
Internal rotation, flexion, and adduction
Exaggerated pronation at the subtalar joint leads to what actions at the knee?
Increased valgus stress
Exaggerated pronation at the subtalar joint leads to what actions at the foot?
Lowering of medial longitudinal arch
What motions occur at the first tarsometatarsal joint?
plantar flexion occurs with slight eversion, and dorsiflexion with slight inversion
What is Hallux Limitus
“turf toe”
limited motion of the great toe
What is the most common MOI of hallux limitus?
forceful hyerpextension
What is hallux valgus?
“bunion”
progressive lateral deviation of the great toe
Hallux valgus is associated with excessive ____ of the first metatarsal
adduction
All muscles that plantarflex the talocrural joint also ____ the subtalar or transverse tarsal joints
invert
What are the 3 primary supinators of the foot?
- tibialis posterior
- flexor hallucis longus
- flexor digitorum longus
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