Week 5 Flashcards
The ankle involves
Tibia, fibula and talus
How much load transfer does the tibia accommdate
90%
Which is the largest tarsal bone
calcaneus
Which tarsal bone is most commonly fractured
calcaneus
Talocrural joint forms what
mortise joint
What attach to the head of the fibula
biceps fem
LCL
Peroneal nerve (posteriorly)_
What is sinus tarsi
area where neck of talus and ATFL is palpable - if pain could indicate ATFL injury, fracture of the talus, sinus tarsi syndrome
What transmits BW from hindfoot to midfoot
calcaneus
What is the most commonly fractured bone of the foot
calcaneus
name the ligaments of the foot
medially - deltoid (tibio-calcaneal, tibionavicular and tibiotalar) - limits eversion Laterally Anterior talofibular calcaneofibular posterior talofibular -resist inversion
what is the most commonly injured ligament
ATFL
lateral malleolus to talar neck
How is the ATFL injured
Inversion + PF
open pack position of the ankle
plantarflexed
What is the role of the calcaneofibular ligament
resist inversion at talocrural (esp in DF) & subtalar
What is the PTFL and what is its role
posterior talofibular ligament
lateral malleolus - lateral tubercle of talus
- stabilises talus in mortise
-limits abduction esp in DF
pronation =
eversion +abduction (+ min PF)
Supination =
Inversion + adduction ( + min DF)
Open chain supination and pronation
S - calcaneal inversion adduction and plantarflexion
P- calcaneal eversion abduction and dorsiflexion
Closed chain supination and pronation
S - Tibia ER, Talus dorsiflexion and abduction, calcaneal inversion
P- tibia IR, Talus PF and ADD, Calcaneal eversion
tibialis muscles support what
The longitudinal arch
What nerve innervates Tib Ant
Deep peroneal nerve (L4, L5)
Which muscles balance out Tib Ant
EHL and Peroneus tertius
Tib ant dysfunction
foot slap (inability to control foot after heel contact)
tightness - develops in absence of strength
pulls foot medially
pes cavus
What is PTTD
Posterior tibial tendon dysfunction
Why are joints with long moment arms commonly injured
Long moment arms can have larger external forces applied to them
Why do bones and muscles have greater capacity for repair
greater blood supply
How does bone heal
in the direction of force
Risk factors for OA
frequency up with age obesity joint injury/trauma joint overuse/repetitive joint loading tasks Joint malalignment muscle weakness family history
what are the three types of OA
idiopathic, familial and post-traumatic
Effect of OA on articular cartilage
thickening to softening, to thinning to loss
impact of OA on synovial membrane
abnormal joint alignment stresses
Impact of OA on ligaments
Abnormal joint alignment stresses
Impact of OA on muscles
Immobility shortens, pain causes guarding ; weakness
Impact of OA on bone
changes in shock absorbing properties ; joint margin spurring leads to bony blockade and pain
Impact of OA on extra articular system
increased energy expenditure from abnormal moving pattern
