Foot/ankle Flashcards
Which position of ankle is there more joint play, PF or DF?
PF. trochlea is wider anterior than posterior, leading to tighter fit
What is function of spring ligament in regards to medial longitudinal arch?
supports arch via preventing talar head dorsiflexion.
Due to this, it is frequently involved in flat foot deformity
What is the Lisfranc joint?
the first set of joints between tarsals and metatarsals
Lisfranc ligament
Strong connection between 2nd metatarsal and medial cuneiform, linking them with 1st ray
Triceps Surae moment arm
much larger than other PF muscles, leading to them contributing majority of force despite only being 40% of muscle mass
Muscles of deep posterior compartment of lower leg
flexor hallucis longus, flexor digitorum longus, tibialis posterior.
Function of tibilias posterior?
support medial longitudinal arch by attachment to medial navicular/cuneiforms
Tib posterior contribution to supination
- primary supinator
- long moment arm and large size means that other muscle unlikely to functionally substitute if muscle is compromised
Tib anterior contribution to supination
Low compared to posterior.
Smaller moment arm
Average subtalar axis
superior 42 degrees, medial 16 degrees
Mechanics of midfoot when hindfoot is pronated
axes of calcaneocubiod and talonavicular joints line up, allowing increased mobility
Which ligament is at risk of failure following PF release
Spring ligament
Which motion of tibia raises medial longitudinal arch of foot?
ER
What is source of tibial motion during gait
Proximal sources (hip/knee musculature)
What is primary source of force for forward progression
Plantarflexors
Subtalar motion during gait
moves into pronation from IC to foot flat.
Then rapidly supinates
At what point is anterior tib more important with controlling hindfoot motion?
following initial contact.
Tib posterior becomes active just before foot flat
Percentage of force from digits during running
25-50%
In pes planus, the talus PF, loading, and potentially compromising which ligament
calcaneonavicular (spring)
Foot kinematics in pes planus
hindfoot eversion
forefoot abduction
forefoot DF
Risks for runners with high arch
increased ankle sprains and 5th met fx
peek a boo sign
when medial heel is visible from anterior.
Indicatvie of pes cavus
Navicular drop test assessment
change in height from neutral to standing
greater than 10mm difference is risk factor for MTSS
What is tested with single leg heel raise
PF endurance.
Often doesn’t capture peak forces, therefore not a true strength test.
typical repetitions: 25
Correlation between static foot position and dynamic foot position
fairly high
Subtalar joint ROM assessment reliability
Poor inter rater, good intrarater
Hallux limitus ROM
less than 40 degrees
Anterior drawer test
ATFL.
positive if pain reproduced anterior/inferior of lateral malleolus, or if 3mm greater excursion.
Talar tilt test
ATFL or CFL
either in 10 degrees DF (CFL) or 20 degrees PF (ATFL).
May not differentiate b/w ligaments
Dorsiflexion external rotation test
for syndesmotic ankle sprain
good Sn (71%), moderate Sp (63%)
Squeeze test
for syndesmotic ankle sprain.
pain reproduction with squeezing tibia and fibula together at mid calf.
Low Sn (26%), high Sp (88)
syndesmotic ligament palpation
high Sn (92%), Low Sp (29%)
Cotton test
translation of talus in ankle mortise
High Sn (71), Low Sp (29)
Thompson test
AT tear
High Sn and Sp (96,93)
AT palpation
for AT tendinopathy
High Sp, mod Sn
Royal London Hospital test
For AT tendinopathy
palpate AT at tender portion. If pain is decreased with active DF, ATendinopathy is likely
Arc sign
Identify area of swelling.
PF and DF foot. if swollen area moves, tendinopathy
high Sp, mod Sn
Windlass test
Reproduction of symptoms with DF of 1st ray in weight bearing.
High Sp, low Sn
