Ankle and foot region Flashcards
Explain pronation for the foot
- a combo of fundamental movements
- DF + EV + abd
- oblique axis
Explain supination for the foot
- a combo of fundamental movements
- PF + IV + add
- oblique axis
What are the applied terms for the foot and ankle?
- pronation and supination
What are the fundamental terms for the foot and ankle?
- dorsiflexion/plantarflexion (sag. plane)
- inversion/eversion (frontal plane)
- abduction/adduction (horiz. plane)
What does the ATFL restrict?
- resists inversion
- anterior translation
What does the PTFL restrict?
- resists inversion
- anterior translation
- limits excessive abduction (ER) of the talus
especially when dorsiflexed
What does the CFL restrict?
- resists inversion across talocrural joint and subtalar joint
- anterior translation
especially when fully dorsiflexed
What does the deltoid ligament restrict?
- resists eversion
Where does pronation and supination mainly occur at in the foot?
- subtalar joint
What joints make up the transverse tarsal joint?
- talonavicular
- calcaneocuboid
most versatile joint in foot
What are the arthrokinematics of open-chain talocrural DF?
Talus:
- rolls anterior
- slides posterior
CFL & posterior capsule taut
What are the arthrokinematics of closed chain talocrural DF?
- Mortise rolls and slides anterior
What are the arthrokinematics of open chain talocrural PF?
Talus:
- rolls posterior
- slides anterior
ATFL & anterior capsule taut
What are the arthrokinematics of closed chain talocrural PF?
- mortise rolls and slides posterior
What are the arthrokinematics of open chain subtalar pronation?
Calcaneus:
- slides laterally (EV & abd)
What are the arthrokinematics of closed chain subtalar pronation?
- leg and talus moves medially
What are the arthrokinematics of open chain subtalar supination?
Calcaneus:
- slides laterally (IV & add)
What are the arthrokinematics of closed chain subtalar supination?
- leg and talus moves laterally
What are the arthrokinematics of open chain talonavicular pronation/supination?
Concave Navicular spins on convex talus:
- Sup: tibialis posterior raises medial foot
- Pro: fibularis longus raises lateral foot
What are the arthrokinematics of open chain calcaneocuboid pronation/supination?
inflexible
- resists sliding
- doesn’t really move
- its rigidity raises lateral side of foot w/ pronation and lowers lateral side of foot with supination
What are the arthrokinematics of open chain 1st TMT joint pronation?
- PF & eversion
What are the arthrokinematics of open chain 1st TMT joint supination?
- DF & inversion
What axis(s) run through the TTJ?
Longitudinal axis
- A-P = inversion & eversion
Oblique axis
- vertical, medial-lateral = abd + DF & add + PF
Which joint has more supination/pronation ability?
- TTJ
- allows for about 2x more pronation/supination
- can supinate/pronate to keep forefoot on ground w/ uneven terrain
How does the tibia move with subtalar pronation?
- tibial IR
How does the tibia move with subtalar supination?
- tibial ER
What is “subtalar neutral”?
- point in which midline of posterior leg algin w/ midline of calcaneus
What is calcaneovalgus?
- increase in subtalar neutral
- greater than 180 degrees
- distal calcaneus moves away from midline
What is calcaneovarus?
- decrease in subtalar neutral
- less than 180 degrees
- distal calcaneus moves toward midline
What is forefoot valgus?
- compensated w/ excessive supination
- distal segment of forefoot away from midline
What is forefoot varus?
- compensated w/ excessive pronation
- sustained TMT supination twist
- distal segment of forefoot toward midline when in “subtalar neutral”
What are the stabilizers of the medial longitudinal arch?
Active:
- tibialis posterior
- FHL
- FDL
Passive:
- plantar fascia
- bone structure
- spring ligament
- 1st TMT joint
How does the arch move during the gait cycle?
Loading response:
- medial L. arch lowers becomes more flexible and absorbs stress
30-35% gait cycle:
- subtalar joint pronates (everts)
- increases flexibility
Late stance:
- medial L arch rises
- move rigid to support loads at push off
Explain what is meant by supination twist
- hindfoot pronation w/ forefoot supination
Explain what is meant by pronation twist
- hindfoot supination w/ forefoot pronation
Why does supination/pronation twist occur?
- occurs @ TMT joint (TTJ has insufficient motion)
- keep forefoot in contact with ground
What joint is most important for directing pronation/supination?
- subtalar joint
What are some consequences of excessive pronation?
- center of plantar pressure falls medially to arch -> stress on plantar fascia, talonavicular joint, & post. tibialis tendon
- rearfoot varus or forefoot varus
- lower leg IR
- stress fractures = navicular, tibia
What does the STJ & TTJ do during stance?
Early stance phase:
- subtalar pronation by calcaneal EV from GRF and tib-fib IR
- Tib. posterior ecc decelerates arch lowering
Mid-late stance phase:
- stance limb reverse from IR to ER
- starts at femur -> tibia -> subtalar joint
- rearfoot supination causes simultaneous forefoot pronation twist
- subtalar makes forefoot rigid for push-off
How does the Windlass Mechanism work?
- increases tension in arch of foot due to plantar fascia being stretched w/ toe extension
- this raises medial longitudinal arch
What happens if the windlass mechanism is not working properly?
- weakened push off occurs
- loss of toe extension = loss of windlass mechanism
What is innervated by the deep fibular nerve?
Anterior lower leg muscles
- tibialis anterior
- EHL
- EDL
- Fibularis Tertius
What is innervated by the superficial fibular nerve?
Lateral lower leg muscles
- fibularis longus
- fibularis brevis
What is innervated by the tibial nerve?
Posterior superficial and deep lower leg muscles
- Gastrocnemius
- soleus
- plantaris
- tibialis posterior
- FDL
- FHL
What does the tibialis anterior do?
- DF + inversion
What does the EDL & fibularis tertius do?
- DF + EV
What do the fibularis muscles do?
- PF + EV
What do the muscles of the posterior deep compartment do?
- PF + supinate
prime supinators
How does the fibularis longus help raise the transverse arch of the foot?
- fixates to 1st ray (1st TMT joint) so it runs across the entire foot
- w/ contraction will raise transverse arch of the foot
How will a tight gastrocnemius affect the knee?
- could limit knee EXT
How will a tight gastrocnemius affect the ankle?
- limits DF ROM w/ knee ext
What is special about tibialis posterior as it pertains to the gait cycle?
- best supination torque
- active the longest which helps decelerate pronation of rearfoot and guides rearfoot toward supination
What action do the plantar flexors have if the foot is fixed to the ground?
- assists in extending the knee
- soleus pulls lower leg posterior
Explain how foot pronation could affect joints up the chain in the rest of the leg?
Pronation -> tibial IR -> knee valgus -> femoral IR + adduction
Explain how foot supination could affect joints up the chain in the rest of the leg?
Supination -> tibial ER -> knee varus -> femoral ER + abduction
Explain how Pes Cavus affects the ankle and foot during walking
- abnormally raised medial longitudinal arch
- rearfoot varus, forefoot valgus
- fixed or progressive
- reduces contact area w/ ground so more pressure through forefoot -> leads to metatarsalgia & met head calluses
- plantar pressure is shifted laterally while walking
Explain how Pes Planus affects the ankle and foot during walking
- chronically dropped/low medial longitudinal arch
- Cause: overstretched/torn/weakened plantar fascia, spring ligament, & posterior tibialis tendon
- subtalar joint pronated = calcaneal valgus + forefoot abduction, depressed talus & navicular
What are the two types of Pes Planus?
Rigid:
- dropped arch WB & NWB
Flexible:
- dropped arch with WB but not NWB
How does Pes Planus differ from Adult Acquired Flat Foot deformity?
AAFFD:
- mainly due to posterior tibialis tendon rupture
- causes arch to collapse and talus & navicular drop
- Talonavicular joint subluxes, rearfoot everts, forefoot abducts
- w/ posterior tibialis out -> fibularis muscles are allowed to pull foot into eversion
- achilles tendon line of pull is now shifted lateral to calcaneal tuberosity
Explain the pathomechanics of Posterior Tibialis Tendon Dysfunction
- over working/stress on posterior tibialis tendon from walking (no time for post. tib. to rest)
- people w/ lower arches are more at risk
What are some risk factors associated with posterior tibialis tendon dysfunction?
- low arch
- muscle weakness
- poor gait biomechanics
- hindfoot eversion & pronation
What are the stages of posterior tibialis tendon dysfunction?
1) mild swelling, medial ankle discomfort, pain with heel raises
2) progressive lowering of medial arch w/ secondary midfoot abduction deformity, can’t perform heel raises
3) All components of stage 2, rearfoot fixed in eversion
How does Hallux Valgus (bunion) develop?
- 1st met adducts, MTP lateral dislocation
Causes muscular imbalance:
- abductor hallucis shifts toward plantar side
- adductor hallucis & FHB unopposed pull increases lateral deviation posture of lateral phalanx
similar to ulnar drift
What is Hallux Limitus?
- “turf toe”
- MTP hyperextension injury
- persistent pain & ROM loss
- impacts late stance gait
What are some causes of Hallux Valgus?
- genetics
- incorrect footwear
- abnormal alignment of LE
- excessive rearfoot valgus & altered AoR at base of 1st ray
- tight achilles tendon
- instability of 1st ray
What happens with an injury at the deep fibular nerve?
- all dorsiflexors paralyzed
- drop foot = can’t dorsiflex
- Pes Equinus = PF contracture
- need ankle/foot orthosis
What happens with an injury at the superficial fibular nerve?
- all evertors paralyzed
- Pes varus
What happens with an injury at the common fibular nerve?
- all dorsiflexors & evertors paralyzed
- Pes Equinovarus
What happens with an injury at the tibial nerve?
- loss of plantar flexion torque = Pes calcaneus
- loss of supinators = pes valgus
- loss of plantar flexors & supinators = pes calcaneovalgus
- medial & lateral plantar nerve loss = clawing of toes
What is a high ankle sprain?
- syndesmotic
- Extreme DF shoves wider anterior talus into mortise (injures multiple ligaments)
- also closed chain abduction/ER torque to talus = same as tib.-fib. IR on fixed foot
What is an inversion ankle sprain?
- wearing high heels
- full PF = OPP for TCJ
- slackens ligaments & PF muscles
- unstable
Why are patients with an ankle sprain likely to incur future sprains?
They experience:
- excessive anterior laxity of talus
- restricted posterior slide of talus = decreased DF
- degenerative changes
subtalar joint already inverted 6-7 degrees more than normal subjects
How can therapists help prevent future ankle sprains?
- give manual posterior slide/glide
- balance training & strength deficits
- bracing, taping, strengthening of evertors
