Lecture foot and ankle Flashcards
at Initial contact the ankle is?
Neutral, and facilitates heel rocker for forward progression
in loading response the ankle is?
- 0-5 PF
- part of heel rocker mechanism
- Facilitates the objective of forward progression
in mid-stance the ankle is?
- 5 PF to 5 DF
- Facilitates the objective of progression of COM over the BOS
What forward progression phase does loading response include?
- heel rocker: a pivot point about the calcaneus, for tibia to roll over
What forward progression phase does mid-stance include?
- ankle rocker: 10 degree arc of motion -> allows forward progression
in terminal stance the ankle is?
- 5-10 DF
- facilitates the objective of progression of COM beyond BOS
what forward progression phase does terminal stance include?
- forefoot/ toe rocker: heel comes off ground, allows COM to progress beyond BOS
in pre-swing the ankle is?
- 10DF - 20 PF (30 degree arc of motion!)
there is no objective (initiating limb advancement occurs at the hip)
in initial swing the ankle is?
- 20 PF to 5 PF (going towards DF)
in mid swing the ankle is?
- 5PF to 0 (neutral)
- facilitates the objective of foot clearance !
in terminal swing the ankle is?
- Neutral
- facilitates the objective of preparing the limb for stance (heel contact)
Frontal plane: initial contact the foot is?
- foot is supinated 3-5 degrees
frontal plane: loading response foot is?
- foot is pronated
- 4-6 degrees of rearfoot eversion
frontal plane: midstance-terminal stance foot is?
- foot is pronated to neutral
what is the objective of frontal plane foot pronation in loading response/midstance?
- shock absorption - pronation “unlocks” the midtarsal joints. therefore increases stance stability because more foot contact with the floor
what is the objective of frontal plane foot supination in loading response/midstance?
- facilitates progression of COM beyond BOS(forefoot rocker)
- supination –> locks midtarsal joints turning foot into a “rigid lever”
what couple motion does foot pronation induce?
- foot pronation and tibial internal rotation happen together
Critical events during loading response ankle?
- Plantarflexion moment (external) controlled by internal response by
- Dorsiflexors (eccentric) –> Tibialis Anterior, EHL and EDL
Crit events during midstance ankle?
- Dorsiflexion moment (external) controlled by internal response by
- Plantarflexors (eccentric) –> gastroc and soleus
Crit events during terminal stance ankle?
- increasing dorsiflexion moment (external) controlled by internal response
- Plantarflexors (eccentric) –> Gastroc and Soleus
(muscle demand here is greater than in midstance due to COM is at forefoot)
Crit events during pre-swing ankle?
- Reducing dorsiflexion moment (due to shifting body weight to other limb)
- reducing calf demand (concentric)
- no push off
crit events during initial swing ankle?
- plantarflexion moment (gravity driven)
- Dorsiflexors (concentric) by the TA, EHL, ED
crit events during mid swing ankle?
- plantarflexion moment (gravity driven)
- dorsiflexors (concentric) - TA, EHL, ED
carry over from initial swing
crit evens during terminal swing ankle?
- Plantarflexion momnt (gravity driven)
- Dorsiflexors (isometric !) TA, EHL, ED
which muscles dynamically control foot pronation during loading response?
- TP, TA, FHL, EDL
pronation to supination: midstance-terminal stance
- Necessary for adequate forefoot rocker in terminal stance
- requires concentric action of invertors: TP, FHL, FDL
