Gait Flashcards
what are the phases of gait
- stance: 60%
contact
midstance
propulsion - swing: 40%
spacial parameters: what is the base of gait
average 7°
what is the % for single support time
38% of gait cycle
what is the % for double support time
22% of gait cycle
speed parameters:
cadence: average steps/min
velocity:
80-120 steps
cadence x step length/60
what are the 6 determinants of gait
- pelvic rotation
- pelvic tilt
- knee flexion instance phase
- ankle mechanism
- foot mechanism
- lateral displacement
what is the role of pelvis rotation in gait (3)
- twists in transverse plane
- reduces need of hip ext/flex
- reduces verticle oscillation of CofG
what is the role of pevlic tilt in gait
- rises to the swing side - the opposite would be a trendellenburg sign
- reduces total vertical excursion of CogG
what is the role of knee flexion in stance phase
prevents excessive rise and fall of the hip by effectively shortening the leg
what is the role of the ankle mechanism in gait
sagittal motion works with the knee to lengthen and shorten the leg, to ensure smooth gait
what is the role of the foot mechanism
the foot acts as a series of rockers to provide stability, weight distribution and aid motion by torque conversion
what is the role of lateral displacement in gait
wider = less efficient but more stable
narrower = more efficient but less stable
what are the key points of the gait cycle
- contact
- midstance
- propulsion
active
passive - swing
what % of gait cycle and stance phase is initial contact, and what is its function
- 16% of gait cycle
- 27% of stance phase
- to adapt to terrain, shock absorbency, and forward progression
in initial contact heel strike, what happens to the:
* hip
* knee
* ankle
* STJ
* MTJ
- hip: flexed
- knee: extended
- ankle: neutral 90°
- STJ: supinated (moving to pronation)
- MTJ: supinated and mobile
during initial contact, what happens at the:
* ankle
* STJ
* MTJ
* leg
* knee
* quadraceps
- ankle: plantarflexes
- STJ: pronates
- MTJ: unstable
- leg: internally rotates
- knee: flexes
- quadraceps: absorb impact
which muscles are active in initial contact:
- tibialis anterior and long extensors: control plantarflexion
- tibialis posterior: controls rate of pronation at STJ
- triceps surae: control internal rotation of leg
- quads: control knee flexion
- hip extensors and ABductors: control thigh and pelvis
what % of gait cycle and stance phase is midstance, and what hapens here
- 24% of gait cycle
- 40% of stance phase
- CogG moves over static foot
- limb and truck stability
at foot flat in midstance, what are the following doing:
* hip:
* knee:
* foot:
* STJ:
* MTJ:
- hip: flexed
- knee: flexed
- foot: plantarflexed at ankle
- STJ: pronated
- MTJ: unstable
what are the following doing during midstance:
* hip:
* knee:
* leg:
* ankle:
* STJ:
* MTJ:
- hip: extends
- knee: extends
- leg: externally rotates
- ankle: dorsiflexes
- STJ: supinates
- MTJ: stabilises
which muscles are active in midstance
- tibialis posterior, long flexors and soleus assist supination at STJ
- peroneus longus starts to stabilise 1st ray
- triceps surae (esp soleus) control dorsiflexion at ankle
- hip extensors pull thigh back
- postural stabilisers control pelvis and truck
what is the purpose of propulsion in gait cycle
foot becomes a rigid lever via:
* STJ supination
* MTJ locking
* active muscular stabilisation
in order to facilitate forward progression and maintenance of momentum
what is active propulsion in gait cycle and what are the % of gait and stance phase
- heel off of support limb to toe off of same limb
- 20% of gait cycle
- 33% of stance phase
of the propulsion phase, what is passive lift
from opposite heel contact to toe off
propulsion: heel lift:
* MTJ:
* STJ:
* ankle:
* knee:
* hip:
- MTJ: locked
- STJ: supinated
- ankle: dorsiflexed
- knee: virtually extended
- hip: extended
during propulsion:
* MTPJ:
* 1st ray:
* MTJ:
* STJ:
* ankle:
* tibia:
* knee:
* hip
- MTPJ: dorsifleced
- 1st ray: plantarflexed
- MTJ: locked
- STJ: supinated
- ankle: plantarflexes
- tibia: externally rotated
- knee: flexed
- hip: continues to extend, starts to flex before toe off
what is the muscle activity at propulsion
- triceps surae and tibialis posterior assist heel lift
- peroneus longus stabilise 1st ray
- peroneus longus and brevis ensure medial weight transfer
- FHL, FHB, AbH AdH stabilise hallux
- EHL dorsiflexes hallux
what is the function of swing phase
- momentum for forward progression
- ground clearance
- provide power for motion
what are the motions in swing phase of:
* hip:
* knee:
* ankle:
* STJ
- hip: continues to flex
- knee: extends
- ankle: dorsiflexes
- STJ: pronates, then supinates
