Lecture 11 - Models of Gait Flashcards
in double stance what is true about the Fy vectors
vectors in opposite directions, sum of both feet as in double stance
mostly up, Fy cancels out
when looking at the ground reaction forces in walking : stance, what is said about the vertical force
vertical force greater than body weight after about 10% of the cycle
when looking at the ground reaction forces in walking : stance, what is said about breaking and propulsion forces
breaking force until mid stance, propulsion after
what is gravitational potential and forward kinetic energy like 50% through the gait cycle
forward kinetic is high, gravitational potential is low
what phase of running is when you are moving the fastest
flight phase
when is the slowest part of running and what is this compared to walking
middle of stance is the slowest, this is the opposite to walking
what is the model of walking
inverted pendulum model of walking
explain the inverted pendulum model of walking using stance and swing limb
stance limb as inverted pendulum, swing limb as double pendulum, both pinned at hip
what is the froude number, and what is an example to use it
way of normalising walking speed, example would be standardise walking speed to test out shoes etc
what would make the froude number (Fr) increase
froude number will increase if you have short leg length or gravity changes (like when walking on the moon)
what occurs when Fr (froude number)is greater than 1
support / stance limb is going to come off the ground, you don’t have gravity pushing it down to keep it on the ground
when is centre of mass lowest in running and what does this result in
centre of mass is lowest in mid stance, this is when velocity is the lowest also
what happens to energy in running
absorbed during early stance and released in late stance
what is the model of running
spring type model
what is forefoot running
landing on your forefoot
what is heel strike running
rear foot
what is Fy
horizontal ground reaction force
what is Fz
vertical ground reaction force
what happens to the vertical ground reaction force (Fz) in heel strike running
double peak
what does Fy show
breaking and propulsion forces
what is impact like in heel strike running
impact transient and push off
forefoot strike running is associated with
associated with barefoot / minimal shoe running
what is the ground reaction force like of forefoot running
single peak, transient rounded off by more gradual deceleration
what is the load and compression like comparing heel strike and forefoot strike running
in forefoot running the load is taken up by Achilles rather than heel and compressive forces
