Gait Flashcards
1
Q
what are kinetics?
A
- forces that cause motion
- analysis of forces and moments acting on a joint
- statics (body in equilibrium)
- dynamics (accelerating or decelerating)
2
Q
What is Kinematics?
A
- description of movements
- defines the range of motion and describes the motion of joint in three dimensions (or planes)
3
Q
What are the forces during locomotion?
A
- ground reaction force
- muscle forces
- joint contract forces (or other reaction forces)
4
Q
Ground reaction force can alter under what conditions?
A
- speed
- incline
- lameness
5
Q
The cycle of limb movements in locomotion can be described as what?
A
- stance - when the foot is on ground
- swing - when foot is off ground
6
Q
What happens to the limb in the stance phase?
A
- experiences high GRF
- muscles need to withstand and counteract GRF at joints (stabilise joints, preventing flexion or hyperextension)
- muscles also need to provide propulsion
7
Q
What happens to the limb while in swing phase?
A
- no GRF acting
- muscles need to move limb
- clear the foot off the ground
- protract the limb
- prepare limb for stance phase
8
Q
Name the modes of locomotion
A
- terrestrial
- jumping
- flying
- swimming (most efficient)
- climbing
9
Q
Name different movement patterns - gaits
A
- walking
- running - trotting- hopping
- galloping
10
Q
You can define gaits based on what?
A
- footfall patterns
- biomechanical principals
- pendular vs spring
- duty factor
11
Q
Describe walking?
A
- overlapping period of support among limbs
- at low speeds, centre of mass is between supporting limbs
- 3 points of support, static stability
- duty factor >0.5
- modelled as an inverted pendulum (potential and kinetic energy out of phase, energy exchange between forms)
12
Q
Describe trotting and running?
A
- no overlapping periods between altering phases of limb support
- centre of mass may not be between supporting limbs
- duty factor is less that or equal to 0.5
- modelled as bouncing spring
- potential and kinetic in phase
- instead converted to elastic energy in spring elements of limb (tendon)
13
Q
Describe canter and gallop
A
- shifts in support phases to allow fore and hind limbs to act in pairs
- allows spinal flexion-extension
- allows rotation of pectoral and pelvic girdle
- increases stride length
- allows quadrupedal mammals to achieve fast speeds
14
Q
How do animals select their gait? (speed)
A
- increase speed by stride frequency or stride length
- mammals tend to increase stride frequency first
- then shift to gaits that increase stride length
15
Q
Animal gait selection (stability)
A
- difficult terrain might favour static stability
- energy efficiency
