Gait Kinetics and Kinematics Flashcards
What are the 3 methods of gait measurement?
- Kinetics
- Kinematics
- Spatial Temporal
What is kinetics?
internal and external forces
What is kinematics?
gait phases, ROM, muscle activity
What is spatial temporal?
velocity and step length
What are some examples of two dimensional gait analyses?
- surface mat: good for estimating COP and COM (spatial/temporal and kinematics)
-markers: used to document ROM and movement during gait - one camera:
What are graphs used for?
For:
- Joint ROM
- GRF
- Power and movements
What is a zenomat and how does it work?
it provides a spatial temporal output and gives a visual video of foot prints
What does 3D motion capture?
- body kinematics
- position velocity
- acceleration
- GRF
- Joint movements (indirectly)
- Powers
What does kinetics refer to ?
- GRF= external forces
- Moments= force to cause rotation around a joint (internal and external moments)
- Power= Force/Time (watts), concentric v eccentric
Gait moments: internal v external moments
Internal moments: created by contraction of the muscle, joint ligaments, and fascia/joint capsule
External moments: created by the landing surface (GRF)
What is the purpose of internal moments?
To counteract the forces from the ground
Why does each joint create a moment (torque/force at the joint)?
- Stabilize/control- most of stance
- Produce Movement
What are some characteristics of internal moments through the gait cycle?
- measured in % of Newtons/body weight
- negative values: flexor movement
- positive values: extension movement
- norms are in gray areas
- Can be a sum of all joints of individual joint internal moments
What are internal movements and what do they do?
- Internal moments are total amount of force created by muscle/joint, ligament/joint capsule/ fascia
- Extensor movements: support for body on surface (quads, sole-gastroc)
- Flexor moments: pull away from surface (illiopsoas, dorsiflexors)
How is power defined in gait kinetics?
- Power is energy/time= the amount of energy produced overtime
- power is measured in watt or joules/sec
- structures can absorb/create power: muscles, tissues
How is greater power created?
When an action is created/performed in a shorter time.
What is negative power?
- Absorption of power
- Eccentric movements
What is positive power?
- Creation of power
- Concentric movements
How is power analyzed?
- Analyzes either joint power or total joint power at specific point in the gait cycle
- Graphs: Concentric power is above null line, Eccentric power is anything below null line
What are some important clinical implications of power in normal gait (at ankle, knee, and hip)?
- Plantar flexors: provide important propulsive energy during push off
- Hip flexors: provide propulsive forces during pull off
- Knee: power is relatively low and often negative, indicating eccentric activity in knee extensors or flexors
