lecture 4 Flashcards
what are the ways that we can assess balance?
Kinetics: Forces under the feet.
EMG: Muscle activity.
Kinematics: Body movement in space.
what is posturography?
Objective measures of postural control in static and dynamic conditions.
how do we measure posturography?
body kinematics, dynamics, and muscle activation patterns.
what is static posturography?
characterizes the performance of the postural control system by
measuring postural responses when in a static position
what is dynamic posturography?
characterizes the performance of the postural control system by
measuring postural responses to an internal or external perturbation
during quiet stance, what happens to COM?
remains the same
how is sway modeled for quiet stance? (Physics)
as an inverted pendulum that rotates around the ankle
during quiet stance, how is the movement of the COM controlled?
ankle torque
how is static posturography measured?
kinematics
- position
- velocity
- acceleration
- timing
how do we measure kinematic measures for posturography?
motion capture
what can motion capture inform us about?
COM can be calculated using relative locations of body segments
what kind of kinetic measures are taken for posturography?
moments generated and ground reaction forces
define center of pressure COP
point location of the weighted average of the sum of vertical ground reaction forces
how is COM different from COP?
- COP acts to control the body centre of mass (COM) COP is the controller
- COP moves rapidly ahead and then behind the COM to keep it in a more central position
- COM is the controlled variable
- COP represents slow COM shifts, and faster adjustments by the CNS that correct COM movement
