Chapter 7: Postural Control Flashcards
def - movement of the COM outside of the BOS
research definition of a fall
def - an event that results in a person coming to rest inadvertently on the ground
clinical definition of a fall
def - controlling the body’s position in space for the dual purposes of stability and orientation
postural control
def - often used to describe both biomechanical alignment of the body and the orientation of the body to the environment
posture
what orientation do we use for most postural tasks?
vertical orientation
what sensory references do we use to establish a vertical orientation?
vestibular, somatosensory and visual systems
def - modifying sensory and motor systems in response to changing task and environmental demands
adaptive orientation
def - pretune sensory and motor systems for postural demands based on previous experience and learning
anticipatory aspects
def - the ability to maintain an appropriate relationship between the body segments, and between the body and the environment for a task
postural orientation
def - the ability to control the COM in relationship to the BOS
postural stability / balance
def - a point that is at the center of the total body mass
center of mass
def - vertical projection of the COM
center of gravity
def - the area of the body that is in contact with the support surface
base of support
____ and ____ can be used interchangeably
COM and COG
def - center of the distribution of the total force applied to the supporting surface
center of pressure
the ____ moves continuously around the COM to keep the COM within the support base
COP
def - the scalar distance between the COP and the COM at any given point in time
stability
def - the boundaries within which the body can maintain stability without changing the BOS
stability limits
what are the components of motor control in quiet stance?
body alignments
muscle tone
postural tone
plumb line (postural alignment)
mastoid process just in front of the shoulder joints the hip joints (or just behind) just in front of the center of the knee joints just in front of the ankle joints
def - activation of antigravity muscles during quiet stance
postural tone
def - the force with which a muscle resists being lengthened, that is, its stiffness
muscle tone
components of the movement strategies during perturbed stance
body sway, feedback control, feedforward control (anticipatory), AP stability, ML stability, multidirectional stability
what does the cerebellum do during postural control?
control of adaptation - ability to modify postural muscle amplitude in response to changing tasks and environmental conditions
what does the basal ganglia do during postural control?
control of postural set - ability to quickly change muscle patterns in response to changing tasks and environmental conditions
visual inputs
relationship of our body to objects in the environment
somatosensory inputs
surface of support - position and movement about the body with reference to the BOS
vestibular inputs
gravity - position and movement of the head with respect to gravity and inertial forces
asking patients to move (lighter/heavier) objects at (slower/faster) speeds increases the likelihood that anticipatory postural adjustments will accompany movements
heavier and faster
