POSTURAL CONTROL, BALANCE AND MOBILITY Flashcards
What is posture?
Represents the overall position of the body and limbs relative to one another and their representation in space
Postures can be in static and dynamic conditions
Postural control
involves controlling body’s position in space for the dual purposes of stability and orientation
Center of pressure
vertical projection of the COM
center of mass
point that is at the center of the total body mass
Stability limits
boundaries of an area in space which the body can maintain its position without changing the base of support
base of support
the are underneath and between both feet
Which test can be used to measure stability limits?
functional reach test
MDRT
Increasing stability limits in older adults and individuals with neurological conditions results in a
decreased risk for falls
Is the effect greater in A/P or M/L direction?
A/P?
Postural Orientation
The way you position yourself in space - biomechanical alignment of the body + orientation of the body vs. environment
Postural Stability (balance)
The ability to:
stay still in a certain position
maintain the projected centre of mass within stability limits (without changing the base of support)
** Orientation & Stability demands ______ with each task **
change
Postural _______ depends on postural ________
stability on orientation
Neural system (perception) :
Integration of sensory information to assess the position and motion of the body in space
Musculoskeletal system (action):
Ability to generate forces for controlling body position systems
Conditions involving neurological (ex: CP, MS, stroke, etc.) and/or musculoskeletal (ex: arthritis, neuropathic pain, amputation fibromyalgia, etc. ) systems can lead to deficits in postural _______ or _________ (because of impairments to neuro + musculo systems)
orientation or stability
2 types of postural control
anticipatory and reactive
Anticipatory postural control
Advance planning of actions
Obstacles, different types of surfaces
ex: getting ready to climb stairs
Reactive postural control
Actions that cannot be planned in advance due to the unexpected nature of an event
Ex: Being bumped in a crowd
Clinical Implications: important for falls prevention
CNS preprograms force based on____________ of what the task requires
anticipation
When doing balance exercises in rehab, is it more important to train anticipatory or reactive postural control?
reactive???
Goal of postural movement strategies :
To restore the COM of the body to a position of stability following a loss of balance
These postural responses are activated in response which 3 inputs?
to proprioceptive, visual and vestibular inputs
3 motor strategies
ankle, hip or stepping
Ankle strategy
Restore COM to a position of stability through body movement centered primarily about the ankle joints
- To oppose forward sway: activation of…
PF
- To oppose backward sway: activation of _______________
DF
Ankle strategy is in reaction to?
small perturbations and firm surface
Which is the first strategy?
ankle
Hip strategy controls..
Controls motion of the COM by producing large and rapid motions at the hip joints
Hip strategy in reaction to?
In reaction to larger and faster perturbations and when support surface is smaller than the feet (beam)
Stepping strategy happens when
When ankle and hip strategies are insufficient to recover balance, a step or hop is used to bring the support base into alignment under the COM
Visual system
Position and motion of the head & body with respect to surrounding objects
Reference for verticality
Which system is very important for neurological conditions?
visual to compensante for decrease in somatosensory system
Somatosensory system
Provides CNS with position and motion information about the body with reference to supporting surfaces (horizontal)
ex: ankle joint in standing position
Relationship of body segments to one another
Vestibular system
Information about HEAD position and motion
(displacement and acceleration; gravity)
Injuries or disorders to these 3 systems can lead to _________ problems ex: ataxic CP, hemiparesis, aging, etc.
balance
Can a loss of any of these systems be compensated by the other 2 systems?
yes
to understand these systems go to p.319
p.319
When standing still, does our nervous system rely more heavily on vision or somatosensory info?
It appears that under normal conditions, the nervous system may weigh the importance of somato info for postural control more heavily than vision and vestibular inputs
It appears that under normal conditions, the nervous system may weigh the importance of ______________ info for postural control more heavily than vision and __________ inputs
somatosensory, vestibular
Neurological lesions : people rely predominantly on : _______ during the early part of their balance recovery process and then use more somatosensory inputs
vision
Based on the stickman graph, if you are aging and over 65 years old, which do you resemble most?
5 and 6
Reducing the availability of ___ senses appears to have a significant effect on postural steadiness in ________ adults
2, healthy older
To maintain standing balance, elderly people with vestibular loss need their… _______ or their ___________________
vision, somatosensory function
