Postural Control Flashcards
Postural control emerges from the interaction of what 3 things?
- task
- individual
- environment
The ability to control our body’s position in space emerges from a complex interaction of musculoskeletal and neural systems is referred to as what?
the postural control system
What can be defined as “controlling the body’s position in space for the dual purposes of stability and orientation”?
postural control
What can be defined as “the ability to maintain an appropriate relationship between the body segments, and between the body and the environment”?
Postural orientation
What can be defined as the ability to control the center of mass in relationship to the base of support?
postural stability
What is the center of mass?
A point that is at the center of the total body mass, which is determined by finding the weighted average of the COM of each body segment
The vertical position of the COM is called what?
The center of gravity
Define the base of support
The area of the body that is in contact with the support surface
What can be defined as the center of the distribution of the total force applied to the supporting surface?
The center of Pressure
All tasks consist of what 2 components?
a stability component and a orientation component
*Orientation and stability demands change with each task
What is the clinical definition of a fall?
an event that results in a person coming to rest inadvertently on the ground (unplanned or unexpected contact with a supporting surface)
What is the research definition of a fall?
movement of the COM outside of the base of support (including stepping to recover stability)
What factors contribute to our stability during quiet stance?
- body alignment
- muscle tone
- postural tone
Describe perfect alignment
- mastoid process
- a point just in front of the shoulders
- the hip joints (or just behind)
- a point just in front of the center of the knee joints
- a point just in front of the ankle joints
What is muscle tone?
The force with which a muscle resists being lengthened (stiffness)
What 3 things contribute to our background muscle tone?
- the intrinsic stiffness of the muscles themselves
- the background muscle tone, which exists normally in all muscles because of neural contributions
- postural tone
Define postural tone
the activation of antigravity muscles during quiet stance
Lesions to what area of the spinal cord result in reduce postural tone. What does this signify?
Dorsal column
The importance of somatosensory inputs to postural tone
What are 6 movement strategies to maintain balance?
- Controlling body sway
- Feedback control
- Feedforward (anticipatory) control
- Anteroposterior stability
- Lateral stability
- Multidirectional stability
How is body sway controlled?
The CoP works to control the CoM moving the body backward and forward.
What does feedback control refer to?
postural control that occurs in response to sensory feedback from an external perturbation
What are 2 examples of when feedback control is needed to maintain balance?
- when the support surface moves
- when there are disruptions to gait