Final Exam Flashcards
What is posture?
A position of a persons body when standing or sitting
What is balance?
An even distribution of weight enabling someone or something to remain upright and steady
What are the 7 components of postural control?
- Musculoskeletal component
- Internal representations
- Adaptive mechanisms
- Anticipatory mechanisms
- Sensory strategies
- Individual sensory systems
- Neuromuscular synergies
What is postural control?
Involves controlling body’s position in space
What is postural orientation?
Ability to maintain appropriate relationship between body segments and between the body and environment for a task
What is postural stability?
The ability to control COM in relationship to the base of support
What is COM?
Center of mass: is the point at the center of the total body mass at L1-L2
What is COP?
Center of pressure: is center of distribution of total force applied to supporting surface (COP is found through GRF)
What is COG?
Center of gravity: vertical projection of COM.
What is the base of support?
The area of the body in contact with the supporting surface
What does COG do during locomotion?
During locomotion COG will be projected outside of the BOS in order to assist with movement
What are the 3 systems in postural control?
- Higher level planning
- Coordination
- Force generation
Where does higher level planning come from for postural control?
- frontal cortex
- motor cortex
What parts of the nervous system control coordination?
Brainstem
Spinal networks coordinating muscle response synergies
What is responsible for force generation in postural control?
Motor neurons and muscles
How does muscle tone assist with motor control if quiet stance?
Muscle tone should provide passive resistance to lengthening
What are the three components of postural tone during motor control of quiet stance
Antigravity muscles
Vestibular system
Vestibuloocular reflex
What are the three movement strategies during perturbed stance?
Cone of stability
Feedback control
Feed foreword (anticipatory) control
What is cone if stability?
How far we can lean forward without falling
True or false: if the COM is within the cone of stability, balance can be maintained
True
What are the three types of feedback control?
Proprioception
Visual
Vestibular
What is feed forward (anticipatory) control?
Muscles and posture react to visual, cognitive and other inputs to get ready for a change
What are the three methods for maintaining stability?
Ankle strategy
Hip strategy
Stepping strategy
What strategy for maintaining balance is used for the most distal direction?
Ankle
What strategy for maintaining balance is used for the most proximal direction?
Stepping (to widen BOS or to correct balance)
What muscles (anterior) are used to correct backward sway?
Tibialis anterior
Quadriceps
Abdominals
What muscles (posterior) are used to correct anterior sway?
Gastrocnemius
Hamstrings
Paraspinals
When is stepping strategy used to correct COG?
If the COG has exceeded the original base of support, then the active limb is used to reestablish a new base of support
What is suspensory strategy and when is it used?
Lowering the COG toward the base of support (when all else fails)
What 2 things are used to overcome mediolateral instability?
Abduction-adduction at the hip
Muscle patterns organized in a proximal-to-distal direction
What three things are falls dependent on?
The particular perturbation
The limitation of the individual
The conditions of the environment
What age does crawling emerge?
2 months
What age does sitting (unsupported) emerge?
6 to 7 months
What age does creeping emerge?
8 to 10 months
What age does pull-to-stand emerge?
9 to 10 months
What age does independent stance emerge?
12 to 13 months
What age does walking emerge?
14 to 18 months
When learning to perform the next milestone, children must revert back to a ____
Symmetric pattern
What is the limiting factor on the emergence of other behaviors as well as the inhibition of reflexes in children?
An immature postural system
What may constrain independent mobility and skills in a child?
Abnormal development
Most developmental tests and measures evaluate emergency of motor behaviors by evaluating what?
Performance on functional skills that require postural control
What are three attitudinal reflexes?
Asymmetric tonic neck reflexes
Symmetric tonic neck reflexes
Tonic labyrinthine reflex
What are 5 righting reactions?
Labyrinthine righting Optical righting Body-on-head righting Neck-on-body righting Body-on-body righting
What are three balance and protective reactions?
Tilting response
Protective reaction
Staggering reaction
What are the symmetric tonic neck reflexes?
Neck extension causes UE extension and LE flexion
Neck flexion causes UE flexion and LE extension
What is the labyrinthine righting reaction?
Orients head to vestibular input
What is optical righting?
Orientation of the head to visual input
What is the body-on-head righting?
Orients the head to proprioceptive and tactile input from the supporting surface
What are some common reflexes that are present during the first month after birth?
Root/suck/swallow Moro Crossed extension Flexor withdrawal Palmar and plantar grasp Stepping anterior side if leg on table and step Positive support
When are reflexes linked to abnormal development?
If they persist beyond their normal time period or if they fail to appear in the normal time period
Can children be classified as having normal development solely based on reflexes?
No
What is the agreement between the two theories (reflex theory and system theory)?
Mapping is the beginning of internal neural representations necessary for coordinated postural abilities
According to reflex theory what appears when a child is 2 months of age?
Visual/motor coordination
According to system theory what is present in an infant at birth?
Visual/perceptual mapping
What is the cause of a lack of head control in a newborn?
Lack of strength and lack of organized muscle activity
This is a statement- direction specific postural responses in the neck muscles underlying reactive balance control occurs in infants as young as 1 month old
Couldn’t figure out how to make that a question.
There are subcortical neural networks involved in the vision-driven control of posture. Are they functional at birth?
Yes
What special sense in infants does vision have a significant effect on?
Vestibular
At what age should a child be able to hold his head and upper trunk up during static balance control in sitting?
4 to 5 months
At what age should a child be able to prop sit?
5 months
At what age should a child be able to independently sit?
6 to 8 months
When is reactive balance control present in a child during sitting?
At birth
What is the exception of progression (think age) of balance control during sitting?
Reactive balance control improves steadily, except at 3 months of age … Where it then reappears with greater frequency and refinement
How can postural response be modified in children?
Postural training may help children with motor delays
Practice increases the emergence of postural responses
What is Base of Support (BOS)?
The part of the body in contact with the surface you’re in contact with or what ever
What is Center of Mass (COM)?
The part of the body in contact with the surface you’re in contact with or what ever…
Which sensory system elicits postural responses earlier than the somatosensory system?
Visual system
What balance strategy is not used during the first year of walking?
Hip strategy
Which strategy is not developed until 7-10 years of age?
Hip strategy
After what age is there no correlation between structural growth and sway during normal quiet stance?
7 years old
Visual reliance for balance is most prominent until age _____.
3 years old
Anticipatory postural control emerges at what age in standing?
10 months
When is anticipatory postural control present in sitting?
Present in infancy
Does postural demands of younger children tax attentional resources more than for older children?
Yea
