Grasp & Reach Flashcards
Response to Target in Peripheral Vision (3)
- Eyes mm activated
- Neck mm activated
- Eyes move first, then the head moves, the eyes reach the target before the head stops moving.
_______1_______ signals from eye muscles contribute to the ability of ___2___ targets in extrapersonal space.
- Proprioceptive
- Localize
Inputs of 2 parallel pathways for the visual system.
- Perception and object recognition [visual cortex to temporal cortex]
- Localization [visual cortex to parietal lobe]
Stream Pathway:
- Visual to partietal cortex
- Action-relevant info for reaching including object position, structure, and orientation
- Mediates sensorimotor transformations
Doral Stream Pathway
Stream Pathway:
- Visual to temporal cortex
- Conscious visual perceptual experience
- Perceptual identifications of objects
Ventral Stream Pathway
Somatosensory information is not required for __1__, ___2___, or ______3______ arm movement initiation or execution. _______4_______ with complex tasks results when visual input is removed.
- Fast
- Simple
- Nonrepetitive
- Incoordination
Input: essential for control of grip forces
Cutaneous afferent input
Cortex: critical for control of grasp
Somatosensory cortex
2 systems that allow for reach and grasp to be updated online
- Visual
- Somatosensory
Normal movement requires the following structure for
- Intact primary motor cortex
- Intact cerebellum
- Intact midbrain/brainstem
- Important for precision grip over power grip
- For coordination of reach/grasp and anticipatory postural control
- For proximal mm in reach
Type of Grasp: finger and thumb pads direct force toward palm
Power Grip
Type of Grasp: Finger and thumb direct forces to each other
Precision Grip
2 requirements for successful grasp
- Hand must be adapted to shape, size, and use of object
- Finger movements must be times in relation to transport
Grip size changes primary by movement of the ___1___. Grip size is ___2___ than width of target and scaled __3__ just before contact with the object.
- Fingers
- Larger
- Down
Term: object’s location with respect to the body
Extrinsic (contextual) properties of object
Define bimanual skill
When one hand performs a simple task while the other performs complex task the pattern of movement of the hand doing the simple task has some elements of the complex task
[even more pronouned when non-dominant hand is doing the complex task]
When the UE is affected by a brian lesion the contralesional side is ____1____, BUT the ipsilesionside is usually ___2___ ____3____.
- Affected
- Mildly
- Affected
When both hands perform at the same time the ____1____ limb assume a temporal pattern similar to that of the _____2_____ limb. As with controls, both hands reach the target at the same time but the _____3_____ does not get faster when both hands move together.
- Non-paretic
- Paretic
- Paretic
If the goal is smooth, coordinated movement, there is some evidence that ____1____ activities can help the affected arm. However, this gains may not transfer to _____2_____ conditions. If the goal is to increase speed of movement of the affected arm, ____3____ movement are probably not a good idea.
- Bilateral
- Unilateral
- Bilateral
4 Factors of increased reaching movement time with age
Due to changes in
- Sensory/perceptual systems
- Central processing systems
- Motor systems
- Arousal/motivational systems
Changes in reaching coordination with age (3)
- Slowing in target approach and deceleration phase
- More movemtn adjustments due to less open loop and more closed loop activity
- Decreased hand steadiness
Changes in grasping with age (3)
- Decreased manual dexterity
- Longer times need to manipulate small objects
- Larger grip forces with less ability to adapt to changes
When presented with unpredictable conditions for reaching and grasping, older adults pick the most ______1______ approach
- Conservative
Leads to longer approach time and use of standardized coordination patterns
In older adults performance can be _____1_____, particulary with more ____2____ tasks.
- Improved
- Complex
