Normal Control of Reach, Grasp and Manipulation Flashcards
(50 cards)
What are 6 concepts related to reach and grasp?
- Movement control principles
- Locating a target
- Characteristics of reach and grasp
- Systems contributing to reach and grasp
- Grasping patterns
- Neural control of reach and grasp
What type of control mechanisms (1) contribute to the control of upper extremity movement? (for example catching a ball)
Both feedforward (anticipatory) and feedback
What does feedback control involve?
Input from sensory receptors (visual or somatosensory) being compared to a reference signal, representing a desired state of the system (e.g., a position of the arm)
What does feedforward or anticipatory control take advantage of?
prior experience to predict consequences of sensory information
Because of feedforward control there is ___ reliance on feedback control
less
When dropping a ball the initial input is ______ (using vision), while final input is _____ (using somatosensory inputs).
feedforward
feedback
In order to reach for an object successfully, what must wee do first?
locate the object in space (2)
Describe the sequence of events that occur when locating a target
1) Eye movements
2) Head movements
3) Trunk movements
When working with a patient having problems with functional grasp what may clinicians consider for treatment? Why?
Training the different control systems separately, as the patient’s problem may be related to the eye movements with little head movement, or eye-head movements for visual regards
What do kinematic studies show once an object appears in the peripheral visual field?
Eye movement begins first due to low inertia; then head movements and followed by hand movement
EMG studies indicate that muscle responses are activated _____ rather than sequentially.
synchronously
What are 2 ways in which eye and hand movements interact and influence each other?
- hand movement becomes more accurate when accompanied by eye movement
- there is an increase in gain during smooth pursuit if the hand is also following the target
When patients are asked to reach and grasp an object the movement duration is of the reach was much ______ than if the subject was asked to grasp the object
longer
When preparing to grasp an object, the acceleration phase of the reaching movement is much ______ than the deceleration phase.
shorter
When asked to point at an object, the acceleration phase of the reaching movement is much ______ than the deceleration phase.
longer
True or False
Reach and Grasp are controlled by different neural mechanisms.
True
In helping patients with problems related to reach and grasp, movements need to be practiced in a variety of task conditions. What are a few examples?
- reach and point
- reach and grasp
- reach, grasp and manipulate
What are 3 areas of the cerebral cortex are critical to the control of reach and grasp(4)?
- primary motor cortex
- premotor cortex
- areas of the posterior parietal lobe
What are the 2 pathways in which sensory inputs from the visual system go through during goal-directed reaching?
- dorsal stream pathway
- ventral stream pathway
What is the dorsal stream pathway related to?
Where the object is in extrapersonal space (localization) and the action systems involved in object manipulation
Therefore, the dorsal stream pathway is aka what?
localization and action pathway
The localization and action (dorsal stream) pathway transmits information from the visual cortex to the _____ cortex
parietal
What is the ventral stream pathway related to?
What is being reached for (perception and object recognition)
Therefore, the ventral stream pathway is aka what?
The perceptual pathway
