Reaching and grasping - UE function Flashcards
UE function
- basis for fine motor skills
- plays a role in gross motor skills like walking
- contextual factors impact UE function (cognition, perception, environment)
Development of grasping
- infants begin using hands and grasping in utero
- hands together, hand to mouth, grasping umbilical cord
- palmar grasp reflex is present at birth
- develops with experience
Development of reaching: early infants
- one of the first movements in infants (randomly swiping)
- triggered by vision: arm movements change in presence of toy
- initially this is not guided by vision
- in 4.5 months they can grasp a moving objects
- as they develop postural control, reaching and grasping control improves
Development of reaching at 18 weeks
- begin to change strategy
- use vision more
- fewer movements and corrections
- coincides with improvements in postural control like reaching
- experience is important
Reaching development and strategies around 7 years old
- stand and balance is more like adult
- coincides with these improvements in postural control
- children with impaired postural control or sensory processing often have difficulties with reaching and object manipulation
Reaching with locating a target
- eye-hand-trunk coordination
- vision: object location and guides movements of hand
- reaching to objects located in far visual fields requires eye, head, and trunk movements
Kinematics of reaching and grasping: what is a critical part of UE function for reaching and what affects reaching phase of movement?
- ability to adapt how we reach is critical part of UE functioning for different tasks
- task constraints and goals (context) affect reaching phase of movement
Pointing vs grasping on EMG
- pointing: not much of a deceleration
- grasping: need to accelerate and decelerate to control
Neural control of reach and grasp: sensory information
- correct errors during execution of movement
- use proactively in helping to make the movement plan
- refined using visual and perceptual information
- essential for most reaching movements: proactive visual and somatosensory control (previous experience/prepared for what will happen)
Neutral control of reaching and grasping sensory Sytstems
- visual feedback in reaching: related to attainment of final accuracy
- reaching movements across midline slower and less accurate
- normal adults show decrements when reaching to contralateral side of body
Precision grip formation
- shaping of hand for grasping occurs during transportation component of the reach
Nervous system adapts precision grip
for difference weights and surface characteristics
- learned through experience
- precision grip requires more muscle activity than power grip
Grasping patterns: hand shapes
- poke
- pinch
- clench
- palm
grasping patterns: hand and finger movements
- hand adapted to shape, size, use of object
- finger movements timed in relation to transport so they close on object at appropriate moment
MSK considerations with grasping and reaching
- joint ROM
- spinal flexibility
- muscle properties
- biomechanical relationships among linked body segments