Reaching and grasping - UE function

Question 1

UE function

Answer 1

• basis for fine motor skills
• plays a role in gross motor skills like walking
• contextual factors impact UE function (cognition, perception, environment)

Question 2

Development of grasping

Answer 2

• 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

Question 3

Development of reaching: early infants

Answer 3

• 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

Question 4

Development of reaching at 18 weeks

Answer 4

• begin to change strategy
• use vision more
• fewer movements and corrections
• coincides with improvements in postural control like reaching
• experience is important

Question 5

Reaching development and strategies around 7 years old

Answer 5

• 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

Question 6

Reaching with locating a target

Answer 6

• 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

Question 7

Kinematics of reaching and grasping: what is a critical part of UE function for reaching and what affects reaching phase of movement?

Answer 7

• 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

Question 8

Pointing vs grasping on EMG

Answer 8

• pointing: not much of a deceleration
• grasping: need to accelerate and decelerate to control

Question 9

Neural control of reach and grasp: sensory information

Answer 9

• 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)

Question 10

Neutral control of reaching and grasping sensory Sytstems

Answer 10

• 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

Question 11

Precision grip formation

Answer 11

• shaping of hand for grasping occurs during transportation component of the reach

Question 12

Nervous system adapts precision grip

Answer 12

for difference weights and surface characteristics
- learned through experience
- precision grip requires more muscle activity than power grip

Question 13

Grasping patterns: hand shapes

Answer 13

• poke
• pinch
• clench
• palm

Question 14

grasping patterns: hand and finger movements

Answer 14

• hand adapted to shape, size, use of object
• finger movements timed in relation to transport so they close on object at appropriate moment

Question 15

MSK considerations with grasping and reaching

Answer 15

• joint ROM
• spinal flexibility
• muscle properties
• biomechanical relationships among linked body segments

Question 16

efficient reaching uses what strategies

Answer 16

• both feedback and feedforward
• feedforward/anticipatory = previous experience

Question 17

Reaching and secondary cognitive task

Answer 17

• reaching performance like postural and gait control requires attention
• complexity of both motor and secondary task contributes to extent of dual task interference in young adults