L4 Reach and Grasp

Question 1

Critical Events

Answer 1

key biomechanical components to successfully complete the task

Question 2

Stage 1 of development of functional hand skills

Answer 2

Learning Approach–lots of feedback
Sensory Focus–exploration
Arm/Wrist Movements–limited
Hand/Grasp actions–power grip

Question 3

Stage 2 of development of functional hand skills

Answer 3

Learning Approach: skills match ability
Sensory Focus: feedback acquisition
Arm/Wrist Movements: Previous experience
Hand & Grasp: Transferring hand to hand

Question 4

Stage 3 of development of functional hand skills

Answer 4

Learning Approach: discovery of optimal approach
Sensory Focus: maturing of motor organization
Arm/Wrist Movements: Organization and efficiency
Hand & Grasp Actions: raking, lateral pincer, tip to tip pincer

Question 5

Precision Grasp

Answer 5

development focused on radial side, forces directed between thumb and fingers

Lateral pincer, tip pincer, palmar, tripod variations

Question 6

Lateral pincer

Answer 6

thumb pad to medial side of index finger

Question 7

Tip pincer

Answer 7

tip of thumb to index in opposition

Question 8

Palmar

Answer 8

thumb opposition to both index and middle finger

Question 9

Tripod Variations

Answer 9

palmar with object to thenar space

Question 10

Power grasp

Answer 10

development focused on ulnar sider, finger and thumb pads directed towards palms, transmit force to object

hook, spherical, cylindrical

Question 11

Prehension

Answer 11

incorporates both precision and power

Question 12

In-hand manipulation

Answer 12

one hand holds and manipulates with various patterns

palm to finger, finger to palm, shift, simple rotation, complex rotation

Question 13

In-hand Stabilization

Answer 13

object within palm does not move

Question 14

Handedness

Answer 14

(left handed or right handed) affected by genetics, the environment, intrauterine and birth-related stresses and trauma

Question 15

Distance Programming

Answer 15

visual perception of distance, activation of agonists, then activation of antagonist to slow

ability to plan and execute movements that involve covering a specific distance. It involves determining the appropriate force, timing, and trajectory needed to move the body or an object over a certain distance

Throwing a ball a certain distance, kicking a soccer ball to a specific point on the field, or jumping over an obstacle

Question 16

Location programming

Answer 16

relative tensions exist between agonists and antagonists. locations in space correspond to these tension relationships

involves planning and executing movements to reach or interact with a specific spatial location or point. It focuses on targeting a precise location in space, often requiring fine motor control and accuracy in the movement trajectory

Reaching for an object on a table, touching a specific point on a touchscreen device, or placing a cup on a coaster.

Question 17

Activation with Reach

Answer 17

Eye–> Head –> Hand
emphasis on role inertia for successful coordination

Question 18

Grasp

Answer 18

anticipatory control in precision grip
shaping of hand occurs during transportation of reach

role of perception plays big role in grasp

Question 19

Grasp and Lift Tasks

Answer 19

Discrete phases to any lifting task

1. Contact between fingers and object to be lifted
2. Grip and load force increase
3. Load force increases enough to overcome weight of object and movement occurs
4. Decrease in grip and load forces after contact surface

Question 20

Feedforward

Answer 20

Anticipatory Control
Visual and somatosensory control of reach grasp involve characteristics of object, vision, proprioception

Question 21

Feedback

Answer 21

reactive response, error correction for unanticipated perturbations to the movement

visual in reach/grasp = final accuracy
somatosensory in reach = muscle spindles
somatosensory in grasp = cutaneous afferents

Question 22

Steps of locating a target

Answer 22

1. Locate object in space
2. Stabilize gaze
3. Shifting gaze
4. Tracking movements

Question 23

Regulatory Environment

Answer 23

aspects of the environment that shape the movement itself

shape of object, weight of a cup, surface

Question 24

Non-regulatory environment

Answer 24

aspects of the environment that may contribute to the performance, but the movement itself does not conform to the aspects

background noise, distractions