Prehension and Ballistic Skills

Question 0

What body part is involved in fine motor development of prehension?

Answer 0

Hand

Question 1

What is prehension?

Answer 1

Process of reaching and grasping - ability to use the hands and the UE effectively

Question 2

What are the primary components of prehension?

Answer 2

Visual regard, reach (approach), grasp, manipulation, and release

Question 3

How does stabilization factor into prehension?

Answer 3

Trunk and UE require varied degrees of stabilization to afford us the ability to reach and grasp objects

Question 4

What is visual regard?

Answer 4

Visual attention of the object

Question 5

What are the two factors of visual regard?

Answer 5

1. Visual regard - accommodation (focus) and convergence

2. Visual perception - ability to use visual information to recognize, recall, discriminate, and understand what we see

Question 6

What does visual regard require?

Answer 6

Eye-head-trunk coordination

Question 7

What is approach (reaching)?

Answer 7

Directing or adjusting of the hand toward an object

Question 8

What does approaching require?

Answer 8

Visual-motor control - eye-hand coordination

Question 9

What does reaching involve?

Answer 9

Movement of all joints of the UE - vision initially important followed by tactile and proprioceptive input

Question 10

What are postural adjustments associated with reaching?

Answer 10

Arms play a role with balance and hand can be used to form a new BOS

Question 11

What does movement beyond arm’s length entail?

Answer 11

Movement of the trunk and the hips

Question 12

What are the three stages of development of reaching?

Answer 12

1. Prereaching - birth to 4 months
2. Visually guided reaching - 4 to 8 months
3. Visual elicited reaching - 9+ months

Question 13

What is prereaching?

Answer 13

Excited thrashing of the limbs and no correction of reach once initiated

Question 14

What is visually guided reaching?

Answer 14

Increased use of vision to guide hands and make corrections as they reach

Question 15

What is visually elicited reaching?

Answer 15

No longer needs to see hand to guide reach and infant shapes hand correctly for the object

Question 16

What are the two types of grip?

Answer 16

Power and precision

Question 17

What is the power grip?

Answer 17

Forcible activities of the fingers and thumb that act against the palm to transmit a force to an object

Question 18

What are three examples of power grips?

Answer 18

Cylindrical, spherical, and hook

Question 19

What is precision grip?

Answer 19

Forces are directed between the thumb and fingers without contacting the palm

Question 20

What are three examples of precision grip?

Answer 20

Pad to pad prehension, tip to tip prehension, and pad to side (lateral) prehension

Question 21

What percentage does the thumb contribute to total hand function?

Answer 21

40-70%

Question 22

What is opposition?

Answer 22

Movement by which the pad surface of the thumb is placed diametrically opposite the terminal par of one or all of the digits

Question 23

What is the second most important finger?

Answer 23

Index finger

Question 24

Which finger is the longest and the strongest?

Answer 24

Middle finger

Question 25

What percentage does the index finger play in lateral pinch and power grip (supinated and pronated)?

Answer 25

``` Lateral pinch - 20% Power grip (supinated) - 20% Power grip (pronated) - 50% ```

Question 26

What two digits are the most anatomically stable?

Answer 26

Index and middle finger

Question 27

What two digits are the most mobile and weakest?

Answer 27

Ring and pinky finger

Question 28

What are the three development grasps?

Answer 28

1. Reflexive grasp - traction response and grasp reflex 2. Transitional reaction - orienting response and instinctive grasp 3. Purposeful grasp - squeeze grasp (palmar grasp) and radial palmar grasp (radial digital grasp)

Question 29

What is the goal of catching?

Answer 29

Retain possession of object that is caught

Question 30

How is catching developed?

Answer 30

Master ability to move left or right/forward or backward and point fingers up or down when catching a high or low ball

Question 31

What is throwing?

Answer 31

Ability to project an object accurately and with sufficient force through space

Question 32

How does throwing develop?

Answer 32

6 months - crude unrefined throwing | 2 years - immature, stiff, and jerky throw

Question 33

What is a fundamental movement used in a number of child and adult games?

Answer 33

Ball-bouncing

Question 34

What is striking?

Answer 34

Propulsion skill - object or body part is used to project an object

Question 35

What are characteristics of early sidearm striking?

Answer 35

Chopping motion (elbow extension) and little leg and trunk movement

Question 36

How does striking progress?

Answer 36

Sideways preparatory stance, arm extended before contact, and swing through a large ROM