Week 11 (Reaching and Manip)

Question 1

Define transport

Answer 1

Movement at the shoulder and elbow transports the hand in space

Question 2

Define orientation

Answer 2

Movement at the forearm and wrist orients the hand in space

Question 3

Define manipulation

Answer 3

Movement within the hand grasps, holds and manipulates the object

Question 4

Conjunct rotation is

Answer 4

Combined movement of flexion, abduction and opposed fingers

Question 5

Kinematics: Reaching component

Answer 5

Transport component and manipulation components are interrelated

• Hand begins to open at the start of reach
• Hand achieved maximum aperture at the same time as the low velocity transport phase begins: 75% get hand to max opening and last 25% slow down and refine size of hand to match object
• Velocity of the transport phase is slower when objects are close compared to when they are further away

Question 6

Kinematics: Grasping component

Answer 6

• Thumb is relatively invariant when grasping an object: thumb is consistent, fingers adjust to size of object
• Hand is opened and closed predominantly by movement at the MCP joint of the fingers

Question 7

Bimanual tasks: picking up tray requirements

Answer 7

Both hands do the exact same thing
Movement time was same for both hands
Hand has to match speed, spatial orientation, grip force of the other hand or else it won’t work

Question 8

Bimanual tasks: opening jar requirements

Answer 8

Hand performing the precision grip (unscrewing) had a longer deceleration phase

Question 9

Kinetics: effect of frictional properties of objects

Answer 9

• Objects that require higher friction (sandpaper) require less force to grip them
• Decrease in friction between skin and object increases grip force
• Change in heaviness of object changes grip force

Question 10

Kinetics: self-initiated vs imposed reaching

Answer 10

• Preparatory hand grip movements occur when movements are self-initiated
• Able to plan and switch on the muscles just enough
• Grip force is less when actions are self-initiated
• Preparatory hand grip movements are absent when movements are in response to an imposed change

Question 11

Kinetics: effect of direction on grip forces

Answer 11

Temporal fluctuations in grip forces of thumbs and fingers varied according to direction of movement
- Need to be able to move fingers independently and create alternating force through fingers

Question 12

Important components: reaching

Answer 12

• Protection and elevation of shoulder girdle
• Shoulder flexion (forward), abduction (side), extension (backward)
• Shoulder external rotation
• Wrist extension with radial deviation
• Opening of hand aperture between thumb and fingers
• Pronation/supination appropriate to object orientation

Question 13

Important components: grasping

Answer 13

• Extension of wrist and fingers
• Conjunct rotation (flex+abd) of CMC jt of thumb
• Conjunct rotation (flex+abd) of MCP jt of ulna fingers

Question 14

Important components: manipulating

Answer 14

• Flexion/extension of fingers
• Cupping of the hand
• Independent finger flexion/extension (e.g. tapping)

Question 15

Important components: holding

Answer 15

• Flexion/extension of wrist holding object

- Lifting, placing and rotating objects of different size and weight

Question 16

Clinical measures of reaching and manipulation

Answer 16

• Time taken to complete task
• Item 6, 7 and 8 of MAS
• 9-hole peg test
• Spiral test

Question 17

Common adaptive strategies of reaching and manipulation

Answer 17

• Uses intact arm for all reaching and manipulation tasks i.e. learned non-use
• In reaching forwards, excessive hip flexion, elevation of shoulder girdle, abduction and internal rotation at glenohumeral j., trunk side flexion to intact side
• Excessive elbow flexion and forearm pronation
• Grasps and releases objects with wrist in excessive flexion
• Excessive aperture between thumb and fingers for grasp and release
• Extension of CMC jt of thumb and pronation of forearm for grasp and release
• Flat hand or lack of cupping i.e. grasps objects without contribution of ring and little fingers
• Inability to move objects within hand

Question 18

Kinematics: cleaning windows with squeegee grip

Answer 18

Power grip: requires a lot of power and force

Question 19

Kinematics: folding a towel

Answer 19

Requires bimanual accuracy

Question 20

Kinematics: putting place of food into microwave

Answer 20

Requires strength and precision in the supinated position

Question 21

Kinematics: using key to unlock storeroom door

Answer 21

Power in grip between fingers to open lock which also comes from the forearm

Question 22

What exercise to give someone if they are unable to flex and extend their shoulder with elbow or to flex and extend elbow while keeping shoulder stationary?

Answer 22

Train shoulder and elbow movements in preparation for reaching

Question 23

What exercise to give someone who has excessive shoulder elevation during reaching?

Answer 23

Train shoulder abduction without excessive shoulder elevation in preparation for reaching

Question 24

What exercise to give someone if they have increased shoulder internal rotation and abduction during reaching?

Answer 24

Train shoulder external rotation in preparation for reaching

Question 25

What exercise to give someone who has excessive trunk flexion instead of shoulder forward flexion with ext rotation and elbow ext?

Answer 25

Train reaching and manipulation using trunk restraint to prevent excessive trunk flexion

Question 26

What exercise to give someone who has increased forearm pronation during reaching?

Answer 26

Train forearm supination and pronation in preparation for reaching and manipulation