Week 11 (Reaching and Manip) Flashcards
Define transport
Movement at the shoulder and elbow transports the hand in space
Define orientation
Movement at the forearm and wrist orients the hand in space
Define manipulation
Movement within the hand grasps, holds and manipulates the object
Conjunct rotation is
Combined movement of flexion, abduction and opposed fingers
Kinematics: Reaching component
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
Kinematics: Grasping component
- 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
Bimanual tasks: picking up tray requirements
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
Bimanual tasks: opening jar requirements
Hand performing the precision grip (unscrewing) had a longer deceleration phase
Kinetics: effect of frictional properties of objects
- 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
Kinetics: self-initiated vs imposed reaching
- 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
Kinetics: effect of direction on grip forces
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
Important components: reaching
- 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
Important components: grasping
- Extension of wrist and fingers
- Conjunct rotation (flex+abd) of CMC jt of thumb
- Conjunct rotation (flex+abd) of MCP jt of ulna fingers
Important components: manipulating
- Flexion/extension of fingers
- Cupping of the hand
- Independent finger flexion/extension (e.g. tapping)
Important components: holding
- Flexion/extension of wrist holding object
- Lifting, placing and rotating objects of different size and weight
Clinical measures of reaching and manipulation
- Time taken to complete task
- Item 6, 7 and 8 of MAS
- 9-hole peg test
- Spiral test
Common adaptive strategies of reaching and manipulation
- 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
Kinematics: cleaning windows with squeegee grip
Power grip: requires a lot of power and force
Kinematics: folding a towel
Requires bimanual accuracy
Kinematics: putting place of food into microwave
Requires strength and precision in the supinated position
Kinematics: using key to unlock storeroom door
Power in grip between fingers to open lock which also comes from the forearm
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?
Train shoulder and elbow movements in preparation for reaching
What exercise to give someone who has excessive shoulder elevation during reaching?
Train shoulder abduction without excessive shoulder elevation in preparation for reaching
What exercise to give someone if they have increased shoulder internal rotation and abduction during reaching?
Train shoulder external rotation in preparation for reaching
What exercise to give someone who has excessive trunk flexion instead of shoulder forward flexion with ext rotation and elbow ext?
Train reaching and manipulation using trunk restraint to prevent excessive trunk flexion
What exercise to give someone who has increased forearm pronation during reaching?
Train forearm supination and pronation in preparation for reaching and manipulation
