lecture 10 upper extremity function Flashcards
(50 cards)
1
Q
UE Function: Components
A
- gross motor tasks
- fine motor skills
- ADLs
Within the realm of individual, task and enviorment.
2
Q
Feed-Forward
A
- Anticipatory control
- Typically initiated through vision
- Previous experience affects movement
example of catching a ball, bowling a ball
3
Q
Feedback
A
- Position of the UE
- Vision and somatosensory input compared to reference
- Correction of movement ← Cerebellum adapts QUICKLY
- Weighted ball example
4
Q
UE function: locating a target
A
- Requires coordination of eye-head movements
- Eyes focus first
- Head and/or trunk movements may follow if necessary
- Depends on where an object is located
- Muscle responses activated synchronously
5
Q
Upper extremity skills and the ICF
A
6
Q
Reaching
A
transportaiton of arm and hanf in space
requires postural support
* functional reach test
* treatmetn for postural control
7
Q
Neural control of reach and grasp
A
Higher centers in cortex active during UE movement
* Primary motor cortex
* Premotor cortex
* Somatosensory cortex
* Posterior parietal lobe (movement planning and internal maps)
Cerebellum receives and updates movement plan with sensory information
8
Q
Sensory sytems in the UE function
Vision
A
Visual system pathways:
1) Perception and object recognition
Visual cortex to temporal cortex (ventral stream: what)
2) Localization (position, structure, orientation)
Visual cortex to posterior parietal lobe (dorsal stream: where)
Vision is required for final accuracy
Can reach fairly well without visual cortex (some input from superior colliculus?)
People with visual cortex lesion
Can you see the object: NO
Point where it is: pointing was not random
Visually controlled contralateral reaching across midline
Slower and less accurate
May benefit from training ipsilaterally first
9
Q
Sensory sytems in the UE function
Somatosensory Information
A
- Not required for simple movements (if vision is present)
Arm movement, initiation, or execution of simple / non-repetitive - Required for fine regulation of movement
Muscle spindle information important for position sense
Joint receptors only at extremes of motion - Grip: CNS uses previous experience and afferent information during the task to choose correct parameters for grip and load force
10
Q
Visual and Somatosensoy information for feedforward control
A
- Used proactively to correct initial direction of limb, and for initial coordination between limb segments
- Used to update proprioceptive and visual body maps
- Vision used to program forces needed for grip, and for pre-shaping hand for grasp
11
Q
Descending pathways for reaching
A
Reach: Midbrain and brainstem pathways (red nucleus, reticular nuclei)
Gross motor movement/automatic
12
Q
Desesnding pathway for grasp
A
Grasp: Requires pre-motor cortex, corticospinal tract, and cerebellum
Fine motor movement/planning
13
Q
MSK and neuromuscular contributions
A
- ROM: Spinal flexibility, scapular rotation, shoulder, elbow, wrist, and hand
- Appropriate muscle tone and muscle strength. To stabilize and to transport arm
- Coordinated muscle activation. In trunk and UE
14
Q
Postural Support of Reaching
A
- Postural demands vary with the task and environment (sitting vs standing, weight of the load, etc)
- Postural demands can affect speed and accuracy of UE movement
- Postural control MUST be part of (re)training UE tasks
15
Q
Grasping
A
- grip formation
- Depends upone the task and perception
16
Q
Classification of grasping patterns
A
determined by shape, size, and intended activity
17
Q
Power grip
A
Force is between the fingers (includes the thumb) and the palm of the hand
18
Q
Precision grip
A
force applied between the tips of the fingers
19
Q
Other types of grips
A
20
Q
Anticipatory control of grasp
A
- hand is shaped sutin the reach
- object size, shap, texture
- contextual properties such as oritation and location
21
Q
Grasp and Release
A
- Movement depends upon the task and the environment (drink vs throw)
- More precision slows the movement
- Water in a cup task
22
Q
The 4 phases of grasp and lift task.
A
- Phase 1: Contact with the object
- Phase 2: Grip force and load (lift) force is increased
- Phase 3: Load force overcomes weight of an object
Predicting force needed for grip (cerebellum)
Slip detected by cutaneous sensors on fingers - Phase 4: End of movement grip and load forces are decreased
Object is in contact with support surface
23
Q
Reach and Grasp are interconencted
A
- Reach and grasp must be coordinated!
- Fingers shaped for grasp while reach is occurring
- Grip size prepared while reach is occurring
- Timing for fingers movements must be appropriate to close on object
- Reach and grasp are controlled by different areas of the brain
24
Q
Reaction Time of Reaching and Grasping
Fitts law
A
- The time required to rapidly move to a target area is a function of the ratio between the distance to the target and the width of the target.
- Variables: Distance to move [(A) or (D)] and Target size (W)
- used with skills that require speed and accuracy; trade off between the 2
Often used in athletics due to the need for perscion
25
Neural control of reach and grasp
How does our brain control these fluid movements?
* Distance programming theory
* Location programming theory
26
Distance programming theory
* Visually perceive the distance
* Activate agonist muscles to reach
* Turn off agonist when they near the object (too slow down)
* Antagonist muscles are used for “braking"
27
Location programming theory
* Balance of agonist and antagonist muscles
* Every location in space corresponds to a certain pattern of muscle activity
* Swinging door hinge analogy (where in space do you need each role of the muscles)
## Footnote
motor program, timing
28
# concept 1
trade off/ optimization
* Not all skills have same requirements
* Some reaches require more than one goal, such as speed and accuracy
* Speed and accuracy are influenced by target distance (D) and target size (W)
29
# Concept 2
Reach and grasp are interconnected
* Prehension components: transport (reach), grasp, object manipulation
* Object manipulation: related to functional goal; component that makes it different than aiming
* Transport: arm transporting hand to object
* Grasp and transport interact synergistically (temporarily coupled
30
# concept 3
Three phases in controlled reach
* Phase 1: Visual feedback for target location and motor planning
* Phase 2: Ballistic (feed forward) movement of arm towards target
* Phase 3: Multi-sensory feedback
Deceleration towards target
Grip opening and hand orientation refined for contact with object
Visual guidance corrects for errors as target is approached
31
# Concept 4
Bimanual Coordintaion
* Skill that requires both arms
May require the 2 arms to move with the same or different spatial and/or temporal characteristics
* Tendency for symmetry
* Decoupling can be difficult
Does movement require symmetric or asymmetric coordination?
## Footnote
Both hemispheres are involved. arms both being used can be together or not. Moving them seperatly can be chalenging
32
UE Function Difficulties
* Difficulties with reach, grasp, or manipulation will alter UE function.
* Arm movements change depending upon the goal of the movement.
Pointing (hand and arm combined unit)
Reach and grasp (hand and arm act as separate units)
33
Clinical implications for UE training
* All key elements are controlled separately, therefore we can perform some (re-)training separately.
* However, the ability to adapt how we reach is critical
* Therefore, training a variety of UE movements and movement patterns is critical
34
Summary of UE stuff
* Coordination of eye, head, and hand movements are critical
* As precision of movements are increased velocity of movements are decreased
* Perception is important for planning reaching and grasping
* Visual and somatosensory information used for error detection
35
Primary Impairments affect reaching and palmar grasp
* visual and sensory impairments
* coordination
* abnormal synergies (aka flexor synergie)
36
Manipulatory Function
* Critical aspect: locating target and maintaining gaze on target
* Requires a combination of eye, head, and trunk motion
## Footnote
trunk stability
eyes first then head next
37
Target Localization problems
Problems might be due to:
* Damage to oculomotor system: Causes a disruption of visually driven eye movements.
* Damage to vestibular system: Causes a disruption of vestibulo-ocular reflex
* Damage to cerebellum: Causes an inability to adapt VOR to task demands
* Visual deficits affecting target localization may impact hand function
* Hemianopsia, Visual neglect / extinction (Hemi-inattention)
* Also affects planning and execution of reach and grasp especially latter part of the reach
* Perceptual aspects of object identification
38
Eye-head-hand coordination problems
Impairments in eye – head – hand coordination are common (CP, stroke, cerebellar pathology)
39
Children with CP and hand movements ...
* Children with CP had slower, less efficient hand movements and were significantly delayed in their ability to isolate their eye, head and hand movements.
* Postural support did not affect eye or head movements, whereas it did influence initiation and execution of hand movements
40
Problems with reach
* Sensory information is critical for adapting movements to task and environment, and for correcting errors during movement to ensure final accuracy
* Impairments can affect regulation of grip forces in response to slip of a lifted object (more likly for this to happen)
## Footnote
cutaneous invervation
41
Sensory Impairments
* Can also affect formation of internal maps, which are needed to properly regulate forces in subsequent lifts (helps us understand where we are in space nad how the body is moving in space)
42
Impaired interjoint coordination
* Common in many patients with neurological diagnoses (CVA, CP, traumatic brain injury [TBI], Parkinson’s)
* Affects both timing and trajectory of movements
* Most also have delayed movement times
## Footnote
timing and trajectory!!! SLOWER
43
Abnormal Synergistic Patterns of Movements
* Abnormal synergies result in difficulty with selective movements
* Impaired joint individuation
44
Impairments of Postural support of reaching
Postural control
* Critical element of speed and accuracy of reaching
* Important as constraint on upper-extremity function in persons with CNS pathology
## Footnote
need trunk control very good before reaching
45
Impairments with Precision grip and lift
* Precision grip forces
* Anticipatory control
* Ability to adapt
* In-hand manipulation
* Release of an object (extension)
## Footnote
what parts of the brain for each of these peices of grip and lift ect.
46
Use of Ipsilateral limb
* Interlimb coupling
Increases speed of reach in the hemiparetic UE
Slows the speed in the sound limb
* Ipsilateral limb
Is also affected by a single hemispheric lesion (CVA)
10-30% of corticospinal tract is uncrossed
Role of proximal stability
47
Interlimb coupling in post stroke rehab
* 50 post-stroke (> 6 months) hemiparetic subjects
* 8-week experimental intervention (3 sessions of 1 hour each, per week)
Activities demanding coordinated, alternate, and rhythmic use of the affected as well as the less-affected limbs
* Experimental group exhibited highly significant difference for Fugl-Meyer Assessment
* Interlimb coupling training may enhance recovery of the upper and lower limbs and gait in stroke
48
Bimanual Training and Constrain-induced movement therapy.
49
Shaping and CIMT
50
Robotic Assisted Hand Retaining
Needs to be active
