UE Reaching Flashcards
Eye-head-hand Coordination Series of Events
Typically…
Eyes reach target first
Then head
Then hand
Eye-head-hand Coordination
-entire reach is guided by vision
-need to “vaguely” know the target or object location in order to plan/execute reach direction and distance (peripheral vision)
-last part of the reach is vision dependent (foval vision)
“Foviate” your eyes on the object
Must know the object characteristics in order to successfully grasp the object
Eye-head-hand Coordination: Encourage…
Encourage our patients to find target with their eyes first in order to locate and facilitate an accurate reach
Smooth pursuit
Track a slow moving object smoothly
Can only be done to a certain speed -> saccades
CN 3, 4, and 6
Saccades
- rapid eye movements
- Don’t process on what’s in between-just focusing on each vocation
Cerebellar trauma (or stroke) Issues
- Gaze-evoked nstagmus
- disrupted smooth pursuit
- Ocular dysmetria when performing saccades
Gaze-evoked nystagmus
- Slow nystagmus in same direction of the spin
- Fast nystagmus in opposite direction of spin
- **Caused by a quick saccade! Just looking at target, their eyes cannot focus
Disrupted Smooth Pursuit
Cannot keep tracking an object
Ocular Dysmetria when performing saccades
- Dysmetric= poor measurements
- Hypometric- falling short of object, undershooting
- Hypermetric- falling past object, overshooting
- Can’t pick up object until eyes target object
Dorsal pathway (superior) “spatial vision”
- parietal lobe
- processing of spatial relationships between you/objects
- Have pt move objects around in space to work on the “spatial vision”
Ventral pathway (interior) “object vision”
- temporal lobe
- processing physical qualities of an object
Transport
- primarily the proximal joints moving the hand where it needs to be
- Scapula, shoulder, elbow and forearm if within arm length reach (trunk stable)
- if reach is beyond arm’s length include trunk:
- Sitting: includes the trunk (trunk dynamic)
- Standing: may include the trunk and LEs (e.g. hip or ankle strategy)
Reaching from the Sitting Position: Within Arm’s Length
Stable Trunk:
Facilitation of abdominal and lumber co-contraction for reach within arm’s length (to avoid falling)
Reaching from the Sitting Position: Beyond Arm’s Length
Dynamic trunk
- Facilitate weight shift from centered to over ischial tuberosity, same side as reach (diagonal is lateral and anterior)
- Facilitate Pelvic Tilt (posterior -> anterior) & Lumbar (flexion -> extension)
- Facilitation of trunk lateral elongation (reach side) and contraction/lateral flexion (contralateral side)
Dynamic trunk reach
The more angular (on a diagonal) the reach, the more you observe the previous patterns. Plus encourage a “high” reach by placing an object.
Reaching from the Sitting Position: Scapula
-Scapular protraction (upward rotation/ER) (abduction, external rotation, elevation)-reach forward
-Scapular retraction (downward rotation/IR)
(adduction, internal rotation, depression) –come back
Reaching from the Standing Position: Within Arm’s Length
Trunk & body fairly stable:
Facilitation of abdominal and lumber co-contraction for reach within arm’s length…need to stabilize more for heavier objects
Reaching from the Standing Position: Beyond Arm’s Length [Trunk and Ankle]
- Dynamic trunk and body & LEs
- Facilitate weight shift to ipsilateral foot and trunk elongation
- Ankle strategy – relative DF to weight shift (rocking)– just a little beyond’s arms length
Reaching from the Standing Position: Beyond Arm’s Length [Hip]
- Dynamic trunk and body & LEs
- Facilitate trunk/hip flexion & relative ankle plantarflexion
- COM of pelvis must shift posterior
- COM of chest must shift anterior, elevate and lateral (ipsilateral)
Reaching from the Standing Position: Beyond Arm’s Length [Stepping]
-Facilitate through pelvis to encourage step
(diagonal lateral and anterior shift)
-Facilitate through upper (chest) & lower trunk elongation
UE Reaching: Scapula, Shoulder and Elbow
-Facilitate scapula protraction,
shoulder elevation and elbow extension
-you could say forearm is pronating and wrist moves into flexion
Grasp
- primarily the distal joints of the wrist and hand performing manipulation
- Fine motor control
- Some reference the forearm as part of transport and some state the forearm is part of manipulation or grasp
Spatial Trajectory
- Reaching is a multi-joint movement accomplished by a straight line trajectory
- Essentially a straight line from start to target locations
Spatial Trajectory: Force and Direction
- had variability in trajectory and end point
- Pt needs to accurately plan and execute the movement
- Essentially straight spatial hand path or trajectory
- Effector - index finger – reach and point
- try to figure out if pt has problem with force OR direction and help you configure a strate
Spatial Trajectory: Effector
can differ [what pt can get on target]
Pointing – tip of index finger
Grasp – tips of thumb and index fingers
Punch – knuckles
Joints involved in Transport Changes with Movement Direction : Simple
- relatively single joint movement
- “relatively a simple movement”
Joints involved in Transport Changes with Movement Direction : Horizontal
- relatively two-joint movement
- Horizontal adduction and elbow extension (opposite coming back)
Joints involved in Transport Changes with Movement Direction : Straight line across page
- joint reversal movement
- Horizontal adduction and elbow flexion then extends [joint reversal]
Spatial Trajectory: Purpose
An individual must correctly plan and execute both the proper direction and distance of the trajectory
Spatial Trajectory: Accuracy
-Direction versus Distance (force) Error
-distance error > direction error
[Distance = force]
[Direction = multi-joint]
-increased both types of error with distance
-This is done on a moradum, where the elbow and shoulder are free to move BUT the motion is restricted to a 2D movement
Constant error (CE)
distance from the mean end point location to the center of the target
Variable error (VE)
- a measure of error dispersion
- one standard deviation in the X & Y directions
- “The Scatter” of the 6 dots
- How variable are they in their reaches/end point
Speed-Accuracy Tradeoff
- Increase movement speed, decrease accuracy
- Decrease movement speed, increase accuracy
Fitt’s Law
MT = a + b log2 (2A/W)
A = amplitude (distance start to target)
–As A increases, MT will increase bc it takes more time to each the target [directly related]
W = width of target
–as W decreases, the MT increases to hit target [inversely proportioned]
MT=movement time (varies with distance of A and with W)
Transport: Clearance
- Movements around obstacle
- Forces curvilinear trajectories
- Minimum clearance – closest approach to obstacle
- Move fast over obstacle, increase minimum clearance
- Move slow over obstacle, decreases minimum clearance
Hand Grasp
- Spatial hand path or trajectory
- Maximum aperture – 60-80% of reach distance or time
- Maximum aperture is relative to object width
- pre-shaping as reach
- finalize shape at end of reach
Maximum Aperture
- Width of fingers spread apart
- Maximum aperture is 2.5 – 3 times larger than object width
- Finger start to match shape of object at end of reach trajectory
- When they “mold” around the object as you touch the object
Grip Force
- Must match grip force to object weight (grip to load ratio)
- Must match grip force to texture of object (grip to texture ratio)
In-hand Manipulation
- Translation - move object to fingers, to palm and back
- Shifting - moving a “pen” closer and further from tip
- Rotation - rotating and stabilizing an object
Clinical Application: Grasp
Vary: size and shape of object weight and texture of object orientation of object use of object “slipperiness” fragility of object vary functional use stationary versus moving objects/person (taxonomy)
Interlimb Timing Constraints and Phase Characteristics
The two hands are temporally and spatial linked
-Ex 1: finger abduction-adduction
-Ex 2: tap two hands at different rates
-example three: spatial/timing constraints
Draw simultaneously
In Clients post-CVA or TBI…
- use non-involved UE to impose temporal and spatial constraints upon involved UE
- Perform bi-manual movements (rolling pin, etc.), mirrored movements, & reciprocal movements
- This will train both the movement pattern (muscles sequencing) and timing
Take Home Message: UE Reaching
- Do not use a haphazard approach when setting up tasks for your patient(s) to perform
- Methodically plan to expose your clients to a wide variety of functional tasks in multiple environments
