Using Technological Advances and
Programming to Improve Successful and
Age Appropriate Powered Mobility
Mobility: When? Why?
• Mobility at ~12 months with typical development
– Supplement mobility
• Manual
– Can child propel efficiently?
• Power
– Is manual mobility too difficult?
– Stimulate development –
cognitive, motoric, emotional, social
• Explore environment
• Peer interaction
Considerations Not Limitations
To be appropriate for power, child, does not:
• Need to be a certain age
• Show certain motor skills
• Possess certain cognitive abilities
• Possess certain visual/perceptual abilities
• Show safety in all “driving” skills right away
• Be completely unable to ambulate or propel manually
– Consider fatigue/endurance issues
• Pathological gait and/or marginal WC propulsion should not be considered a form of exercise or weight control
Considerations – The Evidence
• Learned helplessness is firmly established by age 4 in children who have not had functional mobility.
(Butler 1991 cited by RESNA position paper 2008)
• Mobility is associated with acquisition of important cognitive and perceptual skills throughout development for normally developing children and those with mobility limitations
(Kermoian 1997)
• Children with Spina Bifida have been shown to require 218% more energy to ambulate than their non-disabled peers
(Williams et al 1987 cited by RESNA position paper 2008)
Social Interaction / Inclusion
• Increase child’s access to environment
• Increase access to child by peers
• Decrease
apprehension of others
Furumasu et al 2008
How? Set up for Success
• Observe motion
– Reliable / reproducible
movement to operate input device
• Seating Strategies
– Provide Stability
• Trunk, Head and Neck – Allow dynamic movement – Position for task performance
• Upright trunk
• ? Ant tilt / sloped seat
• LE and feet weight bearing
Input Device
• Switched?
– Easier to eliminate directions
– Use of head array to encourage upright and keep device out of visual field
• Proportional?
– More intuitive
– More options / confusing
Mobility Training
• Going
– Any self initiated movement – Make it fun / functional
– Avoid tasks and cuing and let child direct mobility
• Stopping
– Wait for child to stop and reinforce with verbal cuing
• Input / Access
– Keep consistent
– Does not need to be in
“perfect place” first training session
• Short Duration – 5 mins
“Safe” Training
• Switched control
– Limited directions
• Avoid reverse at first
• Speed
– Very slow
– Maintain torque and acceleration so the chair still responds
– Limit power
• Supervised
– Able bodied kids are permitted to practice and falter within safe limits – Supervised through toddler years
Contraindications
• Limited/no cause and effect skills
• Limited/no problem solving skills
• Deceased spatial relationships
• Lack of motivation/initiation
• Significantly decreased level of alertness
• Uncorrectable compulsive self or other directed abusive
behaviors
• Lack of accessibility
RESNA position paper 2008 www.resna.org
Obstacles to Power Mobility
• Prevalence of outdated theories/attitudes i.e. traditional neuromaturational model of motor development
• Last resort for mobility
• Change the child versus the task or environment
• Child will not be motivated to walk
• Child needs to exercise
• Parental/ care team resistance
• Social stigma –acceptance
• Children have often not developed this but are not the decision makers
• Lack of pediatric power choices
• Funding
The Power Assessment Process
Seating Support
Dynamic Seating
Power Wheelchair Base Drive Controls
Assistive Technology
Making the RIGHT choices…
A Child’s World
Home
Friends School
Community
Family
Bus Driver
Doctors
CHILD
Teachers, PT, OT, SLP
Choosing the Power Chair Base
How and Where will the Power Chair be used?
• Environments
– Home, school, play
– Terrain, inclines, obstacles, ramps
• Type of transportation
• Accessibility
– Turning radius, width, length
• Aggressiveness of use
What must the base accommodate?
• Child weight? Potential for growth?
• Can child perform independent weight shift?
• Can child maintain optimal posture in upright seating?
• Does child have mild/mod/severe spasticity or orthopedic deformities?
• How will child operate the chair? Joystick? Specialty control?
• Is condition progressive?
Base Technology - Drive Wheel Position Considerations
• Maneuverability for:
– Turning
• Turning Radius – Obstacle climbing – Transitions
– Inclines
• Stability
– Tracking
– Power seating functions
Drive Wheel Position - Rear Wheel Drive
Potential Pros
• Easier for current RWD users(?)
• Performs well at high speeds
• Stable
• Good climbing(?)
• Good control with non- proportional inputs(?)
Potential Cons
• Biggest footprint(?)
• Poorer downhill traction on steep slopes
Summary - Front Wheel Drive
Potential Pros
• Good climbing
• Able to clear obstacles (?)
• Can position feet at tighter angles
• Greater stability for power seating
features (?)
Potential Cons
• Less control at higher speed (?)
• Less control with non- proportional inputs (?)
Summary - Mid Wheel Drive
Potential Pros
• Intuitive to drive
• Maneuverability
• Smaller footprint
Potential Cons
• Less stability (?)
• Pitching with grade transition and/or
acceleration or deceleration (?)
• High Centering (?)
• Difficult transition from RWD (?)
Pediatric Power Wheelchairs
So many choices……???
Base Technology -Suspension
• Reduces vibration and jarring for:
– Pain reduction – Postural control
– Spasticity reduction – Minimize sliding
– sitting tolerance
Why is it needed?
– Terrain Navigation – Clinical Benefits
FWD without
veer correction FWD with
veer correction
• Tracks straight while allowing
users to conquer slopes,
thresholds, obstacles
Veer Correction Technology
Clinical Applications of
Veer Correction Technology
• Accommodate what / where the child drives
– Front wheel and mid wheel drive
– Uneven terrain and/or varied surfaces – Higher speeds
• Accommodate how the client drives
– Compensate for marginal joystick user – Veer correct with specialty controls
Limit frustration
Accommodate early learning period Manage fatigue
Avoid increase in tone
Choosing the Electronics
Consider:
• Best point of control
– Hand, head, chin, foot, finger, combination – Speed, accuracy, reliability, endurance
– Affect on tone, reflexes
• Type of control
– Proportional
(360º directional control, variable speed)
– Non-proportional
(one speed, one direction per switch)
Proportional Input Devices
Hand control Chin control Mini joystick
Touch pad
Mushroom joystick
Magitek head control
Proportional head control
The Input Device - Switches
Starboard
CA-5 box with
remote switches Tray Switches
Head Array
Programming…customize
for success
• Every chair should be adjusted for:
• Speeds, accelerations and decelerations in forward, reverse and turning
• Inappropriate programming can cause:
• Inability to learn to drive
• Unsafe driving
• Inefficient driving
• Inability to access all environments
• Lack of confidence/fear with the equipment
• Refusal to use the equipment
Programming for Success
Programming for Performance
Tailor the way the chair drives according to the user’s needs
• Speeds – program based on environment and control within that environment
• Accels and decels - program based on postural control and balance and client’s control of the
input device
• Torque and Power Limit – maintain enough power for turning
Pediatric Joystick Selection Considerations
• Programmable
short-cut buttons
with decals
• Compact joystick
• Mounting options
– Midline – In tray
Pediatric Joystick Programming
• Dampen all directions of hand control ? (sensitivity)
• Increase neutral zone for ataxic or spastic clients
• Convert joystick into switched input
• Low Speed Torque
• Lower Power
- Decrease overall chair power for safe use
Neutral Horizontal and Vertical
Can increase area of neutral
• Globally
• Fwrd/rev – Y axis
• Right/left – X axis Useful for child
• Drives with proximal shld musculature
• Goal post driver
• Athetoid/ Dyskinetic mvts
• Difficulty controlling turns and stopping
Program for Switched Joystick
Select “switch operation” when programming handcontrol
• No additional hardware required Useful for child that:
• Has inadequate motor control to benefit from proportional control
• Has athetoid/dyskinetic movements
• Is learning to use joystick
• Has potential to transition to proportional device
Pediatric Specialty Control Programming
Switches/Switch Arrays
Can program to operate all chair functions if
required via number of switches, timed functions, toggle functions……
Access to Reverse
Access to Alternate Functions
Alternate Proportional Input Devices eg. HMC mini joystick
End of Line Programming much improved
Ability to save profiles
Switch Driving
• Single Switch Scanning
• 2 Switch Driving
• 3 Switch Driving
• 4 Switch Driving
• 5 Switch Driving
Can use separate switches or arrays
Independent Powered Mobility
Toggle between forward And reverse
Electronics Customization – Menu on Display
Includes shortcuts to commonly used functions - loaded from factory with common functions
Customize menus
– Select shortcut menu – Prioritize shortcut menu – Re-word menu headings – Change language
– Choose icons for non-readers
Clinical Relevance: minimize commands
– Less physical demand – Less cognitive demand
Display Icons
• Choose Icons for
most frequently used functions
• Clinical relevance
– Too young to read – Cognitively impaired – Non-reader
Beyond Mobility…what else can child control from power wheelchair?
• Just like a TV remote
– Requires line of sight
• Can be converted into radio frequency
• X-10 technology - lights, fan
• Mouse Emulation
Built in Infra Red Transmitter/Receiver
Assignable Buttons and Ports
Clinical Scenario:
easy access to common functions
less commands to remember
less energy required
Child needs to increase tilt for stability when climbing up hill:
no need to stop driving to adjust seat position
Child wants to turn on light when entering room:
no need to stop - just hit button
Tilt
DVD ON
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Joystick movement designates navigation of icons and switch selects
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