While early independent mobility has positive effects on a child's development (1,2,3), it is still difficult for clinicians to determine when a child is developmentally ready to operate a powered wheelchair. There are various factors that influence a child's ability to learn these skills. Clinicians have identified some of the factors to include consistent motor access, cognitive developmental readiness, sensorimotor integration skills and temperament which includes attentiveness, persistence and motivation. This project focused on cognitive developmental skills and their influence on readiness to learn functional powered mobility skills. The goals of the project were to develop an assessment battery to evaluate cognitive skills and to develop an age-appropriate powered mobility program. For information on the development of the cognitive assessment, refer to Evaluating Cognitive Readiness for Powered Wheelchair Mobility in the Young Child in these proceedings. The development of the powered mobility program is presented in this paper.(4)
PROGRAM DEVELOPMENT
The pediatric population targeted included children, 18-36 months, with severely limited mobility as the result of physical disabilities. To minimize the influence of sensorimotor integration problems, children without cognitive impairments, such as children with arthrogryposis, muscle disease or with a spinal cord injury were selected. The powered mobility program (PMP) is an approach designed to introduce young children to a wide range of wheelchair skills through exploratory play. The program represents a continuum of mobility skills. It begins with exploratory, non goal directed movements; transitions to purposeful skills; and concludes with functional skills needed for independence in the home, school and community. Clinicians experienced in the field of pediatric powered mobility identified thirty four tasks. The tasks represent a hierarchy of mobility skills that begins with spontaneous basic movement and progresses to functional skills needed in structured and unstructured environments. (Appendix A) This mirrors the course of development similar to that of a non-disabled child learning to transition from a non-mobile state to exploratory crawling and finally, to goal directed ambulation.
The PMP incorporates seventeen basic and transitional skills. The basic skills include starting, stopping, directional and speed control. The transitional skills combine these basic skills to foster more goal directed tasks such as moving purposefully towards a toy. Seventeen functional skills are identified; eleven in structured environments and six in unstructured environments. Functional skills include tasks such as maneuvering along a hallway, through a door, and along ramped sidewalks. Unstructured environments are situations like a busy clinic area or shopping mall which expose the child to distracting, unpredictable settings in the community. Rules of the road are introduced, such as staying on one side of the hallway. Attainment of this level of skill allows the child to demonstrate some level of judgement and safety.
Administration
All children preferred to use their hand to manipulate a proportional joystick, even if they had severely limited upper extremity function. The tension of the joystick was adjusted for weakness and the control was mounted where access was the most consistent and accurate to all directions of movement. For the purpose of consistency, a proportional joystick was the standard input device. The issue as to whether a proportional joystick is more difficult than unidirectional switches was not addressed in this project.
The PMP skills were defined in discrete tasks to objectively determine the child's ability, however the learning process is fairly unstructured and the emphasis is on fun and games, positive reinforcement using curiosity as their motivator. For example, creative incentives were used such as rolling over water balloons or packing materials that pop or crunching leaves. Directional control was learned and reinforced in a number of ways such as motivational play like follow the leader or by following pigeons walking around on a patio. Differentiating between slow and fast was learned by one little boy who insisted on holding hands with his 1-8 month old sister while he maneuvered the wheelchair slowly down a sidewalk. The children spend 6 one hour sessions in the wheelchair or until they were fatigued. Within the same 3 week period, the children's cognitive developmental levels were evaluated with the assessment battery developed for the project.
Scoring
The last PMP session was videotaped and each of the 34 tasks were scored. Scores from each task ranged from 0-5, with the final score reflecting the average overall amount of assistance or verbal cueing needed. Each value in the scoring system had well defined criteria to facilitate consistency in scoring between the raters. (Appendix B)
RESULT
Reliability
Interrater agreement for the PMP protocol was analyzed using the Kappa statistic. The score of .87 indicated excellent above chance agreement.(5) The scores for two independent raters were highly correlated (r=.99, p<.01). Consistency in intraobserver rating over time was also evaluated. The Kappa score was .52; values between .40 and .75 representing fair to good agreement above chance.
PMP scores
A total of 26 children (20 males and 6 female), between the ages of 20-36 months (X = 28.9) completed the program. The PMP scores ranged from .03 - 4.85 with an average score of 2.37. Scores of 4 and above were considered to represent functional mobility while scores less than 3 were representative of children not yet able to safely maneuver the wheelchair. Scores between 3 and 4 were considered to be marginally functional, with other factors such as distractibility and parental supervision becoming deciding influences in recommending a powered wheelchair over a powered toy or a manual mobility device. Overall PMP scores were not correlated with prior independent mobility such as scooting, crawling or walking. The youngest child to demonstrate functional mobility in all environments was 25 months.
Cognitive developmental skills
Following completion of data analysis on the cognitive developmental assessment, scores from the developmental scales will be used in a regression analysis with scores on the PMP. This will allow identification of important cognitive developmental skills and their influence on functional powered wheelchair mobility. The preliminary data gathered during this study indicated that there were developmental differences in cognitive skills that can be used to predict the amount of assistance a child will need to functionally operate a powered wheelchair.
DISCUSSION
The PMP is a flexible, age-appropriate approach developed to introduce a wide variety of powered mobility skills to young children. The program begins with spontaneously initiated exploratory play and progressively integrates these basic skills for development of functional mobility. Mastering the basic skills is a necessary step to develop functional mobility in the community. In examining the pattern of performance across the basic, structured and unstructured domains, it was found that every child that accomplished the basics skills went on to score 4 or above, while 6 of the 14 who required minimal to maximal hands on assistance (average 1.15) with basic skills were never able to attempt the structured tasks. Additionally, stages of mobility development, whether exploratory, transitional or functional, appeared to be related to cognitive developmental skills and to how well the children were able to progressively learn.
ACKNOWLEDGMENTS
Funding for research was provided by the National Institute
on Disability and Rehabilitation Research, U.S. Department of Education,
Grant No. H133E00015. Opinions expressed in this paper are those of the
authors and should not be construed to represent opinions or policies of
NIDRR.
REFERENCES
2. Butler C, (1986). Effects of powered mobility on self-initiated behaviors of very young children with locomotor disability. Developmental Medicine & Child Neurology, 28, 325-332.
3. Piaget J, (1936). The Origins of Intelligence in Children. Trans. by M. Cook. New York: International University Press (1952).
4. Furumasu J, Guerette P & Tefft D (Submitted for publication). The development of a powered wheelchair mobility program for young children. Technology and Disability.
5. Fleiss, J.L. (1981). Statistical Methods for Rates and Proportions, 2nd Edition. New York: John Wiley and Sons.
2. Maintains contact with the joystick for minimum of 5 seconds.
3. Pushes joystick to engage wheelchair in motion for 5 sec. and stops on command.
4. Navigates wheelchair in forward direction for 10 sec. and stops on command.
5. Looks in the direction of movement.
6. Stops spontaneously to avoid stationary objects.
2. Navigates in forward direction for 35 feet.
3. Turns to the right starting from a stationary position.
4. Turns to the left starting from a stationary position.
5. Navigates backward (minimum 2 feet).
6. Navigates forward making right and left curving following a person over a distance of 50 feet.
7. Veers spontaneously to avoid stationary object.
2. Changes speed in response to commands "Slow down" or "Let's go faster".
3. Stops at a door with footrests within 12 inches without hitting the door.
4. Stops at a line with front casters within 12 inches without going over the line.
2. Backs up to negotiate a turn between the rails of a ramp.
3. Executes a turn within a 5 by 5 foot space.
4. Drives down a ramp staying between the rails.
5. Stops on command when navigating down a ramp.
6. Slows speed on command when navigating down a ramp.
2. Navigates a 36 inch wide sidewalk with an unmarked 6 inch curb for distance of 36 feet without veering off the sidewalk (supervision within 5 feet).
2. Navigates in an open, busy area around multiple objects and people who are moving in a random pattern.
3. Navigates a sidewalk, down a ramp, and stops before entering a parking lot area.
4. Recognizes difference between a curb and curb cut.
5. Navigates in and out of a small room.
6. Avoids irregularities in ground surface (e.g.; cracks, gratings).
0 - Task not attempted - The task is not introduced because prerequisite basic skills are still at levels 1-2.
1- Maximum assist of joystick with verbal cueing - Child attempts task but requires complete assistance in order to execute task. Indicated by the instructor providing continual (50 - 100% of the time) hands-on assistance of wheelchair control to direct and guide wheelchair in order to complete skill safely. Continuous verbal and/or gestural instructions are provided.
2 - Minimal assist of joystick with verbal cueing - Child able to complete basic components of task independently but needs some assistance in order to complete the entire task safely. The instructor provides intermittent (10 - 50% of time) hands-on assistance of wheelchair control only to redirect a particular deviation from course, not to direct or guide wheelchair in a continual manner. Continuous verbal and/or gestural instructions are provided.
3 - Direct stand-by guarding with verbal cueing - Child able to complete entire task independently but needs guarding for safety. The instructor stands directly next to wheelchair on joystick side in order to assist if the child begins to maneuver unsafely (<10% of time). Continuous verbal and/or gestural instructions are provided.
4 - Verbal cueing only - Child able to complete task independently without immediate stand-by assistance but with frequent verbal cueing. The instructor stands away from the joystick (5 feet or less) and does not provide any hands-on assistance to the child. Continuous (>25% of time) verbal and/or gestural instructions are provided to the child for safety purposes and to remind or redirect the child.
5 - Age-appropriate supervision - Child able to complete skill independently with age appropriate visual supervision and infrequent (<25% of time) verbal cueing. The instructor stands away from the joystick (5 - 10 feet) and does not provide any hands-on assistance to the child. Verbal cueing provided to the child intermittently and only to direct the child's attention to maneuver in a certain direction (e.g.; towards parent, away from curb).
Jan Furumasu
CART, Rancho Los Amigos Medical Center
7601 E. Imperial Highway
Downey, CA 90242 USA