Exploring change in young children's power mobility skill following several months' experience.

PURPOSE: To measure and compare progression in children's power mobility skill among process and task-based measures following a loan of one of four early power mobility devices. Additionally, to explore different power mobility learner groups and skill development trajectories.

METHODS: In this pre-post study, children were purposefully sampled and power mobility skill was measured from video taken pre-post several months' experience (mean 192.40; SD 42.79 days) using the Assessment of Learning Powered mobility use (ALP) and two task-based measures. Associations among power mobility skill measures were examined. Child and environmental factors influencing ALP phase at loan-end were explored.

RESULTS: Forty-six children aged 13 - 68 months (mean 40.40; SD 15.60) participated, with cerebral palsy being the most common condition ( n  = 33; 71.74%). ALP change scores ranged from -2 to +4 ALP phases (median 1.0). Wilcoxon signed rank test was significant for pre-post differences with a large effect size ( z  = 5.50, p  < 0.001; r  = 0.57). End-of-loan Spearman correlations between ALP and two task-based paediatric measures were excellent ( rs = 0.92). Kruskal-Wallis test revealed significant effect of device, access method, diagnostic group and communication abilities on loan-end ALP phase.

CONCLUSION: Positive change was demonstrated with most children ( n  = 39; 84.78%) changing at least one ALP phase during the study. Positive change was seen with children at all phases of tool-use, using all devices and access methods. Process and task-based measures were highly correlated, but differed in application for different learner groups. Different trajectories of skill development may be associated with different child profiles and access abilities. IMPLICATIONS FOR REHABILITATION Children at all phases of tool-use can demonstrate positive change in power mobility skill using different devices and switch as well as joystick access methods The Assessment of Learning Powered mobility use (ALP) is useful for assessing tool-use and learning process skills for young children across the power mobility skill continuum. Task-based measures may also be helpful for guiding training and recording progress; The Power Mobility Training Tool (PMTT) is most useful for children exploring cause-effect and direction (ALP Phases 1-5), while the Power Mobility Program (PMP) is most useful for functional learners and those progressing from exploring direction to functional use (ALP Phases 5-8). Access method may influence power mobility learning trajectory and training.