The three purposes of this study are: 1) to determine the feasibility of applying two types of postural combinations for the ride-on car (ROC) use; 2) to compare the effectiveness of ROC training with various intensity of postural combinations on mobility, socialization and energy expenditure in toddlers with disabilities; and 3) to examine the effects of using the different modes of ROC training (different intensity of postural combinations) on the ICF functioning levels, family perceptions and participation. Modified ride-on toy cars (ROCs) as a type of PMDs have become an innovative, alternative option to enhance independent mobility and socialization in young children with disabilities. Evidence suggested that dose-response effect and energy expenditure of the two postures used for training may result in the observed differences. Therefore, this study is further to examine the effectiveness of ROC training with various intensity of postural combinations on independent mobility, socialization, motivation, physical activity and overall development through low-cost, family-centered approach.

Based on the power analysis from the preliminary results, the investigators will recruit 92 children with disabilities who are between 1 to 3 years old and diagnosed as motor delay (>1.5 sd). They will be randomly assigned to one of the following four groups: ROC-sit group (n=23), ROC-stand group (n=23), ROC training with 45-min sitting and 25-min standing (n=23), and the ROC training group with 25-min sitting and 45-min standing (n=23). The whole study duration will be 24 weeks, including 12-week intervention and 12-week follow-up; the total amount of treatment will be equal for the four groups. Standardized assessments are provided for a total three times, including the time before and after the intervention and in the end of the follow-up phase. All programs will include 120 minutes/per session, 2 sessions/per week. The research team will provide 90-min behavioral videotaping once/per week and let participants wear three accelerometers throughout the 2-hour training. Assessments include mobility, socialization, behavioral coding, family perception and participation. The findings of this study will provide a novel application of ROC training with various intensity of postural combinations on advancing children's mobility, socialization, development and family participation.

Some studies showed the use of laboratory-designed PMDs or modified ride-on cars (ROCs) might increase the child's independent mobility and motivation to master interpersonal tasks and result in positive changes on social functioning.

Modified ROCs as a type of PMDs have become an innovative, alternative option to enhance independent mobility in children with disabilities. Studies have found that the novel application of modified ROCs in home-based, community-based or hospital-based environments might enhance independent mobility, motivation, and social function in young children with motor disabilities. In addition, these studies have indicated that the application of modified ROCs integrating the concept of family-centered service may be beneficial for improving young children's motivation due to their persistence on driving and increased pleasure during training.

The dose-response effect of the ROC use with different postures on mobility function may be the reason relating to the previous findings. The progress of mobility function might be affected due to the focus on increasing socialization over mobility. Moreover, several studies have demonstrated that walking or standing may result in more energy expenditure than other postures, e.g., sitting or lying for children with disabilities. The ROC-stand training group required a total dynamic standing time of 60 to 70 minutes for driving and exploration during each session, which may increase the children's energy expenditure and result in less strength and endurance to move without the ROC. However, the standing posture may provide more opportunities and visual information for children to interact with other people and distal events, which relates to the development of socialization. With these outcomes and possible explanations, the investigators propose that the subsequent research may identify the "dose-response" effect of different postural combinations for the ROC use on mobility and social functions in toddlers with motor disabilities.

In this study, the investigators will modify two types of ride-on toy cars for toddlers with disabilities for the use in the public spaces in the university as part of a 24-week power mobility training program. In addition, the investigators will compare the effectiveness of different intensity of postural combinations for the ROC training on mobility and socialization in toddlers with motor disabilities. The previous 2-hour ROC-training program included an average of 60-to-70-miniute driving (unstructured) and 50-minute natural play (structured) which involved exploration and motor skills training related to mobility and social impairments, such as postural stability, postural control, and social engagement. Based on the previous evidence, the investigators propose two groups which involve different intensity of postural combinations for the ROC use, i.e., one group of 45-minute sitting and 25-minute standing and the other group of 25-minute sitting and 45-minute standing, may be optimal for toddlers with motor disabilities to meet the physical activity guidelines. the investigators further propose these postural combinations of the ROC use may have different effects on mobility and social function, compared to the original use with only one posture. A 4-group comparison design of decreased intensity of sitting posture and increased intensity of standing posture for the ROCs use may provide us a complete examination on the topic of dose-response effect on toddlers with disabilities. In addition, the investigators will examine whether the effects of increased independent mobility and socialization will affect toddler's function on the 3 International Classification of Function (ICF) domains. If our results are generally positive and show significant differences on independent mobility and socialization among the ROC training programs with two different postures and various intensity, it will provide us some alternative ways to improve independent mobility and socialization depending on children's and family's needs.

The specific aims of this study are: 1) to determine the feasibility and examine the effects of ROC training with various intensity of postural combinations on mobility and socialization in toddlers with disabilities; 2) to objectively quantify the intensity and energy expenditure of postural combinations for the ROCs use through accelerometers; 3) to determine the effects of using the different modes of ROC training (different intensity of postural combinations) on the ICF functioning levels, family perceptions and participation.

Method Study Design: A multiple group pretest-posttest control group design will be applied. Four groups will be involved in this project: ride-on car with sitting posture (ROC-sit), ride-on car with standing posture (ROC-stand), and two groups of ride-on car with mixed postures, including one group of 45-min sitting and 25-min standing postures (ROC-sit45 and stand25) and the other group of 25-min sitting and 45-min standing postures (ROC-sit25 and stand45). The study duration for each participant is 24 weeks, including 12-week intervention and 12-week follow-up.

Participants: Participants in the study will be 92 toddlers ages 12 months to 36 months with motor delays. They will be randomly assigned to either the ROC-sit group (23 toddlers), the ROC-stand group (23 toddlers), the ROC-sit45 and stand25 group (23 toddlers) or the ROC-sit25 and stand45 group (23 toddlers). The age group of infants/preschool children is selected based on the previous studies of ROC training in young children with motor disabilities.

Recruitment: The participants will be recruited from self-referrals, health care practitioners, or the hospitals in Taipei or Taoyuan where toddlers with motor delays are receiving outpatient rehabilitations. The research team will initially post flyers describing the study at clinical settings and contact the therapists in the clinical settings to introduce the goals, criteria and general procedure of the study. Parents/guardians will obtain information about the study through the flyers and their therapists. The research team will contact the parent/guardian to explain study details and provide them the opportunity to ask questions. Children of parents/guardians who provide informed consent will participate in the study.

Procedure: Each participant of the ride-on car training groups will have either a customized, sitting-style toy car or a standing-style toy car, depending on the assigned group. The adaptations are all assembled by PVC pipes which can be adjusted easily during each training session. After modifications, they will receive pre-intervention measurements, including developmental assessments, behavioral videotaping and self-developed questionnaires. The self-developed questionnaires were designed to examine parental perceptions on the PMDs use and children's capabilities in the previous studies. The pretest and posttest developmental assessments and questionnaires will be completed in a testing room at Chang Gung University by a licensed occupational therapist who is blinded to the study purpose and not involved in the treatment. These assessments will occur on three occasions: before and after the 12-week intervention (T1 & T2) and the end of the 12-week follow-up phase (T3). During the 12-week intervention, the locomotion (i.e., driving) and socialization behaviors for the four ROC training groups will also be videotaped by the research team for 1.5 hours during one session/per week at the university. In addition, participants will wear three accelerometers on their wrists and right hip to monitor the minutes of exercise, postural change, activity counts and energy expenditure for exploration during the whole 2-hour session, one session/each week for 12 weeks. An activity log will be applied to record the driving and play duration, driving locations, and the caregiver's feedback on the training program every week. All videotapes will be coded by two independent coders.

Intervention: The research team will ask caregivers to identify goals (before intervention), and measure progress using goal-attainment scaling (GAS) at T1 and T2 time points for the four groups. The training principles are similar to those applied in our previous studies of ROC training in various environments. To record the total driving time, locations, and caregivers' feedback regarding training, an activity log will be used for each session. All groups will continue their regular therapy throughout the 24-week duration of the study, including physical therapy, occupational therapy, and speech therapy.

Follow-up: This period will involve 12-weeks following the above treatment programs; during this time no treatment programs will be delivered to the participants except for their own regular therapy.

Instrument and Procedure: To present a complete investigation of participants' changes on the 3 domains of ICF, home affordances and parenting stress levels, the investigators will provide standardized assessments as the quantitative measures at T1, T2, and T3, and behavioral observations and activity logs as the qualitative measures during the intervention. In addition, accelerometers will be applied during the intervention to provide a quantitative measure for exploration, including the minutes of exercise, postural change, activity counts and energy expenditure.

Data Reduction and Analysis Quantitative measures at T1, T2, and T3 Repeated measure one way ANOVA will be used to compare the mean difference of using different toy cars on mobility, socialization and exploratory behaviors before and after the intervention, and after 12-week follow-up, i.e., within group comparison. One way ANOVA will be used to compare the mean difference of all developmental tests, participation and physical activity for exploration among three groups before and after the intervention and the end of follow-up phase.

Descriptive statistics including frequency, means, standard deviations, as well as nonparametric data medians and interquartile ranges will be calculated. Data will be analyzed based on an intention-to-treat analysis. A repeated measures analysis of variance (group [4] × time [3]) will be employed to evaluate the treatment effects on the primary and secondary outcomes among the 4 groups at T1, T2, and T3, followed by a post-hoc analysis using Bonferroni test to determine between which groups the differences occur.

Descriptive statistics (frequency, means, standard deviations) of each behavior will be calculated and repeated measures analysis of variance (group [4] × time [12]) will be used to compare the effects of behavioral measures among the 4 groups during intervention. Furthermore, the quantitative data obtained from the accelerometers during intervention will be organized and calculated. A repeated measures analysis of variance (group [4] × time [12]) will also be used to compare the effects related to exploration among the 4 groups during intervention.

Inclusion Criteria:

1. motor delays that resulted in motor impairments that prevented independent walking (standard deviation (SD) > 1.5, assessed by the Chinese Child Development Inventory59,60 via a pediatric physician)
2. can stand independently for two seconds or to tolerate standing with support for 10 minutes
3. can reach objects with either one or two hands
4. the height is between 69 to 103 cm and the weight is between 7-18 kg
5. parents are able to provide consent for their child's participation in the ROC training programs.

Exclusion Criteria:

1. children with severe sensory impairments such as blindness, deafness
2. the height is not between 69 to 103 cm and the weight is not between 7 to 18 kg
3. parents/caregivers are not able to make a time commitment for the training phase