The proposed pilot study is a pre- post-test design with each participant serving as his or her own control. Children and adolescents with Down syndrome will be recruited from pediatric physical therapy clinics, local school districts, and the Central Mississippi Down Syndrome Association. Flyers will be provided to local pediatric therapy clinics and school districts. The director of the Central Mississippi Down Syndrome Association will be contacted by the PI (see email attached) and asked to send out a target recruitment email to all families of children with Down syndrome that are on the Central Mississippi Down Syndrome Association email list. To be included in the study, the individuals must 1) be between the ages of 5 and 17 years old with a diagnosis of Down syndrome, 2) have the core strength and balance necessary to maintain sitting on a two-wheel bike with their feet on the ground, and 3) be able to follow simple commands. The exclusion criteria for the study are 1) significant cardiovascular event or illness in the past 6 months and 2) another medical diagnosis, besides Down syndrome, that would limit participation in the exercise programs. The Institutional Review Board at the University of Mississippi Medical Center will approve all procedures. Each participant will complete an assent form to participate. Each participant will complete an assent and each parent/caregiver will complete an informed consent prior to enrolling their child in the study. If the child is unable to provide assent, due to age and/or cognitive deficits, only parental permission will be obtained. Additionally, each participant's parent/caregiver will be asked to complete the "registration packet" (attached to the IRB) in order to provide the researchers with health-related information that may be needed to ensure participant safety during the intervention sessions. The registration packet will only be viewed by the PI and co-investigator and will not be directly linked with any PHI to be created during the study. The Strider "Learn to Ride" intervention is designed to accommodate up to 10 children per intervention class, therefore no more than 10 participants will be recruited for the initial pilot study.

Outcome measures used will include the Pediatric Balance Scale (PBS), distance cycled, Participation and Environment Measure-Children and Youth (PEM-CY), and the PROMIS Physical Activity questionnaire. The PBS is a valid, 14-item assessment, developed based on the Berg Balance Scale. The PBS is a criterion-based measure, with each item scored on a 0-4 scale. Distance cycled will be measured based on the longest straight-line distance, out of three trials, that the participant is able to safely and independently propel their Strider bike. Previous research has used 100' as the distance criteria to identify mastery. The PEM-CY is participation level outcome measure used to assess a child's engagement in activities in the home, school, and community environments. The PEM-CY is a valid and reliable measure and is completed by parent/caregiver report, making it appropriate to use with children with DS. The parent/proxy PROMIS Physical Activity outcome measures assesses various aspects related to a child's participation in physical activity. Follow-up questionnaires (PEM-CY and PROMIS) will be sent by mail from the PI to the parent/caregiver to assess long-term changes in participation, time spent engaged in physical activity, and sustainability of the Strider bike intervention.

One the first day of the intervention, each participant will be assessed with the PBS to determine baseline balance ability. The initial straight-line distance, up to 100 feet, that each child can independently and safely ride their Strider balance bike will also be recorded. Additionally, each participants' parent/caregiver will be asked to complete the PEM-CY and the PROMIS questionnaire. This initial data collected will serve as each participants' baseline data. Each child will participate in five, consecutive, two-hour adaptive bike training sessions with instruction guided by the Strider "Learn to Ride" intervention. Each session will have no more than 10 participants. The biking sessions will be under the direct instruction of a pediatric physical therapist (the PI, Meredith Flowers) who has completed the certification to teach Strider "Learn to Ride" classes. Each session will take place in an indoor gym or paved, outdoor facility. Each participant will be fitted with an adaptive Strider bike to use for the duration of the 5-day intervention and to take home as their own, to encourage carry over, at the end of the training period. Each participant will also be required to provide and wear an appropriately fitted bike helmet when engaged in bike riding. Each session will begin with a 5-10-minute warm up, followed by at least 60 total minutes of riding activities based on the proven Strider "Learn to Ride" intervention. Individual participants will be allowed to take rest breaks as needed. Each session will conclude with 5-10 minutes of cool down activities. On the final day of the intervention, each participant will again be assessed with the PBS. The distance that each participant can safely and independently propel their Strider bike will be assessed and recorded. Each child's parent/caregiver will be contacted by mail from the PI to complete follow-up assessments at 3-, 6 months following completion of the initial intervention period. Outcome measures used for long-term follow up include the PEM-CY and PROMIS questionnaire. The PI and co-PI, both licensed physical therapists, will be assessing all participants.

IBM SPSS Statistics program will be used for all data analysis. Dependent t-tests will be used to analyze pre- and post-test scores of the PBS, PEM-CY, PROMIS and distance cycled. If the assumptions for the dependent t-test are not met, a Wilcoxon signed ranks test will be used to analyze the data.