To Participate Participants are needed for the experiments listed below. These links contain more information about these experiments and also contact information.  If you are interested in taking part in any of these experiments kindly read through these pages. Down Syndrome (Infants 0-6 months): Down Syndrome (Children 6 months to 6 years): Understanding and Modeling the Gait Patterns of Individuals with Down Syndrome: New Walkers Down Syndrome: Ages 8 and up: Understanding and Modeling the Gait Patterns of Individuals with Down Syndrome: Adults and Preadolescents The effects of learning to ride a two wheel bicycle in 8-15 year old children with Down syndrome: A randomized trial At-Risk/Cerebal Palsy (Infants 0-13 months): Treadmill training in infants at risk for mild cerebral palsy Spina Bifida Children: Longitudinal Study of the Development of Locomotor Activity in Infants and Toddlers with Spina Bifida