The purpose of the proposed exploratory study is to develop and test an integrated robotics and sensor technology system designed to influence movement learning in infants with cerebral palsy (CP). CP is the most disabling condition for children in the United States with locomotion being the most affected functional skill. Of particular concern to the proposed project is that children with CP do not only show paucity of self-initiated movements critical for locomotion, but that these movements diminish as the children grow (learned disuse/non-use). Many of the mobility constraints that confront adults with CP can be traced back to infancy. Prone locomotion is the earliest and, in some cases the only form of locomotion available to infants during the first year of life, that infants with or at risk for CP rarely attain. Not only is prone locomotion integrated with other systems essential for functional independence and learning, its development in infants who are typically developing also coincides with a period of highly active synaptic formation in the brain, making it a critical gateway and target for intervention. No tested interventions exist to promote this skill in infants. The proposed study is the next step in our work on the use of a self-initiated prone progression crawler (SIPPC) to promote and help sustain limb and body movements by infants with CP during prone locomotion. It builds on promising results of our earlier trials that showed that the 1st generation SIPPC (SIPPC-1), which used device-based positional input sensors as control signals, tended to reward later rather than earlier efforts. The proposed 2nd generation SIPPC (SIPPC-2) will add infant-based sensors (limb-mounted accelerometers and load cells) that will not only serve as control signals, but will also generate kinematic and kinetic data about how infants with or at risk for CP learn to move during prone locomotion. Two (2) related studies will be used to test whether the SIPPC-2 controls will enhance motor learning and promote prone locomotion. In the first study we will gather information to create a menu of canonical limb and body movement patterns that predictably result in infant-driven movement of the SIPPC-2. The second study will test the device- and infant-driven control algorithms and compare the development of movement strategies of infants using active and inactive SIPPC-2 systems. Thirty (30) infants with and without CP will be recruited and tested at 3 - 4 months to determine risk for CP. Training will begin at 4.5 - 6.5 months of age. The design protocol will comprise 15-20 minutes of training on the SIPPC-2 for 12 weeks. The training sessions will be videotaped. The Bayley Scales of Infant Development III will be used to assess domains of development that are associated with prone locomotion. The SIPPC-2 design is unique and innovative in that it is not only an intervention device, but can also be used to gather comprehensive information about the infants'learning and mobility patterns. The results will generate information on how infants with brain lesions learn a new motor skill, provide information on the use of reinforced learning in infants, help determine the feasibility of the SIPPC-2 as a valid intervention system, and refine a self-contained portable battery powered SIPPC-2 to be used in homes and in future clinical trials.
The SIPPC-2 system is unique in that it is not only an intervention device that simultaneously generates performance outcomes, but it can also be used to gather comprehensive information about how infants (with and without CP) learn a movement-related task like crawling. The kinematic and kinetic data generated by the SIPPC-2 will allow us to begin to speculate about brain plasticity in infants with brain lesions. We expect that the use of a menu of patterns of limb movement will help deter learned non-use/disuse by challenging infants with a brain insult, such as cerebral palsy, to attain high levels of psychomotor abilities, and minimize the long term deleterious effects that immobility has on other domains of development and functional independence. Because early prone locomotion is associated with emergence of a wide variety of skills, assisting infants with or at risk for CP to attain this skill have far reaching effects.
