Effect of Targeted Training on Sensorimotor Control of Trunk Posture

One of the major challenges of motor control is to understand how the central nervous system controls the degrees of freedom of the body. This is particularly evident in cerebral palsy (CP), which is the most prevalent chronic childhood motor disability and is one of the most disabling and costly chronic disorders of children and adults. Deficits in postural control and sensorimotor integration are hallmarks of CP. Although postural control of the trunk for independent sitting creates the foundation for all other motor tasks, surprisingly little is known about how children with CP use sensory input to guide their development of upright control (which occurs in typically developing infants by 8 months of age). This lack of knowledge limits our ability to effectively assess and treat children with neuromotor deficits in trunk control.

The objectives of this project are to identify sensory reliance and sensory re-weighting in a study of children with moderate-to-severe CP (4-12 years of age) before and after Targeted Training for Trunk Control. A novel trunk support device will enable testing of participants who lack (or are still developing) stable sitting. In experiments, kinematics of the head and trunk will be measured. Sensory reliance and re-weighting will be identified from postural trunk responses to sensory conflict stimuli consisting of tilts of a visual surround and/or tilts of a surface which participants sit upon. Generally, participants with a high reliance on vestibular feedback will remain upright with respect to gravity during all tests; whereas a high reliance on cutaneous or visual feedback will produce trunk sway away from upright and toward the surface or visual surround tilt, respectively. To tease apart biomechanical, physical, and neurological contributions to trunk sway, sensorimotor integration modeling will be used to complement data interpretation.