Description): The purpose of this proposal is to examine the effects of postural support on reach coordination in twenty 3-5 year-old children with cerebral palsy, spastic quadruparesis type. These children, if they lack functional sitting skills at the time of entering formal educational programs, are typically positioned in a custom seating system (generically referred to as Assistive Seating Devices or ASDs) for trunk support. This approach is based on the long held developmental assumption that proximal stability is a necessary precursor to distal mobility. Thus, providing proximal trunk support to decrease unintentional movement should free up the arms for self-care, prewriting and communication skills. Numerous studies have been conducted to test this reasoning without any clear demonstration that providing external postural support improves fine motor function. This design of this study is based on more recent theories of motor development that focus more on active movement strategies as a source of organization in movement. Furthermore, this newer perspective and more recent evidence suggests that even the earliest attempts to sit and reach display coordination between proximal and distal segments when actively engaged in a task. Therefore, active strategies for function are influencing the development of skilled synergies. Theoretical models for prescribing ASDs are based in reflex and neuromaturational theories without reference to active strategies. The pragmatics of clinical practice, however, are more inclusive and frequently incorporate the child's functional strategies. This study addresses two needs in this area: first, to provide the descriptive base for the purpose of establishing a taxonomy of active strategies for sitting and reaching these children use, and, second, to describe and test specific hypotheses about the effects of increasing postural support on trunk and hand coordination during reaching. This study examines reaching and posture in four support contexts to describe the range of active strategies available to these children. Detailed behavioral and kinematic descriptions will provide a descriptive base for clinical reasoning in conjunction with statistical analyses to test assumptions about proximal and distal motor control.
