This thesis outlines the successful development of an objective measurement . system to assist in the prescription of seating to non-ambulant children with CP at risk of developing scoliosis. Non-ambulant children with CP are at high risk of developing severe spinal deformities that can lower the standard of life and life expectancy. Postural support is an important aspect of clinical care however the process of seating prescription is wholly subjective. During this study appropriate stakeholder groups were fully integrated in the development of a system specification utilising a user centred design approach. An initial seating system was developed to provide comparable seating posture within a surface topography spinal imaging system and a spinal X-ray. A clinical investigation was carried out using this system, results from 18 non-ambulant children with CP identified surface topography to be an acceptable alternative to potentially harmful spinal X-rays for moderate spinal curves. Following the initial clinical study stakeholders were re-engaged and an improved system to assess further key parameters of seating was developed. The Seating Measurement System (SMS) was developed to measure spinal curvature and back shape, force distribution through the torso, pressure distribution through the seat and upper limb function. A feasibility study was successfully carried out involving 4 able bodied children and 6 children with CP. Results from this study identified some similar measures or seating trends between these groups. One child with CP is presented as a case study. Results identified that improved postural support may reduce high muscular tone and (identified though parental feedback) improve arm function. Results from this study were used with an osteo-ligamentous finite element model of the spine and rib cage to simulate the non-surgical correction of scoliosis. This study identified that patient specific simulations may be powerful tools to assist in the prescription of optimum seating. However, to be fully utilised in neuromuscular scoliosis models must consider asymmetrical muscular loading