The world's population is both ageing and gaining weight and the period of time that people live with morbidity is increasing. With increased age comes reduced mobility which can have significant impact on health and well-being. Improving health technologies are also allowing people with disabilities (both acquired or genetic) to live longer and generating increased chances and opportunities for a productive life. Maintaining a sitting posture requires energy and if the person is not supported fully, they will expand additional energy in trying to remain stable. Asymmetry in any part of their body will add to their instability and therefore their energy output. Improving the contact between the sitter and their support surfaces will aid their stability, so making them less tired, reducing discomfort and increasing the time they are able to spend in the equipment. All of these 'physical' benefits translate into better emotional well-being. They are able to focus on completing tasks (rather than maintaining balance) and looking outward rather than inward. Focusing on optimising the fit of the backrest system to the wheelchair user will ensure that it meets their personal wants as well as their clinical needs: a, Discrete - minimal material will ensure the system is not bulky and be minimally visually intrusive. b, Clinically Efficacious - built-in adjustment will ensure good fit to the body allowing postural control to accommodate or correct the muscular-skeletal forces of the user. c, Continuing alterations - the ability to re-modify the contact areas as the client's posture alters with time, Most wheelchair backrest systems currently on the market consist of a single pre-formed metal shell with a foam insert to contact the user. In order to cover the various widths, heights and depths required by the population, a huge number of different shells have to be manufactured and held in stock. By developing a wheelchair backrest system that is modular, the same range that can assembled from a small number of critical components. Therefore, the up-front tooling costs are kept to a minimum, the held stock is significantly reduced and the supply time is improved. The ongoing costs to maintain a client's optimum posture will be reduced as the same backrest system can be adjusted and also 'improved' by swapping out individual components to meet a significant change - rather than replacing the complete system (as is the case in many backrests on the market today).