Designing clothes for wheelchair users demands special pattern construction requirements in accordance with their body shape in the sitting position. The main objective of this research consists in implementing 3D CAD technologies in designing trousers for this group of people. In order to do so 3D scanning is used for better understanding the shape and dimensions of the body of a paraplegic person. The animation of a kinematic body model was studied also in order to obtain information about the body shape in certain movements or positions including the sitting one. Further, 3D-to-2D and 2D-to-3D prototyping was used to create a trouser model that can fit to the shape and dimensions of a wheelchair user. 3D virtual simulation was applied to test the applicability of the pattern modifications and a trouser prototype was designed for a wheelchair user.