Abstract: A splint and a kit from which the splint is assembled include a plurality of components having a planar configuration for compact storage when in the kit, but having a three-dimensional configuration conforming to the desired body contours when the splint is assembled. The individual planar kit components include a rigid support member, a pad for cushioning the support member against the body, a plurality of belts for securing the support member to the body, a pair of flexion members for fixedly retaining the flexion angle of the support member, and one or more straps flexibly connecting the flexion members to the support member. The support member is an elongated surface having two longitudinal grooves formed therein that act as contour joints, and two slits formed therethrough perpendicular to the grooves that act as flexion joints.