The Stair Trainer device promotes gross motor function in children with cerebral palsy (CP), ages two to five years old. The Stair Trainer allows for easy adult supervision, and be easily disassembled and stored when needed. The railings have an appropriate height of 24” for toddlers and were designed to be 24” apart to disallow holding of both railings during climbing. A height of three feet was designated for the platform with a minimum of 24” of railings, as dictated by safety standards. Additionally, wood was the material preferred by the client, and the use of metal was to be avoided due to its hospital-like appearance. The space for use of the stair trainer is the corner of a room with an area of 18’ x 18’.
The minimum final structure height as instructed by representatives at the UCP was designated as 36”. The design is disassembled into large modular components, each of which can be moved by two adults who could lift a combined weight of 150 pounds. The components fit into a storage area with a single door entryway. The dimensions for the stairs are: a height of 8 inches, a width of 10 inches and a length of 24 inches. The Stair Trainer is designed for the smallest child on the device would be 19 inches tall, weighing 20 pounds, and the largest would be 46 inches tall, weighing 68 pounds. Appropriate fall zones were taken into account at a minimum of 6 feet in each direction. To avoid head entrapments, the openings did not exceed 9 inches and were no smaller than 3.5 inches. The angle of the stairs does not exceed 35 degrees. The angle of the slide does not exceed 50 degrees at any portion and had to maintain an average angle of 30 degrees.
The Stair Trainer design consists of the three following subsystems: one set of stairs, one platform, and a slide. Wood was the primary material because of its well-known properties, low cost, and ability to be machined. A lightweight commercial polyethylene slide component was used as an incentive to climb the stairs. The density of ¾” birch plywood (0.01987 pounds in cubic inches) was used in the calculations. To reduce bulkiness, a small platform of 26” x 26” was designed. The completed weight of the structure was 200 pounds. The slide was lightweight, and approximately 20 pounds. The final structure was carpeted to reduce the noise created. The prototype meets all safety standards for the stairs and slide angle. Due to higher-than-expected cost of labor, the project exceeded the $1500 budget by $260. Total cost: $1760.