Research demonstrates that diminished core strength and mobility can make it difficult for the elderly using wheelchairs or walkers (EUWW) to navigate confined restroom spaces. Ensuring adequate room to maneuver within restrooms can support the independence and self-esteem of EUWW and reduce the physical workload of caregivers. The results of this study include recommendations for optimal restroom layouts to facilitate movement and support EUWW to engage in common hygiene routines.
Considering common behaviors and typical restroom dimensions and features, researchers used modeling to identify restroom layouts that would optimize mobility and convenience for EUWW.
Researchers used a path modeling algorithm to first generate restroom floorplans based on distinct spatial variables and then calculate paths based on typical EUWW movement patterns. To establish parameters that would be used to generate restroom layouts, researchers consulted architectural design data sets and regulations from China, Japan, the UK, and the US. Restroom layouts generated for this study featured the three most commonly used elements in Chinese elder care facilities: toilets, sinks, and showers. Researchers used the Rhino platform with the Grasshopper plugin and Python to set room dimensions and wall positions. They next established furniture insertion points at 200mm intervals that were used to place the door, toilet, sink and shower in various orientations.
The path sequence used for mobility determinations was 1) room entrance, 2) move to toilet, 3) wash hands at sink, 4) exit the restroom. Assumptions included the presence of an accessible entrance door and a soft partition around the shower vs. a fixed shower door or bathtub. Modeling scenarios included an elderly person maneuvering a wheelchair with both hands, an elderly person maneuvering a wheelchair with one hand, and a wheelchair user with caregiver assistance. Researchers used the Reed-Shepp path description and an associated algorithm to describe possible motion trajectories for wheelchair and walker users in the generated layouts. For each floorplan computed paths were planned under 13 different conditions including movement patterns for wheelchair users, walkers, and caregivers. The program was set to initialize a map; plan paths from door, to toilet, to sink, to door; generate paths; evaluate paths (based on length and turning angle); and select the path with the shortest distance and fewest turns for each layout.
Using path length and turning angle as criteria to measure the convenience of EUWW movements in the restroom, researchers analyzed 8,475 floorplans without showers and 4,767 floorplans with showers. Floorplans with the highest comprehensive score and corresponding path were selected, with higher scores indicating shorter distances and fewer turns. According to room dimensions studied, restrooms smaller than 1.6m x 2.4m cannot accommodate showers because wheelchair movement with assistance is not possible. Additionally, when the restroom is 2m x 2m it is difficult for wheelchair users to approach the toilet from both the front and at a 90° angle with assistance. The optimal floorplan depends on required minimum turning radius and approach to the toilet, such that when a EUWW uses a rear approach only one of the generated layouts could accommodate. Different approaches to the toilet (frontal, 45° side, 90°, and rear) were also evaluated. Researchers noted that the 45° side approach was the most efficient, followed by the frontal approach, with the 90° having the lowest score.
Researchers next assessed placement of various restroom features, noting that when sinks were placed away from walls scores were higher, but there was no clear trend for toilet or door placement. Investigators also noted that top scoring plans featured the toilet and sink placed opposite or at a 90° angle from one another. Finally, researchers compared the top-rated floorplans with corner toilets or sinks (M = 1.78, SD = .18) with those where the toilet and sink were parallel to the wall (M = 1.75, SD = .17), and noted significantly higher comprehensive (t = -1.941, p = .069) scores for corner placements. Similar results were noted when turning angle scores were compared between rooms with corner (M = .88, SD = .11) vs. parallel (M = .86, SD = .10) sink and toilet placement (t = -1.821, p = .086).
The simulated scenarios relied on assumptions including that the caregiver’s position relative to the wheelchair remained constant and their turning radius was set to zero, which may not represent all movements. Further, the study did not account for EUWW or caregiver handedness which might impact the transfer behaviors related to wheelchair use. Finally, movements of walker users were assessed with a model based on wheeled vehicles such that future studies should develop more nuanced frameworks.