How Spatial Design Changes Human Health

Ami Ogawa (Senior Assistant Professor, Department of System Design Engineering)

It is said that people spend most of their lives inside buildings, and spatial design has a significant impact on our lives. Those of you reading this article may also be unknowingly influenced by the spaces you inhabit daily. For example, have you ever experienced moving to a new place where the stairs were slightly steeper than before? At first, you might have felt like you were about to stumble or found it tiring to climb, but after a few weeks, you gradually got used to it and, before you knew it, were going up and down them with ease. Steeper stairs increase the load on the lower limbs during walking, so depending on the frequency, some training effect can be expected. I began to wonder if there could be design guidelines that make people healthier simply by changing the spatial design, even as they go about their daily lives. This led me to start research investigating the effects of spatial design on users' health.

So, how is the design of a staircase determined in the first place? The steepness of a staircase is determined by two values: the riser and the tread, as shown in Figure 1. If you think about your daily life, you'll notice that stairs in places like train stations have lower risers and longer treads, making them easier to climb compared to stairs in a house. This is because building codes and barrier-free design guidelines stipulate that public spaces used by many people must have gentler stairs than those in residences used by specific residents. Thus, staircase design is planned to meet the constraints of individual spaces within the prescribed design conditions for risers and treads.

Figure 1. Staircase design parameters

The study ¹⁾ I am introducing here shows that it is possible to understand a person's physical function by observing them walking up stairs, and furthermore, that the ease of judging the quality of their physical function depends on the staircase design. We had elderly individuals with knee pain and healthy elderly individuals cooperate in our study. We measured their gait on both steep and gentle staircases and observed how deeply they could step onto each stair. The results showed that individuals with lower physical function were less able to step deeply onto the stairs. Furthermore, when we described the data with a statistical model for each staircase, we found that the coefficients of the explanatory variables and the significance probabilities differed depending on the staircase design. The data from observing walking on the steep staircase explained physical function better than the data from the gentle staircase (Figure 2). In other words, this demonstrated that different staircase designs alter the ability to distinguish between good and poor physical function. We believe this could become a new staircase design standard for achieving a screening effect for physical function.

As shown in Figure 3, staircase design standards vary around the world. Typically, design standards are adopted that are statistically guaranteed to be safe based on public health evidence, but each country establishes these standards independently. We aim for a future where standards reflecting the various effects that spaces can have on people, such as the findings of this research, are added to these design standards, leading to the realization of spatial designs that promote human health.

Figures 2 and 3 were created based on reference 1).

1) Ami Ogawa, Hirotaka Iijima, Masaki Takahashi, Staircase Design for Health Monitoring in Elderly People, Journal of Building Engineering, Vol. 37, p. 102152 (9 pages), 2021.5.