Healthy indoor materials for the elderly

Author: Dr Anders Nyrud STSM Period: 2018-05-01 – 2019-04-30


Hosting institution: Norwegian University of Life Sciences. Ås, Norway

From ITC: Yes



1. Aim & motivation

Visually and tactilely pleasant materials help create healthy indoor environments which have a positive influence on psychological well-being. When people are in contact with materials they prefer, their emotional and physiological functioning tends to improve. The beneficial effects of healthy materials could be especially valuable to older adults who spend a considerable amount of time indoors. On top of that, older adults can have diminished capabilities and options to participate in activities that would be protective of their health, such as physical exercise and mindfulness meditation. For this reason, it is important to offer them health interventions that consider their limited capacities.

Wood is generally one of the preferred materials that can lead to an improvement in human well-being.
However, several lines of knowledge are needed before the increased indoor usage of wood could be recommended as an intervention beneficial to older adults.

1) Studies assessing the preference of materials predominantly focus on people belonging to younger age groups and not on older adults. The special needs and characteristics of older adults may influence their assessment of materials. Therefore, we should study how wood is perceived and evaluated within this age group.

2) It is not known if the usage of wood is preferred in certain specific circumstances. For example, it has been shown that people prefer the usage of wood in some indoor features (e.g., kitchen cabinets) more than in others (e.g., wall-panelling). As they age, older adults increasingly depend on the assistance of railings. For this reason, it is important to examine if they prefer wood for this use more than the typically used steel.

3) It is not known if older adults prefer certain types of wood more than others. This is especially important in light of recent advancements in the area of wood modification. Wood modification processes improve several characteristics of wood, such as dimensional stability and durability against decay, and thus offer an attractive option for building professionals. However, modified wood possesses visual and tactile changes as well, and it is not clear how these are perceived and evaluated by older building occupants.

4) It is not clear which material qualities (e.g., softness, brightness) influence the material preferences of older adults. Understanding this would provide useful information in future choice and development of materials that are suitable for the elderly. Similarly, it is important to investigate how important are material tactile features (e.g., roughness) for older adults in their assessment of material preference. This is especially important in regard to the widespread availability of wood imitations with underdeveloped tactile characteristics.

In summary, using certain materials may be a promising method of increasing the well-being of the elderly. However, additional research is needed before evidence-based recommendations can be made. The proposed study will lead us towards creating and using materials that are attractive and healthy for everyday elderly users.

2. Proposed contribution to the scientific objectives of the Action

Our study will assess how people perceive and evaluate handrails manufactured from modified wood compared to handrails produced from untreated wood and stainless steel based on touch alone in addition to touch and vision combined. Furthermore, we will examine which sensory tactile and visual characteristics (e.g., roughness, lightness) is associated with general evaluation and preference of the materials. Finally, we will investigate the perception and evaluation of the same materials between the tactile and the tactile-visual task. The results of the study will provide several lines of knowledge that will be applicable in improving indoor living spaces of older adults:

1) The results will inform us if older adults generally prefer wooden handrails instead of the typically used handrails manufactured from stainless steel. If so, the choice of wooden handrails should be favoured in the habitats of older adults, due to their potential for improving health.

2) The results will reveal if certain types of wood are preferred over others. If the handrails created from modified wood are favoured similarly as the handrails manufactured from untreated wood, it is reasonable to promote the use of modified wood for handrail construction. Even if modified wood is evaluated similarly than untreated wood, it may be more easily adopted by building professionals due to its improved mechanical and other properties.

3) The study will reveal which characteristics of materials are important to older adults in railings. For example, how important are the characteristics such as softness, roughness, and naturalness in the preference assessment of handrails? This information will provide basic building blocks for choosing and developing materials that are fitting to older adults.

4) The study will provide information on the relative importance of the tactile features in the general (tactile and visual) assessment of preference. If the tactile characteristics are shown to be important even when the material is assessed by touch and vision combined, care must be taken to develop and choose materials that possess attractive tactile (and not only visual) qualities. The long-term main objective of this COST Action is to help create healthy indoor environments for the elderly by improving furniture and building design. One of the fundamental steps in designing health-supporting furniture and buildings is choosing proper materials. Our study will contribute knowledge on which materials are preferred among the elderly (and why) and therefore have the potential to improve their health and wellbeing. With this, the study will contribute mainly to the aims of WG1 (Furniture and Habitat Industry) but also to the WG3 (Healthcare). Specifically, it will contribute most to the COST Action objectives RCO1, (“To define and provide all relevant inputs for the design and development of Smart Support Furniture and habitats from different disciplines: Health care, Psychology, Ergonomics, Construction, etc., and from the users: elderly, caregivers, etc.”), RCO3 (“To design, develop and test smart support furniture and habitat environments according to user’s needs and further validated by these users (elderly and caretakers) for an active ageing.”), and CBO2 (“To foster International cooperation between researchers from COST member countries, COST Near Neighbour Countries (NNC) and International Partner countries (IPC), bringing together different disciplines to enable breakthrough scientific developments in the field of Active Assisted Living”).

In summary, our study will examine how modified wood fares against untreated wood and stainless steel in terms of preference of the elderly and which material qualities have the most influence. Additionally, we will compare the results from the STSM study with the results of the same study conducted in Slovenia. With this, we will assess the potential role of culture on the evaluation and preference of materials. Altogether, the gained knowledge will provide guidance for the proper material choice, one of the basic building blocks in creating health-supporting (and sustainable) furniture and buildings.

3. Methodology

To investigate the perception and evaluation of modified wood we prepared six cylindrical handrail samples. One sample was produced from stainless steel, while the remaining five were manufactured from either untreated or treated spruce or pine. Specifically, we included unmodified spruce, unmodified pine, acetylated radiata pine, thermally modified spruce, and thermally modified pine. The thermal modification was done with the commercial ThermoD process at 212°C and superheated steam at Heatwood (Hudiksvall, Sweden). Handrail samples measured 42mm in diameter and were 30cm long. Each sample was mounted on a wooden base covered with white foil measuring approximately 30 x 15 x 5 cm.

To capture the perception and evaluation of the handrail samples, we created a semantic differential scale suited for the studied context. The scale assesses both sensory (e.g., dry) and evaluative (e.g., pleasant) aspects of touch and vision. In total, it consists of 11-word pairs. Two of these (dark – light, shiny – matte) will be used only in the second part of the study (tactile-visual task). Six of 11 pairs of descriptors measure basic sensory properties (rough – smooth, warm – cold, dry – damp, hard – soft, dark – light, shiny – matte) while the remaining five measure the evaluation of materials (unusual – usual, natural – artificial, cheap – expensive, pleasant – unpleasant, dislike – like). For each word pair, subjects will select their answer from a 5-point scale that consists of the adverbs “considerably”, “somewhat”, “in the middle”, “somewhat” and “considerably”. For example, on a “rough – smooth” pair, subjects could indicate that the rated sample is “considerably rough”, “somewhat rough”, “in the middle”, “somewhat smooth” or “considerably smooth”.

We will invite at least 50 elderly subjects to participate in the study from the Health Innovation Centre in Kristiansund, Norway. Participants will have to be at least 65 years old and possess no health impairments that could interfere with the study protocol (e.g., heavily impaired vision). The study consists of three parts. In the first part, participants will separately rate each handrail sample by touch only – they will be instructed to keep their eyes closed (tactile task). Samples will be presented to them in random order. For each handrail, subjects will provide a verbal answer for each item on a semantic differential scale (described in the that will be read to them. In the second part of the study, participants will rate the samples again in the same order, except they will be able to both touch and see the handrails (tactile-visual task). In the third part, the participants will be presented with all the samples at once to simultaneously see and touch. They will be asked to rank them from the most to least preferred by placing cards numbered from one (preferred) to six (least preferred).

4. Planning

Before the STSM

– Background research on the relevant cultural differences between Norway and Slovenia
– Translation of the relevant materials (informed consent, semantic differential scale)
– Sharing the data and analysis from the 1st part of the study conducted in Slovenia
– Preparing the introductory part of the related journal article
– Making arrangements for survey implementation at testing location (sampling, table, etc.)

During the STSM

– Day 1:
o Meeting Norwegian University of Life Sciences (NMBU) staff
o Testing the translated questionnaire
o Rehearsing the survey implementation
– Day 2:
o Revising and finalising the translated questionnaire and survey methodology
o Completing the final test of the questionnaire and methodology
– Day 3:
o Travelling to the testing location – Centre for Healthcare Innovation (Kristiansund)
– Day 4-6:
o Conducting the survey on 50 participants
– Day 7:
o Travelling back to NMBU
– Day 8-10:
o Data analysis and interpretation with the host
– Day 11:
o Report on initial results
o Outline of the journal article

After the STSM

– Completing the data analysis
– Preparing a scientific article that will be submitted to the journal “Indoor Built Environment” and will be available open-access.
– Identify appropriate conferences and other outlets to share the results

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