Function & Home

There is no place like home.

Home is where the heart is.

Home is your castle.

Comfort and safety are implied in each of these statements. A home has comfort when the work of up-keep (demands of the house) and the daily living tasks are in balance with the ability to live in that house. If a home is too easy to live in, it may be boring. Imagine being healthy and living in a small apartment with no ability or need to shop and all meals are provided. Alternatively, if a house is so much work that it is exhausting, where everyday life can impart anxiety and failure to accomplish all that needs to be done can be frustrating. Figure 1 is modified from a model of Lawton and Nahemow. [1]

Figure 1: Person-Environment Fit

In this graph, where Physical Ability is high and Environmental (House) demands are relatively high, there is a zone of “Maximal performance potential” meaning that the person has the competency to live there and complete the demands of the house. With just slightly lower demands there is the zone of “Maximal comfort”, meaning that the physical ability is more than needed to live comfortably, in other words there is a “physical reserve”.   Person-Environment fit is in balance. Using our example above, if a person of high ability is then confined to living in a small apartment with meals provided and no need to go shopping, he or she falls outside the zone balance (upper left of the graph). The resident is at risk of more sedentary behavior, negative affect, and depression. This can happen if someone moves prematurely to a very supportive environment, such as assisted living. Alternatively someone may choose to live in the same home for 40 + years. For most of that time the person-environment fit is in the balance zone. However, the house may not have been upgraded with modern conveniences. The upkeep on the house increases as the years go by. At the same time, the person aging in that house is getting physically less able despite exercise and good health behaviors. The physical ability may decline to where he or she is no longer in a zone of comfort or maximal potential. The mismatch (low personal ability and high demand) falls into the lower right corner of the graph. The resident is at risk of dependency, injury, malnutrition and social isolation. Modification strategies will need to be employed to remain in that residence (some of these are addressed below). This is the classic “aging-in-place” scenario.

The goal of people wanting to age comfortably is to maintain a balance between Physical Ability and Environmental Demands. Hitting the mark of comfort can be done in two ways, first, to build physical reserve through exercise and good nutrition (see section on Function and Exercise). Systematic exercise is the best hope for keeping physical ability ahead of daily and seasonal demands of the house. Having enough strength to carry a stack of plates and put them on a shelf at shoulder height, maintaining enough flexibility to put a pan on a low shelf, having enough strength to make a bed, the stamina to clean, sweep and garden, and get groceries.



Making a bed requires strength to lift the mattress to tuck the corners and to put on fitted sheet corners. It requires flexibility and back strength to bend and stoop. Endurance and stamina are required to walk around the bed, particularly the larger beds, like king mattresses.







Gardening provides a means of being active with a great deal of satisfaction.
Yet, gardening requires strength, flexibility and stamina. Well-rounded exercise can build physical reserve to make gardening easier. See the Function and Exercise section for more details.









Sweeping the floor requires core strength particularly lower back strength as well as leg strength. Bending and stooping is often reported as a functional limitation. It is the proverbial “canary in the coal mine”, an early warning sign of subsequent functional limitations.






Independence in a home is often linked to transportation. If a person loses the ability to drive, as can happen, well before he is ready to move to a “retirement community”, living within a quarter mile of a bus stop or a grocery store can prolong the ability to live-in-place without moving. The environmental demand may be greater after a person is unable to drive, requiring greater fitness or physical reserve. In Figure 1, the demand moves to the right so life feels more difficult. Instead of being in the zone of “maximal comfort” he is now in the zone of “maximal performance potential”. During this period of greater walking there may be a brief period of stress and anxiety, however as the body adapts to the increased demand and becomes more physically fit, she or he will re-enter the zone of “maximal comfort”. If a disability or other obstacle impedes the training effect the environmental demand must be lowered as can be seen below.



Once a person has done what they can to sustain fitness, the modification strategies for the living environment may need to be addressed. These can involve moving to a more supportive environment like a retirement community. If moving is not the choice, many cities in the US have opted for the virtual village ( of aging-in-place. The virtual village is not a location but a nonprofit membership organization that manages volunteers to help with member’s needs (transportation to gardening), reduce risk of isolation (luncheons to book groups), and facilitate member autonomy. In Bellingham WA, the virtual village is called Bellingham At Home ( This is a nationwide movement. A village locator is available on the Village to Village Network website (

[1] Lawton, MP and L Nahemow, Ecology and the aging process. Eisdorf and MP Lawton (Eds), Psychology of adult development and aging (Washington, D.C.: American Psychological Association, 1973), p 661. Modifications by M. Elaine Cress, PhD

©Copyright M. Elaine Cress, PhD, 5/7/2017.