I suspect there is a Peter Pan problem with a lot of preppers. I also enjoy alliteration for no particular reason. :-) This is very very bad for a TEOTAWKI situation. (I mean the Peter Pan thing, but maybe the other is bad too.)
Very few of us are fortunate enough to have a good supply of Fairy Dust available to prevent aging. The ability to perform hard work and manage stairs and ladders usually decreases along with aging.
It is necessary to give consideration to aging, disability, or injuries in your preparedness. If you are not doing this already, you have a gaping hole in your disaster preparedness.
I have little idea of much of the demographics of my blog readers, but since there are a lot of Baby Boomers worldwide, they are probably represented among readers. If you are a Baby Boomer, you have even more necessity to plan for decreased strength and agility in your plans.
Like many other types of planning, taking aging, etc. into account can seem overwhelming if taken on all at once. This too, can be broken down into bite-sized chunks.
If you have 100 pound containers of food in your storage, you can plan to break them down into smaller units. You can get large scoops that will enable you to empty those larger containers into smaller ones without lifting them. You can build ramps instead of stairs in new construction, or as repairs are needed.
Converting your garden area into raised beds, narrow enough to reach the middle easily from the sides, is a change that you can make gradually.
I am not talking about short raised beds here. I mean beds that are high enough to comfortably sit on the sides and tend plants. Plants at this height can also be easily tended from a wheel chair.
Doorways should not be too narrow to get through in a wheel chair. Bathrooms are often overlooked for convenient doorway width. This can be an expensive alteration, but it will be even more expensive post TEOTAWKI.
Toilets, showers and bathtubs need to be easily accessible. Showers need to be large enough to fit more than one person or someone in a wheeled bath chair. Showering may require assistance.
It is possible to use chamber pots and sponge baths to avoid such changes. You don't need to despair if the alterations are not possible for you. It will be much easier and less time-consuming if you are able to make these accessibility changes, however.
I like to take the saying, "A failure to plan, is a plan to fail", to heart. I prefer to prepare for less agility and strength in myself and others as I go. It is easier and cheaper than modifications later.