I am still drafting the details of a question, and would like to make sure it is a good fit for Outdoors (or if not, which SE might be better).
The gist of it is that my 85-year-old and mobility-limited father has asked for my assistance in brainstorming ideas to give the old "Tim Taylor" treatment (warning: TV tropes) to his walker, so that it will still give him some stability and support while allowing him to remove his hands momentarily to perform an action. The actions he has in mind include yard work and geocaching- i.e. to grab a branch and lob it with pruning shears, or to pull a film can out of the branch of a tree.
In the main question, I would give some details about what exactly my father can and cannot do, the construction of the walker, and some ideas we have already tossed around.