I really like the idea of a device to help elderly walk up and down stairs, but I'm concerned that the cantilever design might not be stable enough for such an important task. What if there was a device that attached on both sides of the stairs, giving a lot of support, and when one is done climbing the stairs one side detached like a hinge and clip on to the wall on the other side? (even possibly magnetic?) This action might be easier for elderly to use than trying to clip it on the stairs every time, especially if they have arthritis or other issues in the hand.
I really love the idea that this can be implemented in a public park setting. At the refinement meeting the other day, I remember someone said the level of difficulty should be adjusted/scaled in a way that provides the users a safer and reasonable level of exercise (i.e. users should have to pass an easier pathway to access a difficult pathway).
When I used to live in Korea, there was this park my parents used to take me that had a pathway of sorts for the purpose of exercising the bottoms of feet- the pathway had different types of pebbles embedded in the sidewalk. Every few feet, a new type of rock surface would be on the path, and although some rocks were harder to walk on, the level got more and more difficult as you went on the path. There were also several exits during the path so users could leave whenever they felt they reached their max. In addition, the entire pathway had support railings on the sides.
Thought this might help with your future vision for this project!