Thanks eds195. I think this work is useful. Not, I think due to the use of robots, but because, in effect, it is similar to, and highlights the specific advantages of, walking on rough ground.

Is this another "use or lose" ability that is affected by Parkinson's.

I'm looking at the problem of falls from a different point of view: using a smart phone to detect the start of the fall, and to immediately send an alarm. Detecting a fall is not difficult, but the trouble is that you get far too many false positives. Also, I don't know if the half second approx notice that this will give, 1.7= 0.5*9.8*t^2, will be enough to take corrective action.

As I see it, you could make a big impact on PD if you had 10, say, tools that addressed specific problems.

John