Bob Arledge wrote:
Why not put a strain gauge on the paddle shaft just below the paddler's
hand. This would give you the moment at that point, so the force would be
the moment divided by the distance between the strain gauge and the centroid
of the paddle blade.



That's the general idea, but because the paddling motion is 3-d, it's
not very easy to determine power just from the strain in the paddle
shaft. You need to know instantaneous velocity (direction and
magnitude) at every moment. In a fixed-pivot environment like rowing,
you can just put a potentiometer on the oar-lock. But the kayak/canoe
paddle has no fixed pivot point. So, I imagine that a virtual pivot
point would have to be derived via 3-d kinematic video analysis.

I haven't yet sat down and done a free-body of the system, but in my
head, it seems like it's going to be an indeterminant system... not fun.

Thanks,
-Kieran