I've used a single pole for a year or so now, I initially started using one to encourage my young boy to use one as I felt it would help him negotiate steps/rocks banks etc. when we were tramping, Being an average 8 year old his legs often weren't as long as the step required and add a pack to that and he was often looking to me for support for balance, now with a walking pole he is tackling most everything on his own.
I have a set with a Tee style handle and find it more stable (for me) especially on down hill stuff. The flat handle is a more natural grip for me when strolling on the flats. I also use mine as a tent pole in conjunction with my fly/tarp for camping.
Leki, Fizan and Macpac poles in camping box.
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