Another advantage I forgot to mention when using poles, is enjoyment. I find that I am a lot more observant of my surroundings if I have poles, because I am not constantly staring at my feet watching every step. I can actually lift my head up and look around without worrying about spraining my ankle or falling.

If you think about it, when hiking you really only have one point of contact with the ground at any time, the other foot is always in the air going for the next step. That one foot has to support all your weight plus the weight of your pack, and you have to use your muscles to balance which put additional stress on your foot. With poles, there is always at least two, and sometimes three points of contact with the ground, which is a lot more stable. You can try it for yourself at home, put on a fully loaded pack and just try and balance on one foot and see how long you can stay there. Now try the same thing while holding onto a hand rail for balance. You can stand there a lot longer with a lot less exertion. That's what hiking poles are like, a hand rail with every step.