Originally Posted by Brian Stone
One other thing which I can't believe I forgot to mention - I can't recommend trekking poles strongly enough for your knees. I used to have major knee soreness. I started using poles and I can't overstate the positive difference they make.
I will second this. I will also add: you don't have to use them forever. When I was significantly overweight, my knees killed me while hiking. Duh. When I lost the weight, my knees still killed me while hiking. Huh? Yeah, I wasn't adapted to it b/c I didn't hike frequently enough. Using poles really takes the stress off the knees. This in turn, lets you hike more, build up better conditioning (both cardiovascular and joint), and become a stronger hiker.
My basic game plan these years is to you use my poles on the first big hike of the season. The second hike, I'll carry them and potentially use them only on the way back down (assuming a big ascent like Camel's Hump). Later, I may literally carry them lashed to my pack just for "backup". Sometimes, even after some conditioning hikes for the year, one of my knees will get a little clicky on me.
Since many of my hikes are very popular with novices and other folks who get themselves in over their heads, I also like having the poles for a variety of emergency purposes (splint, bivy, litter, etc.).