This summer, for the first time in my long backpacking career, I suffered an acute bout of plantar faciitis. The pain in my heels was so bad, I could barely hobble out the Cranberry Wilderness (in West VA). I had been experimenting with different insoles in my New Balance running shoes (no problems for many years prior) when the problem surfaced.
After much research, I am now convinced that the PF was caused by over-cushioned insoles. Too much cushioning, I believe, allowed my feet to severely over-pronate, causing extreme stretching in the plantar facia (a condition that is apparently thought to cause many cases of PF).
To try to correct the problem, I reverted back to tried-and-true shoe inserts, including my custom-molded SuperFeet, but for several months, nothing seemed to help. Even extensive calf-stretching prior to walking didn’t solve my problem. Finally, I found a combination of running shoes that included a stiffener at the rear of the shoe (NB 892’s – no longer made), a semi-rigid orthotic, and a gel under-cushion pad, that seems to work.
Even without calf-stretching now, I can backpack all day without heel pain. One thing I did discover during this process is that the root cause of any particular case of PF can be difficult to diagnose, so you may need to experiment quite a bit before you find the right combination for you. Another thing I found is that there are a lot of “snake-oil” solutions being offered out there on the ‘Net, so buyer beware.