I've had several bouts of plantar fasciitis over the last few years and I'm having one right now. I've read a lot about PF, and I am aware that tight calves & hamstrings are part of the problem. I try to stretch as much as I can, but how do you find the time to warm up before stretching? I have a desk job and sit in an office all day. Is it OK to stretch in my cubicle without warming up? Does anyone have any thoughts on this?