Lily, I am just a standard power walker. I am 5' 10" and have a fairly long stride. I used to walk fast(er) before my injuries as I walked th 96 WDW Marathon in 5:09 and did a 50 mile Ultramarathon in 10:32
I hurt my achilles while running(not walking) a 50K trail race in 2001. I rolled the ankle at mile 15, worked through it, rolled it again with 3 miles left, and hobbled to the finish. It took 2 years, months of PT and many different Ortho DR's before one decided something was wrong and did MRI and scheduled surgeries. Once they did first surgery, right achilles was 50% torn and black and dying tissue. It had been that way for 2 years! Left achillies was just cleanup. He told me he would get me back to walking without pain but running was probably out. Circle of life as walked marathons and ultras for year, than ran ultras, and back to walking again. 14-15 min mile vs 12 min. It beats being 5 weeks on crutches, than 8 weeks in wheelchair, and back to crutches for 6 more weeks. 4 months of H@#$ made me appreciate being upright and I don't take it for granted anymore!
At least I can still do the Goofy

Body hates me after 80 marathons/ultras in 10 years.
Watch achilles as if you don't take care of them, they will take care of you doing anything.
BTW, will have camera and laptop so will be adding photos the night after each race and from the expo(and meets) to my website.
See all soon and take it easy,
Robert
http://www.DisneyRunning.com