When you all of a sudden start using feet muscles you're not used to using, they fatigue quickly and may lead to foot cramps. (sportstarsmag.com)
During a one - hour run, your feet push off the pavement about 10,000 times — enough of a workout to build some pretty impressive foot muscles, you'd figure. (sweatscience.com)
A heel spur is a pointed bony outgrowth of the bone of the heel which is often caused by strains on foot muscles and ligaments, repeated tearing of the membrane that covers the heel bone and stretching of the plantar fascia. (bestmuscleup.com)