This overuse injury is common with runners and people who stand and walk a lot, and can be caused by flat pronated feet, high arched rigid feet, improper footwear, increasing age and overuse. It’s characterized by acute heel pain first thing in the morning and just after you rest. When the plantar fascia is under too much stress, it pulls away from its weakest insertion, causing microtears, inflammation and pain. And the more you use your foot, the more it aggravates things. Treatment involves rest, better shoes and orthotics, and may require night splints, laser therapy, physiotherapy, exercises and hot and cold therapy.