Plantar fasciitis is one of the most common causes of heel pain. It involves pain and inflammation of a thick band of tissue, called the plantar fascia, that runs across the bottom of your foot and connects your heel bone to your toes.
Plantar fasciitis commonly causes stabbing pain that usually occurs with your very first steps in the morning. Once your foot limbers up, the pain of plantar fasciitis normally decreases, but it may return after long periods of standing or after getting up from a seated position.
What is the difference causes plantar fasciitis?

Age. Plantar fasciitis is most common between the ages of 40 and 60.
Obesity. Excess pounds put extra stress on your plantar fascia.
Faulty foot mechanics. Being flat-footed, having a high arch or even having an abnormal pattern of walking can adversely affect the way weight is distributed when you’re standing and put added stress on the plantar fascia.
Certain types of exercise. Activities that place a lot of stress on your heel and attached tissue — such as long-distance running, ballet dancing and dance aerobics — can contribute to an earlier onset of plantar fasciitis.
Occupations that keep you on your feet. Factory workers, teachers and others who spend most of their work hours walking or standing on hard surfaces can damage their plantar fascia.