Plantar fasciitis is a painful condition caused by inflammation of the plantar fascia. The plantar fascia is a thick, flat ligament that connects the heel bone to your toes and supports the arch of your foot. When the plantar fascia is strained, small tears can develop, causing it to become weak, swollen and inflamed.
The end result is a sharp, stabbing pain in the bottom of your foot. That’s plantar fasciitis.
Plantar fasciitis is usually most painful after you’ve been sitting, standing or lying down for long periods of time. For example, those first steps when you get out of bed in the morning are a killer. Climbing stairs can also be painful. Once you’ve loosened up your foot, the pain of plantar fasciitis isn’t as intense in most cases.
Although plantar fasciitis is most common in middle-aged people, younger people who spend a lot of time on their feet doing repetitive movements often develop plantar fasciitis. Athletes, especially runners, and even soldiers who spend a lot of time marching are susceptible.