Plantar fasciitis is the most common culprit for heel pain in adults. The plantar fascia band is the ligament that attaches to bottom of your heel bone and runs the length of your sole and is attached to your toes. The ligament supports the arch and helps your foot absorb shock by stretching slightly with each step. However, too much pressure, repetitive impacts and general overuse can strain the plantar fascia and contribute to tears in the tissue. The ligament can then grow inflamed, irritated and swollen, thickening and stiffening as a result.