Plantar fasciitis is the most common cause of  chronic heel pain as well as the surrounding structures, it involves in inflammation of a thick band plantar fascia ligament that connects the heel to the toes cause foot injury. The plantar fascia is a ligament that lies beneath the skin on the bottom of your foot.

Causes:
• Repetitive strain injury
• Excessive running or walking, inadequate foot gear
• Frequently standing for extended periods
• Overweight

Symptoms:
• Pain on the bottom of the foot near the heel
• Stabbing pain near heel 
• Pain normally decreases, but it might return after long periods of standing or when  you stand up after sitting.
• Grater pain after exercise or any activity 
• Plantar fascia absorb the high stresses and strains we place on our feet. But, sometimes, too much pressure damages or tears the tissues