The causes of plantar fasciitis and flat feet are as follows: 1. Plantar fasciitis: Some patients may have plantar fasciitis caused by standing for too long or wearing shoes that are too hard, followed by the above symptoms. 2. Flat feet: This type of patients may have pain due to Acquired trauma, or congenital genetic factors, resulting in the collapse of the arch, flat, and thereafter in the process of standing for a long time may cause excessive pressure on the blood vessels and nerves on the bottom of the foot, there will be symptoms of pain.