What could cause arch pain?

Plantar fascitiis: Arch supports help greatly.

Plantar fasciitis: Plantar fasciitis or a strained arch is the most common reason. Often the result of insufficient foot support or over use.

Many possible causes: Heel pain and arch pain is most often caused by plantar fasciitis, a condition that is sometimes also called heel spur syndrome when a spur is present. Heel pain may also be due to other causes, such as infection, tendonitis, arthritis, stress fracture, nerve irritation, retained foreign body, bone tumor, or a cyst. Have it evaluated by a professional and get the appropriate treatment.