The first instinct is to consult a podiatrist to assess your plantar fasciitis.
He can prescribe an X-ray, ultrasound, or MRI.
If an anomaly is detected, he will refer you to an orthopedic surgeon.
If he detects problems with tendons, muscles, joints, or ligaments, he will refer you to a rheumatologist, who is a specialist in the musculoskeletal system.