Between March 2013 and April 2014 , 128 patients with plantar fasciitis were randomized to receive radiation therapy ( total dose of 6.0 Gy applied in 6 fractions of 1.0 Gy three times a week ) or local corticosteroid injections a 1 ml injection of 40 mg methylprednisolone and 0.5 ml 1 % lidocaine under the guidance of palpation .