platelet rich plasma (PRP) will be produced through whole blood centrifuge using a specific methodology in a strict aseptic setting. Then, blood will be collected and mixed with anticoagulant and Citrate-phosphate-dextrose adenine in a 10 volume blood to 1 volume anticoagulant ratio. The blood will be centrifuged for 10 minutes at 1000 rpm. Afterward, the plasma will be transferred to a new glass tube and centrifuged for 15 minutes at 3000 rpm. At the bottom of the tube, platelets will form a pellet. Finally, pure platelet-rich plasma will be obtained at a concentration of up to four times higher than baseline. Prior to the injection, calcium gluconate will be combined with PRP (at a ratio of 0.3 ml ca gluconate/ml PRP).

The injection will be done once.

2 ml methylprednisolone acetate 40mg/ml (total 80mg methylprednisolone acetate) together with 1 ml lidocaine 2% (total 3 ml solution) will be directly injected under ultrasound guidance to the plantar fascia.This group serves as active comparative group.

The injection will be done once.

derived from patient own blood

visual analogue scale from 0-10, where 0 denoting maximum pain relief and 10 denoting no pain relief

the Manchester-Oxford Foot Questionnaire is a 16-item instrument answered on a five-point Likert scale (each item is scored from 0 to 4, with 4 denoting 'most severe'). Scores for each item are summed to form three separate sub scales representing underlying domains: walking/standing problems (seven items), foot pain (five items), and issues related to social interaction (four items)

Hypoechogenicity was defined as a lack of the homogeneous fibrillar pattern with loss of the tightly packed echogenic lines after correcting for anisotropy. increased echogenicity is consistent with plantar fasciitis