Background: Plantar fasciitis is the most common cause of heel pain in runners. No studies have described the short-term effects of myofascial release on plantar fasciitis using ultrasound.

Objectives: To describe the immediate sonoelastographic changes in the plantar fascia of amateur runners with fasciitis after applying a myofascial release technique.

Design: A single-centre, experimental and controlled study.

Method: Patients with plantar fasciitis and a group of healthy subjects will be examined using B-mode and real time sonoelastography scanning. Fascia thickness, echointensity and echovariation of the color histogram will be analyzed pre- and post intervention. A two-way (Group × Time) repeated measures ANOVA will be performed.

Participants

Subjects of the plantar fasciitis group (PFG) will be recruited in May2018 to apply to them a myofascial release technique.

Healthy volunteers without a history of plantar fascia disease will be recruited as control group (CG).

The examination will be included B-mode scanning and real time sonoelastography using an US scanner with linear array transducer (ML6-15). All examinations will be conducted by a sonographer with more than 10 years' experience in musculoskeletal imaging.

Using a standardized protocol three images of every pre-post intervention video will be stored uncompressed and with no losses in bitmap format (bmp), and the mean value of the histogram components will be used for statistical analysis. The examination protocol shows good reliability, and has been reported previously.

ImageJ 1.45 software will be used to perform quantitative analysis of gray-scale images and the color histogram of the elastogram.

Inclusion Criteria:

• heel pain at the proximal fascia insertion
• worse pain when waking up in the morning or after a period of rest
• a visual analog score (VAS) of more than 4 on a scale of 10

Exclusion Criteria:

• Patients who had undergone surgery or steroid injections to the heel will be excluded.