To check in patients suffering from chronic plantar fasciitis treated with shock wave therapy, if the outward appearance of the device affects clinical outcomes.

Study Design: a controlled, randomized, parallel assessor-blinded clinical trial.

Patients suffering from chronic plantar fasciitis (duration more than 6 months) will be assigned to three different groups:

• Group I: Treatment applied by standard shock waves device.
• Group II: Shock wave therapy applied by a modified standard device to offer more attractive, more technical, smarter, better appearance, larger and with an expansion of external information devices more sophisticated.
• Group III: Shock wave therapy applied by a modified standard device to offer a more austere, disfigured, unattractive, modest and smaller external appearance.

The shock waves emitted to the 3 devices will be identical; the only difference will be the external image of the device.

The main outcome will be the function of the foot by the FFI (Foot Function Index) questionnaire.

As secondary variables: pain by VAS (Visual Analogical Scale) in different situations, the plantar fascia thickness measured by ultrasound, and the perception of patient recovery measured with the Likert scale. Adverse effects, painkillers consumption and pain experienced during the treatment of shock waves were also assessed.

The patients will be followed and monitored for a month, two months and four months after treatment finished.

For the statistical analysis of clinical variables, ANOVA (analysis of variance) will be performed to check whether the evolution of patients over time was different depending on the device applied.

Inclusion Criteria:

1. Age greater than 18 years.

2. Being able to understand the explanations about the potential benefits and risks of study participation.

3. Diagnosis of chronic plantar fasciitis. Proven by clinical examination: Meeting at least 2 of the following criteria:

   • Tenderness in the proximal insertion of the plantar fascia (area of the medial calcaneal tuberosity).
   • Pain during the first steps to get out of bed in the morning and / or after a period of rest time.

4. With a duration of symptoms ≥ 6 months at the time of study entry.

5. Having received conservative therapy without success, at least two treatments. Treatments may have been made isolated, combined or consecutively.

Exclusion Criteria:

1. Bilateral plantar fasciitis.
2. Hiper/ hypothyroidism.
3. Diabetes mellitus.
4. Treatment with anticoagulants
5. Inflammatory diseases.