The purpose of this research is to collect safety and efficacy data on injection of botulinumtoxinA (AbobotulinumtoxinA /Dysort) into the gastrocnemius (calf) muscle to improve equinus (lack of flexibility to bring the top of the foot towards the front of the leg) in subjects with plantar fasciitis and relieve pain associated with this condition. The use of AbobotulinumtoxinA is considered experimental in this study because it has not been approved by the United States Food and Drug Administration (FDA) for the treatment of plantar fasciitis.

Inclusion Criteria:

1. At least 18 years old and not older than 75 years.
2. History of Plantar fasciitis for a minimum of 6 weeks
3. History and physical examination consistent with plantar fasciitis and a diagnostic ultrasound study showing thickening of the plantar fascia >5 mm (normal is 3 mm)
4. Minimum Visual Analog Scale (VAS) score of 4.
5. Failed conservative care with at least two of the following treatments: Stretching, rest, shoe modifications, insoles or orthotics, physical therapy, or cortisone injection.
6. Females of childbearing potential must be willing to use acceptable methods of contraception (birth control pills, barriers or abstinence) during the course of the study and undergo pregnancy tests.
7. Subject understands and is willing to participate in the clinical study and can comply with visit and post -injection questionnaire schedules.

Exclusion Criteria:

1. Patients with history of diabetes, back issues, nerve issues or previous surgery of the foot or calf.
2. Patients with no pain in the heel region.
3. Subject is pregnant or breast- feeding.