The primary aim of this clinical experiment is to compare, in terms of pain relief measured using the 10-cm visual analog scale (VAS) pain score (5-7), the clinical results of ultrasound-guided injection (USGI) versus anatomic topography-guided injection (ATGI) of corticosteroid for the treatment of proximal PF. Secondary aims will be to compare foot-related quality of life, as measured using the Foot Function Index (FFI)and the Bristol Foot Score (BFS), between the injection groups, and also to compare the pre-injection to late-term post-injection thickness of the plantar fascia as measured in the nested USGI group.

Clinically, proximal PF causes plantar heel pain, which may extend into the proximal portion of the plantar longitudinal arch. Typically, the pain is most notable upon initial weight bearing ambulation (post-static dyskinesia, PSD), such as the first step in the morning or following a period of non-weight bearing or rest. This can be attributed to walking on hard surfaces or barefoot, prolonged weight bearing activity, inadequate stretching and use of poor footwear, as well as increased amounts of walking. Standard treatment of PF includes the use of foot orthotics, both pre-fabricated and custom molded, physical therapy and myotendinous stretching, splinting or strapping the foot, nonsteroidal anti-inflammatory drugs, ice, and corticosteroid injections. Ultrasonography (US) can be useful for examining the plantar fascia, which typically measures between 2 mm to 4 mm in thickness, and findings indicative of PF include diffuse hypoechogenicity at the calcaneal attachment of the plantar fascia, loss of definition between the plantar fascia and the surrounding soft tissues, peri-insertion edema, and thickness over 4.5 mm. Local infiltration of corticosteroids has been used to treat PF since the 1950s. Despite this being a well established treatment, there are still unexamined features of this form of intervention, including the method of injection, type of steroid used, concurrent use of localanesthetic agents, concurrent use of orthoses and/or supportive arch strapping, concurrent physical therapy, and the use of ultrasonographic guidance of the corticosteroid injection. The primary aim of this clinical experiment is to compare, in terms of pain relief measured using the 10-cm visual analog scale (VAS) pain score (5-7), the clinical results of ultrasound-guided injection (USGI) versus anatomic topography-guided injection (ATGI) of corticosteroid for the treatment of proximal PF. Secondary aims will be to compare foot-related quality of life, as measured using the Foot Function Index (FFI)and the Bristol Foot Score (BFS), between the injection groups, and also to compare the pre-injection to late-term post-injection thickness of the plantar fascia as measured in the nested USGI group.

Inclusion Criteria:

• Pain on palpation along the proximal plantar fascia with or without radiographic evidence of a plantar calcaneal bone spur
• ≥18 years of age
• Male or non-pregnant female of any ethnicity or race
• Active, former or non smoker
• With or without peripheral vascular disease without lower extremity intermittent claudication or rest pain
• With or without diabetes mellitus without polyneuropathy
• With or without collagen vascular disease without lower extremity wound formation.

Exclusion Criteria:

• Known drug or alcohol dependence
• Chronic pain syndrome or lumbosacral radiculitis
• Neurological condition that requires the use of analgesic medications or anti-seizure or neuroleptic medications
• Peripheral vascular disease that results in rest pain or intermittent claudication or venous stasis ulceration
• Calcaneal stress fracture or show evidence of a foreign body or tumor of the affected heel as viewed radiographically
• Pregnant females
• Known allergy to any of the components of the injection therapy
• Previously suffered a rupture or surgery of the plantar fascia within the 5 years preceding participation in the investigation
• Existing or prior osteomyelitis of the involved calcaneus
• Unable to consent to participation in clinical research or currently be involved in another clinical investigation.

Participants that do not experience at least a 50% reduction in pain following phase 1 will undergo randomization to either USGI or ATGI, both injections consisting of 0.5 ml 0.25% bupivacaine plain, 0.5 ml dexamethasone phosphate, and 0.5 ml triamcinolone acetonide 40 mg/ml. Execution of the USGI will employ an actual diagnostic US machine (Voluson E8 Expert, General Electric Company, Boston, MA) and a plantarmedial approach, whereas execution of the ATGI will employ a sham diagnostic US machine and a plantarmedial approach. The patients will be randomized into these groups by a specialized statistical computerized system that randomly selects a number to the participant. An even or an odd number represents which form of injection the patient is to receive.