Efficacy of Extracorporeal Shockwave Therapy on Plantar Fasciitis in Patients With Peripheral Neuropathy

Plantar fasciitis is the most common cause of heel pain in clinical practice, accounting for approximately 80% of patients presenting with heel pain. Common clinical presentations include unilateral or bilateral foot pain, particularly upon weight-bearing after a period of rest, such as the first steps in the morning. Some patients may also report associated paresthesia, tingling, or a burning sensation. Notably, a considerable number of patients with peripheral neuropathy (PN) also present with coexisting plantar fasciitis. The proposed pathophysiological mechanisms underlying neuropathy-associated plantar fasciitis include progressive degeneration of the plantar fascia due to chronic somatosensory deficits, thickening of the plantar fascia secondary to metabolic syndromes such as diabetic neuropathy, and the loss of foot intrinsic muscle support due to motor nerve involvement. Conventional treatments for plantar fasciitis include nonsteroidal anti-inflammatory drugs (NSAIDs), local corticosteroid injections, and custom orthotics; however, these interventions exhibit significant limitations. While NSAIDs may provide temporary analgesia, their long-term utility is limited by systemic risks, particularly gastrointestinal complications. Local corticosteroid injections effectively reduce inflammation and provide acute symptom relief; however, they carry a risk of plantar fascia rupture, rendering repeated administration clinically unfavorable. Orthotic insoles redistribute biomechanical loading across the foot to reduce mechanical stress; however, they are primarily compensatory and do not facilitate tissue regeneration or fundamental repair of the chronic lesion. Given these limitations in conventional treatments, this study aims to evaluate the efficacy of extracorporeal shockwave therapy (ESWT) in reducing pain and improving functional outcomes for patients with neuropathy-associated plantar fasciitis. The investigators will assess the effects of ESWT on the pathophysiological mechanism of the neuropathic foot to alleviate the symptoms of plantar fasciitis in participants with peripheral neuropathy. Findings of the investigation aim to validate the clinical application of non-invasive ESWT for this population, thereby enhancing their functional independence and health-related quality of life.

Inclusion criteria

• Age 18 or older and 90 or younger.
• Ability to give informed consent.
• Presence of peripheral neuropathy, confirmed by clinical symptoms, nerve
• conduction study, autonomic function test, quantitative sensory test, or skin biopsy.
• Plantar fasciitis presenting as (1) heel pain persisting for more than 3 months, most noticeable with initial steps after a period of inactivity, but also worse following prolonged weight-bearing, and (2) pain with palpation of the proximal insertion of the plantar fascia.

Exclusion criteria

• Presence of severe systemic diseases, including severe ischemic heart disease or congestive heart failure (left ventricular ejection fraction < 30%), severe lung diseases with dyspnea, severe generalized edema, uncontrolled diabetes, and systemic infection.
• Presence of severe peripheral vascular disease.
• Presence of an implanted cardiac pacemaker, deep brain stimulator, or metallic implants (for example, internal fixation plates, screws, etc.) within the affected foot or ankle.
• Presence of ruptured or pre-ruptured tendons in the target area. A diagnostic softtissue ultrasound of the plantar foot will be performed to assess tissue integrity if any of the following clinical red flags are identified: localized soft-tissue swelling or ecchymosis; physical examination findings indicative of a loss of continuity or tension in the plantar fascia; a history of local corticosteroid injection within the past 12 months; or a history of surgical intervention involving the affected foot.
• Complete loss of vibration and pinprick sensation at the target area due to neuropathy, or the presence of severe mechanical allodynia (pain evoked by friction or pressure) at the target area with an intensity score of 8 or higher on the Numeric Rating Scale (NRS), where 0 represents no pain and 10 represents the most severe pain.
• Pregnancy.
• Coagulation disorders (including localized thrombosis in the target area).
• Patients currently receiving anticoagulant therapy.
• Presence of localized tumors or active bacterial and/or viral infections in the target area.
• Patients who have received corticosteroid injections within the past 6 weeks in the target area.
• Inability to give informed consent.