INTRODUCTION — The deep plantar fascia (plantar aponeurosis) is a thick, pearly-white tissue with longitudinal fibers intimately attached to the skin. Plantar fasciitis, characterized by pain in the plantar region of the foot that is worse when initiating walking, is one of the most common causes of foot and heel pain in adults.
Plantar fasciitis will be discussed in this topic review. Other causes of foot and heel pain are discussed separately. (See "Overview of foot anatomy and biomechanics and assessment of foot pain in adults" and "Achilles tendinopathy and tendon rupture" and "Overview of lower extremity peripheral nerve syndromes" and "Evaluation of the diabetic foot" and "Overview of running injuries of the lower extremity", section on 'Foot and ankle injuries'.)
ANATOMY AND PATHOLOGY — The deep plantar fascia (plantar aponeurosis) is a thick, pearly-white tissue with longitudinal fibers intimately attached to the skin (figure 1). The central portion is thickest and attaches to the medial process of the tuberosity of the calcaneus; distally, it divides into five slips, one for each toe. The plantar fascia provides support; as the toes extend during the stance phase of gait, the plantar fascia tightens (like the shortening of a rope), resulting in elevation of the longitudinal arch, inversion of the hindfoot, and a resultant external rotation of the leg [1].
The site of abnormality is typically near the origin of the plantar fascia at the medial tuberosity of the calcaneum. Specimens of plantar fascia obtained during surgery for plantar fasciitis reveal a spectrum of changes, ranging from degeneration of the fibrous tissue to fibroblastic proliferation, with or without evidence of chronic inflammation [2-4].
EPIDEMIOLOGY — Plantar fasciitis is one of the most common causes of foot pain in adults. The population-based prevalence of self-reported plantar fasciitis with pain in the last month was reported to be 0.85 percent (95% CI 0.77-0.92) in a large internet-panel survey of the adult United States population [5]. It is estimated to be responsible for approximately 1 million patient visits to the doctor per year in the United States [6]. The peak incidence occurs between ages 40 and 60 years in the general population [5], with a younger peak in runners [7,8]. It may be bilateral in up to one-third of cases [7,9,10]. In a community-based population sample of adults aged 50 years or older registered with four general practices in the United Kingdom, and based upon a mailed health survey, the one-month prevalence of plantar heel pain was reported to be 9.6 percent (95% CI 8.8-10.5) [11]. Among those with plantar foot pain, nearly two-thirds (61.5 percent) had consulted a health professional in the last 12 months, most commonly a general practitioner (43.1 percent) and/or podiatrist (32.8 percent). Based upon the general practice records of approximately 1.9 million people in the Netherlands, where all citizens are obliged to be registered with a general practitioner, between 2013 and 2016, the point prevalence of plantar heel pain was 0.44 percent with an overall incidence of 3.83 cases (95% CI 3.77-3.89) per 1000 patient-years [12]. The peak incidence occurred in September and October each year, which the authors postulated might be explained by an increase in activity and change in footwear during the summer months.
ETIOLOGY — The etiology is poorly understood and is probably multifactorial. Possible risk factors for the development of plantar fasciitis include obesity, prolonged standing or jumping, flat feet, and reduced ankle dorsiflexion [8,10,13-16]. However, most studies have been cross-sectional, precluding any conclusions regarding causation [17].
A systematic review of 51 observational studies found that the only significant clinical association with a diagnosis of plantar fasciitis was having a higher body mass index (BMI; odds ratio [OR] 3.7, 95% CI 2.93-5.62) if BMI >27 [18]. However, in the absence of any prospective cohort studies in the general population, the causal role of being overweight or obese is unclear. While heel spurs often coexist with plantar fasciitis, it is also unclear whether they have a causal role; they may instead represent a secondary response to an inflammatory reaction [7,13,19]. One study that assessed presence of foot pain in 137 people with heel spurs compared with age- and sex-matched people without heel spurs found an association between heel spurs and increased BMI, diabetes, and lower-limb osteoarthritis [20]. People with heel spurs had a higher prevalence of foot pain, but the prevalence of plantar fasciitis was similar in both groups. Other positive associations with plantar heel pain that have been reported include lower socioeconomic classification, impaired physical and mental health, low levels of physical activity and participation, anxiety, and depression [11]. Observational data also suggests that the risk of plantar fasciitis may be higher among those with type 2 diabetes compared with those without diabetes [21]. However, the significance of this finding in relation to the pathogenesis of plantar fasciitis remains to be elucidated.
There is a high incidence in runners, suggesting that plantar fasciitis, at least in this population, is due to an injury caused by repetitive microtrauma [22]. In this group, the following have been proposed as risk factors [23-28]:
●Excessive training (particularly a sudden increase in the distance run)
●Faulty running shoes
●Running on unyielding surfaces (including some synthetic running tracks)
●Flat feet (pes planus or pronated ankles)
●Limited ankle dorsiflexion (eg, due to a shortened Achilles tendon)
●Pes cavus (high-arched) foot
●Prolonged walking or standing on hard surfaces
However, high-quality evidence of an association for most of these factors is limited or absent.
Plantar fasciitis is common among ballet dancers [29] and among those performing dance aerobic exercise. Stress applied to the Achilles tendon, due either to muscle contraction or to passive stretching, results in increased tension in the plantar fascia [30]. Decreased knee extension, as may occur with tight hamstring muscles, causes an increase in loading of the forefoot when walking [31]; this could, in turn, increase the stress on the plantar fascia.
Plantar fasciitis usually occurs as an isolated problem but may be associated with systemic rheumatic diseases, particularly reactive arthritis and the spondyloarthritides. Plantar fasciitis has been reported in association with fibromyalgia [32] and with fluoride used for the treatment of osteoporosis [33], and it may be the presenting symptom in patients with nutritional osteomalacia [34].
PATHOLOGY — The site of abnormality is typically near the origin of the plantar fascia at the medial tuberosity of the calcaneum. Specimens of plantar fascia obtained during surgery for plantar fasciitis reveal a spectrum of changes, ranging from degeneration of the fibrous tissue to fibroblastic proliferation, with or without evidence of chronic inflammation [2-4].
CLINICAL MANIFESTATIONS, EVALUATION, AND DIAGNOSIS — The diagnosis of plantar fasciitis is based upon a history of pain in the inferior heel that is worse when initiating walking plus the finding of local point tenderness:
●Patients often describe heel pain that is worse with their first steps in the morning or after a period of inactivity. The pain typically lessens with gradually increased activity, but worsens toward the end of the day with prolonged weight bearing.
●Tenderness is best elicited by the examiner dorsiflexing the patient's toes with one hand in order to pull the plantar fascia taut, and then palpating with the thumb or index finger of the other hand along the fascia from the heel to the forefoot (picture 1). Points of discrete tenderness can be found and marked for possible later injection.
Laboratory testing is not helpful in the diagnosis of plantar fasciitis. Tests for inflammation (eg, erythrocyte sedimentation rate and C-reactive protein) will be normal unless there is coexistent inflammatory disease.
Radiographs are not indicated for the diagnosis of plantar fasciitis but may be required to rule out alternative causes if symptoms are atypical. Plain radiographs including lateral and axial views may be helpful in identifying calcaneal stress fractures. The presence of heel spurs is of no diagnostic value in either ruling in or ruling out plantar fasciitis (image 1). In one study, 85 percent of 27 patients with plantar fasciitis and 46 percent of 79 controls had calcaneal spurs detected on plain non-weightbearing lateral radiographs read by a radiologist blinded to the clinical diagnosis [35]. However, increased plantar fascia thickness and fat pad abnormalities detected in the same radiographs had a sensitivity of 85 percent and a specificity of 95 percent for plantar fasciitis.
Magnetic resonance imaging (MRI) has been used to investigate cases resistant to treatment [36]. Features suggestive of plantar fasciitis are thickening of the plantar fascia and increased signal on delayed (T2) and short tau inversion recovery (STIR) images [37]. Technetium scintigraphy has also been successful in localizing the inflammatory focus and in ruling out stress fracture [38].
Ultrasonography of the foot may detect plantar fascial thickening, hypoechogenicity at the insertion upon the calcaneus, blurring of the boundary between fascia and surrounding tissues, and decreased echogenicity suggestive of edema (image 2) [39,40]. One study reported that plantar heel spurs and plantar fascia thickening frequently coexist in people with plantar heel pain (30 percent), although these changes were also commonly observed in people without heel pain (19 percent) [41], indicating that the presence of these findings also have limited diagnostic value. This study also reported that localized heel tenderness was not associated with these findings, either alone or in combination.
A systematic review identified only a single study that compared ultrasound with MRI as the reference standard in a blinded manner [42]. The sensitivity and specificity of ultrasonography for the diagnosis of plantar fasciitis were 80 and 88.5 percent, respectively, in a study of 77 patients and a similar number of asymptomatic controls [43]. A second study in 25 patients with bilateral heel pain reported lower accuracy (65.8 percent sensitivity and 75 percent specificity), but it was unclear if the reference standard results were blinded [44]. Doppler ultrasound may improve the value of this technique and may provide additional information on local hyperemia [45].
Overall, the diagnostic utility of both ultrasound and MRI for ruling in plantar fasciitis is unproven as they may not add value over a clinical diagnosis alone, and these imaging modalities are not recommended for routine use. They may have value in a research setting such as in randomized trials to determine baseline comparability between treatment groups and/or to assess change over time.
DIFFERENTIAL DIAGNOSIS — Plantar heel pain and pain in the sole of the foot may be induced by a number of other disorders. These include the following [46-48]:
Neurologic causes
●Nerve entrapment or compression syndromes – Entrapment of the posterior tibial nerve (tarsal tunnel syndrome) as it courses beneath the medial malleolus can cause pain, paresthesia, and numbness on the sole of the foot. Percussion tenderness over the posterior tibial nerve in the tarsal tunnel is characteristically found (see "Overview of lower extremity peripheral nerve syndromes", section on 'Tarsal tunnel syndrome'). Compression or trauma to branches of the posterior tibial nerve, particularly the medial calcaneal branch, can lead to medial and plantar burning pain. Compression of the nerve to abductor digiti quinti can also cause burning pain in the heel.
●Neuropathic pain – Patients with peripheral neuropathy are more likely to have a history of diabetes or alcohol abuse and generally report diffuse foot pain with nocturnal symptoms.
●S1 radiculopathy – Patients with lumbar spine disorders may have weakness of plantar flexion (gastrocnemius muscle) and pain radiating down the posterior aspect of the leg to the heel. Absent or reduced ankle reflex is typical. (See "Acute lumbosacral radiculopathy: Pathophysiology, clinical features, and diagnosis", section on 'S1 radiculopathy'.)
Skeletal causes
●Calcaneal stress fracture – Pain arising from the calcaneus may be associated with exacerbation during weightbearing. Stress fractures should be considered if there has been an increase in physical activity. While plain radiographs may be diagnostic, early changes are better differentiated by MRI. Calcaneal fractures can lead to long-term disability but are relatively uncommon. Axial loading of the foot following a fall from a height is the most common mechanism for severe calcaneal fractures. (See "Overview of cancer pain syndromes" and "Nonvertebral osteomyelitis in adults: Clinical manifestations and diagnosis", section on 'Diagnosis' and "Overview of stress fractures" and "Calcaneus fractures".)
●Bone contusion – Direct trauma or excessive weightbearing exercise can lead to a contusion, which is characterized by generalized pain over the inferior heel.
●Osteomyelitis – Infection of the calcaneus may be accompanied by more constant pain and systemic signs such as fever.
●Neoplasm – Tumors in the calcaneal bone are rare and are characterized by deep bone pain and nocturnal symptoms.
●Paget disease – This may be another source of calcaneal bone pain and is generally apparent on plain radiographs with coarsened trabecular bone. An elevated serum alkaline phosphatase may also be present. (See "Clinical manifestations and diagnosis of Paget disease of bone".)
●Haglund deformity – A prominent, enlarged, bony, posterior-superior calcaneal tubercle sometimes causes compression of soft tissue and foot pain (which may be due, in part, to a retrocalcaneal bursitis) in the posterior area of the heel over the bony prominence, above the site of attachment of the Achilles tendon [49]. Patients with this syndrome, termed Haglund deformity or posterior calcaneal tubercle impingement syndrome, may report discomfort when wearing shoes and may have a palpable 2 to 3 mm bony extrusion with an area of erythema and swelling of the overlying skin. (See "Evaluation and diagnosis of common causes of hindfoot pain in adults", section on 'Achilles tendon insertion and Haglund deformity'.)
Treatments include a well-fitted heel cup, a laced or strapped shoe that reduces heel counter friction, and heel padding to raise the heel, although none of these have been subject to randomized trials. Surgical excision may be considered if the exostosis is large and if symptoms persist, but recovery time may be prolonged [50,51].
Soft tissue causes
●Achilles tendinopathy – Disorders of the Achilles tendon typically produce posterior heel pain. Achilles tendinopathy and its management are reviewed in detail separately. (See "Achilles tendinopathy and tendon rupture".)
●Tendinitis of the posterior tibialis or flexor digitorum longus tendons – These typically have an insidious onset with pain and tenderness along the course of the tendons and tendon sheaths. Subtle changes in the position of bones of the midfoot may be indicative of tendon rupture. (See "Non-Achilles ankle tendinopathy".)
●Fat-pad atrophy – Atrophy of the heel pad occurs in older adults. Palpation reveals bony prominence without the padding usually afforded by subcutaneous fat. Unlike pain due to plantar fasciitis, pain due to atrophy of the heel pad is absent in the morning, and it develops and worsens during weightbearing throughout the day.
●Bursitis – Retrocalcaneal bursitis may cause localized swelling and erythema of the posterior heel.
●Painful heel pad syndrome – The painful heel pad syndrome occurs most often in marathon runners. It is thought to result from disruption of the fibrous septae that compartmentalize the fat in the heel pad. Pain is localized to the heel pad. The plantar fascia is not tender, and pain is not accentuated as the examiner dorsiflexes the toes. Insertion of heel cups [52] and "Plastazote" that is individually molded to the patient's heel may be useful [53]. (See "Evaluation and diagnosis of common causes of hindfoot pain in adults", section on 'Heel contusion'.)
●Plantar fascia rupture – Rupture of the plantar fascia generally follows physical activity and has a sudden onset, unlike the more gradual appearance of the pain of plantar fasciitis. Examination of the affected foot may reveal a loss of height of the arch. There may be visible swelling, or ecchymosis may be present.
●Piezogenic papules – Piezogenic papules are herniations of fat that occur as painful papules at the medial inferior border of the heel (picture 2). They may be noted only upon weightbearing and are an uncommon cause of painful heels. Weight reduction, use of felt padding, and cushion- or crepe-soled shoes may provide relief [54]. (See "Evaluation and diagnosis of common causes of hindfoot pain in adults", section on 'Piezogenic papules'.)
Inflammatory disorders
●Reactive arthritis and other spondyloarthritides – Asymmetric involvement and a propensity for the joints and entheses of the lower extremities are frequently seen in the spondyloarthritides. Back pain with inflammatory features (eg, night pain, prolonged morning stiffness) is frequently present in patients with ankylosing spondylitis, while a prior history of enterocolitis or of genitourinary infection is suggestive of reactive arthritis (see "Reactive arthritis"). There are no findings on physical examination that can distinguish between plantar fasciitis and these inflammatory conditions unless other entheses or joints are affected.
●Sarcoidosis – Heel pain has been reported to occur in sarcoidosis [55]. The combination of erythema nodosum, hilar adenopathy, migratory polyarthralgia, and fever is referred to as Lofgren's syndrome and is typically seen in patients with sarcoidosis. (See "Erythema nodosum".)
TREATMENT
General approach to therapy — We generally take the following initial measures (see 'Initial therapy' below):
●Provision of education about the condition including its possible causes and provision of assurance about its favorable natural history. Patients may have unrealistic expectations that medical care can eliminate the pain [56]. It is therefore important to provide an explanation about the likely course of the condition, the fact that treatment is largely symptomatic, and that there are a lack of proven treatments for either substantially alleviating the pain or significantly shortening the duration of the problem.
●Performing of stretching exercises for the plantar fascia and calf muscles, which the patient can do at home.
●Avoiding the use of flat shoes and barefoot walking.
●Using prefabricated, over-the-counter, silicone heel shoe inserts (arch supports and/or heel cups).
●Decreasing physical activities that are suggested by the medical history to be causative or aggravating (eg, excessive running, dancing, or jumping).
●Prescribing or recommending a short-term trial (two to three weeks) of nonsteroidal antiinflammatory drugs (NSAIDs).
●Injecting the tender areas of the plantar region with glucocorticoids and a local anesthetic.
In patients without sufficient improvement from initial measures, more costly therapies can be considered, although these remain unproven (see 'Ineffective and unproven treatments' below):
●Molded shoe inserts (orthotics)
●Night splints
●Immobilization with a cast
Surgery is generally reserved for those patients who do not respond to at least 6 to 12 months of conservative therapy, but it is also unproven. (See 'Resistant disease' below.)
Initial therapy — Treatment of obesity, symptomatic flat feet, and systemic inflammation should be undertaken when these conditions are present. Otherwise, treatment should begin with conservative therapy including measures to relieve pain, alterations in shoes or habits, and exercise therapy. It should be noted that there are limited data for the effectiveness of most of these modalities in the treatment of plantar fasciitis [46,57].
●Rest and icing may give initial pain relief.
●NSAIDs are often used. A well-designed but small trial that randomly assigned 29 patients to NSAID or to placebo reported a nonsignificant trend toward improved pain and disability in the NSAID group [58]. Use for longer than two or three weeks should be reserved for patients with systemic inflammation. Topical NSAIDs are also an option, although there are no data about their effects specifically for plantar fasciitis.
●There are conflicting reports on the benefit of resting padded foot splints [59-62]; these splints can usually be purchased in pharmacies that feature orthopedic supplies (picture 3). The splints are worn at night to keep the ankle in the neutral position with or without dorsiflexion of the metatarsophalangeal joints during sleep. A clinical trial reported they were of similar effectiveness to custom-fitted orthotics (see below), although there was better compliance, as well as fewer side effects, reported with orthoses use [63]. In another randomized trial with 40 unblinded participants, the addition of a night splint to a home exercise program provided no additional clinically important benefit [64].
●Prefabricated silicone heel inserts combined with stretching exercises (see below) may be of value [65]. Felt pads or rubber heel cups appear to be less effective than silicone inserts; magnetic insoles have not been found to provide additional benefit compared with nonmagnetic insoles [66,67].
●Wearing slippers or going barefoot may aggravate symptoms or may result in a recurrence of symptoms. Thus, the first step out of bed should be made wearing a supportive shoe or sandal.
●Patients who work or reside in buildings with concrete floors should use cushion- or crepe-soled shoes. Excessive heel impact from jumping or during walking should be avoided.
●Athletic shoes, arch-supporting shoes (particularly those with an extra-long counter, which is the firm part of the shoe that surrounds the heel), or shoes with rigid shanks (usually a metal insert into the sole of the shoe) may be helpful. Shoes with these features can be found in stores featuring work shoes or "orthopedic shoes."
●Exercises may be beneficial, although evidence is limited [68-70]. Home exercises include plantar and calf-plantar fascia stretches (figure 2 and picture 4), foot-ankle circles (picture 5), toe curls (picture 6), toe towel curls (picture 7), and unilateral heel raises with toe dorsiflexion (picture 8) [71]. Ice massage and deep friction massage may be used prior to exercise, although their effectiveness is unknown. Ultrasound was found to be no more effective than sham ultrasound as an adjunct to plantar fascia and calf muscle stretches in a patient-blinded randomized trial including 54 participants [72], and these findings are consistent with two earlier trials that also reported negative results [73,74].
●Tape support of the affected plantar surface, a technique referred to as low-Dye taping, may be beneficial to some patients particularly for first-step pain [75-77]. Four strips of tape are applied in a specific fashion to provide such support (picture 9). The tape should not be applied too tightly, and use of hypoallergenic tape is recommended to avoid allergic reactions [76].
If these inexpensive and noninvasive measures fail to provide significant pain relief, a trial of a glucocorticoid injection may be of benefit. It should be explained that injection may provide short-term pain relief only, but if effective, can be repeated if needed. It is also important to continue to reinforce the likelihood that the condition will improve over time irrespective of treatment.
The points of tenderness along the plantar fascia may be injected with a glucocorticoid and local anesthetic mixture (figure 3), and a medial approach may be less painful [78]. While the author uses a single injection directed to the site of maximal tenderness, other approaches include injections into more than one tender location along the fascia. There is low- to moderate-quality evidence that use of ultrasound to guide placement of the injection does not improve pain more than palpation-guided injections [79,80].
Numerous randomized trials and systematic reviews have supported that glucocorticoid injections provide modest short-term pain relief [80-85]. Although trials have often extended follow-up to a year, similar to other short-acting antiinflammatory agents and based upon the short half-life of a single local glucocorticoid injection, sustained benefits should not be expected. As an example, in a randomized trial involving 106 patients, significantly less pain was noted in patients who received a single injection of 1 mL each of glucocorticoid and local anesthetic (lidocaine) than in those who received an injection of 2 mL of local anesthetic alone, a difference that was significant at one month but not at three or six months [81]. In a randomized trial including 65 patients, significantly less pain was noted in patients who received a single injection of 0.5 mL (20 mg) of methylprednisolone acetate and 0.5 mL of 0.9 percent saline via either palpation- or ultrasound-guided injection compared with patients who received placebo injection, and these benefits were maintained to 12 weeks [82]. In a study in which four types of injections were compared (25 consecutive patients in each group), those who received glucocorticoid (2 mL of triamcinolone) either as a single injection or using a peppering technique were reported to have better outcomes than those who received either 2 mL autologous blood or 2 mL lidocaine using a peppering technique [83]. A subsequent meta-analysis of three randomized trials, including the aforementioned trial, also concluded that glucocorticoid injection may provide superior short-term pain relief compared with autologous whole blood injection [84].
A 2017 Cochrane review that pooled data from eight trials that compared glucocorticoid injection to either placebo injection (five trials) or no treatment (three trials) confirmed a modest short-term benefit of glucocorticoid injection [80]. However, it may have underestimated the size of the benefit by defining short term as less than four weeks, thereby excluding trials that measured outcome at six weeks. .A three-arm trial including 90 participants that compared glucocorticoid injections with strength training and stretching or with a combination of both reported superior short-term outcomes (three months) in both groups that received glucocorticoid injections compared with exercises alone, while at six months, the combination group had better outcomes compared with either the exercise or glucocorticoid-injection groups [86]. Most participants in both glucocorticoid injection groups received the maximum of three injections at monthly intervals, which was dependent upon plantar thickness (until it was less than 4 mm determined by ultrasound). In the absence of placebo controls for both the injection and exercise interventions, the benefits of adding strength training and stretching to prolong the benefits from glucocorticoid injection await confirmation from further trials.
No serious adverse events have been reported in randomized trials that have evaluated one or more glucocorticoid injections. As suggested by the aforementioned trial, repeat injections may provide added benefit, although judicious use is recommended since repeated injection may cause heel pad atrophy [87]. It may also predispose to plantar fascia rupture [88,89], although evidence for this is limited and nonconclusive. One study reported a series of 37 patients with a presumptive diagnosis of plantar fascia rupture, all of whom had had a prior episode of plantar fasciitis treated with glucocorticoid injection into the calcaneal origin of the fascia [88]. In another study of 765 patients with plantar fasciitis, 43 of 51 patients with plantar fascia rupture had received one or more glucocorticoid injections, although the number of patients without plantar fascial rupture who received one or more glucocorticoid injections was not reported [89].
Other potential measures for people with significant persistent pain and disability include custom orthotics, a trial of iontophoresis therapy, or a short walking cast:
●There are considerable variations in the prescribing habits of podiatrists, orthopedists, and prosthetists [90-93]. Customized orthotics cost approximately two- to sixfold more than prefabricated ones [91]. However, mounting evidence casts doubt on the effectiveness of all forms of foot orthoses for plantar heel pain [93,94].
Custom-fabricated inserts, usually provided by podiatrists, include inserted orthoses with foam-rubber raised arches and rubber or tub heels, as well as molded ankle-foot orthoses. A Cochrane systematic review that identified five trials including 691 participants that assessed the use of custom-made foot orthoses for plantar fasciitis was inconclusive [90]. Comparators varied across trials and included sham orthoses, no treatment, non-custom foot orthoses, night splints, and a combination of manipulation, mobilization, and stretching; all trials were judged to be at high risk of bias. Four trials reported comparable outcomes between treatment groups, while a fifth found better functional outcomes but comparable pain relief with use of custom-made foot orthoses compared with sham orthoses at 3 and 12 months [91].
Two systematic reviews question the use of orthoses for plantar heel pain [93,94]. One systematic review of 20 randomized trials found that foot orthoses of various types were not superior to sham orthoses or other nonsurgical interventions (eg, antiinflammatory agents, exercise) for improving pain and function [93]. Included in the analysis was a comparison between custom and prefabricated orthoses, which were also found to be no different from each other in terms of short-term pain relief (up to three months). The second systematic review, which included 19 trials, drew similar conclusions [94].
Trials comparing different types of orthoses with each other or with other therapies continue to be funded and performed. As an example, one trial of hard versus modified soft custom orthotics and heel pads in 53 adults with heel pain found no between-group differences in outcome other than that the soft orthotics were less expensive [95]. Another trial of foot orthosis compared with glucocorticoid injection in 103 participants recruited via social media and with only moderate average pain at baseline (mean scores of only 51.1 out of 100 and 56.8 out of 100 in the orthosis and injection groups, respectively) reported modest, likely unimportant, greater pain relief with glucocorticoid injection at four weeks, although this group was more likely to report an overall improvement in symptoms (relative difference 18 percent [95% CI 3-36 percent]) [96]. There were no between-group differences in pain at 8 weeks, and by 12 weeks, modest, likely unimportant, pain differences favored the orthosis group.
●Iontophoresis with 0.4 percent dexamethasone (six sessions over two weeks) provided moderate initial relief of plantar pain in a small, randomized, placebo-controlled trial in runners with plantar fasciitis, although this effect was not maintained at four weeks [97]. In another small study, low-Dye taping combined with iontophoresis with a 5 percent solution of acetic acid was superior to taping and iontophoresis with 0.4 percent dexamethasone, but was comparable in benefit to taping and iontophoresis with placebo (in place of either acetic acid or dexamethasone) [98].
●A short walking cast is used by some orthopedists, though there are no published trials of this treatment approach.
Resistant disease — The vast majority of patients with plantar fasciitis will improve. It is estimated that 2 to 5 percent of patients with plantar fasciitis undergo surgical procedures [7,9,22,99], although the rate may be much lower. As an example, a report of the surgical experience at the Mayo Clinic found that only 16 operations had been performed during a 12-year study period [100].
Surgery is generally considered a "last line of therapy," reserved for those patients who do not respond to at least 6 to 12 months of nonoperative therapy. However, the efficacy of surgery remains unproven. While numerous surgical procedures have been described, almost none have been assessed in randomized trials.
Favorable outcomes are reported in more than 75 percent of published case series, although recovery time may be prolonged, and persistent pain is not uncommon. Without a control group, it is not possible to know whether or not these outcomes mirror the outcomes without surgery. Variations of open or endoscopic, partial or complete, plantar fascia release with or without calcaneal spur resection, excision of abnormal tissue, and nerve decompression have been described. A single randomized trial of surgery compared with nonoperative treatment compared endoscopic fasciotomy (and removal of bone spur if present) with glucocorticoid injection in 30 participants recruited from sports magazines, all of whom wished to return to their sports [101]. The authors reported a benefit favoring surgery at six months in pain during function but not morning pain or function. Differences favoring surgery were also reported for function at 12 but not 24 months, and pain at 24 and not 12 months. It is not clear that these differences were clinically important or that differences at these timepoints could truly be attributed to treatment received 12 and 24 months previously in the absence of clinically important differences at earlier timepoints. There also appeared to be baseline differences between groups with respect to age, walking/standing hours per day, symptom duration, and morning pain and pain during function. The observed improvements over time in both groups likely reflect the natural history of the condition, and adequately powered high-quality placebo-controlled trials evaluating the efficacy of surgery are needed.
A small trial compared endoscopic deep versus superficial fasciotomy and reported better early postoperative function scores and fewer adverse events in the superficial fasciotomy group; however, the functional scores at one year were similar [102].Combining release of the plantar fascia and the first branch of the lateral plantar nerve may enhance results. In one series of 28 patients (33 feet), over 90 percent of patients had a good outcome and would recommend the procedure to others [103].
The use of radiofrequency microtenotomy, which can be performed via open or percutaneous surgery, has been described as a treatment for plantar fasciitis either alone or in conjunction with plantar fasciotomy. A retrospective review including 91 patients treated at one center reported similar outcomes from radiofrequency microtenotomy compared with plantar fasciotomy and no added benefit of having both procedures [104]. Patients undergoing both procedures tended to have more complications compared with either procedure alone.
In comparison with open-release, closed procedures may allow more rapid recovery and resumption of usual activities [105,106]. In an uncontrolled series of 16 runners and 10 walkers with refractory plantar fasciitis, uniportal plantar fasciotomy gave good or excellent results, provided that the patient's body mass index (BMI) was less than 27 [107]. Runners in this series required a mean of 2.6 months before returning to jogging.
Potential complications of surgery include transient heel pad swelling, calcaneal fracture, injury to the posterior tibial nerve or its branches, and flattening of the longitudinal arch with resultant midtarsal pain. These potential harms should be balanced against the fact that the true value of surgery currently remains unknown.
Ineffective and unproven treatments — New approaches that may be helpful in patients without sufficient improvement from initial measures are needed. Unfortunately, many unproven and costly treatments continue to become accepted into routine care prior to high-quality evidence demonstrating that they are of value.
Extracorporeal shock wave therapy (ESWT) has been more extensively studied than any other single treatment modality and continues to be both widely promoted and studied. Yet there is high-certainty evidence based upon randomized trials that it is ineffective in treating plantar fasciitis. Autologous whole blood and platelet-rich plasma injections are other costly, unproven treatments that have been widely promoted and studied, although the evidence base does not strongly support their use. These therapies and others are discussed further below:
●Extracorporeal shock wave therapy – A systematic review published in 2005 included 11 trials and performed a pooled analysis of data from 6 trials involving 897 participants [108]. The authors concluded that there was no clinically important benefit of shock wave therapy, despite a small statistically significant benefit in morning pain of less than 0.5 cm on a 10 cm visual analog scale. Further, no statistically significant benefit was observed in a sensitivity analysis that only included studies at low risk of bias. Subsequent systematic reviews have included additional trials and concluded that shock wave therapy is more effective than placebo [109,110]. However, these reviews overestimated benefits of shock wave therapy due to omission of high-quality trials [109] and/or errors in data extraction and data analysis [110]. Revised pooled estimates from one of the aforementioned systematic reviews that corrected for errors in data extraction no longer demonstrated a benefit of shock wave therapy [111]. One open trial reported that outcomes from shock wave treatment were inferior to glucocorticoid injection in people with acute symptoms (<6 weeks' duration) up to 12 weeks [112,113]. A randomized placebo-controlled trial including 250 patients reported superior outcomes of focused shock wave therapy in terms of percentage change in pain from baseline and mean scores on the Roles and Maudsley scale [114]. However, no raw data were provided to verify that the differences were of clinical importance, and the validity of use of the Roles and Maudsley four-point categorical scale for plantar fasciitis and its analysis as a continuous measure was not reported. Success of blinding was also not reported. The major reported adverse effect of ESWT is transient pain at the time of treatment. A systematic review and network meta-analysis confirmed the large number of studies that have evaluated this treatment as well as its lack of benefits compared with other treatments (including placebo) in the short, medium, or longer term [85].
●Autologous whole blood or platelet-rich plasma injections – Injection of autologous whole blood has been proposed as a treatment for plantar fasciitis on the basis that it contains various growth factors that may begin a cascade of local factors to stimulate angiogenesis and healing [115]. While no trials have assessed the efficacy of autologous blood injection compared with placebo for plantar fasciitis, several trials have compared this treatment with glucocorticoid injection. A systematic review that included five trials found that glucocorticoid injection was more effective than autologous whole blood injection in alleviating pain in the short term (up to six weeks), and this finding was consistent across all the trials [116]. The lack of between-group difference in medium-term (7 to 12 weeks) and longer (13 to 52 weeks) outcomes provides further evidence of the lack of benefit of this treatment in view of the known lack of sustained benefit of glucocorticoid injection over time [115].
Autologous platelet-rich plasma injections are an adaptation of autologous whole blood injections. Whole blood is centrifuged to a concentrated state and is injected into the plantar fascia. One three-arm randomized trial involving 75 participants reported that autologous platelet-rich plasma injection was significantly more effective than placebo in relieving pain and improving the American Orthopaedic Foot and Ankle Society Score and was of similar efficacy to glucocorticoid injection [117]. However, mean between-group differences were not reported and the placebo group failed to improve over time, which is out of keeping with the natural history of the condition. There have also been numerous trials of varying quality that have compared this treatment with glucocorticoid injections [118-121]. Most have not blinded participants, and the results have been conflicting. Systematic reviews have graded the evidence as very low certainty based upon very serious limitations of the included trials and serious inconsistency and imprecision [80,116]. An open randomized trial with 115 participants published following these reviews reported no between-group differences in outcomes at 3 and 6 months, but better pain and disability outcomes in favor of platelet-rich plasma injection at 12 months [120]. However, a large loss to follow-up in both groups at 12 months (27 percent in the platelet-rich plasma injection group and 31 percent in the glucocorticoid group) was unexplained, and it is unclear how these were accounted for in the analysis, while losses to follow-up at other timepoints were not provided. A small trial (36 participants) also failed to find a between-group difference in outcome between platelet-rich compared with platelet-poor plasma injection, although it was likely underpowered to detect any difference if one was truly present [122].
Platelet-rich plasma injection therapy has been used for other orthopedic conditions, although the effects are likely similar. (See "Overview of the management of overuse (persistent) tendinopathy", section on 'Autologous blood and platelet-rich plasma injection' and "Elbow tendinopathy (tennis and golf elbow)", section on 'Platelet-rich plasma and other biologic injections'.)
●Botulinum toxin injection – A single, small, randomized trial of 27 patients with unilateral or bilateral plantar fasciitis assessed the effect of two injections of botulinum toxin (total of 70 units), one into the foot near the calcaneal tuberosity (40 units) and the other into the arch (30 units) [123]. Feet injected with botulinum toxin had more improvement in pain and tenderness at three and eight weeks than those injected with saline solution (placebo), although effect sizes were not reported. Another randomized trial found comparable benefit of botulinum injection or glucocorticoid injection for plantar fasciitis at one month [124]. A subsequent trial reported botulinum toxin injection was superior to saline injection in 50 participants at 6 and 12 months with respect to pain and function [125]. A small trial including 32 participants reported superior outcomes with botulinum toxin injected into the medial gastrocnemius muscle compared with placebo (saline) injection that were sustained to 12 months [126]. As botulinum toxin causes localized muscle paralysis, which is postulated to be the mechanism of its action, it is not clear how well participants would have been blinded in any of these trials. Further high-quality trials are needed before considering this treatment approach for usual care.
●Topical corticosteroid – The role of topical corticosteroid was evaluated in a participant-blinded randomized trial including 80 participants comparing the benefit of adding three fingertip units of topical clobetasol ointment or placebo (ie, petroleum jelly) in an occlusive dressing 30 minutes before four weekly sessions of low-energy ESWT [127]. The combination therapy yielded greater improvement in morning pain and function at one but not three months compared with the control group.
●Complementary therapies – Topical application of wheatgrass cream twice daily for six weeks was ineffective when compared with placebo in a randomized trial involving 80 participants [128]. Other trials of complementary therapies are expected.
●Radiotherapy – Radiation therapy is sometimes used in Europe to treat chronic plantar fasciitis that is unresponsive to more conservative approaches [129]. Its effectiveness has not been assessed in randomized placebo-controlled trials, and whether there is a long-term increased risk of carcinogenesis is unknown. In one unblinded and unregistered trial comparing low-dose radiation with platelet-rich plasma injection in 40 sportspeople, similar improvements in pain and function at six months were reported [130]. Because of concern about the possibility of late-onset hematopoietic malignancy, radiation therapy is seldom used to treat plantar fasciitis in other parts of the world.
●Cryosurgery – A single-arm study that used percutaneous cryosurgery, a minimally invasive technique for freezing tissue, to treat plantar fasciitis in 59 patients reported a benefit at one year but did not report earlier outcomes [131]. The effectiveness of this technique needs to be assessed in controlled trials.
●Low- and high-level laser therapy – A systematic review that included six trials that compared low-level laser therapy with placebo (two trials), usual care (two trials), ESWT, or low-intensity focused ultrasound and combined the data into a single meta-analysis reported that low-level laser therapy provides superior short-term (three months) pain relief without differences in disability [132]. Two trials have compared low- versus high-intensity laser therapy and reported conflicting results [133,134]. One trial including 70 participants reported better outcomes for the high-intensity group at the end of treatment, but it was not clear whether or not the patients were blinded [135], while the other trial including 109 participants but a high rate of loss to follow-up (>37 percent in both groups) reported no between-group differences in outcomes [133]. A third trial including 42 participants that compared high-intensity laser therapy with placebo reported no benefit of laser therapy [134]. Further trials are needed before considering these treatment approaches for usual care.
●Electric dry needling – A randomized trial investigated the value of up to eight sessions of electric dry needling (one to two times a week for four weeks, each session needles inserted into eight points for 20 minutes) as an adjunct to exercise, manual therapy, and ultrasound in 111 patients with plantar fasciitis [136]. Patients in the dry needling group were found to have a clinically relevant benefit in pain and disability at one and four weeks and three months, although 67 percent experienced post-needling muscle soreness and over a quarter (25.9 percent) experienced mild bruising resolving within two to four days. A second trial in 73 patients with heel pain found that electrolysis administered by a single needle once a week for five weeks resulted in improvements in pain and function at one week maintained to six months [137]. Further placebo-controlled trials are needed to confirm these results.
●Micronized dehydrated human amnion/chorion membrane (dHACM) injection – A randomized trial involving 145 participants with plantar fasciitis found that a single 1 mL dHACM injection resulted in clinically relevant benefits in pain and foot function at three months compared with placebo [138]. However, collected outcomes at 6 and 12 months were not reported. There were three adverse events following dHACM injection (two patients with post-injection pain and one with itching). The cost of the injection was not specified and the trial was industry-sponsored. Further trials are needed to confirm these results.
●Other injection therapies that have been tested in single trials include dextrose prolotherapy [139], polydeoxyribonucleotide injection [140], and local ozone (O2-O3) injection [141]. Dextrose prolotherapy is purported to induce a regenerative process. One trial including 65 participants reported enormous improvements in pain, disability, and plantar fascia thickness with dextrose prolotherapy (dextrose and saline and lidocaine) compared with placebo (saline and lidocaine) at 7 and 15 weeks [139]. These results require replication. Polydeoxyribonucleotide is derived from salmon sperm and is also purported to stimulate regeneration [140]. One trial including 44 participants compared this therapy with glucocorticoid injection and found superior pain relief with glucocorticoid injection at two and six weeks and superior effects on function at six weeks, while outcomes were similar at six months [140]. Lack of any between-group differences at six months suggests this treatment is ineffective, and improvements in both groups at six months may reflect the natural history of the condition. Ozone is purported to reduce local inflammation [141]. In the single trial of this therapy, 30 participants were randomized to receive either ozone or glucocorticoid injection [141]. Glucocorticoid injection provided superior pain relief at two weeks, while the visual data presented in the paper suggested no important between-group differences at 12 weeks, while only glucocorticoid injection improved plantar fascia thickness at the plantar insertion. Similar to the aforementioned study, these results confirm the short-term benefits of glucocorticoid injection but do not support effectiveness of the new therapy.
Prevention — The efficacy of preventive strategies, such as stretching exercises and control of the intensity of running (eg distance, frequency, and duration), in specifically preventing plantar fasciitis is unknown [142]. Footwear designed to maximize shock absorption may be of value [143]. In a study including 306 naval recruits, use of a contoured prefabricated foot orthosis resulted in a trend towards fewer lower limb overuse injuries compared with use of a flat insole (17.6 versus 26.1 percent, incident rate ratio [IRR] 0.66, 95% CI 0.39-1.11) [144]. Plantar fasciitis occurred in seven participants who had the flat insole versus 12 who received the prefabricated foot orthosis. Further studies are needed to determine whether or not use of prefabricated foot orthoses truly reduces the incidence of plantar fasciitis in the general population as well as specific subgroups such as defense personnel who wear defense-issued footwear and athletes.
PROGNOSIS — The outcome for patients with plantar fasciitis is generally favorable; approximately 80 percent of patients have complete resolution of pain within one year [9,99,145,146]. The favorable natural history of this benign condition should be borne in mind when weighing the potential benefits and risks of unproven and sometimes costly treatments.
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Plantar fasciitis".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
●Basics topics (see "Patient education: Heel pain caused by plantar fasciitis (The Basics)")
●Beyond the Basics topics (see "Patient education: Heel and foot pain (caused by plantar fasciitis) (Beyond the Basics)")
SUMMARY AND RECOMMENDATIONS
●The deep plantar fascia (plantar aponeurosis) is a thick, pearly-white tissue with longitudinal fibers intimately attached to the skin (figure 1). The central portion is thickest and attaches to the medial process of the tuberosity of the calcaneus; distally, it divides into five slips, one for each toe. (See 'Anatomy and pathology' above.)
●Plantar fasciitis, characterized by pain in the plantar region of the foot that is worse when initiating walking, is one of the most common causes of foot and heel pain in adults. The peak incidence occurs between ages 40 and 60 years in the general population, with a younger peak in runners. It may be bilateral in up to one-third of cases. (See 'Epidemiology' above.)
●The etiology is poorly understood and is probably multifactorial. Possible risk factors include obesity, prolonged standing or jumping, flat feet, and reduced ankle dorsiflexion. Plantar fasciitis usually occurs as an isolated problem but may be associated with systemic rheumatic diseases, particularly reactive arthritis and the spondyloarthritides. (See 'Etiology' above.)
●The diagnosis of plantar fasciitis is based upon a history of pain in the inferior heel that is worse when initiating walking, plus the finding of local point tenderness (see 'Clinical manifestations, evaluation, and diagnosis' above):
•Patients often describe heel pain that is worse with their first steps in the morning or after a period of inactivity. The pain typically lessens with gradually increased activity but worsens toward the end of the day with prolonged weight bearing.
•Tenderness is best elicited by the examiner dorsiflexing the patient's toes with one hand in order to pull the plantar fascia taut, and then palpating with the thumb or index finger of the other hand along the fascia from the heel to the forefoot (picture 1).
●For initial therapy, we generally take the following measures (see 'Initial therapy' above):
•Provision of education about the condition including its possible causes and provision of assurance about its favorable natural history. It is important to explain that treatment is largely symptomatic and that there are a lack of proven treatments for either substantially alleviating pain or significantly shortening the duration of the problem.
•Performing of stretching exercises for the plantar fascia and calf muscles, which the patient can do at home.
•Avoiding the use of flat shoes and barefoot walking.
•Using prefabricated, over-the-counter, silicone heel shoe inserts (arch supports and/or heel cups).
•Decreasing physical activities that may be causative or aggravating (eg, excessive running, dancing, or jumping).
•Prescribing a short-term trial (two to three weeks) of nonsteroidal antiinflammatory drugs (NSAIDs).
●Among patients in whom significant pain and disability persists despite the use of conservative measures for three to four weeks, we suggest a single glucocorticoid injection (Grade 2B). (See 'Initial therapy' above.)
●In patients in whom the treatments above have not produced sufficient improvement, we occasionally prescribe molded shoe inserts (orthotics) or immobilization in a cushioned walking boot (see 'Initial therapy' above). However, mounting evidence suggests orthotics are of low value, and cushioned walking boots remain unstudied in randomized trials. We do not use other interventions such as extracorporeal shock wave therapy (ESWT), which is costly and ineffective, or autologous whole blood or platelet-rich plasma injections, which are costly and of unproven benefit. (See 'Ineffective and unproven treatments' above.)
●The vast majority of patients with plantar fasciitis will improve with or without active therapy. Surgery is an option for patients with persisting severe symptoms after at least 6 to 12 months of nonoperative therapy, although its value remains highly uncertain. (See 'Resistant disease' above.)
