Published guidelines for management of plantar fasciitis don’t cover every detail of which interventions to try, in what order, and for how long. As a result, every practitioner tends to interpret the gray areas just a little differently.
By Cary Groner
The wide variability in clinical approaches to plantar fasciitis was vividly illustrated by a survey of surgeons presented at the American Academy of Orthopaedic Surgeons (AAOS) meeting in San Diego a year ago.1 Respondents chose among treatment modalities for patients presenting with fasciitis of four months’ duration, then picked from an expanded menu if symptoms persisted at 10 months. Responses were all over the map, and the survey included only academic orthopedic foot and ankle surgeons—not podiatrists or physical therapists, who would likely have introduced further variability.
The study raised obvious questions about decision trees for treating fasciitis, and what evidence there is to support them. Both the American College of Foot and Ankle Surgeons (ACFAS) and the American Physical Therapy Association (APTA) recently published updated guidelines2,3 for assessing and treating heel pain (see “Heel pain revisited: New guidelines emphasize evidence,” June 2010, page 14). But those guidelines differed on several key points (e.g., the appropriateness of in-shoe orthoses or physical therapy), and levels of evidence varied for recommended procedures. And the guidelines also noted that not all heel pain is caused by fasciitis.
So how do clinicians make decisions about diagnosis and treatment? LER spoke to an array of practitioners and discovered that although the discussion can be fractious, there appears to be growing consensus about certain aspects.
Diagnosis is key
Clinicians emphasize that decisions about treatment begin with correct diagnosis, because getting it wrong means time and money wasted on therapies unlikely to work. The differential diagnosis for fasciitis includes tarsal tunnel syndrome (TTS), entrapment of the first branch of the lateral plantar nerve (Baxter’s nerve), calcaneal stress fracture, and radiculopathy.4 Of these, Baxter’s nerve compression or entrapment is probably the most common neural cause of heel pain and may actually coexist with fasciitis. Practitioners note that other conditions mimic fasciitis, as well.
“We ran a heel pain clinic at the podiatry school; more than half the patients were referred by outside doctors and had had various treatments,” said Paul Scherer, DPM, referring to the California College of Podiatric Medicine in Oakland. (Scherer is now a clinical professor of podiatric medicine and surgery at the College of Podiatric Medicine, Western University of Health Sciences, in Pomona, CA.)
“The majority of patients who had failed treatment did not have fasciitis,” he continued. “They had rheumatoid arthritis, gout, pseudo-gout, ankylosing spondylitis, psoriatic arthritis, neuropathies, calcaneal fractures, tarsal tunnel syndrome, Paget’s disease, or Reiter’s syndrome related to HIV. The workup is necessary, because all these other disorders have easy-to-define symptoms.”
For Jeffrey Johnson, MD, chief of the Foot and Ankle Service at Barnes-Jewish Hospital at Washington University Medical Center in St. Louis, the patient history is vital for accurate detection of fasciitis.
“You’re trying to rule out neurogenic or inflammatory causes,” he said. “Pain that goes away after the first few steps in the morning is classic [for plantar fasciitis], as is pain that resolves quickly when they [patients] get off their feet. People with fasciitis don’t use terms like burning pain, tingling, numbness, or pain like electrical shock, which are likely related to nerve entrapment.”
Judith Baumhauer, MD, the associate chair of academic affairs in the Department of Orthopaedics at the University of Rochester School of Medicine and Dentistry, agreed that the quality of pain is telling.
“For tarsal tunnel syndrome, I want to know if they feel any numbness or paresthesia on the bottom of the foot,” she said. “For a calcaneal stress fracture, I ask if there’s been an increase in activity, and I want to see if there is swelling. In the physical exam, I look for pain near the insertion of the plantar fascia—the plantar medial aspect of the heel—then do Tinel’s and compression testing over the tibial nerve to determine if they have any impingement symptoms.”
Baumhauer squeezes the patient’s heel, medial to lateral, to assess for calcaneal fracture. She also palpates the plantar fascia, the Achilles tendon, and the posterior tibialis tendon to identify localized pain. In addition, she checks for heel pad atrophy, particularly in the elderly.
Richard Blake, DPM, who practices at the Center for Sports Medicine at St. Francis Memorial Hospital in San Francisco, noted that some problems can occur concurrently with fasciitis or even lead to it.
“If someone has a stress fracture, they’re going to naturally shift some weight to the ball of the foot, and that puts tension on the plantar fascia. We might not see them until six weeks in; they’ve been limping and now their Achilles is sore too,” Blake said.
For Michael Gross, PT, PhD, a professor of physical therapy at the University of North Carolina, assessment is essential to determining treatment.
“I want to know how they came to have this condition,” he said. “Is it related to increased activity, or a gain in body weight? Have they been pregnant—and if they’ve delivered the child, are they carrying the child around as the child grows and gets heavier?”
According to Gross, the etiology of fasciitis could also be anatomic, caused by a tight plantar fascia or limited ankle dorsiflexion.5
“Most often we see the motion limitation as a result of a tight triceps surae,” he explained. “Forefoot varus can drive collapse of the arch. Genu varus, or tibial varum, or both, tend to incline the distal third of the leg medially, which makes the lateral border of the foot contact the ground first, and then the ground reaction force causes arch collapse as the foot rolls in. All of these issues can increase tensile stress within the plantar fascia.”
Baumhauer added that gastrocnemius tightness and hallux rigidus can cause problems, as well.
“I check ankle range of motion, because when you have a tight gastroc you may bounce up onto your forefoot quicker,” she said. “It’s similar if the big toe is stiff and you bounce off the heel; both of those can strain the plantar fascia.”
Paul Scherer agreed that assessment of mechanical function is important.
“An easy way to differentiate is with a prefab orthotic or low-Dye strapping, which limits midtarsal joint motion,” he said. “If that improves the symptoms, it’s pretty obvious the problem is mechanically induced.”
Some clinicians order diagnostic imaging, as well.
“I always get foot x-rays, including weight-bearing films, because the buck stops with me and I want to be sure they don’t have a stress fracture or a bone cyst,” Baumhauer said.
Johnson agreed, adding that radiographic signs of erosions or calcifications at the site of the plantar fascia attachment are clearly abnormal.
Once the fasciitis diagnosis is established, the next question is how best to treat it. The clinicians surveyed often hewed reasonably closely to the ACFAS guidelines, which emphasize early treatment including stretching, ice, prefab orthoses, activity limitation, and oral anti-inflammatory drugs. (The ACFAS guidelines also include corticosteroid injections in tier 1, though none of the practitioners LER spoke with considered it a first-line treatment, and only 6% of those in the AAOS survey used it initially.)
“We start people with plantar fascia stretching and icing,” said Blake, noting that stretching has been shown to be effective even in patients with recalcitrant fasciitis.6,7 In one popular nonweight-bearing approach, patients cross one ankle over the leg, dorsiflex the foot, and pull up on the toes. Positive clinical findings are supported by a cadaveric study showing that combined ankle and toe dorsiflexion resulted in significantly greater plantar fascia stretch than did an Achilles stretch.8
“Eighty-five percent of patients who did the plantar fascia-specific stretch in those studies6,7 got better,” Baumhauer said.
Not everyone is certain that stretching is a wise therapeutic strategy, however.
“Research shows that the inflammation is not in the plantar fascia,” said Paul Scherer. “The common belief now is that this may be a periostitis, and how would stretching help that? If [activity-related] stretching of the plantar fascia caused the periostitis, you’re going to treat this by stretching the plantar fascia? Does that make any sense?”
Scherer conceded that the articles cited here showed efficacy, but he isn’t sure why.
“Are you fatiguing the nerves? Can you burn out plantar fascia? I don’t think that physiologically we know that,” he said.
Others contend that the factors causing injury and healing are different.
“Particularly in high-arched feet, there’s more pressure on the ball of the foot, which puts a lot more tension on the plantar fascia,” said Richard Blake. “The point of maximum stress is the heel bone, and it just gets yanked on week after week, month after month. At the plantar fascial level it will make scar tissue, and you can see it on an MRI. We’ve got to get the plantar fascia stretched out so that when you run or walk it gives more and the tension doesn’t build up in the heel.”
Michael Gross advocates a stretch that incorporates the strengths of several methods.
“We have them stand in bare feet, then do a calf stretch, but with a towel rolled under the toes,” he explained. “That way they’re also getting the calf stretch; there is more weight on the foot, and because the plantar fascia crosses the proximal toe joints, having those joints positioned in extension increases the stretch.”
Some cautions are in order, though, according to Blake.
“I don’t like negative heel stretching, where you stand on a stair and drop the heel,” he said. “Your entire body weight is going right into the inch of the plantar fascia in front of the heel bone, and that’s where people tend to tear it. I want the heel on the ground in any type of stretch.”
Most practitioners consider an anti-inflammatory strategy part of a first-line approach as well, though they typically use oral drugs or ice, reserving steroid injections for patients who present with extreme pain or who fail to respond to less drastic tactics.
There is, however, some dissent about the merits of anti-inflammatory therapies. The research mentioned by Scherer, indicating that fasciitis may not be related to inflammation, was conducted by Lemont and colleagues and published in the Journal of the American Podiatric Medical Association (JAPMA) in 2003.9 The researchers examined tissue samples from 50 patients with heel pain and found that none contained inflammatory cells—though they did show degenerative changes. This suggested that in most cases the term “fasciosis” might be more accurate (and indeed it has gained ground), but it also raised an obvious question about anti-inflammatory strategies.
“I agree that some of what we call fasciitis is probably fasciosis, a periostitis-like problem, but I would make a distinction,” said Russell Volpe, DPM, who teaches at the New York College of Podiatric Medicine in New York City. “There are acute cases, due to a particular episode or change in the patient’s activities that suddenly stresses the fascia and are likely true fasciitis; then there are chronic cases—more likely fasciosis—that result from a long-term biomechanical imbalance.”
The difference affects medication decisions, he explained.
“Anti-inflammatories make the most sense in acute cases,” he said. “I sometimes use injected steroids, but judiciously and for a short time [no more than two or three injections] because I think there is validity to the argument that they weaken tissue. If I give them, I am concurrently looking very keenly at what else I’m going to change biomechanically, because we shouldn’t rely on medication to do too much of the job. If someone can barely put their heel down, you have to do something; but we can manage many cases without injections, and I’d call my overall philosophy of treatment comprehensive—meaning a wide range of therapies ranging from conservative to surgical.”
Steroid injections stirred debate among the other practitioners LER spoke with, and the research is as divided on the subject as the clinicians are. For example, a 1994 paper in Foot & Ankle International found that injections appeared to increase the risk of plantar fascial rupture, and a 1998 study in the same journal reported similar concerns, noting that the long-term sequelae were difficult to resolve.10,11 However, a 2010 study concluded that steroid injections were safe and effective, with minimal risk of complications or fascial rupture.12
“I think the biggest concern is atrophy of the calcaneal fat pad, but overall, I’m not worried about injections,” Scherer said. “I’ve never seen any evidence that they weaken the plantar fascia.”
Michael Gross says he has sent plantar fasciitis patients for steroid injections, but only in recalcitrant cases. In his experience, poor injection technique can be a problem.
“If the medicine migrates, there are tendons at risk—the flexor digitorum longus and the flexor hallucis longus,” Gross said. “I had a young man who’d had four injections into his heel, and the cortisone destroyed his fat pad.”
Jeffrey Johnson is similarly hesitant.
“One morbidity of steroid injection is plantar fascial rupture,” he said. “Some people say, ‘Oh, it’s great, it was a miracle when my plantar fascia ruptured [mimicking a plantar fascia release] after the fourth steroid injection.’ But there are just as many with a negative response; they tell you their arch feels weak, and some switch from a typical plantar fasciitis pain to more of a tarsal tunnel syndrome. I’m okay for one injection, but I’m not a big fan, and I don’t typically repeat them.”
Johnson will give an injection only if a patient hasn’t improved significantly after a reasonable time.
“If they’re not better in eight to twelve weeks, I have them come back and see me,” he said. “Then, if they have well-localized pain, I might offer a steroid injection along with a long-acting local anesthetic.”
Many practitioners consider strengthening a valuable component of early treatment that complements stretching and medication, and some research supports the notion that foot strengthening exercises actually do strengthen the foot. For example, a paper presented in 2005 reported that use of minimal footwear improved participants’ foot muscle strength and morphology,13 and a study published last year found that exercises combined with orthoses significantly increased the cross-sectional area of the abductor hallucis, and the strength of the flexor hallucis, in individuals with flat feet.14
Studies of strengthening for plantar fasciitis specifically are also encouraging. Researchers at the University of North Carolina at Chapel Hill reported in 2003 that patients with fasciitis had weaker toe flexors than did controls, but weren’t able to establish cause and effect.15 In the same vein, a 2008 study in Skeletal Radiology found that atrophy of the abductor digiti minimi muscle was associated with plantar fasciitis, though it wasn’t clear whether the atrophy was the cause of fasciitis or its result.16 And, in a 2009 paper from Canada, researchers concluded that a 12-week exercise regimen was associated with reduced pain scores in 21 individuals with plantar fasciitis—although the nine using “minimalist” shoes achieved lower scores than the 12 in conventional training shoes.17
“Ligaments are the primary thing that stabilizes the middle of the foot, followed by that inch or two of muscles, and, finally, the plantar fascia,” said Richard Blake. “Our feet weaken over time, and the muscles don’t provide as much support. The ligaments stiffen, too, so the plantar fascia can end up taking more of a role. I think you should strengthen the foot so you’ll be less prone to these other problems.”
Michael Gross believes that in some cases, however, exercises are simply not enough.
“Some people have severe malalignment, either within the foot or just above it, that drives the foot into collapse,” he said. “The joints and soft tissues get injured, and in such cases it’s very difficult for the plantar intrinsics to support the foot. Asking muscles to do that is unkind, unrealistic, and unproductive.”
For such cases of severe malalignment, Gross recommends orthoses.
“If the arch is collapsing due to these structural problems, we try to support the foot,” Gross said.
Prefabricated orthoses are adequate in many cases, but in certain circumstances, such as when forefoot varus drives the collapse, custom orthoses are more appropriate, he said.
Blake likes a full-length, heat-moldable prefabricated orthosis for many patients.
“Sometimes they’re preferable to custom orthoses when you’re dealing with acute fasciitis, because the latter force you to bend across the ball of the foot where the plastic ends, and you want to avoid overloading the ball.”
While many clinicians prefer to prescribe orthoses early on, Johnson tends to wait.
“If a patient is back at three months and still in pain despite stretching, exercises, and steroid injection, a custom foot orthosis with gel cushioning is the next step,” he said.
The literature about the efficacy of orthotic treatment varies. A paper published in JAPMA in 1998 found that mechanical treatment with taping and orthoses was more effective for treating fasciitis than either anti-inflammatory or accommodative modalities.18 A well-known study by Pfeffer et al in Foot & Ankle International the next year found that, in conjunction with a stretching program, prefabricated orthoses improved fasciitis symptoms better than custom devices did.19
Not everyone agreed. For example, a 2001 paper in JAPMA compared prefabricated arch supports, custom orthoses, and night splints, and found that, although the three interventions were equally effective, patient compliance—a crucial factor in fasciitis treatment—was significantly higher in subjects given custom orthoses.20
Glen Pfeffer, MD, the author of the 1999 Foot & Ankle International paper, told LER that, in fact, he may first prescribe prefabricated orthoses, then switch to custom if the patient doesn’t get results (see “Prefab–custom orthoses debate mellows with age,” May 2011, page 47).
“If someone comes back to me after two months and they still have heel pain…we’ll get them a custom orthotic,” said Pfeffer, who is director of the Foot and Ankle Center at Cedars Sinai Medical Center in Los Angeles. “There’s a huge role for that when people have failed more conservative care.”
In any case, from LER’s conversations with other practitioners and the published literature, it appears that the therapeutic community has largely accepted the notion that prefabricated orthoses are usually adequate at first, barring significant biomechanical pathology or compliance issues.4
Occasionally, when patients aren’t responding to (or compliant with) other approaches, clinicians will opt for walking boots, casts, or night splints. Research shows that immobilization techniques can be effective; for example, a study of night splints in conjunction with other modalities produced 100% symptom remission in 15 patients over roughly three months.21 When night splints were compared with standing gastrocs-soleus stretching for fasciitis, the splint group recovered more quickly.22 And in a 2010 study, researchers found that a day-wear static progressive stretch brace was as effective as exercise and stretching over an eight-week treatment period.23
According to clinicians, night splints can cause compliance issues because people have a hard time sleeping while wearing them—but in some cases this isn’t a problem.
“I see a bunch of attorneys, and they’re perfect for splints because they can sit there all day doing their billable hours, and they don’t get up from their desk for two or three hours at a time,” said Blake, who also prescribes removable boots in cases severe enough to require temporary movement restriction.
Other practitioners opt for casting.
“If my patient isn’t better by eight weeks, I’ll put them in a short-leg walking cast if they’re willing,” Baumhauer said. “I don’t want them to be able to take it off—I want to take away their power to hurt themselves.”
Although some practitioners have found extracorporeal shock-wave therapy (ESWT) beneficial, insurance coverage is unpredictable and many patients can’t afford to pay for treatments, which may run more than $1500.
“Even so, it’s less risky to be shock-waved than to have surgery,” Baumhauer said. In some cases, she recommends that her patients go to Toronto, where ESWT is less expensive.
As it happens, Paul Scherer is one reason for some insurers’ reluctance to pay. As a consultant for a large insurance group, he participated in a proprietary, unpublished study of ESWT that found it no more effective than a single steroid injection.
“The study found that orthotics were four times as effective as shock-wave,” he told LER.
Efficacy depends partly on technology, however. Low-energy ESWT, typically done in a weekly series, has shown mixed results.4 On the other hand, high-energy ESWT, which requires anesthesia, has shown good or excellent results in about 80% of participants in some studies.24-26 And in a 2008 German study published in the American Journal of Sports Medicine, researchers found that shock-wave therapy significantly improved pain, function, and quality of life compared to placebo in 245 patients with chronic plantar fasciitis.27
Jeffrey Johnson, a coauthor of one of the paper cited above, acknowledged that the study was sponsored by an ESWT manufacturer, but felt it was conducted ethically and credibly.
“Shock-wave therapy is noninvasive and definitely helps a high percentage of patients with chronic plantar fasciitis,” he said. “We’ve had very good luck with it.”
When all else has failed, physicians turn to surgery; the options include endoscopic or open plantar fascial release and adjunctive approaches such as nerve release and gastrocnemius recession.4,28,29 Most surgeons prefer partial fasciotomy, because a release of more than 40% destabilizes the medial longitudinal arch, increases strain on the ligaments, and elevates load on the central metatarsals and lateral midfoot, causing dorsolateral pain.30-32 As a result of such concerns, the clinicians LER spoke with were extremely reluctant to perform fasciotomy.
“Given the complications I’ve seen over the years, I don’t want to do a release in patients that have isolated plantar fasciitis unless I feel that there’s some associated nerve entrapment,” Johnson said. “In the right patient, surgery is probably a good thing, but they’ve got to know the downside. Some patients never feel the same again—the arch feels weak, they don’t have the same push-off—and we don’t know how to pick those people out in advance.”
When Johnson does suggest surgery, it’s usually only after patients have failed to improve after a year or two of other therapies. Other practitioners are even more conservative.
“My view is that surgery should never happen, because you’re just asking for trouble,” said Michael Gross. “Like most tissues, the plantar fascia is there for a good reason. If you cut it, the arch will fall, the midfoot joints will gap below, and that stresses the ligaments and capsular tissues. Patients can develop tremendous pain because they’re destroying the articular cartilage of those midfoot joints. If they ever do have that surgery, the foot needs to be supported right away.”
Even the surgeons say they try to avoid doing surgery.
“We have four podiatrists here, and I’d say that one patient in the last ten years has had fasciitis surgery,” said Richard Blake.
“I am more than 90 percent successful in treating plantar fasciitis nonoperatively,” added Judith Baumhauer. “But in terms of surgery, I look for gastroc tightness, and I’ll do a gastroc recession before I go after the plantar fascia. I’ve been here seventeen years, and I’ve done fewer than ten isolated plantar fascial releases.”
As noted earlier, despite their differences (and the wide variation in responses to the AAOS survey), the clinicians LER spoke with are increasingly converging on a stepwise approach to plantar fasciitis, beginning with stretching and strengthening, ice and/or oral anti-inflammatories, and orthoses.
“Some patients want to do everything possible right from the start,” Blake said.
In such cases, he may recommend physical therapy, so the patient can have access to stretching, strengthening, icing, and manual techniques all at once. Only if those fail to address the problem after a few weeks does he progress to immobilization (usually with night splints) and other modalities that may include oral or injected steroids or shock-wave therapy.
If conservative modalities don’t work after three to six months, clinicians may move to more drastic approaches such as steroid injections, shock-wave therapy, and surgery.
“First I do the exercise, the shoe inserts, the oral anti-inflammatories, and instructions of what to avoid,” Baumhauer said.
If her patients are improving at eight weeks—and about 80% are—she stays the course. If not, she prescribes a walking cast.
“That takes care of another 15 percent,” she said.
She reserves shock-wave therapy or surgery for the final, intractable 5%.
“I tell patients to start with nonrisky approaches,” she said. “Only if those fail do you move on, because this is usually a self-limiting problem.”
Cary Groner is a freelance writer in the San Francisco Bay Area.
1. DiGiovanni B, Pinney S, Moore A. Preferred treatment of recalcitrant plantar fasciitis among academic foot and ankle surgeons. Presented at American Academy of Orthopedic Surgeons annual meeting, San Diego, February 2011.
2. Thomas JL, Christensen JC, Kravitz SR, et al. The diagnosis and treatment of heel pain: a clinical practice guideline-revision 2010. J Foot Ankle Surg 2010;49(3 Suppl):S1-S19.
3. McPoil TG, Martin RL, Cornwall MW, et al. Heel pain—plantar fasciitis: clinical practice guidelines. J Orthop Sports Phys Ther 2008;4(38):A1-A18.
4. DiGiovanni BF, Moore A. A review of current treatments for plantar fasciitis. US Musculoskel Rev 2010; 5(1):70-74.
5. Riddle DL, Pulisic M, Pidcoe P, Johnson RE. Risk factors for plantar fasciitis: a matched case control study. J Bone Joint Surg Am 2003;85(5):872-877.
6. DiGiovanni BF, Nawoczenski DA, Lintal ME, et al. Tissue-specific plantar fascia stretching exercise enhances outcomes in patients with chronic heel pain. A prospective, randomized study. J Bone Joint Surg Am 2003;85(7):1270-1277.
7. DiGiovanni BF, Nawoczenski DA, Malay DP, et al. Pantar fascia-specific stretching exercise improves outcomes in patients with chronic plantar fasciitis. A prospective clinical trial with two-year follow-up. J Bone Joint Surg Am 2006;88(8):1775-1781.
8. Flanigan RM, Nawoczenski DA, Chen L, et al. The influence of foot position on stretching of the plantar fascia. Foot Ankle Int 2007;28(7):815-822.
9. Lemont H, Ammirati KM, Usen N. Plantar fasciitis: a degenerative process (fasciosis) without inflammation. J Am Podiatr Med Assoc 2003;93(3):234-237.
10. Sellman JR. Plantar fascia rupture associated with corticosteroid injection. Foot Ankle Int 1994;15(7):376-381.
11. Acevedo JI, Beskin JL. Complications of plantar fascia rupture associated with corticosteroid injection. Foot Ankle Int 1998;19(2):91-97.
12. Kim C, Cashdollar MR, Mendicino RW, et al. Incidence of plantar fascia ruptures following corticosteroid injection. Foot Ankle Spec 2010;3(6):335-337.
13. Bruggemann G-P, Potthast W, Braunstein B, Niehoff A. Effect of increased mechanical stimuli on foot muscles functional capacity. Presented at the 20th congress of the International Society of Biomechanics and the 29th annual meeting of the American Society of Biomechanics, Cleveland, August 2005.
14. Jung DY, Koh EK, Kwon OY. Effect of foot orthoses and short foot exercise on the cross-sectional area of the abductor hallucis muscle in subjects with pes planus: a randomized controlled trial. J Back Musculokelet Rehabil 2011;24(4):225-231.
15. Gross MT. Toe flexors strength and passive extension range of motion of the first metatarsophalangeal joint in individuals with plantar fasciitis. J Orthop Sports Phys Ther 2003;33(8):468-478.
16. Chundru U, Liebeskind A, Seidelmann F, et al. Plantar fasciitis and calcaneal spur formation are associated with abductor digiti minimi atrophy on MRI of the foot. Skeletal Radiol 2008;37(6):505-510.
17. Ryan M, Fraser S, McDonald K, Taunton J. Examining the degree of pain reduction using a multielement exercise model with a conventional training shoe versus an ultra-flexible training shoe for treating plantar fasciitis. Phys Sportsmed 2009;37(4):68-74.
18. Lynch DM, Goforth WP, Martin JE, et al. Conservative treatment of plantar fasciitis. A prospective study. J Am Podiatr Med Assoc 1998;88(8):375-380.
19. Pfeffer G, Bacchetti P, Deland J, et al. Comparison of custom and prefabricated orthoses in the initial treatment of proximal plantar fasciitis. Foot Ankle Int 1999;20(4):214-221.
20. Martin JE, Hosch JC, Goforth WP, et al. Mechanical treatment of plantar fasciitis. A prospective study. J Am Podiatr Med Assoc 2001;91(2):55-62.
21. Batt ME, Tanji JL, Skattum N. Plantar fasciitis: a prospective randomized clinical trial of the tension night splint. Clin J Sport Med 1996;6(3):158-162.
22. Barry LD, Barry AN, Chen Y. a retrospective study of standing gastrocnemius-soleus stretching versus night splinting in the treatment of plantar fasciitis. J Foot Ankle Surg 2002;41(4):221-227.
23. Sharma NK, Loudon JK. Static progressive stretch brace as a treatment of pain and functional limitations associated with plantar fasciitis: a pilot study. Foot Ankle Spec 2010;3(3):117-124.
24. Ogden JA, Alvarez RG, Levitt RL, et al. Electrohydraulic high-energy shock-wave treatment for chronic plantar fasciitis. J Bone Joint Surg Am 2004; 86(10):2216-2228.
25. Ogden JA, Cross GL, Williams SS. Bilateral chronic proximal plantar fasciopathy: treatment with electrohydraulic orthotripsy. Foot Ankle Int 2004;25(5):298-302.
26. Alvarez R. Preliminary results on the safety and efficacy of the Ossatron for treatment of plantar fasciitis. Foot Ankle Int 2002;23(3):197–203.
27. Gerdesmeyer L, Frey C, Vester J, et al. Radial extracorporeal shock wave therapy is safe and effective in the treatment of chronic recalcitrant plantar fasciitis: results of a confirmatory randomized placebo-controlled multicenter study. Am J Sports Med 2008;36(11):2100-2109.
28. Baxter DE, Pfeffer GB. Treatment of chronic heel pain by surgical release of the first branch of the lateral plantar nerve. Clin Orthop Relat Res 1992;(279):229-236.
29. Chilvers M, Rocco JJ, Manoli A II. Gastocnemius recession for chronic plantar fasciitis. Presented at the annual meeting of the American Orthopaedic Foot and Ankle Society, Toronto, July 2007.
30. Tweed JL, Barnes MR, Allen MJ, Campbell JA. Biomechanical consequences of total plantar fasciotomy: a review of the literature. J Assoc Podiatr Med Assoc 2009;99(5):422-430.
31. Sharkey NA, Donahue SW, Ferris L. Biomechanical consequences of plantar fascial release or rupture during gait. Part II: alterations in forefoot loading. Foot Ankle Int 1999;20(2):86-96.
32. Yu JS, Spigos D, Tomczak R. Foot pain after a plantar fasciotomy: an MR analysis to determine potential causes. J Comput Assist Tomogr 1999;23(5):707-712.