Calcaneal enthesophytes are bony growths that form where tendons or ligaments attach to the heel bone, and they are far more common than most people realize. Often called “heel spurs,” these projections develop at either the bottom of the heel (where the plantar fascia connects) or the back of the heel (where the Achilles tendon inserts), and they range from a few millimeters to over a centimeter in size. Whether they cause pain depends less on the spur itself and more on what is happening in the surrounding soft tissue, which is why two people with identical-looking spurs on an X-ray can have wildly different experiences.
What Exactly Forms and Where
The calcaneus, or heel bone, has two main attachment points that are prone to spur formation. At the bottom, the plantar fascia fans out from the front-bottom edge of the heel toward the toes. At the back, the Achilles tendon anchors to the upper rear surface. Both sites are entheses, the specialized zones where soft tissue meets bone, and both can develop bony outgrowths over time.
Plantar spurs (on the sole side) tend to project forward, in the direction the plantar fascia pulls. In one anatomical study of dried heel bones, plantar spurs ranged from about 2 to 8 mm in length and were always directed anteriorly. Dorsal spurs at the Achilles insertion pointed upward and were generally larger, ranging from 3 to 11 mm in height.
1PubMed Central. A study of calcaneal enthesophytes (spurs) in Indian populationThe distinction matters because each type involves different tendons, different loading patterns, and sometimes different treatment strategies. Someone with a posterior spur at the Achilles insertion often feels pain at the back of the heel during activities that stress the tendon, like running or climbing stairs. Someone with a plantar spur tends to feel it under the heel, especially with that characteristic first-step-in-the-morning pain.
How Heel Spurs Form
Researchers have debated the mechanism behind calcaneal spur formation for decades, and the argument still is not fully settled. The two main camps are the traction theory and the compression theory, and both have devoted supporters in the orthopedic literature.
The traction theory holds that repetitive pulling from the Achilles tendon or the plantar fascia creates microdamage at the attachment site, and the body responds by laying down new bone in the direction of the pull. The compression theory, by contrast, argues that plantar spurs in particular form as an adaptive response to vertical ground-reaction forces pushing up through the heel pad. In this view, repeated loading from standing and walking causes small injuries in the enthesis region, and the body builds bone to reinforce the area against those compressive loads.
2PubMed Central. Plantar calcaneal spurs in older people: longitudinal traction or vertical compression?A more recent histological study took a fresh look at the internal structure of both plantar and posterior spurs. The researchers expected that if the compression theory were correct, they would find a clear pattern of vertically aligned bone tissue inside plantar spurs, since that orientation would best resist downward force. Instead, they found that the trabeculae (the tiny struts of bone inside the spur) followed a complex, unpredictable pattern with no preferred orientation in either spur type. The strongest morphological evidence the study identified for the traction theory was that all spurs sat at the enthesis of either the Achilles tendon or the plantar fascia and pointed in the direction of those tissues. Some spurs were actually narrower near their base and wider at the tip, which is the opposite of what you would expect if the spur were being shaped by compressive weight-bearing loads.
3Scientific Reports. Why heel spurs are traction spurs after allIn practical terms, the mechanism debate matters less to patients than to researchers trying to design better prevention strategies. What both theories agree on is that repetitive mechanical stress at the heel’s attachment points drives the process, whether that stress comes from pulling, pushing, or both.
The Connection to Plantar Fasciitis
One of the most common misconceptions is that a heel spur and plantar fasciitis are the same thing. They are related but distinct. Plantar fasciitis is inflammation or degeneration of the plantar fascia itself, the band of connective tissue running along the sole. A plantar calcaneal spur is a bony growth at the fascia’s attachment point. Many people with plantar fasciitis have a spur, and many people with a spur have no pain at all.
That said, the overlap is significant. In one study comparing people who had been diagnosed with plantar fasciitis to matched controls, roughly 89% of the fasciitis group had a calcaneal spur on X-ray, compared to about 32% of the control group.
4PubMed. Plantar fasciitis and the calcaneal spur: Fact or fiction?Another study found that people with plantar heel pain were about twice as likely to have both a plantar spur and a thickened plantar fascia together, compared to pain-free individuals.
5PubMed Central. Coexistence of plantar calcaneal spurs and plantar fascial thickening in individuals with plantar heel painThe spur alone probably is not what hurts. The current thinking is that the pain comes from the inflamed or damaged fascia, the irritated fat pad, or nerve entrapment near the spur, not from the bony projection poking into tissue. This explains why treatments that reduce inflammation or offload the fascia often relieve pain even though the spur remains untouched on follow-up X-rays.
Risk Factors That Make Spurs More Likely
Obesity is one of the strongest and most consistent risk factors. A study examining patients with plantar heel spurs found that those who also had plantar fasciitis tended to have larger spurs (about 5.9 mm on average versus 4.6 mm in controls), and that a BMI over 30 roughly tripled the odds of having painful fasciitis alongside the spur.
6PubMed Central. Association of Obesity and Plantar Fasciitis in Patients With Plantar Heel SpursAge is another major contributor. The enthesis becomes less resilient over time, and decades of cumulative loading take a toll. Calcaneal spurs are uncommon in people under 40 and become increasingly prevalent after that. Occupations that involve prolonged standing on hard surfaces, being on your feet for long shifts, or carrying heavy loads all add mechanical stress to the heel’s attachment points. Flat feet and overpronation can shift loading patterns in ways that put extra strain on the plantar fascia, though the evidence on foot posture is less consistent than the evidence on weight and age.
Posterior Spurs and the Achilles Tendon
While plantar spurs get most of the attention, posterior (dorsal) spurs at the Achilles insertion deserve separate mention because they involve different anatomy and sometimes different treatment. These spurs develop where the Achilles tendon inserts into the back of the heel and tend to grow upward into the tendon’s substance. They are a hallmark of insertional Achilles tendinopathy, a condition where the lower portion of the tendon degenerates and becomes painful.
7PubMed Central. Calcific spurs at the insertion of the Achilles tendon: a clinical and histological studyPosterior spurs can cause pain when wearing shoes with rigid heel counters, because the spur creates a bump that rubs against the back of the shoe. Runners and people who do a lot of hill work tend to be more susceptible, since those activities place high tensile loads on the Achilles. Unlike plantar spurs, posterior spurs sometimes need direct surgical attention when conservative management fails, because the calcified bone within the tendon can mechanically impair the tendon’s function.
Inflammatory Diseases and Calcaneal Enthesophytes
Not all heel spurs are purely mechanical. Enthesitis, inflammation at the points where ligaments and tendons attach to bone, is a characteristic feature of spondyloarthritis, a family of inflammatory conditions that includes ankylosing spondylitis and psoriatic arthritis.
8PubMed Central. Pivotal role of the synovioentheseal complex in the imaging of arthritis and rheumatic diseasesIn these conditions, the immune system drives inflammation at entheses throughout the body, and the calcaneus is one of the most commonly affected sites. The resulting bone formation tends to be more aggressive and can appear at younger ages than typical degenerative spurs. If you are under 40 and develop heel pain with morning stiffness that improves with activity rather than rest, a rheumatologic cause is worth considering. The distinction matters because inflammatory enthesitis responds to disease-modifying medications, whereas a mechanical spur does not.
When Spurs Cause Pain and When They Do Not
The frustrating truth is that spur size does not reliably predict pain. Plenty of people have large spurs visible on X-ray and walk around with zero discomfort. Others have tiny spurs and experience debilitating heel pain. The pain is better explained by what is happening in the soft tissue envelope around the spur.
Several pain generators can be at work. The plantar fascia itself may be thickened and inflamed. The heel fat pad, which serves as a natural shock absorber, can become edematous or atrophied with age. And in some cases, a nerve called Baxter’s nerve (the first branch of the lateral plantar nerve) gets trapped near the spur, adding a neurological component to the pain. One case report highlighted that Baxter’s neuropathy can present alongside plantar fasciitis, with imaging showing a thickened plantar fascia adjacent to the calcaneal spur plus significant heel fat pad edema.
9PubMed Central. Plantar Fasciitis with Chronic Baxter’s Neuropathy Causing Hindfoot Pain – A Case ReportThis is why clinicians treat a symptomatic heel spur by addressing the surrounding soft-tissue pathology rather than focusing on the spur itself. The spur is often more of a marker of chronic stress than a direct cause of pain.
Imaging and Diagnosis
A standard lateral X-ray of the foot is the quickest way to spot a calcaneal spur. But as noted, finding a spur on X-ray does not automatically explain your pain. A systematic review and meta-analysis of imaging for plantar heel pain found that the features most reliably associated with actual heel pain included a thickened plantar fascia on ultrasound or MRI, abnormalities in the fascia, and changes in adjacent tissue like a thickened heel fat pad. A plantar calcaneal spur on X-ray was also associated with pain, but it was just one piece of a larger picture that often included increased blood flow in the fascia on Doppler ultrasound and bone marrow edema in the calcaneus on MRI.
10PubMed Central. Medical imaging for plantar heel pain: a systematic review and meta-analysisMRI is generally reserved for cases that are not responding to treatment or when surgery is being considered, because it provides superior soft-tissue contrast and can reveal problems an X-ray would miss entirely, such as partial tears of the fascia, nerve entrapment, or stress fractures of the calcaneus.
11PubMed. MRI of heel painConservative Treatment
The good news is that the vast majority of symptomatic calcaneal enthesophytes respond to non-surgical treatment. The cornerstone approaches include rest and activity modification, stretching of the calf and plantar fascia, over-the-counter anti-inflammatory medications, and footwear changes. Most guidelines suggest trying conservative measures for at least six months before considering anything more invasive.
Custom and modified insoles have good evidence behind them. A randomized trial in women with calcaneal spurs compared minimalist flexible footwear to custom orthotic insoles and found that both reduced pain significantly after six months and improved functional scores and walking distance.
12PubMed Central. Effectiveness of mechanical treatment with customized insole and minimalist flexible footwear for women with calcaneal spur: randomized controlled trialA separate study tested a modified silicone insole with targeted pressure relief against a conventional silicone insole. The modified version achieved a treatment response rate of 90% versus about 56% for the standard insole, with faster pain improvement (around 19 days to meaningful pain reduction versus 29 days).
13Acta Medica Alanya. Evaluation of the Effect of Modified Silicone Insoles Versus Conventional Silicone Insoles on Pain in Calcaneal Spur Treatment: A Retrospective Clinical StudyThe takeaway for insoles is that not all heel cushions are equally effective. Ones designed with a specific cutout or relief zone under the spur area seem to work better than generic padding. If off-the-shelf insoles are not helping after a few weeks, it is worth consulting a podiatrist about a custom or modified option.
Extracorporeal Shockwave Therapy
When basic conservative measures stall, extracorporeal shockwave therapy (ESWT) is one of the more popular next steps. It delivers focused sound-wave pulses to the affected area, and while the exact mechanism is not fully understood, it appears to stimulate healing responses in the soft tissue and possibly modulate pain signaling.
One study of over 100 patients treated with ESWT for symptomatic heel spurs reported that about two-thirds achieved an excellent outcome (no pain), and another 16% had a good outcome (pain reduced by half). Interestingly, the study found no correlation between clinical improvement and any change in spur size on X-ray. A small number of patients showed some decrease in spur dimensions after five sessions, but even patients with no radiologic change experienced significant pain relief.
14PubMed. Effects of extracorporal shock wave therapy on symptomatic heel spurs: a correlation between clinical outcome and radiologic changesThis reinforces the earlier point: the spur itself is not the primary pain source. Treating the soft-tissue inflammation around the spur delivers results even when the bone stays put. A literature review on ESWT for calcaneal spurs concluded that it is a promising non-invasive option for patients whose symptoms have not responded to conservative methods.
15Quality in Sport. Is extracorporeal shockwave therapy an effective treatment for calcaneal spur? A literature reviewSome emerging evidence suggests that combining ESWT with pulsed electromagnetic field therapy may produce better outcomes than ESWT alone, at least in the short term.
16PubMed Central. Efficacy of Extracorporeal Shock Wave and Pulse Electromagnetic Field Therapies in Calcaneal SpursInjections for Heel Spur Pain
Corticosteroid injections are a well-established option for heel pain that has not responded to stretching, insoles, and oral anti-inflammatories. A steroid injection can deliver rapid relief by tamping down inflammation in the area around the spur and fascia. However, the relief is sometimes temporary, and repeated injections carry real risks including skin depigmentation, atrophy of the heel fat pad, and in rare cases, rupture of the plantar fascia.
17PubMed Central. Comparison of corticosteroid injections and conservative treatments for heel spursPlatelet-rich plasma (PRP) injections have gained traction as an alternative. A comparative study found that both PRP and corticosteroid injections significantly reduced pain and improved function in patients with chronic plantar fasciitis, but PRP showed longer-lasting beneficial effects at six months. The PRP group also had better improvement in functional scores (a jump from about 54 to 91 on a standard ankle-foot scale, compared to 55 to 75 in the steroid group).
18International Journal of Research in Orthopaedics. A comparative prospective study of platelet rich plasma versus corticosteroid injection in chronic plantar fasciitisPRP is more expensive and is not always covered by insurance, which limits its accessibility. But for patients who have had only short-lived relief from steroid injections or who are concerned about fat pad atrophy from repeated steroids, PRP is worth discussing with a specialist.
When Surgery Becomes an Option
Surgery is typically reserved for the small percentage of patients whose pain persists after six to twelve months of aggressive conservative treatment. The traditional open approach involves removing the spur and sometimes partially releasing the plantar fascia. More recently, endoscopic (minimally invasive) techniques have become the standard at many centers.
One question that has generated research interest is whether you need to release the plantar fascia at all, or whether simply removing the spur is enough. A study of endoscopic spur resection without plantar fascia release found good outcomes, with early return to full weight-bearing and few complications. The authors concluded that spur removal alone was sufficient to relieve symptoms and improve function in patients whose spurs measured at least 2 mm.
19PubMed Central. Fluoroscopic and Endoscopic Calcaneal Spur Resection Without Plantar Fascial Release for Recalcitrant Plantar FasciitisConversely, another study that directly compared endoscopic fascia release with and without spur excision found no significant difference in outcomes between the two approaches; both groups improved substantially.
20PubMed Central. Comparison of Endoscopic Plantar Fascia Release With and Without Calcaneal Spur Excision for Recalcitrant Plantar FasciitisThe emerging picture is that the surgery works regardless of which specific structure you address, the spur or the fascia, which further supports the view that the spur per se is not the core problem. Surgeons are still sorting out the optimal technique. Studies comparing different endoscopic portal placements (medial versus combined medial-and-lateral incisions) have found comparable pain and function scores, though the simpler medial-only approach tends to have shorter operative times.
21PubMed Central. Comparison of Short-Term efficacy between medial and lateral dual incision approach and medial dual incision approach for endoscopic spur resection combined with plantar fascia release in the treatment of heel pain syndromeLong-term satisfaction after heel spur surgery is generally high. A 10-year retrospective study found that about 85% of procedures were associated with patient satisfaction, and 94% of patients said they would recommend surgery for relief of severe heel pain.
22PubMed. Long-term follow-up of heel spur surgery. A 10-year retrospective studyThat said, surgery does not guarantee a cure. A minority of patients continue to have some residual discomfort, and if the underlying mechanical factors (excess weight, poor footwear, high-impact activity without adequate recovery) are not addressed, symptoms can return.
Heel Pain in Children and Adolescents
Children and teenagers rarely develop true calcaneal enthesophytes, but they do get heel pain, and the cause is quite different. Sever’s disease (calcaneal apophysitis) is an overuse injury involving the growth plate at the back of the heel. It typically affects active kids between the ages of about 8 and 14, often during or just after a growth spurt. The pain is usually at the back and bottom of the heel and worsens with running or jumping.
23PubMed Central. Sever’s Disease of the Pediatric Population: Clinical, Pathologic, and Therapeutic ConsiderationsSever’s disease is self-limiting because it resolves once the growth plate fuses, usually by age 15 or so. Treatment focuses on reducing activity levels, heel cushions, calf stretching, and sometimes a brief period in a walking boot for severe cases. It is worth mentioning here because parents sometimes worry that their child’s heel pain means they have a spur or a structural problem. In nearly all pediatric heel pain, the growth plate is the issue, not an enthesophyte. True spur formation requires the kind of cumulative mechanical loading that takes decades to produce.
Living With an Asymptomatic Spur
If you had an X-ray for an unrelated reason and were told you have a calcaneal spur but you have no heel pain, there is generally nothing you need to do about it. Asymptomatic spurs are an incidental finding and are extremely common in older adults. They do not inevitably become painful, and removing them preemptively is not standard practice.
Where it gets more practical is in prevention. If you know you have a spur and you are carrying extra weight, on your feet all day, or ramping up a running program, the spur is a signal that your heel’s attachment points have been under stress. Good footwear with adequate heel cushioning, maintaining a healthy weight, and stretching the calf and plantar fascia regularly are low-effort steps that reduce the chance the spur will become symptomatic. Treating the spur as a warning sign rather than a disease diagnosis is probably the most useful framing for most people who learn they have one.