Plantar Fasciitis

The purpose of this blog is to provide a succinct, reader friendly overview of the plantar fascia, the diagnosis and prognosis of plantar fasciitis, common myths, and treatment strategies. You can read it from start to finish or choose the sections that are relevant to your interests.

What is the Plantar Fascia & What Does It Do?

The plantar fascia is a dense, fibrous connective tissue intricately attached to the heel, toes, and many of the surrounding muscles and structures on the sole of the foot [25]. It is designed to be a passive transmitter of mechanical forces, as well as a supporter of the medial longitudinal and transverse arches. Additionally, it is believed to play a role in proprioception secondary to the presence of mechanoreceptors such as pacinian and ruffini corpuscles [25,26].

The plantar fascia is often discussed as it relates to a mechanism known as the windlass effect, first described by John Hicks over 50 years ago [16]. Essentially, if you lift your big toe while standing, it should raise the medial longitudinal arch as the metatarsal head (base of toe) becomes closer to the calcaneus (heel) [15,16]. This is done somewhat passively, or at least unconsciously, during a phase of gait known as push off to assist in propulsion and is often accompanied by femoral and tibial external rotation, rearfoot supination, and forefoot pronation [15,16].

These will be important considerations for understanding the treatment of plantar fasciitis as tensile strain on the plantar fascia has been shown to increase with extension of the 1st metatarsophalangeal joint (big toe), Achilles tendon loading, and weightbearing in general [3,5]. The peak loads on the plantar fascia have been measured to be 1.8 and 3.7 times bodyweight during walking and running toward the latter half of the stance phase of gait [12].

Although its composition is unique in nature, the plantar fascia shares some similarities with tendons and ligaments with regards to its histology and mechanical properties, and we’ll examine how that influences our treatment strategies in the last section [26].

Who Gets Plantar Fasciitis?

Affecting 10% of individuals in their lifetime, plantar fasciitis is a condition that is seen across the spectrum [7]. On one end, we have athletes, often runners, who demonstrate higher overall training volumes [9,23]. On the other, we have an older and more sedentary population with a higher body mass index (BMI) [23,27]. While there is often speculation that various biomechanical and postural factors predispose people to developing plantar fasciitis, the research at this time deems most of these considerations inconsistent or inconclusive [27]. The strongest clinical association has been found for BMI, and this is likely more relevant for the less active individuals [27].

What’s the Prognosis?

The prognosis for plantar fasciitis varies quite drastically. Some research has shown that it is a self-limiting condition as the majority of people diagnosed (80%) will have a complete resolution of symptoms within 12 months [1]. In more chronic cases, however, symptoms can last more than 15 years [13]. Indeed, a study by Hansen in 2018 followed persistent cases of plantar fasciitis for 5 to 15 years and found that a large percentage of individuals were at risk of still having symptoms at 1 year (80%), 5 years (50%), 10 years (45.6%), and 15 years (44%). Fortunately, the severity of the pain for the symptomatic patients on the Numeric Pain Rating Scale (NPRS) was 1.8 and 2.8 (out of 10) for walking and running, which many would likely consider manageable. Additionally, 77.5% of these individuals reported experiencing at least one asymptomatic period during the course of the study [13].

The group that eventually had a resolution of symptoms (54%) had pain that lasted a mean of almost 2 years. In both groups, individuals who were female or had symptoms in both feet displayed longer-lasting symptoms than their counterparts. Features like BMI, age, smoking status, and imaging findings had no bearing on prognosis [13]. Once again, it is important to note that this study was looking at patients who had already been experiencing pain for nearly 1 year on average.

What are the Symptoms of Plantar Fasciitis?

The symptoms for plantar fasciitis are fairly recognizable. The chief complaint for most people is a sharp, localized pain experienced at the anteromedial aspect of their calcaneus (bottom of foot) upon waking and taking their first step. However, it is not unique to this scenario as standing or walking after any prolonged period of rest is usually provocative [23]. Due to this, pain may actually temporarily decrease with increasing activity, but begin to rise again after a certain point or toward the end of the day. Aggravating activities generally include standing, walking, and running, and these may further be affected by shoewear or terrain. Prior to the onset of pain, individuals may report sudden or gradual changes in activity, such as preparing for their first ever 5K run [1].

Myth #1: Inflammation

It’s been a long-held belief that plantar fasciitis is an inflammatory condition and this is reflected by the suffix “-itis” used to denote its supposed nature. However, in 2003, these beliefs were put to the test underneath a microscope. The researchers found no evidence of inflammation, but they did reveal degeneration and thickening [20].

As we alluded to in the first section, the plantar fascia shares many common characteristics with tendons, including several key pathological findings such as the degeneration and thickening of the tissue [20,25,26]. Therefore, the two are often managed using a similar treatment paradigm, although the literature on tendons is much more extensive. There appears to be a clear correlation between mechanical load and the etiology, as well as symptomatology, and this will help guide our treatment strategies [2,6,11,27].

We cannot completely discount the role of inflammation, but it likely isn’t the primary driver or focus of treatment at this time. For that reason, it has been suggested that plantar fasciopathy or, more simply, plantar heel pain be used in replacement of plantar fasciitis [23].

Myth #2: Adhesions and Scar Tissue

Beginning with the structure and function of the plantar fascia helps us develop an understanding of the biological plausibility of various interventions. For example, the very first line introduced the plantar fascia as a dense, fibrous connective tissue. It’s strong. So strong in fact, that a study found that it takes over 1,800 pounds to compress it just 1% [4]. To put that into perspective, the weight of the average midsize car is 3,500 pounds which means that driving over your plantar fascia with one wheel would only compress it about .5%! That’s crazy to think, but why does it matter?

Well, many methods of treatment are aimed at breaking up scar tissue or adhesions located within the plantar fascia. Based on the research just discussed though, it seems rather unlikely that any tennis ball, foam roller, or manual therapy technique would have the capability of altering the composition of the thick plantar fascia. I am not saying that these tools haven’t helped you, can’t help you, or won’t help you. Along with other mechanisms that are beyond the scope of this blog, the authors of the study suggest that these interventions may stimulate the mechanoreceptors to trigger tonus changes within the nearby muscles [4]. However, we do not have the force to deform the tissue any appreciable amount.

Myth #3: Imaging

While the technological advancement of imaging techniques like MRIs and X-rays have significantly enhanced the healthcare field, it has also led to unnecessary utilization in certain scenarios. It is not uncommon for individuals to hear that the simple cause of their heel pain is a bone spur. However, it has been shown that heel spurs may have no influence on the development or prognosis of plantar fasciitis [13]. They are most strongly associated with obesity and seem to be quite common as we age as they can be found in 55% of individuals between the ages of 62 and 94 [28]. Therefore, the general recommendation is to reserve imaging for people who are not showing any signs of improvement with conservative management [23].

How Can I Manage Plantar Fasciitis?

A myriad of treatment options currently exist for plantar fasciitis. Although this section may not serve as a completely comprehensive review, it will discuss the major suggestions for non-surgical management.

Load Management

Simple, practical changes in your daily routine will likely provide a larger benefit than any single intervention. For the athletic population, it’s going to involve altering your training regimen. Cross-training, via weightlifting, swimming, and/or cycling, will be an important alternative to walking, running, and other painful activities to maintain fitness levels while minimizing symptoms when appropriate. However, this does not mean you have to completely avoid meaningful activities that are painful.

Manipulating parameters like intensity, duration, or frequency will be a key factor when symptoms are quite irritable. If walking or running 3 miles is unbearingly painful, but 2 miles is not, it may be useful to reduce your top end mileage. There is no set program so you will have to adjust as needed to suit your demands.

Monitoring pain will be an important consideration as well. There is no gold standard for how much pain is acceptable, but it is generally understood that it will be a part of the process. So what’s a good guideline to follow? Keep pain tolerable. Whether that’s a 2 out of 10 (10 being the worst pain possible) or a 5 out of 10 is completely unique to you. If the pain during activity is tolerable and doesn’t worsen later that day or the next day and you’re still making progress toward your goals, you’re most likely moving in the right direction.

For the less athletic population or for individuals on the heavier side, the same principles apply. Additionally, it may be helpful to begin a weight loss journey by implementing small changes to your exercise routine and diet.

Corticosteroid Injection

Although the chief concern regarding corticosteroid injections is the potential risk of rupturing the plantar fascia, the data is mixed. One study that followed 174 individuals with plantar fasciitis for 5 to 15 years found that no rupture happened despite the vast majority of participants (93%) having ultrasound-guided corticosteroid injections [13]. On the other hand, a retrospective study published in 2014 determined that the only risk factor for a rupture was having a previous corticosteroid injection [19]. It is interesting to note that many of the individuals were unaware that a rupture occurred. To that point, Landorf suggests that a “plantar fascia rupture is not necessarily a harmful phenomenon, as it may be clinically silent in some people” [29].

But is it efficacious? Well, a recent study found that corticosteroid injections combined with strength training and stretching provided superior results compared to either intervention alone without negative outcomes [17]. As a whole, however, the research tends to support the stance that a corticosteroid injection may slightly reduce symptoms for up to 4-6 weeks with minimal adverse effects [8,21,29,30].

We do not recommend corticosteroid injections as a first line of defense secondary to the potential risks, but it may be indicated in certain scenarios.

Shoewear

There is a lot to unpack with this one! Enough, actually, for it to have its very own blog. If you want more in-depth information on the topic, check out the blogs by Tom Goom and Ian Griffiths. For now, we recommend wearing shoes that are comfortable. While some individuals may swear by minimalist shoes and others by rigid and supportive ones, it is likely best to find what suits your feet and needs. Simple rule of thumb: if something is consistently making your symptoms worse, whether it’s walking barefoot or wearing high heels, an alternative is probably indicated.

Orthotics (Foot Orthoses)

Similar to shoewear, there are a lot of strong opinions about foot orthoses, especially if your feet are shaped a particular way. First and foremost, it’s important to point out that custom-made foot orthoses do not seem to be superior to off-the-shelf orthoses when it comes to treating plantar fasciitis [14,18,30,31]. With regards to effectiveness, only one study demonstrated short and long-term benefits of foot orthoses [24]. However, the majority of research reports that they likely only provide a medium-term (7-12 weeks) benefit as they relate to pain [30,31]. Therefore, foot orthoses may better serve as a temporary modification rather than a long-term solution, or at least should not be used as a stand-alone intervention.

If you’re going to pick up a gel insert or foot orthoses, choosing a less expensive model based on comfort may be a suitable choice initially.

Ice

As mentioned above, inflammation does not appear to be the primary driver of pain or pathology in individuals diagnosed with plantar fasciitis. Ice may be used to acutely manage symptoms in irritable cases, but should not be a standalone treatment. If you find relief from icing, it can be beneficial as part of a comprehensive program; however, do not feel required to use it.

Exercise Selection for Plantar Fasciitis

Based on the research presented thus far, the purpose of exercise selection will be two-fold: short-term relief, or symptom modification, and long-term resolution.

Short-Term

We discussed that individuals often experience a worsening of symptoms after periods of prolonged rest such as sleeping or sitting; therefore, we’d like to minimize those symptoms through the use of a convenient and effective exercise. Two different studies have demonstrated the effectiveness of a plantar fascia stretch for improving pain and function [10,22]. The stretch is quite simple: place the affected foot on the opposite leg, pull the toes up toward the shin, and palpate the tension of the plantar fascia (optional – not shown). Hold the stretch for 10 seconds and repeat 10 times.

It is important to note that the plantar fascia stretch is not likely lengthening the tissue any appreciable amount. The purpose of the exercise is to decrease the overall sensitivity of the region to make the transition from sleeping to walking or sitting to standing more tolerable.

Long-Term

As useful as symptom modification may be, the ultimate goal is to find a more permanent solution. The pain associated with plantar fasciitis can have a variable time course, so placing the emphasis of rehabilitation on function will likely lead to better outcomes. Before diving straight into the exercises, there are a few key considerations that must be discussed.

1. Pain – As mentioned earlier, it is to be expected. As long as the pain is tolerable for you during activity and you are making progress toward your functional goals, you are likely heading in the right direction.
2. Frequency – Exercises should be performed approximately 3 times per week or every other day to allow for appropriate recovery. This does not apply to the plantar fascia stretch as it can be done daily.
3. Duration – Exercises should ideally be performed for a minimum of 12 weeks, even if symptoms begin to resolve.
4. Load – The difficulty of the exercises should increase over time. Examples of this will be given, but more resistance should be applied throughout the process.
5. Purpose – The plantar fascia experiences strain during walking and running because they are weightbearing activities that load the calf complex and cause extension of the big toe. Some of the exercises were specifically chosen to purposefully strain the plantar fascia. We want to induce resilience of the tissue over time and help to increase the capacity for load. Given enough time and persistence, the hope is that your first step out of bed will feel like standing on feathers compared to the difficult exercises you’ve been performing regularly.

The first exercise recommendation is a unique heel raise presented by Rathleff and colleagues in 2014 [22]. As shown below, it involves placing the toes on a rolled up towel and performing a heel raise on the edge of a step with light support from your hands. It is to be done barefoot with the intention of maximally straining the plantar fascia. Rise up to a 3 second count, hold for 2 seconds, and lower to a count of 3 while executing a full range of motion. Throughout 12 weeks, continue to add resistance via dumbbells, barbell, smith machine, backpack with weights, etc. If you cannot perform the movement with a single leg secondary to pain or balance deficits, begin with two legs (pictured).

The movement described above may be insufficient as a stand-alone exercise for treating plantar fasciitis, and recent research has demonstrated the importance of the strength and endurance of the soleus as it relates to other lower limb pathology [32,33]. For those reasons, the next movement is a traditional seated heel raise with shoes on that is meant to preferentially target the soleus muscle. This will also affect the plantar fascia, Achilles, and the rest of the foot and ankle complex. It can be done using a machine or with weights placed on the thighs with your feet on a step. Similar to the exercise above, rise up to a 3 second count, hold for 2 seconds, and lower to a count of 3 while executing a full range of motion.

Although the primary focus is on the calf, foot, and toes, rehabilitation should be as comprehensive as possible. No body parts work independently in a bubble. Be sure to strengthen the rest of the leg and trunk muscles using a variety of single and double limb movements appropriate for your skill level and symptoms.

Closing Thoughts on Plantar Fasciitis

The etiology of plantar heel pain is complex and its management can be difficult. This blog is meant to serve as a broad, reader-friendly overview for both clinicians and clients.

If you want to learn more, I highly recommend checking out our podcast episode with Dr. Henrik Riel: