Understanding Plantar Fasciitis: Causes, Risk Factors and Prevention

Plantar fasciitis is one of the most common causes of heel pain, affecting millions of people worldwide. It involves inflammation of the plantar fascia, a thick band of fibrous tissue that runs along the bottom of the foot from the heel bone to the toes.

This condition typically causes a stabbing pain in the heel, especially with the first steps in the morning or after long periods of rest.

In fact, about one in ten people will experience plantar fasciitis at some point in their life.

The pain often improves with movement but can return after prolonged standing or activity.

Left untreated, it can become chronic and debilitating, interfering with daily activities and even work productivity.

Despite its prevalence, the exact cause of plantar fasciitis is not fully understood.

It is believed to result from chronic overloading of the plantar fascia, leading to micro-tears and tissue degeneration rather than acute inflammation.

Many cases develop without a single obvious cause, but researchers have identified a variety of risk factors that can increase susceptibility.

This guide will explain what plantar fasciitis is, delve into its root causes (from biomechanical issues to lifestyle factors), highlight key risk factors, and provide practical steps for prevention and early intervention.

Real-world examples and case studies are included to illustrate how different people develop plantar fasciitis and what can be done to address it.

What Is Plantar Fasciitis?

Plantar fasciitis is a painful foot condition caused by irritation or injury to the plantar fascia.

The plantar fascia acts like a rubber band or a bowstring, supporting the arch of the foot and absorbing shock during walking or running.

When the fascia is repeatedly stretched beyond its capacity, it can develop tiny tears.

Over time, these micro-tears cause the tissue to become inflamed or degenerated, resulting in the characteristic heel pain of plantar fasciitis.

Despite the name “fasciitis,” research shows that chronic plantar fasciitis is actually more of a degenerative condition (sometimes called fasciosis) rather than an acute inflammatory one.

Under the microscope, there are usually signs of collagen breakdown and scar tissue rather than active inflammation.

This explains why it can be stubborn to treat – the body’s healing response to chronic degeneration is less well-understood and less effective than its response to acute inflammation.

Common symptoms of plantar fasciitis include sharp pain at the bottom of the heel (especially with the first steps in the morning or after resting) and tenderness at the heel or along the arch.

The pain often eases after a few minutes of walking as the fascia warms up, but it can return after standing or walking for long periods.

If ignored, plantar fasciitis can cause chronic heel pain and lead to changes in your walking pattern, potentially causing secondary problems in the knees, hips, or back.

Fortunately, with proper care and prevention, most people recover from plantar fasciitis within a year.

Early understanding of the causes and risk factors is key to managing this condition effectively.

Root Causes of Plantar Fasciitis

Plantar fasciitis typically arises from repeated stress and overuse of the plantar fascia.

The root cause in most cases is the cumulative effect of forces that strain the fascia beyond its capacity.

This can be due to biomechanical imbalances, anatomical factors, or excessive load on the feet.

Biomechanical Factors & Foot Structure

Your foot’s structure and mechanics play a major role in whether you develop plantar fasciitis. Certain foot types or gait abnormalities can place extra stress on the plantar fascia.

For example, people with flat feet (pes planus) or very low arches tend to overpronate (the foot rolls inward excessively) when walking or running.

This overpronation stretches and strains the plantar fascia, often leading to micro-tears and pain.

On the other hand, high-arched feet (pes cavus) have limited shock absorption and can also predispose to plantar fasciitis, because the stiff, inflexible arch doesn’t distribute forces well, causing high tension on the fascia.

In short, both excessively flat feet (too much motion) and excessively high arches (too little motion) can create abnormal stresses on the plantar fascia.

Foot deformities like a forefoot varus (inward angulation of the forefoot) can also force the foot into excessive pronation to compensate, overloading the plantar fascia.

Another biomechanical factor is the windlass mechanism of the foot.

This refers to the tightening of the plantar fascia when you raise your toes (dorsiflexion), which helps elevate the arch during the push-off phase of walking.

If the windlass action is compromised – for instance, due to a tight Achilles tendon or restricted ankle motion – it can increase strain on the plantar fascia.

In fact, a tight Achilles tendon is thought to be a significant contributor to plantar fasciitis: when ankle dorsiflexion is limited, the foot compensates by overpronating, which in turn increases tension on the plantar fascia.

This is why limited ankle flexibility is considered a top risk factor

Poor foot biomechanics  whether due to arch type, gait abnormalities, or tight tendons can set the stage for plantar fasciitis by causing the plantar fascia to endure greater stress than it can handle over time.

Overuse and Repetitive Strain

One of the most common causes of plantar fasciitis is overuse or repetitive strain on the feet.

Any activity that repeatedly stresses the heel and arch can contribute to micro-trauma of the plantar fascia.

Long-distance runners, for example, often experience plantar fasciitis because each running step subjects the plantar fascia to high tensile forces (the fascia stretches and recoils with each stride in what’s called an elastic stretch-shortening cycle).

Over time, this repetitive strain can cause the fascia to break down. Sudden increases in activity level or mileage are a frequent trigger – for instance, a runner training for a marathon who ramps up distance too quickly may develop heel pain as the plantar fascia fatigues.

Similarly, sports like ballet dancing, basketball, or aerobics involve a lot of jumping, landing, and quick direction changes that can overload the plantar fascia.

Even brisk walking or hiking for long durations can contribute if the feet aren’t properly conditioned or supported.

Repetitive strain injuries often develop when there is too much activity, too soon, or on unforgiving surfaces.

Running on hard pavement or concrete, for example, subjects the feet to higher impact forces than running on a softer surface.

Soldiers who march long distances or athletes who train on hard surfaces are at increased risk for plantar fasciitis for this reason.

In essence, when the plantar fascia is asked to absorb excessive force repeatedly without adequate recovery, tiny tears accumulate and the tissue becomes painful.

Overuse is often the root cause in younger, active individuals – it’s essentially a stress injury of the foot.

Proper training techniques, gradual progression of activity, and rest can help prevent this type of injury (we’ll cover prevention strategies later).

Poor Footwear and Insufficient Support

The shoes we wear have a significant impact on foot health. Inappropriate footwear is a well-known contributor to plantar fasciitis.

Shoes that lack proper arch support, cushioning, or stability can cause the plantar fascia to overstretch and sustain damage.

For example, flat shoes, flip-flops, or worn-out sneakers provide little support for the arches and shock absorption for the heels, forcing the plantar fascia to bear more stress.

High-heeled shoes are another culprit – they shift weight forward onto the ball of the foot, shortening the calf muscles and Achilles tendon and increasing tension on the plantar fascia when the foot is flat on the ground.

Wearing high heels frequently can lead to chronic tightness and strain on the fascia. Ill-fitting shoes (too tight or too loose) can also disrupt normal foot mechanics and contribute to heel pain.

A recent study of patients with plantar fasciitis found that the majority (83.2%) were wearing inappropriate footwear on a daily basis.

In particular, minimalist or unsupportive shoes (like thin-soled flats or worn-out athletic shoes) were common among those with heel pain.

These shoes often have little to no arch support and a hard or thin insole, which fails to cushion the impact on the heel.

The lack of proper support causes the plantar fascia to overstretch and can lead to tiny tears and inflammation.

In contrast, supportive shoes with a cushioned midsole and arch support can help distribute forces more evenly and reduce strain on the plantar fascia.

In summary, wearing the wrong shoes – whether they are too flat, too high, too old, or poorly fitted can significantly increase your risk of developing plantar fasciitis by altering foot mechanics and overloading the plantar fascia.

Other Contributing Factors

In addition to biomechanics, overuse, and footwear, several other factors can contribute to the development of plantar fasciitis:

Obesity and Weight Gain

Carrying excess weight puts extra strain on the feet and plantar fascia.

Each pound of body weight adds several pounds of force on the feet during walking or running.

It’s no surprise that obesity is a major risk factor for plantar fasciitis – one study found that people with a BMI over 30 have over five times the risk of developing heel pain compared to those with a BMI under 25.

The more you weigh, the harder your plantar fascia has to work to support you, increasing the likelihood of micro-tears and pain.

Even modest weight gain or pregnancy (which adds weight and shifts biomechanics) can trigger plantar fasciitis in susceptible individuals.

Aging and Degenerative Changes

As we get older, the tissues in our feet lose some of their elasticity.

The plantar fascia may become less able to withstand stress as we age, and the fat pad under the heel (which cushions impact) can thin out.

This is why plantar fasciitis is most common between the ages of 40 and 60.

The cumulative wear-and-tear over decades, combined with age-related tissue degeneration, can lead to heel pain in middle-aged and older adults.

In fact, the condition is sometimes called a “wear-and-tear” injury because it often develops gradually as the body ages.

That said, plantar fasciitis can affect younger people as well, especially if they engage in high-impact activities or have other risk factors.