What Causes Plantar Fasciitis? Risk Factors Explained

If you're living with plantar fasciitis, you're not alone. About one in 10 people in the United States will develop the condition at some point in their lives, and it's one of the most common causes of heel pain. Plantar fasciitis is a condition involving the plantar fascia, a strong connective band of tissue that runs along the bottom of the foot from the heel bone to the base of the toes. This band of tissue helps support the arch. Repeated stress can lead to changes in the plantar fascia. It's these changes that contribute to pain. 

Unfortunately, there isn't always a clear reason why plantar fasciitis develops. There are several factors that can play a role in the condition, such as physical activity, foot mechanics, flexibility, body weight and age. Having one or more risk factors doesn't necessarily mean you'll develop plantar fasciitis.

Plantar fasciitis occurs when repeated or excessive stress causes microtears in the plantar fascia tissue that connects your heel to your toes. A range of causes (including overuse, changes in activity, foot mechanics, tight calf muscles, prolonged time on your feet, or a combination of factors) can trigger this condition. Inflammation often plays a role as well. 

The plantar fascia supports your foot and arch, absorbing some of the stress your feet endure when walking, standing and running. When you repeatedly put stress on the tissue, it has to continually adapt. Placing greater demand on the plantar fascia than it can comfortably adapt to can contribute to degenerative changes that may lead to pain. These factors don't automatically cause plantar fasciitis, but they may raise your risk.

There is rarely a single, isolated reason why people develop plantar fasciitis. However, certain factors may increase your risk. 

Plantar fasciitis can affect people of all ages, but it's more prevalent between the ages of 40 and 60. Like other parts of the body, the plantar fascia can experience structural changes as you get older, altering how the tissue adapts to repeated stress. Furthermore, age often contributes to other risk factors, such as changes in activity, flexibility and body weight, which may also affect your risk.

The shape and structure of your feet, especially your arches, can affect how pressure and weight are distributed when you move. A flatter foot may force the plantar fascia to stretch or work harder to support the arch. High arches may result in increased pressure in the heel and forefoot, which also puts additional load on the plantar fascia. 

Feet come in all shapes and sizes, and arch height varies from person to person. Having flat feet or high arches does not necessarily mean you will develop plantar fasciitis. Like other risks, certain foot shapes may be a risk factor rather than a direct cause.

Your plantar fascia isn't the only part of your body working to absorb shock and manage pressure. The Achilles tendon and calf muscles also come into play.

When your calf muscles become tight, you might struggle to flex your foot upward. This movement, known as ankle dorsiflexion, affects how your entire foot moves, which may potentially impact the plantar fascia. The combination of limited ankle flexibility, tight calf muscles, and changes in foot movement may increase stress on the plantar fascia. While there is an association between ankle dorsiflexion issues and plantar fasciitis, limited ankle mobility doesn't necessarily cause the condition.

Spending long periods standing and walking can place repeated stress on your feet, especially when these activities take place on hard surfaces, such as concrete. People with jobs that require long periods of walking and standing may be at an increased risk of plantar fasciitis. These include professions such as healthcare workers, retail associates, fast-food workers, bartenders and construction workers. 

Your daily routine outside of work can also play a role in plantar fasciitis. Long walks on hard concrete sidewalks, sightseeing tours while on vacation, and other physically demanding activities can take a toll and increase pressure on the plantar fascia.

Running and other high-impact activities that involve repeated movements can place substantial stress on your feet and raise the risk of plantar fasciitis. The risk may also increase if you increase the intensity, duration and frequency of your workouts too fast. 

Some people run into this issue when they return to regular exercise after taking time off. Suddenly upping your workout intensity may make it difficult for the feet to adapt. Gradually increasing your activity level, rather than diving into a strenuous routine, allows your feet and other tissues to accommodate new physical demands.

Overall body weight can affect the amount of force and stress your feet experience during everyday activities. Changes in body weight can also alter the amount of force placed on your feet during weight-bearing activities. Researchers continue to study the relationship between body weight and plantar fasciitis, including how weight may contribute to other risk factors.

With every step you take, your shoes influence the impact on your feet. Footwear with adequate cushioning and support may help manage the demands placed on the plantar fascia. Good shoes add a layer of protection to absorb shocks and stabilize the feet.

On the other hand, ill-fitted shoes that lack support and padding may place more stress on the feet and contribute to pain. Changing your footwear and adding supportive insoles may help reduce the risk of plantar fasciitis.

Dr. Scholl's Plantar Fasciitis All-Day Pain Relief Orthotics and Advanced Pain Relief Insoles are two types of shoe inserts designed to relieve pain associated with plantar fasciitis.

While anyone can experience pain from plantar fasciitis, certain individuals have a higher risk:

• People who are on their feet all day: Jobs and routines that involve prolonged standing or walking, especially on hard surfaces, can increase the demand on your feet.

• Runners and athletes: Repetitive high-impact activities can put more stress on the feet, including the plantar fascia, particularly when you increase intensity in a short period of time.

• People with higher-risk foot structures and limited flexibility: Flat feet, high arches, tight calf muscles, and limited ankle flexibility have all been associated with plantar fasciitis.

• Adults ages 40 to 60: It's common for the plantar fascia to gradually lose its ability to handle stress with age.

• People who are overweight or have recently gained weight: With added weight comes an increased load placed on your feet as you stand, walk or engage in other physical activities.

There is no guaranteed way of preventing plantar fasciitis, but you can take measures to lower your chances of developing the condition. While some risk factors, such as age and foot shape, are unavoidable, you can adjust certain habits to manage unnecessary strain and stress.

If your foot pain doesn't improve or it worsens after several weeks of basic self-care and lifestyle modifications, speak to your healthcare provider. They can make a diagnosis and recommend treatment options. Your provider may also recommend you work with a physical therapist who can develop a routine that includes targeted exercises and stretches.

A podiatrist can provide a more extensive evaluation of your symptoms, consider other possible causes and help you determine the appropriate next steps.

1. American Academy of Orthopaedic Surgeons - Plantar Fasciitis and Bone Spurs

2. Mayo Clinic - Plantar Fasciitis

3. Cleveland Clinic - Plantar Fasciitis

4. National Institute of Arthritis and Musculoskeletal and Skin Diseases - Heel Pain

5. American Podiatric Medical Association - Heel Pain

6. American Physical Therapy Association - Heel Pain (Plantar Fasciitis)

7. MedlinePlus - Plantar Fasciitis

8. Johns Hopkins Medicine - Plantar Fasciitis

9. Harvard Health Publishing - Plantar Fasciitis

10. American College of Foot and Ankle Surgeons - Plantar Fasciitis