Plantar fasciitis is a common cause of heel pain that affects an estimated 2 million people per year in the United States. It occurs when the long band of tissue that connects the heel bone to the toes (the plantar fascia) becomes inflamed or irritated. This can cause stabbing pain in the bottom of the heel, especially with the first steps in the morning or after long periods of rest. While plantar fasciitis tends to come on gradually over time, there are certain factors that can aggravate the condition and trigger flare-ups of symptoms.
Overuse or Exercise
One of the most common causes of plantar fasciitis flares is simply overuse of the feet. Activities that involve excessive running, jumping, or walking can overstretch the plantar fascia over time. Sudden increases in exercise levels or intensity can also trigger inflammation. This is especially true of high-impact exercises like running on hard surfaces or sports that involve jumping like basketball. If you ramp up your activity level too quickly without giving your body time to adapt, it can lead to microtears and irritation in the fascia.
Footwear
The shoes you wear on a regular basis can play a major role in plantar fasciitis flare-ups. Footwear that lacks appropriate arch support or has thin, worn down soles can fail to stabilize the foot properly. This strains the plantar fascia and can cause excessive pronation (inward rolling of the foot). High heels, dress shoes, and shoes with little cushioning or shock absorption are common culprits. Switching to shoes that do not provide adequate support for long periods of time can also trigger inflammation.
Weight Gain
Carrying excess weight puts additional strain on the plantar fascia, especially if the extra pounds are concentrated around the abdomen and upper body. The cumulative effect of excess weight over time can lead to overstretching and microtears in the fascia. Sudden weight gain in a short period of time can be particularly problematic, as the rapid increase in stress on the foot may cause the plantar fascia to become inflamed before it has time to adapt.
Standing for Long Periods
Being on your feet all day, either for work or play, can be a factor in plantar fasciitis flares. Standing or walking for long stretches of time, especially on hard surfaces, puts a lot of stress on the plantar fascia. This repetitive pressure day after day can cause tiny tears and inflammation. Jobs that involve being stationary in one place, like working on an assembly line or as a cashier, tend to be high risk. The lack of movement allows the fascia to tighten up, making it more prone to injury.
Tight Calf Muscles
Having tight calf muscles or limited ankle flexibility can increase strain on the plantar fascia. When the calf muscles are tight, it limits the ability of the ankle to flex properly when the foot hits the ground. This means more stress is placed on the plantar fascia to absorb shock and impact. Calf stretches and massage techniques that improve ankle flexibility can help reduce the pull on the fascia and prevent flare-ups.
Age
Plantar fasciitis becomes more common with age. The normal wear and tear on feet over many decades of use can cause the plantar fascia to weaken and become prone to injury. Older adults are also at increased risk of gaining weight and losing flexibility, which are contributing factors. Sudden flare-ups are more likely to occur in middle age adults rather than young, active people. The elderly may be using their feet less, but their fascia is less able to handle impact when they do walk or stand.
Flat Feet or High Arches
Having either very flat feet or very high arches can make you more prone to plantar fasciitis flares. Those with flat feet and low arches tend to roll their feet inward excessively when walking (overpronation). This strains the plantar fascia and causes tension and microtears over time. People with high arches have tight Achilles tendons, which limits ankle flexion similar to tight calf muscles. This also leads to more stress on the fascia with each step.
Change in Surface
Sudden changes in the walking or running surface are a common trigger for plantar fasciitis pain. Transitioning from soft surfaces like grass or dirt trails to hard surfaces like pavement or concrete floors can overload the plantar fascia and cause inflammation. The fascia may also be bothered when going from bare floors to carpeted floors, or vice versa. Keeping activity on one type of surface helps reduce irritation.
Pregnancy
Hormonal changes and weight gain during pregnancy often lead to foot problems like plantar fasciitis. The extra weight carried up front stresses the plantar fascia. Loosen ligaments and flattened arches from pregnancy can also contribute to strain. Plantar fasciitis often starts in the later months of pregnancy as weight gain occurs and continues on after giving birth. Managing weight gain and wearing supportive shoes can help minimize problems.
Poor Flexibility
Limited flexibility in the calf muscles, Achilles tendon, and base of the foot can all lead to increased tension in the plantar fascia. Lack of flexibility increases strain on the fascia when walking, running, or standing. People who are overall less flexible or do not stretch regularly tend to be at higher risk for plantar fasciitis flare-ups, as their tissue is tighter and less able to handle stress.
Foot Structure
Certain foot structures or conditions may increase your risk of plantar fasciitis problems. Having high foot arches or excessive rolling inward of the ankles when walking (overpronation) are two examples. Bunions, flat feet, and tight Achilles tendons can also contribute to plantar fasciitis flares. Getting prescription orthotics to correct these issues can sometimes help.
Heel Spurs
Heel spurs are another common foot problem that often coexists with plantar fasciitis. A heel spur is a hook of bone that forms on the heel bone due to repeated pulling of the plantar fascia. The presence of a spur indicates longstanding strain in the fascia. Heel spurs do not necessarily cause symptoms themselves, but they are linked to more severe plantar fasciitis that is prone to flares.
Poor Footwear Choices
Shoes that do not provide proper arch support, cushioning, or shock absorption will overload the plantar fascia and lead to irritation and inflammation. Common culprits include flat shoes like flip flops, shoes with thin soles, shoes with worn out padding, and going barefoot. Transitioning to these types of shoes from supportive athletic shoes or orthotics can trigger a flare-up.
Obesity
Carrying a lot of excess body weight puts tremendous stress on the plantar fascia and can lead to overstretching and injury. Obese individuals are more prone to plantar fasciitis problems in general. Losing a significant amount of weight quickly through crash dieting or bariatric surgery can sometimes lead to flare-ups as well, since the fascia may not adapt fast enough to the new stress levels.
Diabetes
People with diabetes have higher risk of plantar fasciitis complications due to nerve damage and poor circulation in the feet.Peripheral neuropathy causes numbness in the feet, leading to reduced stability and more strain on tissues like the plantar fascia. Those with diabetes are also more prone to flare-ups that are resistant to treatment and turn into chronic long term cases.
Rheumatoid Arthritis
The presence of rheumatoid arthritis appears to be linked to a higher risk of plantar fasciitis as well as more severe symptoms. Rheumatoid arthritis can cause inflammation in tendons and ligaments of the foot. It also contributes to heel bone erosion. The compromised foot structure and function puts extra stress on the plantar fascia, often resulting in inflammation and tearing.
Other Risk Factors
There are a few other factors that may contribute to plantar fasciitis flares, including:
- Spending long periods on the feet on hard surfaces
- Wearing unsupportive footwear like flip flops
- High intensity athletic training without rest
- Being a runner, dancer, or obese
- Having tight calf muscles or limited ankle flexion
- Poor posture that puts strain on the feet
- Having flat feet or high foot arches
Preventing Flare-Ups
While plantar fasciitis flares can sometimes seem to occur out of nowhere, there are things you can do to lower the chances and prevent aggravating the condition:
- Wear shoes with good arch support and cushioning
- Maintain a healthy weight
- Increase exercise levels gradually over time
- Stretch calves and feet before and after activity
- Take frequent breaks when on your feet all day
- Use orthotic inserts or night splints to support the fascia
- Consider physical therapy if needed to improve flexibility
- Get a new pair of athletic shoes every 300-500 miles
Treatment for Flare-Ups
If you do experience a plantar fasciitis flare-up, here are some treatment options to help calm symptoms:
- Rest and limit activity that aggravates it
- Ice the heel for 15-20 minutes several times per day
- Take over-the-counter anti-inflammatory medication
- Do calf and foot stretches
- Wear night splints to stretch the fascia overnight
- Consider physical therapy modalities like massage or ultrasound
- Use orthotics, heel cups, or heel pads to support the foot
- Get a corticosteroid injection if symptoms persist
When to See a Doctor
You should consider seeing a podiatrist or orthopedic doctor if:
- Symptoms last longer than 2 weeks
- You have excessive foot arch pain or instability
- Home care and OTC medications do not help
- You have diabetes, RA, or other medical conditions
- Imaging is needed to look for potential fractures
- You experience numbness or tingling in the heel
- Inflammation persists despite several weeks of treatment
Severe or chronic cases may require prescription orthotics, physical therapy, immobilization boots, medication, injections, or even surgery as a last resort. Getting an accurate diagnosis and treatment plan from a foot specialist is important for proper healing.
Conclusion
Plantar fasciitis flares have many potential causes, but most involve increased strain on the plantar fascia from overuse, poor foot support, or excessive weight and impact. Sudden ramp-ups in activity levels, exercise on hard surfaces, inadequate stretching, and wearing unsupportive footwear are common triggers. While flare-ups can be painful, there are things you can do to prevent them. Resting the foot, icing, stretching, and maintaining a healthy weight will also help calm inflammation when it does occur. Seeking medical treatment may be needed for severe or recurrent cases.