What is Pes Planus (Flat Feet)?
Pes planus, often known as “flat feet,” is a common foot problem. It’s when the arch of the foot, which normally doesn’t touch the ground, collapses and either touches the ground or nearly does. The foot’s arch, sturdy and flexible, is made up of a network of ligaments, tendons, and a layer of tissue called fascia that connects the front of the foot to the back. Several ligaments help keep the arch stable.
The arch plays a vital role as it acts as a shock absorber, helping to distribute the body’s weight and store energy when we walk or run. An issue with the arch of the foot, especially in cases of flexible flat feet, may not always have symptoms but can change how the lower limbs and lower spine work. This can potentially increase the risk of pain and injury.
What Causes Pes Planus (Flat Feet)?
Flat feet, otherwise known as “pes planus,” can either be present at birth or develop later in life.
Babies and young children commonly have flat feet because their feet are flexible, and they don’t yet have full control over their muscles and ligaments. Additionally, babies have a small fat pad in their foot that helps protect their foot’s arch. By the age of 5 or 6, most kids develop a normal foot arch. However, obesity in childhood can cause the foot’s arch to collapse. It should be noted that some kids may not develop a normal foot arch even when they grow into adulthood.
When adults get flat feet, it’s often due to a problem with a tendon in the foot known as the posterior tibial tendon. This tendon helps support the foot arch and allows us to twist our foot inward and point it downward. Flat feet are more common in women over 40, particularly those with conditions like diabetes and obesity. Other causes can include injuries to certain foot bones or ligaments, or conditions that cause joint disease, such as rheumatoid arthritis.
Some groups of people are more likely to develop flat feet. For instance, those with conditions that make their ligaments unusually flexible, like Down syndrome, Marfan syndrome or Ehlers-Danlos syndrome. Pregnant women may also temporarily develop flat feet due to the increased laxity of their ligaments, but this typically resolves after childbirth.
Rigid flat feet, where the foot’s arch doesn’t develop at all, are less common. They can occur at any time in life, sometimes due to birth defects in the foot.
Risk Factors and Frequency for Pes Planus (Flat Feet)
It’s estimated that roughly 20% to 37% of people have some level of flat feet, otherwise known as ‘pes planus’. The majority of these cases are a type called ‘flexible pes planus’. A study in 2003 found that 17% of non-Hispanic white people have this condition, and the rate is even higher among African Americans at 34%. Flat feet affects men and women equally, and it’s often more common in kids. However, most children develop regular arches in their feet by the time they are 10 years old. Flat feet tends to run in families, suggesting a strong genetic factor. Do note that having flat feet may show up in x-rays or clinical exams, but doesn’t necessarily mean it’s causing problems. It’s important to consider other symptoms and signs in the patient.
- Approximately 20% to 37% of people are estimated to have some degree of flat feet, or ‘pes planus’.
- The majority of these cases are ‘flexible pes planus’.
- It was found in 2003 that 17% of non-Hispanic whites have flat feet, and the rate is even higher among African Americans, at 34%.
- Men and women are equally likely to have flat feet.
- Flat feet is typically more common in children, but most kids develop normal arches by age 10.
- There is a strong genetic component with flat feet, and it often runs in families.
- Having flat feet can be seen in x-rays or during a clinical exam, but it’s important to examine other symptoms and signs too, as it doesn’t always cause problems.
Signs and Symptoms of Pes Planus (Flat Feet)
When looking at someone’s foot condition, often called ‘flat feet’ or ‘pes planus’, doctors primarily observe how it is during a clinic visit. Flat feet are quite common in children and usually cause no issues. However, sometimes pain or a lack of flexibility can occur, indicating a possible problem in the foot, such as a tarsal coalition, which is a Fusion of two bones in the foot.
Doctors need information about a child’s development, medical background, any past surgical history, family history of flat feet, and their activity level, including their participation or avoidance of sports.
In adults, flat feet might be a normal finding. But, people with related symptoms might complain about pain in different parts of the body from the middle of the foot to the back. In more severe cases, they can alter their way of walking, might keep spraining their ankle, and might notice changes on their feet. Questions about the onset of the problem, past and current symptoms, past injuries, family history, surgical history, and other medical conditions (that can affect the foot like – hypertension or high blood pressure, diabetes, rheumatoid arthritis, sensory neuropathies, seronegative spondyloarthropathropathies, and obesity) would be asked.
During physical examinations, doctors would inspect, touch (palpate), move (test ROM or range of motion), test muscle strength, and observe the patient’s gait. They’d usually compare the affected foot with the healthy one.
During the inspection, doctors check for the presence of an arch in the foot, whether weight-bearing or not. In flat feet, an apparent arch disappears when weight is put on it. They’d also check for signs of overpronation. From behind, the foot may show the “too many toes” sign, and both feet should be inspected for symmetry.
Tenderness on palpation might be found in the posterior tibial tendon (a tendon along the inside of the ankle), lateral rear foot (outer side of the back of the foot) and, the plantar fascia (thick band of tissue at the bottom of the foot). The range of motion helps tell the difference between flexible and rigid flat feet. Flexibility can also be assessed using the Hubscher maneuver (Jack test) to check if the deformity is reducible, meaning the arch reappears when not bearing weight.
The strength of the muscles can be evaluated, mainly by doing a single toe rise and by inverting the foot against resistance to check the posterior tibial tendon’s strength.
When observing the person’s gait, doctors might notice an antalgic gait (a limp to avoid pain) or overpronation during ambulation (the foot’s inward roll when walking).
Testing for Pes Planus (Flat Feet)
Your doctor may use X-ray pictures of your feet while you’re standing to help make a diagnosis. If you can’t stand, they’ll take simulated X-rays that mimic you standing. They might take additional X-rays to check for other problems if necessary.
There are a couple of things your doctor might look for in these standing X-rays:
- A Meary’s angle, or the angle between the center lines of the talus and metatarsal bones in the foot, is more than 4 degrees pointing downwards. This could suggest you have flat feet.
- A calcaneal inclination angle, or the angle between the heel bone axis and the flat surface on which the foot is placed, is less than 18 degrees. This could also mean you have flat feet.
If your doctor suspects a problem with the tendon at the back of your calf or the spring ligament or other tissues that support the foot, they might order an MRI. This is a type of imaging scan that can show soft tissues like muscles and ligaments in more detail than X-rays.
Your doctor could also perform EMG and nerve conduction studies to check for sensory neuropathy – a condition where the nerves that sense pain and other sensations are damaged.
Treatment Options for Pes Planus (Flat Feet)
For children:
Kids rarely need treatment for flat feet. However, if a child’s flat feet are causing foot pain, or pain in the legs, knees, or back, the use of special shoe inserts called orthotics may be recommended. It’s uncommon, but sometimes, if the arch of the foot is rigid and not flexible, surgery might be needed.
For adults:
Similar to children, adults with flat feet can use foot orthotics and anti-inflammatory medications (NSAIDS) to help manage any discomfort or pain. Recommendations about the right type of footwear may also be given, with motion control shoes typically being beneficial for those with flat feet. For those who are overweight, guidance on weight management through a healthy diet and regular exercise could be provided, as this can help alleviate the pressure on the feet.
If a condition known as posterior tibial dysfunction is the cause of flat feet, initial treatment usually involves rest, anti-inflammatory meds, and orthotics. Physical therapy can also help decrease pain, improve foot flexibility, strengthen weak muscles, and train a person’s sense of the relative position of one’s own parts of the body and strength of effort being employed in movement (proprioception). In cases where these strategies aren’t effective, surgery may be considered.
What else can Pes Planus (Flat Feet) be?
Pes planus, or flat feet, can be caused by various factors and can sometimes be confused with other conditions. Differentiating it from other possible conditions usually involves considering a short list of presentations and using medical examinations and imaging tests to rule these out. Some of the conditions often mistaken for flat feet are the following:
- A prominent fat pad, usually in children
- Swelling that looks like flat foot, often due to issues with blood flow or heart failure
- Non-cancerous and cancerous growths that distort the arch of the foot. These can include plantar fibroma/fibromatosis, giant cell tumors of the tendon sheath, lipoma, osseous lesions, and in rare cases, melanoma
What to expect with Pes Planus (Flat Feet)
Flat foot is a condition influenced by many factors. Its outcome may change based on the cause, how long the patient has been experiencing symptoms, and the course of treatment. Conditions like degenerative and inflammatory arthritis, and Charcot arthropathy that cause flat foot, can be tough to treat, and symptoms usually become worse over time.
Surgery for conditions such as a tear in the posterior tibial tendon (an important tendon in your foot that supports your arch), a strained gastrocnemius muscle (an important muscle in your calf that helps you walk), or problems with the Achilles tendon (the large tendon at the back of your ankle) usually lead to an improved outcome.
Modifying actions in patients who perform high impact activities, such as running or jumping frequently, can also aid in non-surgical treatment.
Possible Complications When Diagnosed with Pes Planus (Flat Feet)
After a surgery, patients may experience different types of complications, depending on the specific procedure done. Common complications can include:
- Infections at the surgical site
- Bones not healing properly or at all
- Constant pain
- Dislocation or fractures in the surgical materials used
- Various issues with the surgical hardware
It’s also worth noting that healing and recovery from surgery can be more challenging for individuals with more severe deformities. The more advanced the deformity, the higher the risk of complications during recovery.
Preventing Pes Planus (Flat Feet)
It’s important for patients to understand the risk factors of flat feet (also known as pes planus) that they can potentially control or improve. These risk factors include:
- Being overweight or obese. It’s emphasized that losing weight can help reduce the risk of developing flat feet.
- Having diabetes. The goal here is to prevent sensory loss (loss of feeling) in the feet and a condition known as Charcot arthropathy, which can lead to deformed feet.
- Doing high-impact activities repeatedly. People who do activities that put repeated heavy stress on their feet should limit these activities to avoid developing flat feet.
In addition, patients should also stick to using the foot support device (called an orthotic device) that has been prescribed.
