Can Flat Feet Cause Knee, Hip, or Back Pain?

If you have flat feet and nagging knee, hip, or lower back pain, you might wonder whether the two are connected. They can be. Your feet are the foundation your whole body stands on, and the way they move affects the alignment of your ankles, knees, hips, and spine. That said, flat feet don't cause pain for everyone, and knee or back pain has many possible causes.

This article explains how flat feet can contribute to pain further up the body, what the connection looks like, and what you can do about it.

What are flat feet?

Flat feet, also called fallen arches or pes planus, means the arches of your feet are low or collapse when you stand, so most of the sole touches the ground. Many people have flat feet without any symptoms at all. For others, flat feet are linked to aching arches, heel pain, and discomfort elsewhere. For a full overview, see understanding flat feet.

How flat feet can affect the joints above

Your body works as a linked chain, sometimes called the kinetic chain. When one link moves differently, the others adjust. Here's how flat feet can affect that chain:

The arch collapses as you put weight on your foot.
The foot rolls inward, a movement called overpronation.
The shin rotates inward along with the foot.
The knee may drift inward, changing how the kneecap tracks and how load passes through the joint.
The hip can rotate inward and the pelvis may tilt, which can affect the lower back.

These changes are often small, but repeated thousands of times a day, they can add up, especially during running, long walks, or hours of standing.

Knee pain and flat feet

The knee is the joint most often linked to flat feet. When the foot rolls inward and the shin rotates, the knee can be pulled slightly out of its ideal alignment. Some people experience this as pain around or behind the kneecap, particularly when running, climbing stairs, or squatting. Research suggests a link between flat feet or overpronation and some types of knee pain, though not everyone with flat feet develops knee problems.

Hip pain and flat feet

Inward rotation of the leg can continue up to the hip. This may increase strain on the muscles and tendons around the hip, particularly on the outside of the hip. If one foot is flatter than the other, it can also create a small imbalance between the two sides.

Lower back pain and flat feet

Changes in the way the legs and pelvis line up can affect posture and the lower back. Some people with flat feet find their back feels better when their feet are better supported. Back pain has many causes, though, so flat feet are only one possible contributor.

Signs your feet may be contributing

Pain that gets worse after long periods of standing, walking, or running.
Shoes that wear down faster on the inner edge.
Knees that seem to drift inward when you squat or walk down stairs.
Aching arches along with your knee, hip, or back pain.
Pain that's worse on the side with the flatter foot.

What helps

Strengthen your feet and hips

Strong foot muscles help support the arch, and strong hip muscles help keep the knee in line. Useful exercises include:

Short foot exercise: Draw the ball of your foot toward your heel to lift the arch, without curling your toes.
Calf raises: Rise onto your toes and lower slowly.
Glute bridges: Lift your hips while lying on your back to strengthen the glutes.
Side-lying leg lifts: Strengthen the muscles on the outside of the hip.
Single-leg balance: Keep your arch lifted and your knee over your toes.

See 10 exercises for flat feet for more.

Stretch tight calves

Tight calves can increase how much the foot rolls inward. Daily calf stretches help.

Wear supportive shoes

Look for shoes with good arch support, a firm heel, and stability, and replace them when they wear out.

Use arch support

Orthotics support the arch and help control overpronation, which can improve alignment through the knee and hip. Because custom orthotics are made from the shape of your own feet, the support lines up with your arch. Learn more in can orthotics help correct flat feet?

For runners, the Running orthotic is designed to control overpronation, and Maximum Comfort suits everyday shoes. Every style is $249 with free shipping. To order, scan your feet with your iPhone in the Fits Perfect app, or use the mail-in foam impression box if you don't have an iPhone.

When to see a professional

See a doctor, physical therapist, or podiatrist if your knee, hip, or back pain is severe, came on after an injury, causes swelling or locking in the joint, or hasn't improved after a few weeks. A professional can work out whether your feet are involved and recommend the right treatment.