10 Causes of Pain on the Outer Side of Your Foot
Have outer foot pain? Here are common causes of pain on the outer side of your foot, the symptoms to watch for, and how to treat it.
The agony of pain on outer side of foot
Pain on the outer edge of your foot can range from annoying to debilitating.
When the stabbing, burning, or aching is severe, it can limit your ability to stand, walk, exercise, work, or engage in some of your usual activities.
Fortunately, pain on the outer foot—known by doctors as lateral foot pain—is not as common as other types of foot pain, including toe pain or heel pain caused by plantar fasciitis, says Kenneth Hunt, MD, an orthopedist and medical director of the UCHealth Foot and Ankle Center in Denver.
But with at least a dozen different causes, correctly identifying the source of outside foot pain can be challenging.
“The differential diagnosis for lateral foot pain is broad,” Dr. Hunt says. (These foot symptoms can reveal signs of disease.)
Causes of pain on the outer side of your foot
If your lateral foot pain does not get better with rest or starts to feel worse, it’s important to seek medical attention.
Your doctor will be able to provide you with a diagnosis and advise the best course of treatment for you.
Here are the main causes of pain on the outer side of the foot, treatment options, and how to prevent recurring foot pain.
Ankle sprains are the most common causes of lateral foot pain and are more common in people with high arches, according to Dr. Hunt.
They usually occur during activities that cause the foot to twist, roll, or suddenly change directions—think basketball, volleyball, and trail running or hiking on uneven surfaces.
When the foot twists, it can cause a tear in one of the ligaments that supports the ankle bones.
How do you know if you’ve sprained your ankle? There are some key indicators: In addition to pain, you may experience swelling or bruising. And the area may be tender to the touch.
If the sprain is severe, you may hear a popping sound.
It’s important to have any ankle sprain treated promptly or it may lead to chronic instability.
“A previous ankle sprain is a risk factor for more ankle sprains,” says Dr. Hunt.
If the sprain is mild, your doctor may just recommend the RICE protocol: rest, ice, compression (with an elastic bandage), and elevation.
This should reduce the swelling and pain, though you might also need to take a nonsteroidal anti-inflammatory drug (NSAID) like ibuprofen or naproxen. In some cases, you might need crutches, a walking boot, or a brace for added support.
Arthritis causes inflammation and pain at the joints. With 28 bones and more than 30 joints in the foot, arthritis is a common culprit of lateral foot pain.
In osteoarthritis, sometimes known as the wear-and-tear type of arthritis, the cartilage that reduces friction between bones erodes, leading to pain and stiffness.
In rheumatoid arthritis, which is an autoimmune disease, the lining that protects the joints (called the synovium) becomes swollen and eventually damages the bones, cartilage, and other supporting structures of the joint. It often begins in the foot and ankle, before moving on to other joints.
Symptoms of arthritis-related lateral foot pain include warmth and redness at the joint. Your pain may increase with activity.
You’ll need to see a physician to get an arthritis diagnosis. Your doctor will probably watch you walk, looking for bone misalignment and unusual gait patterns, and may order X-rays to look for joint deformities.
Treatment may consist of medications, like NSAIDs or steroid injections, and lifestyle changes, like switching to lower-impact forms of exercise and losing weight, if necessary.
Your doctor may recommend that you wear a brace or orthotics inside your shoes, and may suggest physical therapy to strengthen your foot muscles and increase your range of motion.
If those approaches are unsuccessful at relieving pain, you might need surgery.
Sometimes called a “tailor’s bunion,” a bunionette is a bone malformation that causes the base of the pinky toe to jut outward.
Bunionettes can be painful, especially if too-narrow shoes rub against them. That can cause corns or calluses to form over the bony bump, which in turn creates more pressure and friction.
Usually, people find relief by wearing shoes with a wide toe boxes.
The cuboid, a saddle-shaped bone on the outside edge at the rear of the foot, can become dislocated.
Experts don’t know the exact cause of cuboid syndrome, but they think it’s often a result of overuse, sudden injury (like an ankle sprain), or maintaining certain foot positions for long periods.
The condition is especially prevalent in ballet dancers and other athletes. People with high arches are also at higher risk.
“They tend to overload the outside of the foot and are putting increased strain on the ligaments, tendons, and bones,” says Dr. Hunt.
If your outer foot feels tight or aches, you may have cuboid syndrome.
“When [the cuboid] moves out of position, it results in tightness or stiffness,” says Dr. Hunt.
You might feel a sharp pain on the outside of your food—sometimes on the bottom too. The pain generally worsens when you stand or walk on it.
The condition is often difficult to diagnose. The cuboid bone will be sensitive to touch, but swelling is uncommon.
The issue won’t show up on an X-ray, but it may become apparent when your doctor moves your foot in different directions. Fortunately, once it’s diagnosed, treatment is fairly straightforward.
“Manipulating it back into position is the most common treatment to get it articulating correctly,” Dr. Hunt says. Steroid injections or topical NSAIDs, like diclofenac (Voltaren), can help with the pain.
You’ll also want to address structural issues that may have caused the condition in the first place.
“Orthotics and footwear changes are a mainstay of treatment,” he says. They support the outside of the foot and allow the inside of the foot to bear more of the load.
Fifth metatarsal fractures
The fifth metatarsal is the long bone on the outside edge of your foot that connects your pinky toe to your ankle.
It’s broken more often than any other metatarsal bone (the long bones that connect your ankle with your toes), accounting for more than two-thirds of metatarsal injuries, according to a 2016 study in the World Journal of Orthopedics.
The most common type of injury to the fifth metatarsal is called an avulsion fracture. It occurs when the tip of the bone closest to the ankle is pulled off by a tendon, often during an ankle sprain.
A Jones fracture, in contrast, occurs more toward the toes. It usually happens with repetitive stress or overuse, though it can also result from a new injury, particularly if an athlete’s heel is off the ground during a rapid change in direction.
The symptoms are similar for both types of fractures: The site of the injury will be tender to the touch and may have swelling or bruising.
Standing or walking might be painful. Your doctor will most likely order X-rays to determine the type of fracture, as treatments for each is quite different.
Avulsion fractures tend to heal quickly with RICE and a walking boot.
Jones fractures are harder to heal because the segment of bone they affect receives little blood supply. If you have a Jones fracture, you may need to wear a cast and use crutches for several weeks or months.
If these conservative measures don’t heal your Jones fracture, you might need surgery.
Your doctor may also recommend a course of bone stimulation, a type of therapy that uses ultrasound to promote bone repair. It can help treat the fracture whether you’ve had surgery or not.
Sinus tarsi syndrome
The sinus tarsi is a tunnel-shaped space on the outside edge of the foot between the calcaneus (heel bone) and the talus, the bone just in front of the ankle.
The sinus tarsi cavity holds numerous ligaments, nerves, and blood vessels.
If you have sinus tarsi syndrome (STS), you might develop inflammation and persistent pain on the outside/front of the ankle.
You also may experience ankle instability, especially when walking or running on uneven surfaces like hiking trails, grass, or gravel. Stiffness in the ankle is another potential sign of STS.
The cause of the condition isn’t clear. Many people report their pain starting after twisting or spraining an ankle, but up to 30 percent say no such injury occurred.
For that reason, STS is difficult to diagnose, though an MRI may show swelling, bruising, sprains, or fractures in the area.
Treatment initially consists of RICE and changes in footwear, possibly including orthotics and ankle braces. NSAIDs or steroids may help with pain.
Physical therapy will include joint mobilization exercises, balance exercises, and foot and calf stretching and strengthening. If these approaches don’t provide relief, surgery to reconstruct the ankle joint may be necessary.
Stress fractures usually occur as the cumulative result of overuse, primarily in teenage and twentysomething athletes.
They also occur in people who have had a sudden increase in training, wear shoes with inadequate stability, or have a deficiency in important bone health nutrients, like vitamin D, says Dr. Hunt.
Stress fractures of the foot occur most commonly in the metatarsals and frequently near the point where the fourth and fifth metatarsals meet, though Dr. Hunt says stress fractures can also occur in the cuboid and calcaneus (heel) bones.
Usually, he says, there’s a point of tenderness right on the bone that’s been fractured, but your doctor will often order an MRI to confirm it.
Because stress fractures develop progressively, they often require surgery to repair by the time they are seen in a doctor’s office.
The term tendinopathy refers to any injury to a tendon, the fibrous cord that connects muscle to bone.
This can include tendinosis, a degenerative process in the tendon, and tendinitis, an inflammation or irritation resulting from overuse or a sudden increase in activity, which is easily seen on ultrasound or MRI.
Tendinitis is much more common—9 percent of the people in a 2018 American Podiatric Medical Association survey reported experiencing it—and it can affect the foot in several ways.
Both Achilles tendinitis and peroneal tendinitis can cause pain on the outside of the foot.
The Achilles tendon is the largest and strongest tendon in the body, attaching the calf muscles to the heel bone.
While an injury to this tendon usually results in pain at the back of the heel, Dr. Hunt says it can also lead to lateral foot pain.
Treatment generally consists of RICE, followed by stretching exercises for the calf muscles. Physical therapy may include eccentric strengthening exercises that focus on lengthening the involved muscles.
There are two peroneal tendons, which run behind the lateral malleolus—a fancy term for the outer knob-like ankle bone—and along the back of the fibula (shin bone).
These include the peroneus brevis and the peroneus longus, which turn the ankle toward the outside and help point the toes.
Injuries to the peroneal tendons are common; in fact, Dr. Hunt says it’s the second most common cause of lateral foot pain he sees.
One clue your pain is from peroneal tendinitis? The pain comes on gradually.
It can affect the outside of the foot and ankle, and possibly the outside of your leg. The pain may be worse when you try to turn your foot outward against resistance or flex it upwards.
Another sign: the tissue behind your ankle bone may be tender or swollen.
Long-distance runners and other athletes with tight calf muscles are commonly affected, though the condition can also arise in people who have a muscular imbalance, high arches, or a previous ankle injury.
The treatment generally consists of RICE and footwear changes. Both orthotics and heel wedges can help.
If your pain is severe, your doctor may recommend a walking boot or ankle brace. There’s a good chance that ankle-strengthening and stabilizing exercises will be included in your recovery program.
Newer treatments include shockwave therapy, platelet-rich plasma injections, and nitroglycerin patches, all of which may potentially stimulate a healing response. Anecdotally speaking, doctors say they’re often effective.
But Dr. Hunt says not to expect miracles.
Most of the research on these technologies has been done on the Achilles tendon, not the peroneal tendons.
“The theory is good, but there’s not a lot of evidence in the literature” that supports using them for this kind of injury, he says.
Painful os peroneum syndrome (POPS)
About 20 percent of people have an os peroneum, a tiny accessory bone that sits within the peroneus longus tendon. And most of the time, it does not cause any discomfort.
But if the bone fractures, or the peroneus longus tendon is tears or gets trapped near the bone (sometimes from an ankle injury), you can have considerable pain. No surprise—the word painful is right there in the name.
Up to 60 percent of the time, the condition will affect both feet. Like peroneal tendinitis, POPS can cause outside foot and ankle pain, swelling, and tenderness, as well as difficulty turning the foot outward or pointing the toes downward.
You’ll typically treat the condition the same way you’d treat peroneal tendinitis: RICE, orthotics and/or heel wedges, and possibly an ankle brace or walking boot. If conservative approaches are unsuccessful, your doctor may recommend surgery.
This painful condition is one you may have been born with. It happens when two bones at the back of the foot—usually the calcaneus and navicular bones or the calcaneus and talus bones—are fused together, either before birth or due to arthritis or an infection.
The result is a flat foot and rigid ankle that is easily sprained.
Symptoms often don’t appear until adolescence. Once the condition is diagnosed, it’s usually treated with pain medications, orthotics, and physical therapy.
If those therapies don’t work, you might need surgery.
Preventing outer-side-of-foot pain
The best way to prevent lateral foot pain, is to protect your feet. Since poorly fitted shoes can lead to some of the conditions that cause pain on the outer side of the foot, consider new kicks.
Dr. Hunt suggests replacing athletic shoes after every 300 miles.
If you’re an athlete, start new sports slowly, and gradually increase your time, speed, and distance. And add lower-impact activities into your training regimen. For example, he says, “switch running with swimming or biking.”
He also recommends strength training, along with a healthy diet packed with plenty of calcium and vitamin D, which will help prevent early muscle fatigue and keep bones strong. And always see your doctor if you have a persistent area of concern or discomfort.
- Kenneth Hunt, MD, orthopedist and medical director of the UCHealth Foot and Ankle Center in Denver
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