Bunions develop when the big toe gradually drifts toward the second toe while the bone behind it angles outward, creating that visible bump on the inner edge of your foot. The good news: while genetics load the gun, your daily habits pull the trigger. Most prevention comes down to reducing abnormal pressure on the big toe joint through smarter footwear, stronger foot muscles, and awareness of your personal risk factors.
Why Bunions Form in the First Place
Understanding the mechanism helps you prevent it. A bunion starts when the first metatarsal bone (the long bone behind your big toe) shifts inward while the toe itself angles outward. Once this drift begins, the tendons and muscles that normally keep the toe straight get pulled out of alignment, and they actually start making the problem worse. The flexor and extensor tendons, now off-center, begin pulling the toe further sideways instead of straight ahead. Even the muscle that’s supposed to pull the toe back into line gets repositioned so it does the opposite.
This is why bunions tend to worsen over time if nothing changes. During walking, especially the push-off phase, tension in the connective tissue along the sole of your foot pulls the small bones under the joint further out of place. The result is a self-reinforcing cycle: the more the joint shifts, the more the surrounding structures accelerate the shift. Abnormal pressure on the exposed bone leads to the characteristic bony bump growing larger. Prevention means interrupting this cycle before it starts, or at least before it gains momentum.
Know Your Risk: Genetics and Foot Shape
The National Library of Medicine notes that the causes of bunions involve both inherited and lifestyle factors. For bunions appearing in adulthood, inherited traits related to foot shape, structure, and the way your foot moves during walking are the primary underlying risk. If your parents or grandparents had bunions, you’re more likely to develop them.
Specific foot types carry higher risk. People with flat feet or overpronation (feet that roll inward excessively when walking) put more abnormal force on the big toe joint. Research shows that flat feet contribute to abnormal elevation and rotation of the first metatarsal bone, which is part of the three-dimensional shifting that creates a bunion. People with hypermobile or especially flexible feet face even more stress at the big toe joint: during the push-off phase of walking, the forces at this joint are roughly 10% higher than in a foot with normal flexibility, and forces at the joint further back in the arch are 27% higher.
You can’t change your genetics, but knowing you’re predisposed means you should take the preventive steps below more seriously and earlier in life.
Choose Shoes That Protect the Joint
Research suggests that poorly fitting shoes probably don’t cause bunions on their own, but they can make bunions develop earlier or progress faster in people who are already susceptible. That distinction matters: if bunions run in your family, your shoe choices become significantly more important.
The key features to look for:
- Wide toe box. Your toes should be able to spread naturally without pressing against the sides of the shoe. If you can see the outline of your big toe pushing against the upper, the shoe is too narrow.
- Low to moderate heel height. High heels shift your body weight forward onto the ball of the foot, increasing pressure directly on the big toe joint. Women who regularly wore high heels between ages 20 and 64 had a 20% higher likelihood of developing bunions compared to women who didn’t, according to the MOBILIZE Boston Study of older adults.
- Adequate length. Shop for shoes at the end of the day when your feet are slightly swollen. There should be about a thumb’s width between your longest toe and the front of the shoe.
The simplest test: take the insole out of a shoe and stand on it. If your foot spills over the edges, particularly at the ball of the foot, that shoe will compress your toes inward every time you wear it. Pointed-toe shoes and narrow dress shoes are the most common offenders, but even athletic shoes can be too narrow depending on your foot shape.
Strengthen the Muscles That Keep Toes Aligned
Your foot contains small intrinsic muscles that help stabilize the arch and keep the toes in proper alignment. Like any muscle, they weaken with disuse, and modern cushioned shoes do a lot of the work these muscles are designed to handle. Strengthening them creates a natural defense against the lateral drift that starts a bunion.
The foot doming exercise (sometimes called the “short foot” exercise) is one of the most effective options. While standing, press the tips of your toes down into the floor while lifting the arch, creating a dome shape with your forefoot. Keep your toes long and straight, not curled. Do 15 repetitions for 3 sets on each foot. This activates the muscles along the bottom of your foot that support the arch and help the big toe track straight.
Other useful exercises include toe splaying (actively spreading all five toes apart and holding for a few seconds), picking up small objects like marbles with your toes, and simply walking barefoot on varied surfaces when it’s safe to do so. Barefoot time forces your foot muscles to engage in ways that shoes normally prevent. Even 10 to 15 minutes of these exercises daily can make a meaningful difference over months and years, particularly if you have flat feet or a family history of bunions.
Address Flat Feet and Overpronation
If your feet roll inward when you walk or you have visibly low arches, addressing this is one of the most impactful things you can do. Overpronation places the first metatarsal bone in a pronated, rotated position that sets the stage for bunion development.
Supportive arch insoles or custom orthotics can help control excessive inward rolling during walking and running. You don’t necessarily need expensive custom-made versions. Over-the-counter arch supports with firm medial posting (the inner edge is built up to resist pronation) work well for many people. Stability or motion-control running shoes serve the same purpose if you’re active. The goal is to keep the arch from collapsing so that the big toe joint stays in a more neutral position during each step.
What About Toe Spacers and Splints?
Silicone toe spacers that sit between the big toe and second toe have become popular, and there is some evidence supporting their use. A study on customized orthotics combined with a toe separator showed a significant immediate reduction in the bunion angle and pain. However, nighttime bunion splints appear to be less effective. Research has found that wearing a hallux valgus splint at night did not significantly influence the deformity or pain.
Toe spacers are most useful as part of a broader strategy, not as a standalone fix. Wearing them during rest or inside roomy shoes can help remind the big toe to stay in a straighter position and may gently stretch the soft tissues that tend to tighten on the outer side of the joint. They’re inexpensive and low-risk, so they’re worth incorporating, especially if you notice your big toe starting to angle inward.
Daily Habits That Add Up
Prevention is cumulative. A few practical habits make a real difference over years:
- Rotate your shoes. Wearing the same pair every day means the same pressure points hit the same spots repeatedly. Alternating between different shoes with different shapes gives your feet varied stimulation.
- Limit time in heels and narrow shoes. If you wear them for work or events, change into wider, flatter shoes as soon as possible. Even reducing daily high-heel time by a couple of hours matters over the course of decades.
- Watch for early signs. A slight inward lean of the big toe, redness or soreness at the base of the toe after long walks, or a small bump forming on the inner edge of the foot are early signals. Bunions are far easier to slow down when they’re just starting than after the self-reinforcing cycle has taken hold.
- Maintain a healthy weight. While the research on body weight and bunions is mixed, carrying extra weight increases the total load on your feet with every step. For people already at risk, this additional force on the big toe joint during walking is worth minimizing.
The earlier you start these habits, the better. Bunions typically develop over years or decades, meaning prevention is a long game. But because the deformity tends to accelerate once it begins, the most effective intervention is the one that happens before you notice a problem.