A bunion, medically termed Hallux Valgus, is one of the most frequently observed foot deformities, affecting millions of people globally. This condition can lead to significant foot pain, difficulty walking, and challenges in finding comfortable footwear.
Defining the Hallux Valgus Deformity
Hallux Valgus describes a structural misalignment of the joint at the base of the big toe, known as the first metatarsophalangeal (MTP) joint. The condition develops when the long bone of the foot leading to the big toe, the first metatarsal, begins to drift inward toward the opposite foot. This inward drift causes the great toe, or hallux, to angle severely outward toward the smaller toes.
The visible bony prominence, commonly called the bunion, is not an abnormal growth of bone but rather the head of the first metatarsal bone protruding from the side of the foot due to this shifting alignment. Over time, the constant friction and pressure from footwear can lead to inflammation of the soft tissues and bursa surrounding the joint, making the area red, swollen, and painful. This progressive deformity can eventually alter the mechanics of the entire forefoot, sometimes leading to problems like hammertoes in the adjacent digits.
Global and Demographic Prevalence Data
Estimating the exact number of people with bunions is complicated, but large-scale studies show the overall global pooled prevalence of Hallux Valgus is approximately 19% across all ages.
Prevalence is strongly linked to age, rising substantially in older populations. While approximately 12.2% of adults between the ages of 20 and 60 years are affected, this rate jumps to a range of 22.7% to 35.7% in individuals over the age of 60 or 65. The most striking difference is observed between the sexes, with women being affected far more frequently than men. Pooled data indicate that the prevalence in females is between 23.7% and 30%, whereas the rate in males is substantially lower, sitting between 11.4% and 13%.
Key Contributing Factors to Bunion Formation
Bunion formation is a complex process resulting from the interplay of genetic predisposition, foot structure, and external environmental factors. The single most important factor is heredity, as studies suggest a family history is present in 63% to 90% of individuals with the condition. People do not inherit the bunion itself, but rather an inherited foot type, such as having a longer first metatarsal bone, specific joint instability, or a tendency toward flat feet (pes planus) that predisposes them to the deformity.
The biomechanical failure that creates the misalignment is closely tied to muscle imbalances in the foot. In a healthy foot, the abductor hallucis muscle pulls the big toe away from the second toe, stabilizing the joint. In Hallux Valgus, this muscle becomes weakened, while the adductor hallucis muscle, which pulls the big toe toward the second toe, becomes tight and acts as a deforming force, accelerating the misalignment.
Footwear serves as the primary environmental factor that accelerates this underlying structural vulnerability, which helps explain the higher prevalence in women. Shoes with high heels shift the body’s weight forward onto the forefoot, increasing the load on the MTP joint and encouraging the toe to slide and pronate. Furthermore, narrow or pointed toe boxes compress the toes together, which physically pushes the hallux into its valgus position, compounding the pressure and speeding up the progression of the deformity.
Minimizing Risk and Monitoring Progression
Since bunion development is often related to inherited foot structure, non-surgical management focuses on slowing the progression and alleviating symptoms. The most direct and effective action involves selecting appropriate footwear that accommodates the forefoot without compression. This means wearing shoes with wide toe boxes, low heels (below 6 cm), and sufficient arch support to maintain proper foot mechanics.
Individuals can proactively strengthen the intrinsic foot muscles to counteract the deforming forces. Specific exercises, such as the “short-foot” exercise, involve contracting the foot muscles to lift the arch without curling the toes, which isolates and strengthens the abductor hallucis.
Another technique is big toe abduction, where the individual practices moving the big toe away from the second toe, sometimes against the resistance of a band, to restore muscle function and alignment. Maintaining joint mobility through gentle, manual range-of-motion exercises for the big toe can also help preserve flexibility. Monitoring the foot for any increase in pain, redness, or rapid structural change is important, and consulting with a podiatrist early can lead to the prescription of custom orthotics or toe spacers, which manage symptoms and provide support to the arch and joint.