Causes of Bunions
Although the causes for the appearance of the bunion are not completely known, there ae some generally accepted predisposing factors for the development of bunion.
External Factors
The biggest external factor is the incompatibility of shoes with the feet.[3] Shoes that don’t fit your feet, especially high heels, are considered to be the number one cause of hallux valgus.
When wearing high heels, the weight on the sole of the foot is concentrated on the forefoot. As a result, the legs spread sideways and become open legs.
However, because the tip of the high heel is tapered, the mother toe is bent into a “dogleg” shape at the base, causing valgus deformity, and the small toe is conversely varus deformity.
Another external factor is lifestyle. In modern society, the time spent wearing shoes getting longer and the time we are barefoot is decreasing by the day. In addition, the number of people using vehicles has increased, and the chances of walking on their own feet have decreased.
In recent years, shoes have been worn since infancy, which may have an adverse effect on the most important period of foot musculoskeletal formation. It is important for the musculoskeletal formation of the foot of an infant, to walk barefoot or to walk with clogs or sandals with a thong.
In this way, in modern society, the muscle strength of the legs tends to decrease steadily, and the number of flat feet with no arch and wide open feet is increasing. This is also one of the factors that make hallux valgus more likely to occur.
Internal Factors
However, some people do not wear high heels or tight shoes at all, and even though they didn’t trigger external factors, they develop bunions. There may be some internal factor in such a person. Examining the frequency of hallux valgus by gender, it is overwhelmingly high in women by a ratio of 1 to 10. [4] This may be due to the softer joints and weaker muscles of women than men. Therefore, being a woman can be said to be one of the internal factors.
Another internal factor is the morphological characteristics of the foot. Bunions include those who are congenitally flat, those who have a longer toe than the second toe (called Egyptian type), and those who have a rounded joint at the base of the toe (metatarsal head).
There seems to be a genetic predisposition/heredity (flat foot, ligament laxity), which leads to abnormal foot function. [5] This is especially common in younger individuals therefore, those whose parents have bunions need to be careful.
There are also other factors that contribute to the deformity occurring, namely, autoimmune and metabolic diseases (rheumatoid arthritis, gout, etc.) and neurological changes (stroke, cerebral palsy, vertebromedular trauma), among others. [6] Other less frequent causes of deformities are trauma (sprains, fractures, and nerve injuries), neuromuscular disorders (polio or Charcot-Marie-Tooth disease) and limb dysmetrias (one leg shorter than the other), in which leg longer develops bunion.