Conway McLean, DPM, Journal columnist

Various and sundry medical conditions occur to the human body, many of them the result of time. A particularly common one is the dreaded bunion, in which a bump develops on the inside of the foot as the big toe angles over towards the other toes. Some estimates claim as much as 23 percent of the adult population develops one at some point during their lives. That is a lot of bunions. Naturally, when they develop and how quickly vary tremendously from person to person.

The root of this malformation is the mechanical function of your foot. When the joints of the foot don’t move correctly and in concert, the arch of the foot will often end up in an inappropriate, lowered position. Commonly, this results in excessive stresses to the inner side of the foot. Although a lowered arch is a common condition leading to bunion development, there are many. On occasion, a bunion grows because of an injury. Shoes are frequently blamed but are rarely the root cause; a genetic predisposition for this malformation is usually essential. (Although a good shoe will support the foot better and so minimize the chance of developing a bunion.)

The stresses of walking and standing are significant. And these forces are generated about five thousand times a day, in other words with every step. Consequently, conditions such as this often take years to develop. No one is born with this problem, although a small percentage develop one quite early, sometimes as young as early adolescence.

When your foot mechanics are not working quite right, excessive force can be placed on the first metatarsal (the one connected to the big toe). In those with a genetic predisposition, this bone will drift away from the pressure, the head of the bone becoming prominent on the inner side of the foot. But the big toe joint is quite mobile and is able to move in many directions, which unfortunately means the big toe becomes progressively more angled over towards the other toes.

The same abnormal motion leading to this gradual displacement of the metatarsal and big toe are also very commonly the cause of bent toes, generally called hammertoes. Consequently, these two deformities often occur together. But a bent toe is just one of many potential problems produced by this ubiquitous deformity (although there are many who have one and not the other).

When questioned, most people would assume a bunion is painful only when there is pressure to the bump from shoes. Predictably, it is much more complex than that, with surprising ramifications. Although there are exceptions, bunions, technically known as hallux valgus, can become a source of numerous, and very different, problems. Certainly, an abnormal bump on some part of the foot is probably going to get pressure from shoes. Yet, this recurrent and excessive force on human tissue has consequences.

A sack of fluid can develop over a bunion, a structure referred to as a bursa, labeled bursitis after becoming inflamed. These structures develop in a variety of places throughout the body, the hip being an especially frequent one. Typically, a nerve runs right past this area of the foot so it often gets pressured when a bunion exists. Any nerve getting excessive, repeated pressure will induce pain, so this peculiar type of discomfort is common.

Bunions are much more prevalent in the senior population; they have had many years to develop the deformity. The years also take a toll on our “vascularity”, how much healthy blood is getting to the tissues. The product of these changes is that skin becomes less durable, weaker, more prone to “wearing out”. This is a polite way of saying an ulcer develops. A frequent location is the adjacent surface of the 2nd toe, where the joint in the big toe is pushing against the 2nd digit. These are challenging to heal in the face of declining blood flow and years of pressured, weakened skin.

Any joint in the body intended to move in some particular direction(s), which is forced to work in some other altered motion, will develop degenerative changes. This typically includes thinning of the cartilage, inflammatory changes in the capsule of the joint, and many other predictable and progressive alterations in the complex anatomy of this structure. With enough of this degeneration, the joint becomes diseased and no longer functional.

A foot so deformed is not good for your gait. The big toe joint helps us bear weight during a range of activities. Effective gait requires a functioning big toe joint. A bunion deformity at this critical junction of tendons, ligaments, and bones can seriously impair the functioning of the pedal extremity. The human body is not able to propel itself forward efficiently without it. As a bunion progresses, this task cannot be performed properly. We simply can’t walk well.

Even nail problems may result from this aberration. Along with drifting over, the big toe rotates as well. The outer side of the toe begins to bear weight, causing pressure to the edge of the nail. Another one of the abundant causes of ingrown nails. But that pressure also elicits a thickening of the skin in an attempt to protect itself. Most people call them calluses. As they grow, this extra tissue adds to the pressure, and pain increases. This callusing of the inner side of the foot is one of the most frequent symptoms associated with this bent appendage.

A common consequence is compression of the spaces between the metatarsal bones, which are now being compressed by the enlarging space between the 1st and 2nd bones. There is only so much space inside a shoe. The condition is often called a neuroma (although, as is so often the case in medicine, there are many others). Pain is experienced in the ball of the foot and out into the two adjacent toes. By correcting a bunion, these nerve compression problems sometimes resolve without further treatment.

As the misshapen joint becomes more uncomfortable and harder to fit into shoes, people curtail their exercise activities. The act of walking becomes more difficult, and our bodies become less efficient ambulators. Walking takes energy and those afflicted tend to walk shorter distances at a noticeably reduced rate. The lesseced support provided by the deformed foot can even stress the knee or low back, resulting in chronic pain from these regions.

Especially in older individuals, foot disorders are a major cause of disability and sedentary habits. Certainly, a pandemic can do that, but the human body doesn’t know about them: our bodies need to move. Women are more likely to have bunions as they get older, and the more severe their bunions are, the lower their quality of life. But with a thorough evaluation of your musculoskeletal function and body mechanics, bunion development can be slowed and sometimes even prevented. If you have a family history or you see indications something is developing, prevention is worth a pound of cure. Another ancient proverb rings true.

EDITOR’S NOTE: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula, with a move of his Marquette office to the downtown area. McLean has lectured internationally on wound care and surgery, being double board certified in surgery, and also in wound care. He has a sub-specialty in foot-ankle orthotics. Dr. McLean welcomes questions or comments atdrcmclean@outlook.com.