Many adults find that shoes which once fit comfortably suddenly feel tight, leading them to wonder if their feet are still growing. This phenomenon is real, and purchasing a larger shoe size later in life is frequent. The technical reason behind this size change is structural adjustment rather than actual growth. The body’s foundational support system, absorbing decades of impact, undergoes subtle changes that alter the footprint.
The Anatomical Reality of Foot Size Changes
The simple answer is that the bones of your feet do not continue to grow once you reach skeletal maturity. Bone growth occurs in childhood and adolescence through specialized cartilage areas called growth plates. These growth plates harden into solid bone, or “close,” typically in the late teens or early twenties, ending true bone elongation for the foot and the rest of the skeleton.
Even though the bones stop lengthening, the overall size and shape of the foot can still change significantly over the adult lifespan. These changes are structural adjustments, not true growth, and they often result in an increase in both foot length and width. The foot is a complex structure of 26 bones, 33 joints, and over 100 tendons, muscles, and ligaments, all subject to wear and tear. Therefore, the change in foot size is due to the shifting of these soft tissues rather than the growth of hard bone.
The Mechanisms Behind Foot Lengthening and Widening
The primary driving force behind the change in foot size is the combination of time and gravity. With every step, the body absorbs two to three times its weight, placing constant, cumulative stress on the foot’s structure over decades. This sustained pressure gradually takes a toll on the ligaments and tendons that support the foot’s arch.
Over time, these soft tissues lose their original elasticity and become more lax. This ligamentous laxity causes the complex structure of the foot to spread and flatten. As the longitudinal arch collapses, the distance between the heel and the ball of the foot increases, making the foot longer and wider. This condition is often referred to as adult-acquired flatfoot.
Weight gain is another factor that accelerates structural changes by increasing the force applied to the foot’s supporting structures. Extra pounds put greater pressure on the ligaments and tendons, encouraging the arch to flatten more quickly. For women, the hormone relaxin, which circulates during pregnancy to loosen pelvic ligaments for childbirth, also affects the ligaments in the feet. This hormonal change, combined with the added weight of pregnancy, often results in a permanent increase in foot length and width.
Changes in the fat pads on the sole of the foot also affect how shoes fit. As a person ages, the protective fat pads that cushion the bottom of the feet tend to grow thinner. While this reduction does not make the foot bigger, the loss of natural cushioning can make shoes feel less comfortable and may necessitate a change in footwear style. Furthermore, foot deformities such as bunions and hammertoes, which develop due to imbalances and ill-fitting footwear, can change the overall volume and width, requiring a larger shoe size.
Addressing the Change: Why Shoe Sizing Matters in Adulthood
Since feet change shape throughout a lifetime, wearing a size based on a measurement taken years ago is often inaccurate and can lead to foot problems. It is advisable to have your feet measured regularly, perhaps once a year, to ensure proper fit. The correct size should be determined by measuring both the length and the width, as one foot is frequently slightly larger than the other.
Wearing shoes that are too small or narrow can have negative consequences beyond simple discomfort. Poorly fitting footwear can contribute to the development or worsening of painful conditions, including bunions, calluses, and hammer toes. When shopping, always measure while standing, as the feet are at their largest when bearing weight, and select a shoe that fits the larger foot. Prioritizing comfort and adequate space for the toes over previous sizing history is the most practical response to the foot’s natural, age-related structural changes.