The foot arch is a dynamic structure that serves as the body’s shock absorber and force distributor during movement. This structure, known as the medial longitudinal arch, is an interplay of tarsal and metatarsal bones, reinforced by specialized ligaments and the active tension of tendons. While many people think of the arch as a fixed feature of the adult foot, it is subject to continuous change throughout a person’s lifespan. The answer to whether a foot arch can change over time is yes, beginning in infancy and continuing into adulthood due to various biological and mechanical factors.
Natural Arch Development from Infancy
At birth, the foot arch is present only in its skeletal outline, and it is not yet functional or visible. Most infants appear to have flat feet because a thick pad of fat sits on the sole, effectively masking the developing arch structure. The bones are still largely cartilaginous, and the ligaments that connect the joints exhibit significant laxity, adding to the flat appearance.
The true formation of the arch begins as a child starts to walk and the muscles and tendons are increasingly used to support body weight. The fat pad gradually resorbs, and the arch becomes more visible as the surrounding soft tissues gain strength and tone. This developmental process is typically completed, and the arch structure is mature, sometime between the ages of six and ten.
Triggers for Adult Arch Collapse or Height Increase
Once fully formed, the adult arch is susceptible to changes caused by the degeneration of soft tissues, particularly tendons. The most common cause of a collapsing arch in adults is Posterior Tibial Tendon Dysfunction (PTTD), now often referred to as progressive collapsing foot deformity (PCFD). The posterior tibial tendon runs along the inside of the ankle and is the main dynamic support structure for the medial arch.
When this tendon becomes overworked, inflamed, or degenerated from repetitive stress, it loses its ability to sustain the arch. Increased body weight places greater load on the tendon, making obesity a contributing factor to its failure. Systemic conditions like diabetes and hypertension also compromise the health of the tendon, accelerating its degeneration.
Hormonal shifts can also instigate arch changes by affecting ligamentous structures. During pregnancy, the hormone relaxin is released to increase joint flexibility in preparation for childbirth. This hormone acts systemically on the ligaments in the feet, increasing their laxity and allowing the arch to drop and the foot to lengthen or widen. Inflammatory joint diseases like rheumatoid arthritis can also destabilize the joints supporting the arch, leading to structural collapse.
Physical Manifestations of Arch Changes
A collapsing arch results in a visible change known as acquired flatfoot, or excessive pronation, where the foot rolls inward more than normal upon impact. This over-pronation can be easily observed from behind, sometimes presenting the “too many toes” sign, where more of the toes are visible on the outside of the foot than usual. Conversely, a less common change is an increase in arch height, known as supination, causing the foot to roll outward excessively.
These alterations in foot mechanics lead to symptoms and discomfort throughout the body. Common complaints include pain along the arch or heel, often diagnosed as plantar fasciitis, due to the stretching of the plantar fascia ligament. Changes in gait can also lead to instability in the ankle and knee joints, as the foot is no longer efficiently absorbing shock. The change in the foot’s width and length often makes finding comfortable, properly fitting shoes increasingly difficult.
Supporting Foot Health and Stability
Proactive management of foot health involves strengthening the muscles that support the arch structure. A focus is the tibialis posterior muscle, which can be strengthened through exercises such as arch doming, where the individual contracts the foot muscles to lift the arch without curling the toes. Weighted heel raises performed with an inward bias can also help to restore the muscle’s capacity to lift and stabilize the arch.
Maintaining a healthy body weight is an effective preventative measure, as it reduces the mechanical load placed on the arch-supporting tendons and ligaments. For those experiencing arch-related pain, supportive footwear is essential for daily activities. Professional intervention can include custom-made orthotic devices, which provide passive support to the medial arch, limiting excessive pronation and helping to distribute pressure evenly.