The human foot is a complex structure, with the medial longitudinal arch serving as its primary support mechanism. This arch, a curved arrangement of bones, ligaments, and tendons, acts as a natural shock absorber during movement. A collapsed arch, medically known as pes planus or fallen arches, occurs when this supportive structure flattens, causing the entire sole of the foot to make contact with or come very close to the ground. This structural change can significantly alter the biomechanics of the entire lower limb, potentially leading to discomfort and other problems.
Identifying Arch Collapse Through Symptoms and Self-Assessment
Recognizing a collapsing arch begins with noticing specific symptoms, which can extend beyond the foot itself. Pain or aching along the sole of the foot, particularly in the heel and arch area, often intensifies with prolonged standing or activity. Swelling may appear on the inner side of the ankle (medial side) as the foot rolls inward, a motion called overpronation. This overpronation can also cause pain on the outside of the ankle due to bone misalignment and strain on surrounding soft tissues.
The altered mechanics of a fallen arch affect the entire kinetic chain, potentially causing issues higher up the leg. Individuals may experience shin splints, knee pain, or discomfort in the hips and lower back due to the misaligned gait. Another telltale sign is the uneven wear pattern on shoes, where the inner edges of the soles wear down much faster than the outer edges. Over time, the foot itself may visibly change shape, appearing longer or wider than before the arch collapse began.
A simple and effective way to self-assess the arch is the “wet footprint test,” which requires only water and a piece of cardboard or dark paper. Wet the sole of your foot and step onto the paper, placing your full weight on it, then step off to examine the imprint. A normal arch leaves a print with a noticeable curve or indentation along the inner edge, where the midfoot is raised off the ground. Conversely, an imprint that shows almost the entire sole, with little to no inward curve, suggests the presence of a flat foot.
It is important to understand the difference between flexible and rigid flatfoot, as this distinction relates to severity and cause. With flexible flatfoot, the arch is visible when the foot is non-weight bearing, such as when sitting or standing on tiptoes, but it disappears when standing. A rigid flatfoot, however, lacks an arch regardless of whether the person is standing or sitting, often indicating a more serious structural problem.
Primary Causes of Fallen Arches
The majority of adult-acquired flatfoot cases result from a progressive deterioration of the structures supporting the arch. The most common cause is Posterior Tibial Tendon Dysfunction (PTTD), a degenerative condition affecting the posterior tibial tendon. This tendon runs along the inside of the ankle, acting as the dynamic stabilizer that holds the medial arch up. When the tendon becomes weakened, inflamed, or torn, it loses its ability to bear the necessary load, causing the arch to gradually flatten.
This gradual weakening often stems from chronic overuse, particularly in individuals who participate in high-impact activities or who are overweight, which increases strain on the tendon. Progression can start with simple inflammation (tendinitis) and advance to tendon elongation and eventual failure, leading to fixed foot deformity. Risk factors that make a person more susceptible to PTTD include age over 40, being female, obesity, and co-existing conditions like diabetes and hypertension.
Other potential causes of arch collapse exist beyond PTTD. These include:
- Genetic predisposition, where an individual inherits a foot structure naturally prone to collapse.
- Acute trauma, such as a fracture or severe ligament tear, which immediately compromises the arch’s structural integrity.
- Chronic conditions like rheumatoid arthritis, which damage the joints and ligaments in the foot.
- Age-related wear and tear, including laxity in the ligaments, contributing to progressive flattening.
Treatment Options and When to Seek Professional Help
The first line of defense against a collapsing arch, especially in the early, flexible stages, involves conservative treatment focused on reducing strain and providing support. Rest and the application of ice to the inner ankle area help manage pain and inflammation associated with tendon stress. Physical therapy plays a significant role, targeting the strengthening of the muscles that support the arch. Specific exercises, such as toe raises and stretches for a tight Achilles tendon, help improve the overall alignment and function of the foot.
Appropriate footwear is also a core component of conservative management, with supportive shoes helping to control the inward roll of the foot. Orthotic devices, which can be either over-the-counter inserts or custom-molded devices, are used to provide mechanical support to the fallen arch. Custom orthotics are typically more effective because they are precisely designed to match the foot’s contour and provide targeted correction for the specific degree of collapse.
It is prudent to seek professional medical advice from a podiatrist or orthopedic specialist if the pain is severe, persistent, or interferes with daily activities. A consultation is also necessary if the arch collapse occurs suddenly, affects only one foot, or if the foot has progressed to the rigid flatfoot stage. The specialist will perform a physical examination, assessing the foot’s flexibility and strength, and may order imaging tests like X-rays or MRI to evaluate bone alignment and tendon condition.
For cases that do not respond to conservative measures, or for advanced-stage rigid deformities, more aggressive treatments may be considered. Steroid injections can be used to reduce localized inflammation, offering temporary relief. Surgical intervention is reserved for severe cases, such as a complete tendon rupture or a fixed deformity, and may involve procedures like tendon transfers, bone realignment, or joint fusion to reconstruct the arch and stabilize the foot.