Running with flat feet, formally known as pes planus, presents unique challenges due to altered foot mechanics. Flat feet are characterized by a lowered or absent arch, causing the entire sole of the foot to contact the ground. While this foot structure is common, affecting an estimated 20 to 30% of the general population, it can increase the likelihood of discomfort and injury for runners. A collapsed arch can compromise stability, potentially leading to pain in the feet, ankles, knees, or even the back. Addressing this requires a comprehensive strategy that combines appropriate footwear, refined running technique, and targeted muscular conditioning.
How Flat Feet Affect Running Gait
The primary mechanical consequence of a flat foot during running is excessive inward rolling of the foot, known as overpronation. Some degree of pronation is natural and necessary for shock absorption, where the foot rolls inward approximately 15 degrees after heel strike. With flat feet, however, this inward roll often exceeds 15 to 20 degrees and lasts for an extended period of the gait cycle, delaying the necessary transition to supination for an effective toe-off.
This prolonged overpronation causes a chain reaction of misalignment that travels upward through the leg, commonly referred to as the kinetic chain. As the foot rolls excessively inward, it forces the lower leg to rotate internally. This rotation can lead to stresses on the ankle, strain on the Achilles tendon and plantar fascia, and altered tracking of the kneecap. The resulting imbalance can contribute to shin splints, plantar fasciitis, and knee pain.
The inward rotation can also affect the pelvis and lower back, as the forces transmitted up the leg can alter the alignment of the hip and sacroiliac joints. Managing flat feet requires maintaining proper joint alignment throughout the entire body. Understanding these mechanics is the foundation for implementing effective countermeasures.
Selecting Supportive Running Shoes and Inserts
The most immediate and accessible solution for managing flat feet while running is selecting the correct footwear. Runners with significant overpronation typically benefit from shoes categorized as “Stability” or “Motion Control.” These models are specifically engineered with features designed to counteract the excessive inward roll of the foot.
Stability shoes often incorporate a medial post—a denser foam material placed under the arch side of the midsole—to resist the collapse of the arch upon impact. Motion control shoes offer the highest degree of support, featuring a firmer midsole and a reinforced heel counter. Determining the necessary level of support can be done through a simple wet test or, more accurately, through a gait analysis performed at a specialty running store.
Beyond shoes, supportive inserts can provide additional arch support within the shoe. Off-the-shelf insoles offer general cushioning and mild arch support. These pre-made inserts are designed to fit a wide range of foot types and can offer temporary relief or cushioning.
For those with significant biomechanical issues or chronic pain, consulting a podiatrist for custom orthotics is often recommended. Custom orthotics are personalized medical devices crafted from a detailed 3D scan or mold of the foot. This ensures a precise fit that addresses the individual’s unique foot structure and gait pattern, providing optimal alignment and durability.
Adjusting Running Form and Cadence
While equipment provides external support, adjusting running technique offers internal, dynamic control over gait. One of the most impactful changes a runner can make is increasing their running cadence (SPM). Increasing this rate by a small percentage can significantly reduce ground contact time and impact forces.
A higher cadence encourages a quicker foot turnover, which minimizes the duration the foot spends in the pronated, unstable phase of the gait cycle. Experts often suggest aiming for a cadence in the 170 to 180 SPM range. This subtle adjustment naturally shortens the stride and encourages the foot to land closer to the body’s center of mass, reducing the tendency to overstride.
The foot strike pattern can also be consciously adjusted to reduce strain. Many runners with flat feet are heavy heel strikers, which can exacerbate the inward rolling motion. Shifting the focus toward a midfoot or forefoot strike encourages the foot to land more evenly.
The midfoot strike, where the heel and the ball of the foot land nearly simultaneously, is often considered the most balanced and injury-preventive. This change in landing position helps distribute impact forces more broadly across the foot and leg, reducing the stress concentrated in the heel and arch area.
Targeted Foot and Lower Leg Strengthening
Long-term stability and injury prevention rely on strengthening the muscles that actively support the arch. The tibialis posterior muscle is a primary focus, as it runs along the inside of the lower leg and acts as a major stabilizer of the medial arch. Exercises that involve ankle inversion, such as resisted movements with a band or calf raises focusing on keeping the arch lifted, can build strength in this muscle.
Strengthening the intrinsic foot muscles is also important for creating an active, stable arch. Exercises like “arch doming” or the “short foot exercise” teach the runner to lift the arch without curling the toes. This improves the foot’s ability to stabilize itself and absorb shock, contributing significantly to balance and running efficiency.
Flexibility and capacity in the calf muscles and Achilles tendon must also be addressed, as tightness in these areas can contribute to the collapse of the arch. Performing eccentric calf raises can help build strength and capacity in both the calf and the tibialis posterior muscle. Regular stretching helps ensure the ankle has the full range of motion necessary to transition smoothly through the gait cycle, reducing the strain that can worsen flat foot issues.