Flat feet, or pes planus, occur when the arches of the feet are lower than normal or entirely flattened, causing the sole to make complete or near-complete contact with the ground. This condition can be present from childhood or develop later in life due to various factors such as age, injury, or overuse.
Flat feet can range from asymptomatic to causing discomfort, pain, or fatigue in the feet, ankles, knees, hips, or lower back. Left untreated, it may lead to biomechanical imbalances and increased risk of other foot-related issues.
The arch of the foot plays a critical role in absorbing shock, distributing weight, and stabilising the body during movement. When the arch collapses:
• The posterior tibial tendon, responsible for supporting the arch, becomes overworked, leading to inflammation, pain, and potential posterior tibial tendon dysfunction (PTTD).
• The peroneal tendons, which stabilise the foot on the outer side, may also compensate excessively, resulting in strain and discomfort.
• Ligamentous strain such as the spring ligament and deltoid ligament can become overstretched, causing further instability and foot deformities.
• Misalignment of the foot can place abnormal stresses on the plantar fascia, leading to conditions such as plantar fasciitis.
• Overpronation, the main characteristic of flat feet, can disrupt gait mechanics and strain the knees, hips, and lower back.