The sensation of your ankles turning inward when you walk is a common biomechanical issue known scientifically as overpronation. This describes the excessive inward roll of the foot after the heel strikes the ground. While some inward roll is necessary for shock absorption, too much motion can disrupt the entire alignment of the leg and body, creating a chain reaction of stress that travels upward to the knees, hips, and lower back.
Understanding Foot Pronation and Gait
Pronation is a normal movement of the foot that functions as the body’s natural shock absorber upon impact. This movement involves the foot rolling inward (eversion), the forefoot moving away from the body, and the ankle slightly bending upward. During a normal stride, the foot pronates immediately after the heel strikes the ground, allowing the arch to flatten slightly to absorb the force of impact.
Overpronation is an excessive or prolonged inward roll that causes the arch to collapse too much during the gait cycle. This excessive movement causes the ankle joint to drop medially and the lower leg to rotate internally, disrupting the body’s alignment. Two simple ways to assess potential overpronation are by examining shoe wear patterns or performing the “wet test.” Wear patterns typically show heavier wear along the inside edge of the sole, while the wet test reveals a flat, full impression of the foot, which is often linked to overpronation.
Primary Causes of Inward Ankle Turning
The underlying reasons for inward ankle turning can be separated into structural and muscular factors. A common structural cause is an inherited foot shape, such as naturally flat arches, medically termed pes planus. Other structural alignment issues higher up the leg can also contribute, such as an inward twist of the shin bone (tibial torsion) or the thigh bone (femoral anteversion).
Muscular deficiencies also play a significant role in the development of overpronation. The muscles responsible for stabilizing the foot, particularly the tibialis posterior, may be weak or fatigued, leading to arch collapse and inward ankle roll. Furthermore, generalized weakness in the hip and gluteal muscles can also contribute, as these larger muscles are responsible for stabilizing the entire leg and controlling rotational forces. Factors like obesity or high-impact sports can increase the downward force on the arch, exacerbating existing structural or muscular weaknesses.
Related Pain and Alignment Issues
The foot’s excessive inward roll sets off a reaction that travels up the body, known as the kinetic chain. When the ankle turns inward, it forces the shin bone (tibia) to also rotate internally. This internal rotation alters the position of the knee, placing abnormal stress on the joint and often leading to conditions like patellofemoral pain syndrome, or pain around the kneecap. The altered mechanics can also strain soft tissues in the lower leg, commonly resulting in shin splints.
The misalignment continues upward, affecting the hip and pelvis, often causing the pelvis to tilt forward (anterior pelvic tilt) as the body attempts to compensate. This compensatory movement can lead to chronic lower back tension or pain due to the altered mechanics and muscle strain. At the foot level, the flattening of the arch stretches the plantar fascia, which can cause sharp heel pain known as plantar fasciitis.
Management and Correction Strategies
Management of overpronation typically involves a combination of supportive devices and targeted strengthening exercises to address both the symptom and the cause. Footwear selection is a primary step, where choosing a stability shoe or motion-control shoe can help. These shoes feature a denser midsole material and a firm heel counter to prevent the excessive inward roll of the foot during the stance phase of gait.
Orthotic devices are another highly effective strategy for correcting foot position and controlling the rate of pronation. Over-the-counter arch supports can offer temporary relief and basic correction. Custom-made orthotics are molded specifically to the individual’s foot, providing precise correction of the foot angle and better support for the medial arch.
Physical therapy focuses on strengthening the muscles that stabilize the foot, ankle, and hip. Exercises that target the intrinsic foot muscles and the tibialis posterior are important for improving arch strength. Strengthening the external rotators and abductors of the hip, such as the gluteal muscles, is also beneficial because strong hips help control the internal rotation of the leg, which reduces stress on the ankle. Regularly performing exercises like heel raises, towel scrunches, and resistance band work can help restore a more neutral gait pattern.