High arches, formally known as pes cavus, describe a foot structure with an abnormally elevated arch that does not flatten when bearing weight. Supination, or underpronation, is a gait pattern where the foot rolls outward, placing the majority of the weight along the outside edge during walking or running. While distinct, these two conditions frequently occur together, creating a foot type poorly equipped to absorb the forces of movement.
The High Arch Supination Connection
High arches are strongly correlated with an excessive supination gait because the foot structure is inherently rigid. A healthy foot naturally rolls slightly inward (pronation) upon impact to act as a shock absorber and adapt to the ground surface. The skeletal structure of a high-arched foot remains “locked” and inflexible, severely limiting this necessary inward movement.
This rigidity prevents the foot from pronating enough to distribute impact forces across the entire sole. Consequently, the foot remains in a supinated position throughout the stance phase of the gait cycle. The foot acts more like a stiff lever than a flexible spring, concentrating the force of each step onto the outer border.
The hindfoot, or heel, often tilts inward (varus), which further contributes to the outward rolling pattern. The restriction of the foot’s natural shock-dampening mechanism is caused by the lack of flexibility and the inability to unlock the midtarsal joint, rather than the arch height alone. This structural predisposition means individuals with pes cavus are far more likely to underpronate.
Consequences of Inefficient Shock Absorption
The primary issue arising from a rigid, supinated foot is the diminished capacity for shock absorption. Since the foot cannot cushion the impact adequately, concentrated forces are transmitted directly up the lower limb, creating stress throughout the body. This repetitive impact significantly increases the risk of various musculoskeletal issues.
One common problem is ankle instability, making the foot vulnerable to frequent lateral ankle sprains as it rolls outward. The repetitive, high-impact force can also lead to stress fractures in the lower leg bones, such as the tibia, calcaneus, and metatarsals. Painful soft tissue conditions are common, including plantar fasciitis, which is inflammation of the thick band of tissue across the bottom of the foot.
The uneven distribution of pressure often results in the formation of calluses under the heel and the ball of the foot, especially along the outer edge. Chronic supination affects the entire kinetic chain, contributing to shin splints, knee irritation, hip tightness, and lower back discomfort. The body attempts to compensate for the foot’s rigidity, leading to strain on muscles and joints far removed from the foot.
Support Strategies for Pes Cavus
Managing the supination associated with high arches focuses on accommodating the rigid foot and improving shock absorption, rather than trying to force the arch to flatten. Proper footwear selection is a foundational step, and individuals should seek shoes with maximum cushioning in the midsole. Since the foot is already structurally stable, shoes designed with motion control or stability features should be avoided, as they can exacerbate the foot’s rigidity.
Orthotic devices can provide significant symptomatic relief by distributing pressure more evenly across the sole. Custom orthotics are often preferred because they can be molded to perfectly accommodate the elevated arch and offer cushioning beneath the heel and the ball of the foot. The primary goal of these devices is to support the foot and absorb impact, not to actively correct the arch posture.
Beyond supportive gear, physical therapy can address the muscle imbalances and tightness often accompanying a high-arched foot. Specific stretching exercises targeting tight structures like the plantar fascia and calf muscles can improve flexibility. Strengthening exercises focusing on ankle stability are also important to help reduce the risk of recurrent ankle sprains.