In orthotic design, which aspect is crucial for ensuring proper support for rigid cavus feet?

Custom arch support is essential for providing the necessary support for rigid cavus feet. Individuals with rigid cavus feet typically have a high arch that does not easily adapt to weight-bearing activities. This condition can lead to an imbalance in the foot's biomechanics, resulting in increased pressure on certain areas and susceptibility to pain and discomfort.

By incorporating custom arch support in orthotic design, the arch can receive targeted cushioning and reinforcement, helping to distribute weight more evenly across the foot. This support not only alleviates the strain on specific areas but also contributes to improved stability and alignment during movement. Custom supports are tailored to the individual's unique foot shape and characteristics, which is crucial for addressing the specific contours and needs of those with cavus feet.

In contrast, flexible materials may not provide the rigidity and support needed for such a high arch, increased heel height could exacerbate instability issues, and inadequate toe box space does not directly address the arch's support requirements. Hence, custom arch support stands out as the most critical aspect in the orthotic management of rigid cavus feet.