This podcast challenges the traditional orthotic assumption that medial arch support should be a default component of foot orthoses used to correct foot posture or control pronation. It argues that the human foot is a dynamic, deformable and energy-storing system, rather than a static structure requiring permanent external support. Experimental evidence demonstrates that substantial restriction of arch compression can reduce locomotor efficiency, while prolonged orthotic use has been associated with reductions in intrinsic foot-muscle cross-sectional area, raising the possibility of "muscular detraining".

Research also indicates that increasing arch-support height does not produce a predictable dose-response reduction in rearfoot eversion, medial-lateral centre-of-pressure displacement, or pronation control. The most consistent effect of increasing arch contour appears instead to be a redistribution of plantar load toward the medial midfoot.

Rather than following historical manufacturing conventions based primarily on foot shape, neutral casting,and arch height, the article argues for a kinetic-based prescription model in which orthotic design is determined by the specific force, joint moment, or tissue stress that requires modification.

Ultimately, clinicians are encouraged to regard arch contour as an active mechanical intervention rather than a benign default, to appreciate the potential negative effcts of directing high magnitudes of GRF into the apex of the vault, and to preserve physiological foot deformation and function unless there is a clearly defined biomechanical reason to alter it.