A small study of 25 boys (age 10-12y) with flexible flat foot (FF) sought to understand the impact of intrinsic- versus extrinsic-first corrective exercises on on muscle morphometry and navicular drop (ND). The boys underwent a 12-week exercise program that shifted focus midway. The results were significant. Leading with intrinsic exercises led to sustained improvement throughout the 12 week program, while leading with extrinsic exercises caused deterioration in intrinsic muscle morphometry, but that was recovered in latter part of the program. Staring with intrinsics also saw significant improvements in muscle thickness and cross-sectional area (as measured by ultrasound), as well as more reduction in ND. These authors found that starting with corrective exercises in intrinsic muscles proved more effective in improving foot muscle morphometry and reducing ND in boys with flatfoot.
Source: Ketabchi J, Seidi F, Haghighat S, Falsone S, Moghadas-Tabrizi Y, Khoshroo F. Differential effects of intrinsic- versus extrinsic-first corrective exercise programs on morphometric outcomes and navicular drop in pediatric flatfoot. Sci Rep. 2024 Dec 28;14(1):31393. doi: 10.1038/s41598-024-82970-y.
