„All the phenomena of biology, are ultimately obedient to the laws of physics and chemistry.“ (E. O. Wilson)
Pain, decreased mobility and poor quality of life resulting from structural disorders of the feet affect over 60% of older adults (Dunn et al., 2004). Hallux valgus (big toe squashed inwards) is the most common disorder (Nix et al., 2010) leading to a host of mobility problems and pains in the feet, lower legs, knees and beyond. Regular use of shoes with a non-anatomically-shaped-restrictive toe box predicts development of hallux valgus (Munteanu et al., 2017) in accordance with Wolff’s law that bone adapts to forces imposed upon it (Wolff, 1892). The same law dictates that, given appropriate conditions (room to expand and force), foot structure can be positively altered.
An early case study reported complete reversal of hallux valgus over a two-year period when the patient was prescribed anatomically-shaped footwear (Knowles, 1953). Appropriate shoe shape is however only half of the solution. Yes, the foot must be given space to expand and for the toes to spread, but feet also need to be loaded with body weight if they are to expand into the space provided. Feet lengthen (1.5%), widen (4.3%) and flatten (-9.3%) when loaded with body weight during standing (Houston et al., 2006), making standing the ideal stimulus for beneficial structural changes to compromised feet.
Further evidence for the stimulus of bodyweight on foot structural change comes from the study of feet during pregnancy. In a longitudinal study of 49 women, arch height decreased and foot flexibility, length and width increased with increased bodyweight over the course of pregnancy. Moreover, the structural changes were permanent (Segal et al., 2013).
In summary, to rehabilitate feet with hallux valgus and high-tight arches, feet must be loaded with the force of body weight (standing) in footwear that provide the freedom for the bones to spread back into a natural-anatomical configuration. It should be noted that this recommendation pertains to mild/moderate structural problems. Exposing severely compromised (collapsed/severe hallux valgus) feet to the loads of standing will worsen pain and deformity. In these circumstances, surgical realignment must precede rehabilitation by standing in appropriate footwear.