„Balance is not something you find, it is something you create.“ (Buddha)
The purpose of the foot in an upright biped is to control and direct body weight in static and dynamic activity. Static balance is important in tasks of daily living as well as fitness activities such as yoga, and is a powerful predictor of falling risk in old age (Gehlsen, 1990). The shape and structure of the foot, in particular the position and function of the big toe, is crucial in this regard.
Single-leg balance is characteristic of key yoga poses and is a simple test regularly used in clinical settings to detect balance impairment (Gehlsen, 1990). Studies examining the determinants of single-leg static balance show the engagement of the big toe with the ground to be the most important determinant of postural control (Tanaka et al., 1996; Saeki, 2015). Morton (1935) showed a valgus (squashed in) position of the big toe impaired postural control, and Chou et al.(2009) showed that removing the big toe from the ground dramatically impaired static balance.
Deformity of the big toe is a common disorder affecting around 23% of 18-65 year olds and over 36% of those over 65 years old (Nix et al., 2010). It is linked to years of wearing shoes with restricted toe boxes (Munteanu et al., 2017), but can be reversed by wearing anatomically-shaped shoes that allow restoration of natural toe position and function (Knowles, 1953). The logic is therefore clear, to improve your balance, choose anatomically-shaped shoes and fix your feet.