"For a ship without a port, no wind is right." (Seneca the Younger)
The function of the foot is not only to support, but also to control the direction of the body's weight during movement (Rolian et al., 2009). Part 1 explained the importance of foot shape in general for these purposes. But the important role of the toe deserves special attention.
The big toe is the rudder that provides directional control for the body weight during weight transfer (Yavuz et al., 2009). This is only possible when it is in the correct position. The marked splaying of this toe from the other toes usually characterizes barefoot walkers (Hoffman, 1905; D'Aout et al., 2009; Shu et al., 2015) and is an evolved functional adaptation that provides directional stability. Chou et al. (2009) showed that forcing the toe into an elevated position resulted in a loss of balance ability. Plank (1995) evidenced excessive pronation during walking when the position of the big toe was compromised (squeezed), a condition that affects 23% of 18-60 year olds and more than 36% of those over 60 years of age (Nix et al., 2010) and results from wearing shoes with a tight toe box (Munteanu et al., 2017).