https://phys.org/news/2019-01-human-feet.html

These arches were thought to be supported by plantar intrinsic muscles (PIMs) - but a study by the University of Queensland and the University of Exeter shows PIMs have a "minimal impact" on this.

The findings show that foot muscles are important for helping us push against the ground during walking and running. This suggests that strong foot muscles could be key to our ability to walk and run.