Flexor digitorum brevis: A muscle in the sole of the foot that helps flex the middle phalanges (the middle parts) of the four lesser toes.
Plantar fasciitis: An inflammation of a thick band of tissue that runs across the bottom of your foot and connects your heel bone to your toes, commonly caused by strain injury affecting the plantar fascia.
Arch support: Refers to devices or shoe modifications designed to support the arches of the foot, often used to relieve pain for people with conditions affecting their plantar group or plantar fascia