Final answer:
The plantar group is the group of muscles found in the center of the sole of the foot which consists of four layers that help in toe movement and support the foot's arch.
Step-by-step explanation:
The group of muscles located in the center of the sole of the foot is known as the plantar group. This plantar group consists of four layers of muscles that are involved in flexing the toes and supporting the foot's arch. Specifically, the muscles of the deepest (fourth) layer aid in abducting and flexing the middle toes at the metatarsophalangeal joints, as well as extending the middle toes at the interphalangeal joints. Intrinsic muscles of the foot like these are crucial for maintaining balance and stability while standing or moving.