footprint, remains
趾 centers on a physical trace left behind: a footprint or, more broadly, remains that mark where something once was.
趾 combines 足 (foot) with 止, which likely contributes both sound and the idea of stopping or a footprint.
The left side is a foot 足, and the right side 止 looks like a stopped foot. Together they make a footprint left behind.
For シ, imagine a single footprint in the sand: the shape of the print looks like the letter 'C', which sounds like シ.
Cochin (breed of chicken)
hallux valgus; bunion
big toe; great toe; hallex
hallux valgus; bunion
first toe; big toe; great toe; hallux; hind toe (birds)
middle toe
second toe; long toe; inner toe (bird)
little toe
fourth toe; ring toe; outer toe (bird)
footprints
pediphalanx
digitigrade (walking on the toes)
footpad dermatitis (in animals); FPD
phalanx (of the foot); phalange