boot

climb

crumb

crunch

crush

debris

dirt

dusty

feet

flat

foot

footstep

footwear

grating

gravel

graze

grit

ground

gym

impact

junk

litter

pace

rasp

rock

rubble

runners

sand

scour

scrape

scratch

scratchy

screenings

scrunch

shale

shard

shaving

shoe

sneakers

soil

stamp

step

stomp

stone

stride

tennis

tramp

tread

walk

walking

grate

runner

screening

sneaker