Frequently I have a problem of pebble getting inside of my sandals from back side (red in the image). It travels through the sandal forcefully as I try to remove it without actually removing the sandals (white line in image). That pebble is thrown in front when I give it angular momentum to forcefully remove it (the yellow line). There are two problems I feel.
1 - The pain it gives me as it hurts. And removing it by removing sandals within the public does not feel good.
2 - (rare case) Some times the pebble that goes from the sandal (in direction of yellow line) it "hits somebody".
Is there any life hack to prevent the pebble from coming within sandals at the first place?