So when they get momentarily distracted,throw a tantrum, or turn to go the other way, I simply keep walking the direction I need to go. They always follow.
Now, please always keep that mommy half-eye open to your child who is lagging or throwing a tantrum just in case they decide to break the norm and run or go the other way. If they run away or won't stay close enough for proper supervision then put them into the cart promptly. They probably won't be happy, so get out of the store as quickly as possible if drama ensues! Good luck!