There are sandals which are very odd in Japan.
Believe or not, with slipping your feet into the sandal, you would be able to get healthier.
The sandal is called “KENKO SANDAL” (Health Sandal”) and the feature is the insole has projections and they stimulate acupuncture points of your foot.
You would not feel anything if you are healthy but if not, you would not be able to walk because it is too painful.
Even it hurts at first, try to keep using them then you would not feel pain at last which means you are more health than before.