However, for your health you should really slim it down.
Your Butt, Your Back, Your Legs
Many people like to keep their wallets in their back pockets. When you sit down, the wallet then presses on the piriformis muscle. That muscle is small. It’s in your buttocks, but is also very close to your sciatic nerve.
Your sciatic nerve, which is the largest your body, runs from your butt to your lower back to your legs. Sitting on your wallet or anything else for that matter, can irritate that nerve.
Irritating your sciatic nerve can cause severe pain in your lower back and legs.