The Wallet-in-Back-Pocket Back/Pain Connection

Geezer recently dined with a friend who, after suffering a series of stress-related back spasms, stopped carrying his wallet in his back pocket, on the theory that constant pressure on one side of his butt was a contributing factor to his spasms. Believing his friend to be not quite correct about the wallet-in-pocket/back pain connection, Geezer politely bit his tongue. Now it looks like his friend was right.
The New York Times and the BBC both report that back pain, and more likely, sciatica, can be caused by pressure from a wallet carried in a back pocket. Wait, there's more. The Times reports that wallets are not the only culprits; large handkerchiefs, golf balls and other objects carried in back pockets can set the stage for chronic pain. Geezer's solution? Leave the wallet home. That will  reduce the chances of suffering from sciatica, and it will increase the chances that friends who do carry wallets will pick up the entire bill for dinner.