Set-up just as you would for an inverted row with a pronated or neutral grip and your feet on the floor. Curl your hands to your forehead while supinating your wrists. Keep your body straight by squeezing your glutes and bracing your abs.
If barbell curls aggravate your wrists or forearms, you'll find that these allow for a more natural range of motion and feel great. They're not only more joint-friendly, they cause a tremendous contraction of the biceps.