Iyengar is, so to speak, Jesuit yoga: precise and disciplined. Iyengar utilizes props such as straps and blocks to help practitioners hold a pose. A strap helps you slowly and safely stretch your leg if you lack flexibility. Say you can't sit comfortably cross-legged on the floor: A block placed under one or both thighs can help prop you up.
Precision rules in this yoga style. "Iyengar appeals to Type A people," says Schumacher. "Teachers provide detailed instructions so that people are clear about what to do as they move into a pose."