• Work out your core. Never mind a six-pack—you need to concentrate on the transverseabdominus, the deep abdominal muscle that acts as a “corset” around the lumbar spine, accordingto Sullivan. To do this: lay on your back with your knees bent, put your hands on your hips,breathe normally, and pull your belly button straight down to your spine. You don’t want yourpelvis to tilt or lift, which is why you have your hands on your pelvis. Hold it for 5 seconds andrepeat. “Once you get it, you can do it all the time, just sitting at work and it becomes a habit,”Sullivan says.