You roll around on your Swiss ball like a grizzly with a back itch. You do crunches and work your obliques like a champ. So you must have good core stability, right? And core stability will reduce back pain and prevent injury, right?

Yes, no, maybe. Research on back pain, experts say, is spotty and the subject of debate.

Research suggests that, yes, exercises that target core muscles might reduce back pain and prevent future injury, but whether these exercises are substantially better than other structured exercise programs for chronic back pain has not been proved. And not all researchers agree on which components of the body's core muscles are most crucial to preventing a back injury and reducing pain after suffering an injury.

A seminar on the role of core stability in reducing and preventing back pain attracted a full house last week at the American College of Sports Medicine's Health and Fitness Summit and Exposition in Long Beach, Calif. Presenter Marjorie King, director of the graduate athletic training program at Plymouth State University, in Plymouth, N.H., outlined the current state of the field: a need for more research and moderate support for the use of core stabilization exercises to decrease low-back pain and increase low-back function.

King thinks that some who practice core stability are missing at least part of the boat. "One of the biggest misconceptions people have about core stability is that by doing crunches, they're getting at core stability," she says.

Crunches address the trunk, or "global" muscles, which exercisers more commonly work. But to really target core stability, she says, exercisers need to attend to the often-ignored spinal, or "local" muscles.

Local muscles include the little intersegmental muscles, the multifidi, that run along the vertebrae. These muscles don't move a lot but are thought to play a role in keeping the spine stable during movement.

Other musculature involved in local stabilization include pelvic floor muscles and the transversus abdominis muscle, the deepest of the abdominal muscles. This muscle is horizontal in design, King says, and functions like a corset, stabilizing the spine.

Core stability training "is the standard of care, it's what people do, in my field anyway," says Dr. Christopher Standaert, a physiatrist (a physician specializing in physical medicine and rehabilitation) and clinical associate professor of rehabilitation medicine at the University of Washington in Seattle. But, he adds, "There's never even been a uniform agreement on the definition."

Among those who think - based on their clinical experience - that core training works, there are two schools of thought on exactly how it works. Some think, as King does, that local muscles such as the multifidi and the transverse abdominis are critically important.

But, Standaert says, "there are other people who … think it's more about training movement patterns and broader motions and coordination of multiple muscles through your trunk to help your spine move more effectively. … So it's about the whole system."

In fact, Standaert adds, whether one is talking about local or global core stabilization, the rush to embrace core training has moved ahead of the science. "People need to know that the scientific clinical foundation, the research, doesn't match the extent of emphasis that trainers and therapists and all sorts of people put on it," he says.

As back experts continue their debates and research, those who want to prevent or deal with their back pain need solutions now.

Those with persistent, chronic back pain should see a physician and get a proper diagnosis, says Dr. Robert S. Bray Jr., a neurological spinal surgeon and founding director of D.I.S.C. Spine and Sports Center in suburban Los Angeles. A sports-medicine physician or physiatrist is a good place to start.

In addition, anyone who is doing exercises to reduce back pain should do so with guidance from an exercise or back-care professional, such as a physical therapist, chiropractor or certified athletic trainer.

Regardless of the state of the science, working the core's local stabilizers won't hurt and probably will help, King says.

The best way to stabilize the spine, she says, is to stand up straight (stomach in while still breathing, equal weight on both feet, feet straight ahead, glutes flexed, pulling up through the pelvic floor) and sit up straight (stomach in, both feet on the ground, again, pulling up through the pelvic floor).

"Any time you sit or stand, in the line at the grocery store, stuck in traffic, brushing your teeth" is an opportunity to correct your posture, she says. "You don't necessarily need a huge difference; you just need a bit of a difference."

The exercises

Back pain is the bane of millions, but some simple exercises might help prevent and alleviate those aches and twinges.

These maneuvers don't just target the muscles surrounding the spine - they hit the abdominal and oblique muscles on the sides of the trunk, as well. Shoring up all the muscles around the back not only makes lifting heavy loads easier - it also allows for less pain during daily tasks such as gardening, getting in and out of the car or even sitting for hours in front of a computer.

The drills - including popular ones such as the front plank, side plank and bird dog - were presented recently at the American College of Sports Medicine's annual Health and Fitness Summit and Exposition in Long Beach, Calif., by Michael Bracko, a Calgary, Alberta-based exercise physiologist. At a group participation session, he demonstrated key exercises - with modifications for beginning exercisers.

Bracko suggests that beginners start with the modified exercises, then work up to full-strength versions. Advanced exercisers can add weights to some of the drills. Positions should be held, if possible, for 10 to 20 counts, fostering muscle endurance. As your strength and endurance build, your counts can go longer and you can add more repetitions.

Modifications completed in a standing position (for office settings) can be done every day, but the more vigorous versions should be done every other day. Modify or stop the exercise at any sign of pain.

Front plank: Targets the abdominal muscles. Body is horizontal, face down, arms directly underneath the shoulders. Lower arms and toes support the body, and the back is straight. Head is aligned with the spine.

Modification one: Knees and toes are on the floor. Back is straight.

Modification two: Arms are in the same position, but the exercise is done leaning against a wall. Back is straight.

Modification three (advanced): Increase the intensity by moving the elbows forward.

Side plank: Targets the obliques. Legs are crossed at the ankles, and the body's weight is supported by the feet and one forearm, with the elbow directly underneath the shoulder. The other arm is extended along the side, and the back is straight, with the head in line with the spine. The exercise should be done on both sides.

Modification one: The knees are bent, with the weight supported on the lower legs as well as the arm.

Modification two: Arm is in the same position, but the exercise is done against a wall. Back is straight.

Modification three (advanced): Increase the intensity by moving the elbow forward or holding a dumbbell with the top hand, or both.

Bird dog: Targets back muscles from the shoulder to the buttocks. Starting on all fours, with elbows directly underneath shoulders and knees directly below hips, raise one arm in front and the opposite leg in back at the same time, keeping both straight, and the head in line with the spine. Raise and lower leg and arm several times, then switch arm and leg.

Modification one: Do arm and leg raises separately.

Modification two: Do the exercise while leaning against a wall.

Modification three (advanced): Do the exercise with dumbbells or ankle weights, or both.

Cat-camel: Targets flexing and extension of abdominal and back muscles. Begin on all fours, with elbows under shoulders and knees below hips. Arch the back into a convex shape, then reverse it into a concave position. Repeat.

Modification: Do the exercise while standing and leaning against a wall, or seated, leaning against a desk.