In treating low back pain, one important aspect of the treatment plan is to recommend activity precautions, those movements that are likely to further injure the spine. One precaution that comes as a surprise to many of my patients is the advice to avoid sit-ups.
This unexpected advice runs counter to what many people believe about the back. They believe that core (ie abdominal) strength leads to a healthier back, and that’s why an exercise that strengthens the core would also be good for the back.
While it is true that core fitness is good for your back, the loads caused by sit-ups, crunches and curls tend to damage the spine. What these motions have in common is they lead to the spine being in a flexed position that can damage the disks.
Stuart McGill, a prominent spine researcher, found that the forward bending movement of a traditional sit-up creates an amount of pressure on the spine that exceeds what the U.S. National Institute for Occupational Safety and Health deems safe. One experiment using a pig spine, for example, found that simulating a sit-up repetitively causes the disks to rupture, which can lead to a type of nerve damage called lumbar radiculopathy or “sciatica.”
How should core fitness be developed instead?
McGill recommends exercises that strengthen the core while maintaining a straight spine. Exercises such as bridges and planks allow you to keep your spine completely straight while getting a good workout. My patients with low back pain often find it remarkable that they feel the challenge from these exercises without causing any pain whatsoever.
And that’s why there’s no contradiction to developing a strong core and maintaining a healthy spine without ever doing a single sit-up.