Q: I read that too much flexion of the spine is bad for you. Is this true? And if so, does this mean crunches and sit-ups are bad too?
A: According to Stuart McGill (the leading spine researcher in the world), absolutely. First let me tell you something about Stuart. When Stuart talks, you listen. I had the pleasure of meeting Stuart last weekend and that’s exactly what I did. I sat in awe and listened to the smartest human being I have sat (I was actually standing) in front of.
Here is the thing, research shows us that repeated flexion is bad. Not just bad, but it will eventually herniate a disc. If you look at how often the majority of people are in a flexed position, be it sitting at a computer, driving, or watching tv, it doesn’t even make sense to perform things like crunches, sit ups and forward flexed stretches. Our core is meant to keep our spine in a safe and stable position. Think “movement preventer”,not “movement producer”.
And its not just the general population that should avoid repetitive flexion. Athletes need to focus more on core stability and McGill says, “Sparing the Spine”. Ask yourself this, “Can you think of anything in sport that emulates a crunch?” Click here for alternatives to crunches.
And don’t just take my word for it. Check out the research:
1. Repeated flexion of the spine is necessary to cause herniation (Adams and Hutton, 1982). In fact, herniation of the disc seems impossible without full flexion.
2. Thousands of cycles of flexion are needed (Gordon et al., 1991 ; King, 1993 ;Callaghan and McGill, 2001) to herniate a healthy disc.
3. Prolonged sitting exacerbates the risk (Videman et al., 1990; Wilder et al, 1988).
4. Flexing forward with some lateral bend to the right will most likely result in a bulge, posterior lateral to the left in the disc.
5. It appears that repeated twisting causes the annulus to slowly delaminate
*Ultimate Back Fitness And Performance third edition, Stuart McGill, PhD