Crunching and NOT Twisting
Updated: May 1, 2020
“Injury is not always caused by a single event but by multiple sub-maximal repetitive stresses that reduce tissue tolerance over time or a sustained load applied repeatedly and for a long time” (Leibenson)
At some point, up to 80% of the population will have a low back pain episode in their lifetime. Most can be relieved with a multidisciplinary and comprehensive rehabilitation program since less than 15% can be attributed to a structural pathology (Leibenson) To learn more, pick up Dr. Craig Liebenson's book Rehabilitation of the Spine: A Practitioner's Manual.
According to the Mayo clinic, a herniated disc occurs when the inner jelly-like nucleus of the disc breaks through the outer fibers of the annulus (Figure 2,3). When the nucleus pushes too far out, it can press on a nerve or in severe cases protrude into the spinal canal and cause severe pain, numbness, tingling and/or weakness in the effected limb. Most disc issues go undiagnosed or can be treated with proper exercises. When it comes to lumbar discs issues, a back stabilization program can be very effective in rehabbing and preventing this injury but having a strong core and avoiding high risk exercises are key factors in prevention (Leibenson).
Believe it or not, putting together a bunch of crunches with twisting (repetitive flexing with rotation or side bending) has a higher correlation to disc herniation than how much load you lift (Leibenson).
During spinal flexion (Ex: a crunch), the jelly-like nucleus is squished backwards and presses out into the annulus fibers that keep it contained. Adding rotation to the motion (Figure 3) adds even more pressure like twisting the top closed on a bottle. The annulus fibers become further stretched and over time, weaken and eventurally break to spill the nucleus out (Kapandji). When this presses out on the spinal nerves or pushes into the spinal cord is when pain is most likely to be felt.
Do you have concerns regarding disc issues, safety, and general effectiveness of your exercises? Then perhaps those aggressive bicycle crunches, poorly done Russian twists with a ball, or the over exaggerated,diagonal-flex-cable,cross-over-twists things you saw on Gym Fails might not be the best options.
Thinking outside of the box:
Alternative exercises could include anti-rotation training, planks, and multi-planer training (MPT). With MPT, you could do your normal in-line crunches while at the same time doing an isometric in rotation to target obliques- without rotating! An example of this would be placing a dumbbell on your shoulder while you do a basic crunch. We have numerous anti-rotation and MPT options using the Ki-RO Core Trainer with one shown below.
MPT: Flexion with rotational resistance using the Ki-RO
Muscles Emphasized: Abdominals that Flex & Rotate
Place resistance on a lateral ring
Face away from the resistance that is attached to one of the lateral rings placed in back
Can be done: standing, seated, kneeling, or supine on a bench
Levels of Attachment and Intensity: 1, 2, 3
Video: See below
Trunk Flexion with Rotational Resistance
With so much information out there it is often hard to discern what is science based and what is "guru" based. You do not need to do 500 crunches or feel the pain to build a strong and stable core. If you are looking for information, one book you might find useful is Dr. Stuart McGill's Ultimate Back Fitness and Performance. To learn more about the effects of exercise and forces on the body, check out an RTS class which will blow your mind!
For those that are interested, the Ki-RO Core Trainer was designed to aid in the safe and effective strengthening and stabilization of the core from seated to sprinting. Please check us out at here and sign up for our email list to get our latest blog posts discussing the core.
Reminder: Always check with your doctor or exercise professional before engaging in an exercise program or adding anything new to your current work out. Just to be safe!
Please let us know if you have any questions!
Contact us at: firstname.lastname@example.org or follow us on IG @kirocore
Leibenson, Craig. Rehabilitation of the Spine: A Practitioner's Manual, 2nd ed. Baltimore/Philadelphia: Lippincott Williams & Wilkins, 2007: 4,53,94,34
Kapandji, A.I. The Physiology of the Joints: Volume Three: The Spinal Column, Pelvic Girdle and Head, 6th ed. Philadelphia: Elsevier, 2008: 34, 136.
Kika Mela is Co-Owner of Mela Therapeutics, Inc. and the creator of the Ki-RO Core Trainer. She is a Master Level MAT Specialist, MAT Rx Specialist, and has been a Licensed Massage Therapist since 1995. With a focus on mechanics and anatomy, she has worked for an NFL team as an MAT Specialist, is a contributor to the training process at Bommarito Performance Systems as part of their medical team (since 2006), and has consulted with numerous coaches, trainers, and therapists on exercise, massage, and muscle activation.