I'm looking for research to support both sides of the neutral spine/posterior tilt debate when performing abdominal exercises. Can you help?
The answer to your question requires the answers to a few more questions:
- What are your client's current bio-motor abilities (i.e., core stability/strength/endurance levels, general total body neuromuscular efficiency or lack there of, exercise experience/tolerance levels, present/past injury history)? Note: This will only be discovered through the preliminary interview and the essential integrated kinetic chain assessment (KCA) on your client's static and dynamic postures. If you're not assessing, you're guessing.
- What is your client's ultimate goal? And perhaps more importantly, what are your goals for your client based on what you've determined she/he needs from the KCA?
- Do you understand from a functional anatomy perspective, the mechanics rationales for training spinal flexion (posterior tilt) versus neutral spine?
I'm going to assume you're asking about these two positions specifically regarding core training. Training in neutral spine (NS) can be primarily beneficial in initial core stability progressions to teach optimal alignment and posture, which the average health club member rarely achieves in day to day life due to our automated and seated society. It is important to remember, specifically with any sport specific progressions, that the body was designed to operate "out of NS" and does so in virtually all functional movement patterns (i.e., reaching, bending, twisting, etc.). Training in NS can also be very load specific, meaning the heavier the load, the more optimal the spinal posture/alignment should be.
A posterior pelvic tilt (PPT) or spinal flexion simply implies the recruitment of the spinal flexors (i.e., rectus abdominis and internal/external obliques, primarily). If a "crunch" is the chosen exercise, than a PPT must occur in order for these muscles to fire; the muscles and their actions are essentially one in the same. Whether this exercise is appropriate or not is an entirely different matter and beyond the scope of this article.