It is one of the most important questions in the field of strength training:
Should your lower back be allowed to round in the squat and deadlift – or is this occurrence a red flag for risk of injury?
The common notion we find in field of weightlifting is that a “neutral spine” shall be maintained at all times during lifts where the back is heavily involved in order to prevent acute or chronic spinal pathologies such as ligament damage, vertebrae injuries, or disc herniation. As such, even the slightest level of spinal flexion is commonly strongly discouraged.
The question this article is trying to answer is whether keeping a "neutral spine" in the squat and deadlift is a justified goal or a flawed concept that requires further analysis.
If we look at a number of studies conducted to date, lumbar flexion is likely to occur in the squat and deadlift at some point in every lifter - and it appears to be unavoidable no matter how much we coach it.
Indeed, lumbar flexion of around 25 degrees has been reported in powerlifters, all while an increase in injury risk has NOT been observed at the same time.
At Strong For Life, we are observing that at a certain weight and level of strength, our members find it challenging to keep their back in full extension. Is this something to be corrected, or a natural occurence in their respective stage of training?
While there is truth in the argument to avoid an uneven distribution of compressive forces on the spinal discs and vertebrae by rounding our lumbar area, biomechanical analyses conducted to date do not support the obtaining of a neutral spine to keep it “healthy” and injury-free.
In fact, there is currently little scientific evidence to support the notion that greater flexion in the lumbar spine increases the risk of injury to the lower back.
To further support this evidence, hundreds of thousands of lifters are performing tens of thousands of reps each year without incurring a lumbar disc herniation or vertebrae fracture despite lumbar flexion likely occurring at some stage in the squat and deadlift in their training.
This points to the conclusion that despite a degree of lumbar flexion present in the squat and deadlift, all structures in and around the spine – muscles, ligaments, tendons, discs - appear to adapt to the stress they are exposed to without increasing their risk to injury.
If we take the deadlift as an example, we are also finding that there is a distinct advantage to lifting with a slightly flexed lower back: the bar is closer to the hip joint – thus decreasing the moment arm of the bar and resultantly making the weight easier to lift.
From our experience at Strong For Life, several important considerations have to be made when determining if a rounded lower back should be allowed during the squat and deadlift:
While lumbar flexion is all but inevitable at some point, it shall under no circumstances be ENCOURAGED. The main point of the deadlift and squat are to make the lumbar extensor muscles STRONGER and BIGGER – and a flexed lumbar position will prevent this from happening.
There are various degrees of lumbar flexion that can happen in the spine during a lift. A FULLY rounded back is an absolute no-go – while a slightly flexed lower back appears to be an inevitability at some stage in every lifter’s career. Whether this should be deemed as normal or discouraged at all costs is something which the coach has to decide.
As long as the LEGS are actively performing the movement in the squat and deadlift, compression and shear forces on the lower back are reduced.
A BELT must be worn at all times after about one month into one’s training. This adds vital support and integrity to the spinal structures in the presence of lumbar flexion.
OLDER LIFTERS (age 70 and beyond), as well as those presenting with severe bone frailty in their spinal structures should be paid extra attention to. It doesn’t mean that they can’t successfully lift with a slightly flexed lumbar spine. However, the risk of injury is potentially higher in this kind of population.
Loads must not be increased in big jumps but rather INCREMENTALLY in oder to give the spinal structures enough time to adapt to increased demands. Every lifter should be exposed to a weight that he or she can fully manage on a given day without grinding through reps or displaying high degrees of form breakdown.
All steps must be taken to diligently coach LUMBAR EXTENSION (i.e. “setting the back tight”) in the squat and deadlift in order to develop strength in the back musculature.
"To round or not to round?" - that is the question.
While there are deeply-ingrained concerns with letting the low back round in the squat and deadlift, scientific evidence and practical experience are putting this notion into serious question.
Then again, the eternal student has more questions than answers.
References:
Adams MA, Hutton WC, Stott JR. The resistance to flexion of the lumbar intervertebral joint. Spine 5: 245-253, 1980.
Adams MA, McNally DS, Chinn H, Dolan, P. The clinical biomechanics award paper 1993 posture and the compressive strength of the lumbar spine. Clin Biomech 9: 5-14, 1994.
Bird S, Barrington-Higgs B. Exploring the deadlift. Strength Cond J 32: 46-51, 2010.
Chiu LZ, Burkhardt E. A teaching progression for squatting exercises. Strength Cond J 33: 46-54, 2011.
Duba J, Kraemer WJ, Martin G. Progressing from the hang power clean to the power clean: A 4-step model. Strength Cond J 31: 58-66, 2009.
Cholewicki J, McGill SM. Lumbar posterior ligament involvement during extremely heavy lifts estimated from fluoroscopic measurements. J Biomech 25:17-28, 1992.
Hales ME. Improving the deadlift: Understanding biomechanical constraints and physiological adaptations to resistance exercise. Strength Cond J 32: 44-51, 2010.
Khoddam-Khorasani P, Arjmand N, Shirazi-Adl A. Effect of changes in the lumbar posture in lifting on trunk muscle and spinal loads: A combined in vivo, musculoskeletal, and finite element model study. J Biomech 104: 109728. 2020.
MacLean JJ, Lee CR, Alini M, Iatridis JC. Anabolic and catabolic mRNA levels of the intervertebral disc vary with the magnitude and frequency of in vivo dynamic compression. J Orthop Res 22: 1193-1200, 2004.
Piper TJ, Waller MA. Variations of the deadlift. Strength Cond J 23: 66, 2001.
Potvin JR, Norman RW, McGill SM. Reduction in anterior shear forces on the L4/L5 disc by the lumbar musculature. Clin Biomech 6: 88-96, 1991.
Saraceni N, Kent P, Ng L, Campbell A, Straker L, O'Sullivan P. To flex or not to flex? is there a relationship between lumbar spine flexion during lifting and low back pain? A systematic review with meta-analysis. J Orthop Sports Phys Ther 50: 121- 130, 2020.
Skrzypiec D, Tarala M, Pollintine P, Dolan P, Adams MA. When are intervertebral discs stronger than their adjacent vertebrae?. Spine 32: 2455-2461, 2007.
Straker LM. A review of research on techniques for lifting low-lying objects: 2. Evidence for a correct technique. Work 20: 83-96, 2003.
van Dieën JH, Hoozemans MJ, Toussaint HM. Stoop or squat: a review of biomechanical studies on lifting technique. Clin Biomech 14: 685-696, 1999.
Waller M, Townsend R, Gattone M. Application of the power snatch for athletic conditioning. Strength Cond J 29: 10-20, 2007.