The Jefferson Curl: Benefits and Proper Form

The spine is a segmented structure (33 bones to be exact, spanning from the vertebral column to the coccygeal region, aka, tailbone), separated by discs, fiberous tissues, fluid, and thousands of nerve cells. The spine plays a pivotal role in all human movement, with the supporting connective and muscle tissues there to stabilize detrimental shearing and rotational forces that could result in injury to the disc and nerve cells. 

For most weightlifters, powerlifters, and functional fitness athletes, minimizing spinal flexion, excessive extension, and rotation (shearing forces) is paramount, especially under loads.

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The Jefferson Curl has been seen in the training of weightlifters, powerlifters, and competitive gymnasts (as well as general fitness and training), however, many coaches and doctors have contrasting perspectives (and research) making cases for and against the implementation of this posterior lengthening and potentially strengthening movement.

In this article we will shed some light on the case for and against the usage of the Jefferson Curl and if an athlete should perform them.

Should You Do Them?

The Jefferson Curl is a strengthening and lengthening movement for the posterior chain, more specifically the spine and supporting tissues and muscles, as well as the hamstrings. Unlike goodmornings, Romanian deadlifts, and other posterior chain movements, the Jefferson Curl specifically reinforces segmented spinal flexion through a full range of motion, rather than movement with a neutral back.

Dr. Stuart McGill, Professor of Spine Biomechanics at the University of Waterloo and a leading spinal biomechanics researcher has documented that the majority of injuries to spine occur in either flexion or rotation positions, especially under load. His research suggests that for most individuals (excluding some elite athletes who may have to wager spinal integrity for function based upon the sport), excessive training and lengthening or spinal flexion may not be the best option for overall health and athletic performance.

That said, let’s take a look at some specific sports in which Jefferson Curls may or may be advised.

Formal Gymnastics / Acrobatics

Often seen in gymnastics and acrobatics training programs, the Jefferson Curl is used to lengthen and strengthen the spine, specifically while in spinal flexion. Based upon the inherent demands of the sport, coaches and athletes, like Christopher Sommers of Gymnastics Bodies, has been training gymnasts on this move for years. In response to this, Dr. McGill stated that although it conflicts with his findings regarding spinal health and integrity, the inherent demand of the sport may warrant the Jefferson Curl, with an understanding that coaches and athletes may be compromising spinal health and integrity of the tissues, which may have long-term consequences.

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Nonetheless, for gymnastic-based athletes, hamstring and spinal flexibility are necessary for elite levels, making this exercise a potentially effective at increasing flexibility and end range of motion.

Strength and Power Sports

While seen in some weightlifting and powerlifting programs, this movement can pose some potential risks, and some benefits. In a podcast, Dr. McGill (fast forward to 51:41 minute) specifically addressed Jefferson Curls and the risks they may present athletes (excluding gymnasts), concluding that the risks outweighs the benefits. For the sake of injury prevention, Dr. McGill’s research has suggested athletes are most prone to injury in the flexed and rotated positions, making a loaded movement that reinforces lengthening and increasing end range spinal flexion potentially damaging in the long run. Additionally, although many athletes “feel” good after the initial stretching and acute response to the stretch reflex in the movement, damage to the connective tissues of the spine may cause potential detrimental spinal health in the further.

On the contrary, many sports, such as strongman and contact sports, have athletes moving and lifting with a flexed spine, making the application of this exercise arguably sport specific. Many coaches and athletes feel that proper mobility and strength need to be exemplified THROUGHOUT the fullest ranges of motions (dictated by the specific needs of an athlete, for example a gymnast versus a strongman).

The individual needs and considerations may make this a viable flexibility and elongating exercise.

Functional Fitness

Similar to strength and power athletes, Dr. McGill questions the overall benefit of reinforcing spinal flexion with most individuals. Generally speaking, many individuals are subject to excessive spinal flexion throughout daily life (sitting in front of a computer, cell phones, driving in cars, poor posture, etc), making the Jefferson Curl a redundant and potentially determinant exercise. Rather, coaches and athletes should focus on hips and thoracic mobility, correcting spinal dysfunctions rather than reinforcing them.

Proceed with Caution

In the event coaches and athletes choose to go forward with training the Jefferson Curl, caution is advised. Additionally, the following guidelines should be taken into consideration:

  1. Start with bodyweight, and work up in very small increments, if at all. The goal of this exercise is not maximal strength, rather controlled range of motion and finite position strength, tissue adaptation, and controlled mobility. If chosen, be cautious when proceeding with loaded movement in spinal flexion.
  2. Stop if there is pain. If there is pain or discomfort in any aspect of this movement (either loaded or bodyweight), stop. This could be a warning sign that could result in serious and/or nagging injury
  3. Do your research. As with most exercises, there are always inherent risks. While this article summarizes the views and finding of Dr. Stuart McGill, some of the interpretations are that of my own. Seeing that I am not a spine specialist, these views and perspectives have been formulated based upon my knowledge, education, and research. Coaches and athletes need to make the decision to the best of their abilities, rather than rely 100% on the views of others.

How to Perform a Jefferson Curl

In the event coaches and athletes a looking to implement this Jefferson Curl within a formalize training program, proper technique, minimal loading, and control is paramount to minimize the risk of injury. Below is an instructional video on how to properly perform a Jefferson Curl. It is important to note, that coaches and athletes should refer to the guidelines above prior to executing if they decide this exercise is justifiable to their end goals.

Final Thoughts

The Jefferson Curl is a controversial exercise for most athletes, with research and real-world examples making both cases for and against the usage of them in mobility and strengthening programs. When determining the goals of a lifter, coaches and athletes should take the time to weigh out the potential risks and seek out alternative exercises to minimize risks if they choose so.

Editors note: This article is an op-ed. The views expressed herein are the authors and don’t necessarily reflect the views of BarBend. Claims, assertions, opinions, and quotes have been sourced exclusively by the author.

Featured Image: @logeil on Instagram