How to Do The Jefferson Curl To Improve Low Back Pain

Flexibility/Mobility 9 min Read

Written by

Keith Hansen

To flex or not to flex? No, not your biceps—your spine.

In strength training, we are taught to always lift with a flat back.

This recommendation comes with good reason. Lifting heavy things, loading the spine, and then bending will likely get you hurt. But at Seriously Strong Training we think about strength training a lot, and question everything.

That’s why we were able to develop training methods to get beginners to move well and strength train pain-free.

So during all this questioning, we found that doing everything with a flat back may not be the best way to bulletproof your spine.

This is where the Jefferson Curl comes in.

We found that the Jefferson Curl could be a great exercise for spinal health—if you’re ready.

The Jefferson Curl

It’s like a straight-legged deadlift but pushed to the extreme.

Now, I do not recommend this exercise if you have a back injury without consulting your physician first. Sorry. It needed to be said.

So let’s get into the meat and potatoes of the Jefferson Curl.

The Jefferson Curl is an exercise that moves your entire mobile spine from your lower back through your neck into flexion and then extension.

This move can seem scary at first, but when we think about how any muscles grow and get stronger, it makes sense.

Watch the video if you haven’t already.

To “curl” stand on a box or bench that is at least 12″ high with your toes at the edge in a conventional deadlift stance.

You can do this move with either a barbell or dumbbells, but a barbell is best.

From a tall standing position slowly lower the bar or dumbbells toward your feet but keep them as close to your body as possible while keeping your knees slightly bent.

Your flexibility will determine how low you can go but you want to reach as far down as possible. In the beginning, this may be near your toes, but as you gain flexibility you will need to pass the bar in front and below your feet. That’s why you’re on the box.

At the bottom, fully exhale then inhale before returning slowly to the top ensuring the bar stays close to your body. You may get some back-cracking at the bottom with the breath. It feels like heaven. It’s even better than the chiropractor.

Do the exercise slow & try to maximize your range of motion for the most benefit.

You may have to watch the video and perform the move a few times to really understand it. I recommend taking video of yourself doing it and compare it to ours. You can even DM us on instagram for some feedback.

Common Causes of Low Back Pain

Low back pain is common and usually persists for too long.

Most of the time proper strength training can be the best remedy.

There are many causes of low back pain beyond the scope of this article; If you’re interested in learning more about low back pain, start with this article by Sam Spinelli about lifting with a flexed spine.

The two most common causes of pain I see from our clients are strength and posture.


A lack of strength can create protective back tightness and cause muscular lower back pain. The spinal column is a delicate structure and there are a lot of different muscle groups surrounding it for support.

When muscles of the back and core lack strength they increase in tension to create rigidity and provide “protection”. If you’re always tight, especially on one side, chances are there’s a muscular imbalance in your back.

Poor Posture

Most commonly a posture called anterior pelvic tilt can cause lower back pain. This is characterized by a very arched lower back and stuck out butt.


Both of these common causes can be remedied with the Jefferson curl and proper core training.

Let me explain how the Jefferson curl aids in bulletproofing your spine.

How We Gain Strength

There are two main contributors to strength gain. These are: cross-sectional muscle area (the size/volume of muscle present), and neural improvements (your brain’s ability to recruit said muscle efficiently).

There are many other factors in strength, but they are beyond the scope of this article. If you would like to read more, Greg Nuckols has a great write-up on all of the factors in strength and you can find that here.

So to get strong we can undergo hypertrophy or improve our nervous system.


The most recent science points to three main contributors to hypertrophy (muscle growth): mechanical stress, metabolic stress, and muscular damage.

Mechanical stress occurs when you load a muscle with tension, normally through weight training. Heavier loads mean higher mechanical stress.

Metabolic stress occurs when you change the metabolic environment of a muscle. This normally happens through an increase in metabolic by-products that are created when a muscle is being pushed to fatigue. This is characterized by that burning sensation you get when you go to failure on an exercise or use blood flow restriction training(insert article on BFR).

Muscle damage occurs when you cause micro-tears in a muscle. This happens from all types of exercise but eccentric-focused exercise creates the most damage.

Additionally, to maximize hypertrophy you must move a muscle group through a full range of motion. This means that your usual lower back and core training can only grow so much muscle since it’s all isometric (holding a position) and doesn’t involve a full contraction.

A proper strength training program incorporates all of these to maximize muscle growth and subsequently, strength gain.

Because bigger muscles are stronger muscles you must grow your muscles to be truly strong.

Neural Improvements

When you strength train, your nervous system also plays a large role in increasing strength. There are two types of neural improvements that improve strength: motor control and motor unit (muscle fiber) recruitment.

Motor control largely improves when you first start strength training. This is how well you can contract your muscles in conjunction to perform a specific movement. When you first start to do a new exercise you’ll look like a new-born deer trying to walk. Over time if all other factors stayed equal, you would still get stronger by improving your motor control.

Motor unit recruitment improves strength later in your training career. As you continue to strength train for a long period of time the nervous system continues to increase strength by increasing the amount of muscle fibers that are contracting at one time. This is done by increasing motor unit recruitment, a motor unit is a part of the nervous system that innervates a set amount of muscle fibers. This means that you are able to contract more muscle fibers during a given muscular contraction and therefore produce more force.

Strength Gain is Movement Specific

When you strength train—in any movement—the range of motion that you perform the exercise in is the range that your muscles will get strongest due to neural improvements.

You will gain strength outside of this range of motion as well, but strength gains fall off significantly at ~15 degrees beyond where you began and where you ended the movement.

This means that if you were to do an isometric curl where you hold the weight at a 90-degree bend in the elbow and train there for a while, you’ll get strongest at 90 degrees, and gain some strength from 75 degrees of bend up to 105 degrees of bend.

If we apply this thinking to the spine we can see that training the core and spine in just “neutral” is a great way to get strong in that “neutral” position.

But what happens if you pick something up outside of neutral? Or curl-up to get out of bed in the morning? Or sit at your desk all day with a rounded back?

A lot of times injury happens when you’re in the most vulnerable position, not when you’re braced with a neutral spine and a lifting belt on.

But sometimes injury can even happen then, when you’re lifting past your limits.

This means you need to be strong, whether you’re rounded, arched, or neutral, to handle whatever life throws at you.

This means you need the Jefferson curl. But only after you fulfill the prerequisites to perform it.

Prerequisites to the Jefferson Curl


Know how to brace your core. Proper core bracing uses all the muscles of the core. Knowing how to do this will help you lift with the most support for your spine possible.



Know how to move your spine. After you master bracing you need to understand true spinal flexion and extension. In full flexion your entire spine should be rounded, this is easier than it sounds if you’re too tight. Try the cat/cow movement to gain some motion and awareness in your spine. If your cat/cow looks like the one in the video below then you’ve met this prerequisite.



Implement a mobility routine. This will create balance and decrease muscular tightness. Both things that will help you have the mobility to round and extend your back. Movements that are necessary for a proper Jefferson curl.


Implement a core routine. If you’re not training your core already, download our core training guide to help you get started, then revisit this article.

Injury Free

Be free of any disk herniation. Fix this first by seeking a medical professional. Back pain caused by disk herniations is different than muscular tightness. Don’t do this exercise if you have one!

Progressing the Jefferson Curl

Once you’re ready to start performing the Jefferson curl you need to know how to progress it. This is not an exercise you can progress carelessly.

Like I mentioned in the beginning, start with very low loads. Start with a dowel or PVC pipe the very first time you do it to warm-up.

Then only perform the Jefferson curl with a 45lb barbell or two 20lb dumbells that day. Perform sets of 8 slow and controlled reps. Stick with this weight for two weeks.

After two weeks of consistent Jefferson curls only increase the weight by 10lbs.

Remember, you are training your spine in its weakest position. There is no need for heavy loads.

Keep this new weight for 4-6 weeks. From here continue to increase the weight by 5-10lbs every 2-4 weeks. I recommend stopping your weight progression at 95lbs.

From here increase to sets of 10 reps. After another few weeks go to sets of 12 reps.

This exercise is suggested to help avoid injury. Don’t let it cause injury because you progressed too fast.

Remember that back pain is multi-factorial. But being strong is a good way to cover your bases. Get stronger in every position and reap the benefits of the Jefferson curl.

Even if your pain improves and you’re getting stronger, be sure you have a solid core training program to maintain balance and strength. Download our core training guide, it’s free.

Download The Serious Guide to Core Training

Keith Hansen

Keith was an All-State wrestler in high school and in 2007 hung up his singlet to attend Florida State University to pursue a B.S. in business management. He wasn't sure what industry he wanted to be involved in at the time, but soon realized after graduating in 2011 that fitness was the ever-constant activity in his life. Keith began studying to become a personal trainer and in 2013 earned the National Strength and Conditioning Association's Personal Trainer certification. After a short stint as a big box gym trainer he realized he wanted to bring something different to Tallahassee. Keith competes in Powerlifting, Olympic Weightlifting, and Crossfit.