If you don’t know how to separate myth from fact, identifying and dealing with your own back issues can be overwhelming. How should I exercise to keep my back healthy? And how do I not get injured in the gym?
Part 3: Squats & Your Back
Spine health and back pain. Where to even begin? The healthcare and fitness industries are like shopping aisles full of hundreds of options for the consumer, from corrective exercises and pain medications to surgery, and everything in between. And if you don’t know how to separate myth from fact, identifying and dealing with your own back issues can be overwhelming.At a minimum you should be able to answer a few basic questions to your own satisfaction: How should I exercise to keep my back healthy? And how do I not get injured in the gym?
Low back pain is a leading cause of activity limitation in much of the world, costs the United States $100-200 billion dollars annually, and is the number 2 cause of disability among U.S. adults. Back pain is a significant global health burden, but does that mean that we all need to be afraid of hurting our backs, and walk around protecting our spines like our 4th grade egg drop project? No! Before we delve in to some myths about barbell training and your back, let’s look at some facts and statistics.
Facts & statistics about back pain
- About 8 in 10 adults will experience back pain at some point in their life.
- 9 out of 10 of these individuals will never know the cause.
- The majority of cases (50-90%) of acute low back pain resolve on their own within 6 weeks.
- 9 out of 10 asymptomatic individuals will show some sort of abnormality on lumbar imaging tests.
- Back pain is rarely a sign of a serious problem.
So what does this all mean? First, although back pain is extremely common, it’s very likely that if you experience an episode of back pain, it’s nothing serious, and it will go away on it’s own. In fact, those who continue to be active and avoid taking pain medications have a better prognosis than those who limit their activity and seek medications.
Second, these statistics also show that imaging is poorly correlated with pain. If you have back pain and you get an x-ray or MRI that shows something, there’s a 90% chance that thing existed before you had any pain, which means it’s very unlikely to be the source of your pain. The best thing you can do to prevent and manage back pain is to stay strong and active, and not freak out that you’re going to damage something.
Most of our clients already know how good squats are for your back, but there are still a lot of myths and misconceptions out there about what you should do with your back when squatting so as to not injure yourself. Many of these misconceptions come from the extremely high prevalence of back pain as discussed above. There is also the pervasive belief that the spine is fragile and in need of protection. But actually, quite the opposite is true.
The spinal column is made up a 24 bones (called vertebrae) plus the sacrum, connected by ligaments and muscles – over 300 of them – that allow the spine to bend and twist. Some of them are tiny, and some of them are big. Like, really big. In fact, the anterior longitudinal ligament, which runs along the length of the spinal column, is the strongest ligament in the human body. The vertebrae protect the spinal cord and support the majority of the weight put on your spine. And they’re not tiny little bones that are prone to breakage. They’re actually quite large, especially in the lumbar region. Healthy vertebrae can safely sustain the weight of hundreds and hundreds of pounds. In between each vertebra is a soft, gel-like cushion called an intervertebral disc, that acts like a shock absorber and prevents the bones from rubbing against each other. And finally, the spinal column has built-in holes between the vertebrae called foramina, through which nerve roots from the spinal cord exit and innervate the rest of our bodies. Pretty cool, huh?
I could probably write an entire article series on the above information alone, but I’ll save that for another day so we can get to the stuff you came here for: how does this relate to squatting?
Myth #1 – Look Up To Keep Your Back Straight
Many people are taught they have to “look up to go up” when squatting. Where your eyes go, the rest of you follows, right? When driving a car, sure. When training for strength, we’re concerned with a little more than just making it to the top by any means necessary. And maybe we don’t necessarily need to keep our back perfectly vertical.
We want to utilize the most muscle mass. The squat trains more than just your legs. By using the low bar position, we’re utilizing more of the posterior chain, including the hamstrings, glutes, and spinal extensors, due to the more closed hip angle and the leaned over back angle. That’s right, we are also using the squat to strengthen our back!
Most people believe that the back should stay straight when squatting. They’re right, but there’s a difference between straight and vertical. The closer your back is to vertical in a back squat, the less moment force there is on the back segment, and the less of a training effect you will get for your spinal extensors and glutes. You can look down and have a more horizontal back angle while keeping the spine straight. This requires that the lifter is able to lock the spine in rigid extension through isometric contraction of the spinal extensors, and maintain this anatomical position throughout the rep, even as they hinge forward at the hips. Think of the spine as a single, solid segment that is tilting in space, without bending or flexing. This leaned over position allows us to train more muscle groups, while keeping the spine straight and rigid.
We want to use “hip drive.” Hip drive is what we use to drive up from the bottom of the squat. If you lead with the head or chest, rather than keeping your gaze down and leading with the hips, the hips and knees will be pulled forward and you will either be off-balance forward or your back angle too vertical. The knee angle will close and the hamstrings lose tightness, which is an important component of both the stretch reflex out of the bottom as well as the hamstrings’ ability to generate force.
We want to stay balanced. A properly performed squat has the center of mass balanced over midfoot with the feet flat on the floor. With the bar in low bar position, this means that we must lean over in order to satisfy this criteria. With a too-vertical back angle, as is the result of trying to look up or straight ahead, the knees slide forward in order to maintain balance, and the lifter’s weight may shift to their toes. The knee angle becomes more closed with the hip angle staying more open – the implications of this discussed in the previous paragraph.
A vertical back angle during a low bar squat will lead to decreased tension in the muscles of the lower extremity, less overall muscle mass used during the movement, a loss-of-midfoot-balance, or a decrease in your ability to use hip drive (or all of the above!). Looking up will certainly lead to a more vertical back angle, but keeping the spine straight while leaning over and looking down is perfectly doable.
Myth #2 – “Butt Wink” Is Due To Poor Hamstring Flexibility
Butt wink. One of the most well-known and dreaded of all squat movement errors. If you haven’t heard of butt wink before, it’s when the lumbar spine flexes and the pelvis tilts posteriorly at the bottom of the squat, and someone somewhere thought this looked like your butt was winking. I don’t know. I prefer to call it what it is, which is lumbar flexion.
“Butt wink” is often thought to be the result of tight hamstrings. In theory, as one approaches the bottom position, the hamstrings are being stretched, and when they can stretch no more, they pull the low back and pelvis out of position. Sounds plausible at first since the hamstrings cross the hip joint and attach to the pelvis, but let’s not forget that they also cross the knee. Even though the hip is flexing as you descend, which would stretch your hamstrings, the knees are simultaneously flexing, which shortens the hamstrings. The net result is that the hamstrings do not change much in overall length as you squat. It’s highly unlikely that the hamstrings are stretched to their max in the bottom position, because the knee is bent. If you have the hamstring flexibility to sit in a chair with your spine straight, you probably have the hamstring flexibility to squat with your spine straight. You just need to learn how to do it.
To fix lumbar flexion or “butt wink”, the lifter needs to learn how to use their spinal extensors to hold their back in rigid extension and not squat too deep. Squatting too deep (or “ass to grass”) can result in lumbar flexion because as the thighs approximate with the pelvis and the hips cannot flex further, the back will have to round in order to keep going lower. This is exacerbated if the lifter is not shoving their knees out enough. And if your back has rounded, your spinal extensors have relaxed. In a lifter who knows how to hold their back in extension, learning to shove the knees out and stop at just below parallel can usually solve lumbar flexion.
Unfortunately, poor control over the spinal extensors is common. The spinal extensors have the job of keeping the spine in rigid extension, but also locking the pelvis in position relative to the lumbar vertebrae. As a lifter approaches the bottom, the leaned-forward position and large moment arm on the back segment can cause the back to round in people who lack this control, pulling the lumbar spine and pelvis out of position. Because the hamstrings are contracted, which unchecked would cause the pelvis to tilt posteriorly, the lifter is essentially letting the hamstrings win the fight for control over pelvic and spinal position. But the spinal extensors must win. In order to correct butt wink, you must have good enough volitional control over the spinal extensors in order to keep them contracted at the bottom of the squat when other forces are attempting to pull you out of position. No need to stretch your hammies.
Myth #3 – Leaning Over Will Shear Your Spine
Shearing your spine sounds super scary, and you may have been told that loading your back while it’s at an angle will predispose you to a shearing injury in which one vertebrae “slips” on another, which could mean very bad things for you spinal cord. First of all, I could not find a single reported incident of this happening in the gym. Second of all, this claim demonstrates a poor understanding of anatomy and the forces at play.
Shear forces push one part of an object in one direction, and another part of the object in the opposite direction. So it’s true that the moment force placed on the back segment in a low bar squat is a shear force, as it is composed of two different forces acting in opposite directions – the weight of the bar and gravity pushing down, and the force you generate to push the bar up. So it is correct to say that the back is under shear stress. Since moment forces are shear forces, does that mean that failure to overcome that force will result in a shearing injury?
The spine is built to be able to tolerate very high amounts of shear stress! And just because it’s under shear stress, does not mean it will fail by “shearing” – meaning one vertebrae slides forward on another. There is a condition called spondylolisthesis in which this does happen, but this is prevalent in less than 5% of people, and typically occurs during activities that put high amounts of repeated stress on the pars interarticularis through repeated hyperextension, leading to fracture of the vertebrae. We are not talking about hyperextension, pars fractures, and spondylolisthesis. We are talking about the chances that your spine with shear in half if you bend over when squatting, which is slim to none.
While there is a certain amount of shear stress at each vertebral level, remember that the spine is extremely strong and built to withstand this type of stress with very strong ligaments and large muscles. An isometric contraction of the muscles surrounding the spine holds the spine rigid as you lean over. This means that the back segment is loaded as a single, solid segment, and not as individual segments. If the muscles fail to overcome this force and keep the spine rigid, the spine will fail into flexion.
We’ve all seen a round back deadlift. That’s what spinal flexion looks like. The lifter’s inability to use his spinal extensors to keep his back in rigid extension while trying to withstand a heavy moment force – one that is trying to bend the spine—results in a rounded back. A rounded back under a load will not shear the spine. Rather, it puts one side of the spine under compression, and the other side under tension. This isn’t necessarily dangerous so much as it is inefficient. Think about a crane – would you rather lift a heavy object with a crane that is straight and rigid, or one that bends like a slinky? While a low bar squat does not use a back angle as horizontal as a deadlift, the back segment is still subject to moment forces that are trying to bend it. Failure of the spinal extensors to withstand these forces will result in the spine bending, not shearing.
So how do we prevent our spine from flexing under a load? Train our back, of course! Starting with learning how to volitionally control our lumbar position, then training with weights where we can maintain rigid extension with a horizontal back angle, and gradually progressing this load over time to strengthen the spinal extensors. The more leaned over you are, the greater the moment force on the spine, and the more training stress your spinal extensors receive.
The bottom line is this: the thing that keeps your spine straight and protects you from injury is not keeping your back perfectly vertical – it’s the isometric contraction of the muscles around the spine that locks it into a rigid position and maintains the pelvis’ alignment with the spine as you lean over.
Trying to squat with a vertical back reduces the amount of muscle mass involved, shifts the center of mass forward of the midfoot, and decreases the overall efficiency of the lift while doing little to nothing to make the lift “safer.” If you want to make your back stronger, you need to get over the notion that bending forward is bad. You need to decide that you are going to look down, make your back flat, and lean over when you squat. And then you need to intelligently select a load where you can keep your back flat, then progress yourself gradually over successive sessions while not allowing the spine to flex. This is how you resist injury and build a strong back!