Barbell Front Squat vs High bar back squat

[MikeTheBear]

I'm trying to get my head around this. I've always thought of things in what are probably way too oversimplified of terms, namely that the HBBS is a quad-dominant exercise with the hamstrings / glutes / lower back serving secondary functions and the LBBS is a hamstring / glute-dominant exercise with the quads and lower back playing secondary roles. It's hard for me to think of the LBBS as still being a quad-dominant exercise, mostly just because of what my muscular recruitment feels like during the exercise, and where I'm sore afterwards. From now on, I should think of the LBBS as quad-dominant, just to a lesser degree than the HBBS?

If you're interested in this topic Greg Nuckols wrote several articles on this. Greg is a powerlifter so he is hardly anti-LBBS. But he also cares about accurate information which is why he pioneered, for lack of a better word, the idea that the squat is not an effective hamstring exercise. Here are three of his articles on the subject that should get you started:

Hamstrings – The Most Overrated Muscle Group for the Squat • Stronger by Science

Hamstrings: The Most Overrated Muscle for the Squat 2.0 • Stronger by Science

Squats are Not Hip Dominant or Knee Dominant

 

[the hansenator]

I can't help feeling the whole debate over squat styles is kind of splitting hairs. They all work pretty much the same muscles to varying degrees don't they? It's all squatting after all. As long as you're improving in your preferred squat variation and adding weight to the bar you should be fine shouldn't you?

 

[GeoffreyLevens]

Adjusting your stance can help you find a good and deep squat.

-S-

I have great respect for Oly lifters and "I like to watch." But I don't see any reason at all to squat ATG. Sometimes I will "sit" like that for a few minutes if doing something on the floor, cleaning house type stuff, but no need to transfer large loads from muscles to connective tissue. I have some arthritis in one knee, quite visible on xray, and it is right at the spot that heats up and hurts it I don't respect it. I don't much care about "standards" or how it looks in the gym. I'm just trying to stay fully mobile and functional to the end; functional in this context means things like hiking, rucking 20 pounds of groceries for a couple miles, moving furniture as needed to vacuum, etc. I'm happy to go to powerlifting depth and call it good

 

[Joe Fraser]

@MikeTheBear hamstrings also are involved in rotation of the femur. Even the act of turning the feet out and driving your knees out is also going to involve hamstrings (and some other muscles).

I think there is an injury prevention side to being less quad dominant. Having very strong quads and weak (in comparison) hamstrings is going to lead to less knee stabilization and more likelihood of a knee injury. Doing low bar squats keeps this in balance. Even if they are not the best hamstring exercise, they do work the hamstrings.

I don't see many people that do front squats including hamstring curls or glute-ham raises in their training to help offset the imbalance. There is also something to be said for efficiency, which is why compound movements are king. Few of us want to double our time in the gym adding multiple isolation exercises that could be worked in one compound exercise.

 

[North Coast Miller]

I can't help feeling the whole debate over squat styles is kind of splitting hairs. They all work pretty much the same muscles to varying degrees don't they? It's all squatting after all. As long as you're improving in your preferred squat variation and adding weight to the bar you should be fine shouldn't you?

I think some versions are more quad or more glute/erector intensive, but overall I agree.

FWIW I do include hamstring specific accessory exercise.

 

[GeoffreyLevens]

I do front squats and fairly heavy kettlebell swings as counter balance.

 

[freeflowme]

Just take a look at the lower body of the vast majority of the powerlifting community: they generally have big quads but waaaaaay more developed hamstrings and glutes.

Conversely, most olympic weightlifters have giant, enormous quads and a way less developed hamstrings and glutes.

A low bar squat is kind of a deadlift with the bar on your back. It makes sense that works basically the same muscles almost the same way.

On the other hand, Li Xiaojun back squats rather upright. It is almost a front squat with the bar on his back.

The back angle changes everything.

I love Lu. He's certainly one of my favorite strength athletes to follow. I wonder what a LBBS would even look like for him. I think his torso would still be more upright than most of us. He's got such an optimal weightlifting physique with those incredibly short legs and long torso. My torso is so much more horizontal than that during a HBBS simply because my legs are stupid long and my torso almost clownishly short. In fact, I've thought to myself from time to time that me doing a HBBS is perhaps almost the same - in terms of muscle recruitment - as others doing a LBBS, simply due to leverages created by my physiology.

 

[Alan Mackey]

I love Lu. He's certainly one of my favorite strength athletes to follow. I wonder what a LBBS would even look like for him. I think his torso would still be more upright than most of us. He's got such an optimal weightlifting physique with those incredibly short legs and long torso. My torso is so much more horizontal than that during a HBBS simply because my legs are stupid long and my torso almost clownishly short. In fact, I've thought to myself from time to time that me doing a HBBS is perhaps almost the same - in terms of muscle recruitment - as others doing a LBBS, simply due to leverages created by my physiology.

That's precisely why I do love front squats.

My anthropometry tends to turn my high bar squats into something that resembles a low bar squat with a somewhat upright torso.

So I decided to do front squats instead. They force me to maintain a strict form and keep me honest.

 

[Bill Been]

I'm probably whistling in the wind responding to this, but my goal is to provide information to the rest of the forum members who have an interest in this topic as opposed to trying to convince you.

First, I owe a "thank you" to Mark Rippetoe. I've criticized him about his views on the low bar squat and he told me I was wrong. He then sent me a free copy of his book and told me to read the squat chapter to see why I was wrong. So thanks for the book. I did read the squat chapter, and it is probably one of the most detailed explanations of the squat I've ever read. Mark clearly has a passion for this stuff. The other reason I need to thank him is that while researching this issue, I've learned a ton of information about the squat - stuff I probably would not have learned otherwise.

So, after reading the squat chapter, have I changed my mind? No, and I'll explain why.

Mark analyzes the squat based on moment arms. He states that placing the bar lower on the back allows us to use a more horizontal back angle. This more horizontal back angle, in turn, creates a longer moment arm at the hip, which requires the hamstrings to work harder in the low-bar squat. From a pure physics standpoint, he is correct. However, things are different when you look at this from a biomechanics standpoint. I'll come back to this.

One thing that Mark does not mention is that placing the bar lower on the back, while lengthening the moment arm at the hips, shortens the moment arm for the knee extensors - the quads. This creates a leverage advantage for the quads, which means the quads now need to produce less force to move the same amount of weight. This one of the reasons why most people can lift more weight with the low-bar squat. The quads are able to move more weight by producing the same amount of force as in a high-bar squat, more or less. So yes, despite the sarcastic leverage comment from @Bill Been the low-bar squat does in fact create a leverage advantage for the quads. Magnetic fields are optional.

But what about the longer moment arm for the hamstrings? This is where biomechanics comes in. If the hamstrings only function was to extend the hip, then I wouldn't be typing this post. Mark would be 100% correct and the low-bar squat would be superior in all respects. However, the hamstrings cross two joints - at the hip and the knee. They are responsible for hip extension and knee flexion. Knee flexion is when you bring your heel to your butt and knee extension is when you move your heel away from your butt, i.e., straighten your leg. The quads are responsible for extension. This means that the hamstrings and the quads are antagonists - their actions conflict with each other. What would happen if your quads and your hamstrings contracted maximally at the same time? Nothing. Your leg would not move at all. Fortunately, our nervous system has found a way around this problem so that the two muscle groups can work together without interfering with each other - it's what allows us to walk. However, even with this nervous system magic, the two muscle groups still cannot maximally contract at the same time. For purposes of the squat, the quads are the prime movers doing the brunt of the work. The hamstrings function to stabilize the knee. Near the end of the lift when the lifter is close to standing straight up, the quads' work is mostly done and the hamstrings can kick in a bit more to extend the hip and allow the lifter to stand up straight. So there is no question that the hamstrings are involved in the squat, and they are probably involved a bit more in the low-bar squat given the more horizontal back position. However, the realities of biomechanics prevent the hamstrings from being involved to such a degree as to make the squat a good hamstring exercise.

But what about the fact that your entire body is supporting more weight in the low bar squat? Leverage and biomechanics cannot magically make the bar lighter. This is true, but how much more weight are we talking about? I've said this before and I'll say it again - most lifters can use about 5 to 10% more weight in the low-bar squat than in the high-bar. So, if your normal working weight on the high-bar squat is about 200 lbs., you should be able to use about 10 to 20 lbs. more in the low-bar. This additional weight is shared by the quads (which have a leverage advantage), the lower back, the glutes, and to a small extent the hamstrings. These are the strongest muscles in our bodies. How much stronger are these muscles going to get if they share the work of moving an additional 10 to 20 lbs.?

But what about the fact that some lifters experience soreness in the back of their legs after a squat session? I've experience this myself and I squat high-bar only. The question is whether experiencing "soreness in the back of the leg" indicates soreness in the hamstring, which would mean they worked hard, or soreness in some other muscle that is located near the back of the leg? It's the second one. The adductor magnus is a large muscle that contributes to hip extension. It is likely that the soreness felt after a heavy squat session is coming from the adductor magnus rather than the hamstrings. Adductors

If you like to low-bar squat for general strength training, go for it. I have no problem with that. However, if you're using the low-bar squat to strengthen your hamstrings, you're using the wrong exercise. With the possible exception of the box squat, no squat is ever going to be a good hamstring exercise. Period.

The purpose of sliding the bar down your back to just below the spine of the scapula is to transfer moment force to the GLUTES, not the hamstrings. You sorta went on to discuss why the hamstrings are not that important as if Rippetoe had made your version of his argument. Read that squat chapter again.

The glutes are the largest muscle group in the body. They are responsible for and uniquely suited for the task they are assigned in a low bar squat - HIP EXTENSION. The Quadriceps are lovely muscles, the enamorata of every bodybuilder. But it's your butt that drives the boat. As you concede later on, the result of this transfer of moment force to the muscle group that is better suited to handle it creates the ability to lift more weight. Holding the knees out during the movement as you read in the book is uniquely capable of involving gluteus minimus and medius, increasing the trained muscle mass by actually forcing them to act as hip extensors. A similar effect is created with the adductors - which DO change length during the movement and are therefore eccentrically loaded and are therefore, as you noted, uniquely likely to suffer DOMS. Anyhow, that's how the low bar squat actually allows one to move more weight - more muscle mass is involved and forced to work to extend the hip. It is not due to advantageous leverage on the quads.

As you mentioned during the part where you were misstating the rationale for intentionally reducing the moment arm against the knee, the hamstrings are in fact knee flexors as well as hip extensors. You state this makes them antagonists to the Quads. However, a deeper dive into biomechanics calls that "free body" analysis into question. The hamstrings are not functioning as knee flexors for two reasons: first, during a squat descent the hamstrings are being shortened distally by the flexing of the knee as they are being stretched proximally by the flexing of the hip. The result is that the hamstrings do not change length appreciably during the descent and therefore the ascent of a low-bar squat. Their function is isometric maintenance of pelvic alignment with the torso. "Let go" of your hamstrings and the result will be your chest collapsing into your thighs. Note that if the hamstrings were countermanding the quads to any significant degree, the sudden disappearance of their input would result in rapid knee extension, which I think is unlikely. Secondly - and this one is mildly cosmic - the hamstrings CANNOT act as knee flexors because in a standing posture there can be no "heel to butt" movement because your feet are anchored to the floor. Sure, there is posterior pull from the hamstrings on the tibia, but that force is being reacted out at the floor, not through the quads.

 

[MikeTheBear]

I can't help feeling the whole debate over squat styles is kind of splitting hairs. They all work pretty much the same muscles to varying degrees don't they? It's all squatting after all. As long as you're improving in your preferred squat variation and adding weight to the bar you should be fine shouldn't you?

Winner, winner chicken dinner.

Pick the squat variation you like. If your goal is "general strength," I could care less which version you pick. Work hard. Get strong.

 

[MikeTheBear]

The purpose of sliding the bar down your back to just below the spine of the scapula is to transfer moment force to the GLUTES, not the hamstrings. You sorta went on to discuss why the hamstrings are not that important as if Rippetoe had made your version of his argument. Read that squat chapter again.

Fair enough. However, as a point of clarification, I never said that the hamstrings were not important in the squat. They function to stabilize the knee and, as you wrote, "isometric maintenance of pelvic alignment with the torso." Because they function as dynamic stabilizers in the squat, they do not contract as hard as they could in a more hamstring-specific exercise. This makes the squat a poor hamstring exercise, but that does not mean that the hamstrings are not involved in the squat or that they are not important in the squat. The analogous upper body lift and muscle group are the bench press and the biceps. I have never heard anyone, gym bro or otherwise, say that the bench press is a good biceps exercise. For most people this would be a very silly statement. But biceps are in fact activated during the bench press. They function as stabilizers for the shoulder and elbow, analogous to the hamstrings in the squat. As stabilizers, the biceps do not contract very hard during a bench press. Thus, the bench press is not a good biceps exercise, but the biceps play an important role in the bench press.

Anyhow, that's how the low bar squat actually allows one to move more weight - more muscle mass is involved and forced to work to extend the hip. It is not due to advantageous leverage on the quads.

Perhaps the intent is not to create a leverage advantage by moving the bar lower but rather to access more of the posterior chain, but the reality is that the low-bar position shortens the moment arm on the quads which does provide a leverage advantage.

Let's talk about glutes. The idea is that leaning forward causes the glutes to be more involved in the lift. According to the following study (PDF) A Comparison of Gluteus Maximus, Biceps Femoris, and Vastus Lateralis EMG Amplitude in the Parallel, Full, and Front Squat Variations in Resistance Trained Females, that may not necessarily be the case. The study examined the front squat, parallel squat, and full squat. I imagine the two back squat variations involved a high-bar squat. However, because a high-bar squat involves more forward lean than a front squat (which essentially has no forward lean), the study is relevant to the issue of whether the degree of forward lean changes muscle recruitment. The study found no significant difference in gluteus maximus or hamstring activation between the three variations. The study does have some flaws. First, it used EMG analysis, and as we discussed before, EMG has some limitations. However, we currently do not have a way of analyzing muscle activation other than the EMG. Whatever its limitations, EMG data is objective, and I would rather have an objective measurement as opposed to a bunch of gym bros saying "Dude, low-bar squats wreck my glutes!" The study used 10 reps which, as we also discussed, can produce different muscle activation than a 1RM. But at least it's something better than the anecdotes of gym bros.

Then there is depth. We know that more weight can be lifted with a shallower squat than a deep squat. As a general rule, many lifters find it difficult to go very deep with the low-bar position. When I played around with the low-bar, I found it difficult to go very deep. Rippetoe gets around this issue by stating that going ATG is not necessary because squatting to just below parallel results in the most effective range of motion. Perhaps that's true, but the reality is that pretty much everyone can lift more weight squatting just below parallel than ATG. Shorter ROM is another reason why more weight can be used low-bar without necessarily having to recruit more muscles.

Let's recap. There are two "mechanical" reasons why more weight can be lifted low-bar without necessarily using more muscle mass:

1. The leverage advantage that the quads get with the lower bar placement;
2. Shorter range of motion.

Is some of the work shifted from the quads to the glutes in low-bar? Possibly, but on the other hand, low-bar squats may not be as good at developing the quads. The study referenced above found that the deeper squats produced greater quadricep activation than parallel squats despite being performed with lighter loads.

 

[Timo Keskitalo]

Louie Simmons' knowledge of box-squat is immense, now that I finally understood his methods. So correctly done box-squat.