CPT Fitness NASM CPT Podcast Muscles

Overactive and Underactive Muscles Part 2: Excessive Forward Lean and Low Back Arch

National Academy of Sports Medicine
National Academy of Sports Medicine
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You asked for it – you got it! This is part two of three episodes (listen to part one here) where the topic of over- and underactive muscles will be discussed. This episode will cover two common movement compensations in the overhead squat assessment:

Listen for a review of short muscles that lead to this compensation and lengthened muscles that allow the compensations to occur. These episodes are anatomy heavy and may help the listener better understand functional anatomy. Functional anatomy helps listeners better understand how muscles can contribute to movement compensation and dysfunction. The outcomes may provide a better implementation of exercise preparation AND maybe, just maybe, help you if you're studying for an exam… ;-) 

Get 20% off your order now by calling 800-460-6276 or visiting NASM.org, and using the code Podcast 20.




You're listening to The NASM-CPT Podcast, with Rick Richey, the official podcast of the National Academy of Sports Medicine.

Welcome to the NASM-CPT Podcast. My name is Rick Richey, and today we're going to be going back into some of the topics that you guys have been giving to us. Now, this is a follow up with the topics that have come back primarily from everybody, so the majority of the feedback that we've gotten, which is a review of the overactive and underactive muscles, so particularly today we're gonna be looking at two things.

We're gonna look at excessive forward lean and low back arches. So those will be our two things that we're gonna look at today, excessive forward lean and low back arches. I think a lot of people have been providing feedback about this because it's a major focus of NASM, which is trying to find balance, trying to create movement in an ideal form, an ideal position, and it's not that, necessarily, when you do an overhead squat that's how that has to look, but you should be able to, when doing an overhead squat, your feet pointed straight ahead, with your second and third toes pointed straight ahead, not just your big toe, second and third toe straight ahead, knees pointed straight ahead, hips in alignment, chin tucked, shoulders up, shoulders retracted or in a neutral position, arms overhead, all of these wonderful things, and when you drop down into a squat, and you get to a chair depth, and come back up, ideally, there's no compensation.

Ideally, after you go through several of those squats, and you come back up, and we evaluate you and we look at you, you look the exact same way you did before you started squatting. Your feet still pointed straight ahead; your knees are still aligned, your pelvis is still aligned, your head's still there without jutting forward or arms falling forward, so there are multiple things that we're looking at in regard to the assessment, and assessments are going to put you in unique positions in order to see if you move out of those positions.

Number one thing in assessment we gotta be aware of is that, first of all, if there was pain, we have to be aware of it, but we're not focusing on that right now; that is part of our assessment and that's when we know to stop, but now we're looking at feedback on those assessments, so if I've got somebody, we'll go with the first one, excessive forward lean.

If I have somebody with an excessive forward lean when they do a squat, which means they start to lower down in an overhead squat position, and they fold their body forward, so it's almost like they're bowing down, then I'm gonna create, I'm gonna notate that. As a matter of fact, I'm gonna notate it if you move out of what we refer to as the tibia torso angle. So if my tibia shifts forward 20 degrees, my torso is going to shift forward also 20 degrees. If one is 40 degrees, the other one will be 40 degrees. So we're just looking at a tibia torso angle, and 40 degrees is a bit excessive, but just understand that, if you were to take two dowels or rods and you line it up parallel with the shin and the torso and somebody goes into their squat, those things should move in tandem so that the tibia and the torso stay parallel, or relatively parallel.

Now, in an excessive forward lean, you're going to see the torso break that parallel line and fold over onto the body a little bit. Excessive forward lean. So what causes that? In our textbook, and right now, at the time of recording, we're in our sixth edition of the textbook. These are some of the things that we're going to focus on and pay attention, and this current component, you might look there and you see the very first thing on there might be the soleus and gastrocnemius. And for relatively new people into exercise science and understanding human mechanics, biomechanics, human movement science, you are befuddled by the fact that if I have an excessive forward lean, at my torso, what in the world are you talking about when you say I have tight calves, that's why I have an excessive forward lean in my torso? They just don't connect, it doesn't make sense, and it didn't to me either.

When I first heard this, I was like, here we are with this crazy talk again, but there's a lot of truth to this, and actually I would say this is not an NASM quote, it's not on research, but I would say that 95 or more percent of excessive forward lean is because you have tight calves.

So these gastroc and soleus limiting the amount of dorsiflexion you get in your squat. I mean, they are a huge component, a primary factor in why people have an excessive forward lean or why they lean forward when they do their overhead squat assessment or squats in general. Why? Some of it is because you don't have dorsiflexion, and some of it is because you were taught, most likely, not to let your knees go past your toes when you do a squat, and I will say this, that, if you don't let your knee translate forward in front of your toes, to a small degree even, then you're not gonna be able to do this in an ideal form. The knees need to be able to go past the toes and if they don't, you're going to have an excessive forward lean.

Well, that's when people are like, I was told not to ever let the knees go past the toes. Why? They can't let the knees go past the toes. But you can. Here's what I want you to think about. I don't want your heels to come up off the ground. If your heels start to elevate, not even come up off the ground, but you shift your weight into the ball of your foot, and you feel that less weight on the heel, then what's gonna happen is you're gonna start seeing the feet turning out, or the heels, as they lift up, they might start to shift in. You might get a lot more pressure in the knees because you have more weight in the ball of the foot, so it's not about the knees going forward over the toes; when you don't share the weight of your body over the entire platform of your foot.

Now what this also doesn't mean is that, when you squat, I hear a lot of people saying put your weight in your heels. No, put your weight in the heel and the ball of the foot and share it, but as the weight starts to shift forward and the knees go too far past the toes, then the heels start to come off the ground and that's where the flaw is. You wanna maintain weight and pressure in the ball and the heel of the foot, and descend, and your knees can go past the toes, and if the heels stay on the ground, you are fine, and your knees will go past your toes unless you have an extremely long foot.

So, with that said, the knees are okay to go past the toes. Don't let the heels come off the ground. It became a wonderful queue that turned into exercise dogma, and it doesn't need to maintain that status anymore. Let's pull back on that. The knees can go past the toes; don't let the weight come out of the heels, though, and you're gonna have to look and check and evaluate your client from multiple and various different angles. You're gonna have to walk around them. You're gonna have to see what it looks like on the lateral side of their foot, if the heels are coming up, on the posterior side, check it out. You may have to do it without their shoes on, which, ideally, that's how you're setting up your overhead squat. Your client does not have shoes on, and then the excessive forward lean comes because you can't let your knees, or you can't get the dorsiflexion by the tibia translating forward, and so if you don't have that sagittal plane range of motion at the foot and the ankle, then your hip will steal it, right? I can't get this range of motion at my ankle, I will take it at my hip.

And so the range of motion will get gotten, but it's gonna take it from different joints, and so it's gonna cause you to create this excessive forward lean, so the gastroc and the soleus, the calf muscles, are listed there primarily because if I'm queued, don't let your knees go over the toes, or my muscles are so tight that I can't keep my heels on the ground and let my knees shift slightly over my toes, then you are going to fall forward at the torso or create an excessive forward lean.

And what is something else that could cause an excessive forward lean? Well your hip flexors, because an excessive forward lean, in all reality, is a lot of flexion at the hip. So you get a lot of hip flexion, so the forward lean of the torso is coming from the hip flexion, so your hip flexor complex may be a component, may be a driving factor of an excessive forward lean. A component, a piece of it. We also have, in that context, the abdominal complex, as overactive, and really what that is probably referring to is not so much an excessive forward lean, but spinal flexion.

So you have people not leaning forward from the hip, but flexing forward at the spine, then that's gonna be the abdominal complex. The abs are gonna create spinal flexion, so you might have some overactivity in that abdominal complex, creating flexion or posterior pelvic tilt, something like that, that's allowing this to take place.

Well, let's look at the underactive muscles here. This coincides with the muscles of the calf, the gastrocnemius and soleus, and an underactive muscle, it would be the anterior tibialis. Anterior tibialis, if you go to your shin bone, that shin bone is called your tibia, and you go right to the side of it, and on the front of the leg, on the front of the leg, the anterior, and you feel it, that's the anterior tibialis, so as you pull your foot up into dorsiflexion, you feel that muscle pop into your fingers as you dorsiflex, while you're pushing on the muscle. Your anterior tibialis, it's a much smaller muscle than your calf, so it makes sense that it loses to your calf muscles.

However, your calf muscles should have the extensibility to go into 15 to 20, ideally 20 degrees of dorsiflexion, and your anterior tibialis should be strong enough to pull you there, which means that I have to have both extensibility of my calf muscles and strength in my tibialis anterior to pull me into that range of motion. So there's a give and take, right here. I should have extensibility with the overactive muscles, which I likely don't have. I should have strength in the underactive muscles through a full range of motion, which I likely don't have.

So I'm looking at, right now, overactive muscles, excessive forward lean, gastrocnemius and soleus limiting dorsiflexion, and the anterior tibialis underactive is a dorsiflexor and the primary one, then I need to create balance at the foot and the ankle complex. At the hip flexors, if my hip flexors are short, tight, overactive, and they are leading to my excessive forward lean, then my primary muscle that's underactive, that is not decelerating that, would be my gluteus maximus.

The glute max's your primary hip extensor, and so it may not be appropriately decelerating flexion at the hip, because you're going into a lot of hip flexion, hence the hip flexor complex being a primary component of that. And then the abdominal complex. If I go into flexion at my spine when I do my squat, then what are my spinal extensors? And as a grouping, we will refer to your primary ones as the erector spinae.

So the erector spinae are not doing what they need to do in order to maintain that kind of upright position needed at the spine. All right, well I'm liking what I'm hearing right now. This is all good content. So let's continue down this vein and go into our next component, which is low back arches or, we'll refer to it a lot of times, as an anterior pelvic tilt.

An anterior pelvic tilt. Now one of the things that confuses a lot of people in an anterior pelvic tilt, people get really confused with an anterior pelvic tilt, it is a lot of times they think, when you stick your butt out, because they focus on it, they have a hard time identifying anterior and posterior pelvic tilt, so if I stick my backside out, which is my posterior, that is not a posterior tilt. That's an anterior tilt.

So what you have to do is identify what your point of reference is. Because you can't say, you can't have a moving point of reference. The point of reference we will use is going to be the superior anterior portion of the pelvis, so we're looking at the top of the pelvis from a front view, and when the top of the pelvis leans forward, right, or tilts forward, then the butt sticks out. So an anterior pelvic tilt is gonna cause an arch in the back because there is a rhythm that goes along with the lumbopelvic hip complex, so in a standing position, when the anterior pelvic tilt happens, there's a low back arch, and there's flexion at the hip that follows suit.

Now let's look at what muscles might be tight when the low back arches in an overhead squat assessment. Overhead squat assessment, low back the arches or an anterior pelvic tilt, the first thing that we're gonna pay attention to would be the hip flexor complex. Now this has a couple of components that are tricky here. One is there are a lot of muscles in the hip flexor complex. There's the psoas, and this one is a primary one we'll look at, but also the iliacus, and let's pay attention to this and why it's important is because the psoas has its proximal attachment point at the anterior transverse processes bodies and even discs of the lumbar spine, even up to T-12, so thoracic 12 all the way through the lumbar spine, and it connects to the spine and then crosses over the hip and is your primary hip flexor.

But with that being said, when that muscle gets tight, it can compress the spine, and it can also cause the back, by pulling it forward, cause the back to arch and increase that lordotic curve in the spine, and that lordosis will be exacerbated by the anterior public tilt anyway, so you've got one muscle that are causing two of these primary compensation patterns we'll look at. Arching of the lower back and an anterior pelvic tilt. So we've got the hip flexor complex, psoas, iliacus, what are some other hip flexors? You could probably throw in rectus femoris in there. Let's say TFL. There are a lot of other hip flexors, too, but I don't wanna overwhelm with content, but at the hip flexor complex, what we're primarily looking at, and then what else is happening, causing the back to arch? Well what muscle directly connects to the spine, causing the back to arch?

Well that is gonna be the erector spinae. The erector spinae will create, and you can do it right now, just arching your back, that's most likely where you're going to feel it, is in your back, and you'll feel the erector muscles working. One of the other things we'll look at, too, with the low back arching, think about this, because this is arms going overhead, as I put my arms over my head, or when your clients do it, and from a standing position, when the arms go up over the head, you see their back arch.

That's because the lats, which, when we look at the anatomy of the lats, it attaches to the arms, so the anterior medial portion of the humerus and it goes kinda through the armpit, down the back, and it goes into our thoracolumbar fascia, so in reality our lats connect to our lumbar spine, and actually also will connect to the posterior part of our pelvis, so as we reach our arms overhead, and I lack range of motion at my lats, as I push my arms overhead, I will steal range of motion from my spine by arching my back in order to give it to my shoulder so I can take my arm all the way overhead. So the lats are gonna be tight, or potentially tight, in this position, and then I've got a series of underactive muscles.

These are overactive muscles that are causing this lumbopelvic hip-- not lack of optimal alignment, they say dysfunction, there are a lot of things that I don't wanna think so much in dysfunction, but it's certainly not as functional as it should be, and it can also lead to things like lower back pain, so obviously we don't want that, but we've got muscles that are overactive, our hip flexor complex, erector spinae, and latissimus dorsi, what are our underactive muscles? Well if my hip flexors are the primary overactive muscle, then what's my primary hip extensor? Here we go.

The glute max, showing up again when it comes to dysfunction, and potentially because we sit on our glute maxis all day long, as a society, and it's very hard for us to activate those muscles, and when we do so, we do so, oftentimes we'll create movement in cheats, so the synergistic muscles start to jump in, because the glutes aren't firing as much as they should be, and then that leads to a phrase or a term called synergistic dominance that you may be aware of, so the glute seems to be consumed with inactivity due to constant inhibition by people sitting on it and then other muscles jumping in and saying, I'll get it, I'll get it, I'll get it, well, this is the point where we need to look at this muscle and say, nobody else jump in, we need our primary mover to be our primary mover, and let's do some specific activations for our gluteus maximus, have gotta get my glutes to fire.

But you also see on there the hamstring complex. Now the hamstrings can be a component of this. Obviously if my low back is arching, then my hamstrings will pull down on my ischial tuberosities and it can create a neutral position, or lead to a posterior pelvic tilt, so if I'm in an anterior pelvic tilt, my hamstrings are in a lengthened position. But, let me stop you there and say the first thing that you should focus on will be the glute maximus, because the hamstrings will tend to be the synergists that are creating that dominating activation for the glutes. So if you do hamstring activations, and you haven't worked on your glutes, then it's gonna be even harder for your glutes to fire. I do this and see this anecdotally with clients all the time in this setting, where if I don't calm the hamstrings down, the hamstrings will be the primary movers in so many of the glute activation exercises that I'm trying to get people to do and think things like bridges and hip thrusts, so if my hamstrings are more active than my glutes, I need to backpedal on that, need to try to limit hamstring activation and this underactive component so that my glutes are starting to function as a primary mover. And then also if my low back arches, they're gonna be some weaknesses, potentially, in my intrinsic core, and when we talk about intrinsic core, we're generally talking about local stabilization systems, so the transverse abdominis, internal obliques, multifidi muscles, muscles that are more stabilizers, and it could be a component of some larger muscles as well, but it's primarily those intrinsic core stabilizers that we'll be paying attention to that could be adversely underactive, and we need to stabilize those.

So, one more time just going over what we talked about. Excessive forward lean, overactive muscles, soleus, gastrocnemius, hip flexor complex, abdominal complex, the underactive muscles in an excessive forward lean might be the anterior tibialis, gluteus maximus, and erector spinae. Low back arches, overactive muscles would be the hip flexor complex, the erector spinae, and latissimus dorsi; the underactive muscles, gluteus maximus, hamstring complex potentially, and intrinsic core stabilizers.

Now, just so you know, this is not an exhaustive list of short type, overactive muscles or underactive muscles, and it also doesn't mean that these muscles are what the problem is, but from our perspective, when we look at human movement science, we will say based off of biomechanics and functional anatomy, these are the muscles that would be indicated as tight, and here's the thing, you're gonna do a warmup anyway. You're gonna warm your clients up anyway. Make sure that you're doing a warmup that makes sense for your clients based off of specific assessments. And the overhead squat assessment is an excellent all-encompassing assessment that allows you to look at the upper extremity, lumbopelvic hip complex, the lower extremity, as you go through your process as a personal trainer, trying to identify how you can best work with your client's individual needs. Thank you so much for listening. This is The NASM-CPT Podcast, with Rick Richey.

The Author

National Academy of Sports Medicine

National Academy of Sports Medicine

Since 1987 the National Academy of Sports Medicine (NASM) has been the global leader in delivering evidence-based certifications and advanced specializations to health and fitness professionals. Our products and services are scientifically and clinically proven. They are revered and utilized by leading brands and programs around the world and have launched thousands of successful careers.


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