the squat is often nicknamed the king of all exercises and this is because there are few other exercises that compare to the squat as far as intensity and the sheer number of muscles that are required to perform this movement which means you could definitely make the argument that almost everyone should include some form of squatting as part of their exercise routine So today we're going to dive deep into the anatomy of squatting by using the cavers to show you the majority of the surprising muscles involved with squats how those muscles have to contract differently when lowering down versus Rising back up and even discuss how breathing properly can protect your spine and also make you a better squatter we've definitely got some anatomical awesomeness to cover so let's do this so when we're talking about the squat we'll focus mainly on three joints of the lower limb as well as talk about stabilizing the spine but when I go down to say like a barbell squat position if I lower down we'd look at my ankle my ankle would be in what's called dorsal flexion and if you haven't heard of dorsal flexion before when your foot's off the ground dorsal flexions when the top of the foot comes Towards the Sky like when you're pulling your foot off the gas pedal but in a squat position because the foot's planted that movement comes because the tibia slides over the foot now when I come back down again to that lower position dorsal flexion of the ankle my knee is flexed and then my hip is flexed but when I stand up my ankle goes into a little bit of plantar flexion the knee knee extends and the hip extends now the reason I went over those joint movements is because there are multiple muscles or specific muscles I should say they're going to be involved in mobilizing or moving each one of those joints so let's start with the muscles that mobilize the ankle now admittedly most people don't think about working their calves when squatting but these muscles are technically active during a squat so let's quickly cover some of the main ones here you can see the most superficial muscle of the posterior calf called the gastrock nemus as well as part of the Sol with which most of it lies deep to the gastrus so on this side we've removed the superior bellies or Superior portion of the gastrock so you can see the upper portion of that Solus kind of looks like a soulfish here now how are these muscles active during a squat now I often like to show students the length changes that occur with a muscle kind of using a rubber band throughout various movements or certain exercise movements and so let's use this rubber band as we go down into a squat position now remember we already talked about the ankle going into dorsal flexion when I lower down and then plantar flexion when I come up and so the gastrock and Solus how they would be active as I go down into the squat especially the Solus because my knee gets bent we're going to see that these muscles will eccentrically contract or lengthen as I'm stretching the rubber band there and as we stand up into plantar flexion those muscles will concentrically contract or get shorter now I'll get into more detail about concentric eccentric and isometric contractions when we talk about the thigh but what's crazy about this is that we could technically get into even more muscles that are active during a squat especially like the intrinsic foot muscles like if you were to even squat Barefoot those foot muscles would become even more active now there are 12 intrinsic foot muscles on the bottom of the foot or the sole of the foot so we're going to actually save the foot muscles for a foot dedicated video but again most of the muscles that we're talking about down in the calf and the foot aren't going to be the main focus of the squat because most most people think about those thigh muscles being engaged during a squat especially these anterior thigh muscles that we call the quads technically the quadriceps quad means four seps means heads so we're going to actually see the quads are made up of four individual muscles we have the vastest lateralis out here on the side we have the vastest medialis on the inside and then the rectus florus here and the fourth quad muscle that we'll see is if I slide that rectus Fus out of the way you can see underneath there there's another muscle and I'll touch it with the tip of the probe and this is called the vast intermedius now the quads are primarily going to be involved in mobilizing the knee during a squat so let's Orient this rubber band as if it's one of the Quad muscles and as I lower down to that flexed or again lowered position you can see the rubber band actually lengthens this would be considered an eccentric contraction of the quads eccentric contractions are when the muscles are actively lengthening think of it as like controlling the movement controlling ourselves down and as an FYI our muscles tend to really respond well to Centric loading from a strength and hypertrophy perspective but let's say I decided to hold the bottom of the squat which I'm doing now and feeling a little bit of the burn this would be considered an isometric contraction the muscle's active but not changing its length but when we need to stand up and extend the knee with the quads the quads will shorten and we call that a concentric contraction but let's go back to some of the thigh muscles specifically the muscles on the posterior thigh and we can take a look at these on the Cav by magically flipping the Cav over so here you can see we've turned the body over we're looking at a posterior view of the thigh and we've got the hamstrings on both sides here and let me actually hook the hamstrings with the probe here and you can see we've got three muscles that actually make up each hamstring we've got the biceps forus the semiosis and look at why it got called the semiosis you can see this long cylindrical Tenon this is an FYI the semiosis Tenon can be used as an ACL graft and then we have the semimembranosus and you can see why it got its name membran is because of this membrane wide broad tendon here now the hamstrings do mobilize the knee with certain movements but in the case of the squat they're primarily going to be working at The Hip now I apologize that you're going to have to deal with the back side of my body here for a second but let's put the rubber band In the orientation of one of the hamstrings and as we come down into hip flexion the hamstrings will eccentrically contract on the way down but then concentrically contract shortening and bringing us up into hip extension the gluteus Max Maximus does something similar but let me show you the gluteus maximus you can see it here on the left side as well as here on the right one of the largest muscles in the human body so in the case of the squat if I make my makeshift rubber band glutitis Maximus similar to the hamstrings as we come down into hip flexion the glutitis Maximus will eccentrically contract and then when we come back up it'll shorten or concentrically contract to bring us up into hip extension and so that takes care of the main muscles involved in the squat at the knee and the hip but we also need to protect our spine when we're squatting especially if we're loading up with a barbell we don't want to be twisting or folding forward at the lumbar spine or anywhere at the spine for that matter and so we need some core stabilizers and some extensor muscles for the spine some core stabilizers like the external oblique is active as well as the internal oblique and another muscle called the trans verus abdominis which helps us to kind of create this natural weight belt in our abdomen to really stabilize I our lumbo pelvic region and protect that spine now I did mention some spinal extensors spinal extensors would do a movement so let me show you what flexion looks like flexion of the spine looks like this I'm trying not to get my hips involved because that would be something else but your spinal extensors will contract and pull you upright and keep your spine erect in this position that we want our spine to maintain as we go down with a squat especially for loading with the barbell or some other form of weight but let me show you these spinal extensors on this CAD Cav dissection so to orient you to this particular Cav dissection you're looking at a posterior view or the back side of the body and we've removed some pretty familiar muscles on this right side like the lausus dorsi the lats have been removed the trapezius often nicknamed the traps has been removed and obviously you can see the right upper limbs been removed to expose these long strapl likee muscles that are part of this erector spiny group and they're the true back muscles and what I mean by the true back muscles is they actually mobilize the spine with that spinal extension that I showed just a second ago but there again are three muscles in this erector spiny group we have the ilio costalis between my probe then we have the longissimus and then we have the spinalis right along the spine here now I'll often give my students little pneumonics to help them remember the names of certain muscles like these because one starts with i another starts with L and another one starts with s we would often say I love school or I love soccer but the pneumonic that seemed to stick the most with students for some reason was I love sex and I guess that makes a little bit more sense because they are part of the erector spiny Group after all but what's remarkable about all of this is all the muscles that are involved in creating this amazing compound exercise movement that we call the squat and so we might as well add two other muscles to this list because these muscles are going to be extremely important for protecting us and we don't think about these muscles really when we squat but they are very important and one's technically a muscle group and that muscle group is the pelvic floor the pelvic floor muscles form this bowl within your pelvis and they help to support your pelvic organs and they also contain some sphincters like a urethal sphincter so you can control when you pee and choose to when you choose to pee when you want to pee and they also are engaged when you contract your abdominal muscles so think about Contracting the obliques and the transverses that we talked about earlier and that will also Shore up that pelvic floor but let's pause on the pelvic floor muscles for just a second because they are going to work in conjunction with the next muscle the diaphragm so you can see the diaphragm here it's this Dome shaped muscle and we T typically think of the diaphragm is the breathing muscle because it is the breathing muscle and so when the diaphragm contracts it pulls down in this direction and that will increase the volume of the thoracic cavity and so if we have more space up here that allows air to rush in and fill the lungs with more air because now they have more available space to fill when the diaphragm pulls down in this direction but what happens when the diaphragm pulls down in this Direction let me show you on this angle let's say this hand is the pelvic floor and this is shored up because we're Contracting it with the abdominal muscles and the diaphragm contracts and pushes downward that's going to increase the pressure in that abdominal cavity you can see kind of how that would work by pushing downward we're going to increase the pressure here and we actually want to increase the pressure with in the abdominal cavity while we squat think of as think of it as if we increase the pressure in here the abdominal muscles are going to have more to reinforce themselves on or to kind of push against if you will and so that will help us to shore up even more our lumbo pelvic region and to stabilize and protect our spine now one thing that I want to talk about is how to breathe now you don't want to get a bar on your back when you're squatting and do some weird breathing where you're like opening up your ribs and shrugging your shoulders up or anything like that you want to think of almost like breathing downward into your belly and so how you could test to do this is if you put your fingers on your obliques and you breathe properly like a lot of people do it in through their nose you want to kind of feel your abdominal muscles wanting to push out but when you squat think of these two words breathe and brace so if you're at the top of the squat you're going to breathe Embrace and think of almost like bracing like if somebody's going to punch you in the stomach because if you knew somebody was going to punch you in the stomach you'd and you'd brace that and that's kind of what you want to do with the squat here so if I get the barbell on my back here again we're going to think breathe and brace so breathe in and hold go down now the exhale is you can start to Exhale when you get close to the top of the squat or you can wait till you get to the very top but you don't want to breathe out all your air when you're at the bottom and most vulnerable because then you're going to lose that connection in your lumbo pelvic region and not be able able to stabilize your spine so it's pretty incredible to think that breathing properly one will help you to protect your lumbo pelvic region and two you'll likely be able to be a more effective squatter and potentially even squat more W weight obviously safely now again the pelvic floor and the diaphragm are muscles that you could kind of think of as protecting you and making you a more effective squatter but again we typically think of the thigh muscles and the glutes as the muscles that were really working with the squat and there is one last muscle I do want to talk about with squatting and it's a muscle people don't typically think about and this muscle will also be important for our next video called built the squat because we're also going to do a video on why some people might be a little bit better built for squatting than others but let's talk about this last muscle have you ever done a squat workout and afterwards you've noticed like the inside of your thighs are sore well you can think a muscle called the adductor Magnus for that soreness abductor because this muscle will be involved in adduction of the hip which is bringing the hip into towards the midline and Magnus because it's a huge muscle now this adductor Magnus does more than just getting involved in adducting the hips it does something very important for squatting and let me show you this muscle on this cadav section so I actually need to glove up for this one because I need to move the hamstrings out of the way but you can see this big muscle called the adductor Magnus here on the left and you can even see it over here on the right now there's two heads to this muscle one of the heads the fibers are more oblique or in a diagonal orientation going in this way towards the femur on both sides if I showed you on me be going in like so on my left and going in like this on my right but the other head that you can see specifically right here is called the cond head and this head's very important as an FYI it's called the cond head because it attaches to this bump called the adductor tubric on the medial cond dile of the femur hence called the cond head but this cond head the fibers are not oriented in that oblique Direction they're going more vertically mimicking the fiber orientation of the hamstrings and so this cond head is very important to mobilizing the hip of the squat as well and so when we talk about the adductor Magnus it's very similar to what the hamstrings would do again I apologize for the backside view again but if we were to do this the adductor Magnus will also eccentrically contract when we go into hip flexion and then concentrically contract to help bring us up and it gets even more active or more worked the deeper you go in a squat and this muscle can get a little bit involved in limiting some of your movements depending on your body type but we're going to wait and talk more about how your body type and certain muscles like the adduct or Magnus can affect how you squat in our next squat video which will also cover why some people could be a little bit better built for squatting than others but more importantly what you can do to make yourself a better squatter regardless of your body type so stay tuned for that next video but hopefully today's video helped to give you a strong anatomical foundation on squatting and why squatting can be such a bang for buck exercise just based on all the joints and muscles required to perform this exercise movement so thanks for watching and supporting the channel if you are watching this video a week or two after we released it I'll link the next squat video here as well as link a video on back pain to help motivate you to protect your back during squatting and I'll see you down in the comments and in the next video