Imagine, for a second, that I was to tell you that there's a muscle that:

has serious growth potential can dramatically increase your squat and deadlift poundages can drive your bench press through the roof can keep your shoulders, upper back, lower back, and hips healthy can help you run faster affects the way you breath

You'd probably think I was nuts. Surely the strength training community would've caught on by now, right? Well, I wouldn't say that they haven't caught on; I'd just say that they haven't learned how to utilize this muscle – and it does exist – in the right ways. Perhaps the worst part is that this muscle has a big cross sectional area already, so it's staring people right in the face.

I'm talking about the latissimus dorsi, lats for short. Let's get to it...

Functional Anatomy

I can almost hear a collective groan from the T-Nation villagers as I type the words functional anatomy. "What the hell is this geek going to confuse us on now? I know all about deltards, trapezoids, and the vastus meaty-alis already." Fear not. I won't bore you too much, and I'll water it down as much as possible.

Go to any classic anatomy text, and alongside a picture of an isolated latissimus dorsi on a skeleton, you'll find a list of the lats' actions, including:

Humeral Extension (bringing the arms back toward the hip from an elevated position, as in a chin-up) Humeral Adduction (bringing the arms toward the midline of the body, as in the "down" portion of a jumping jack) Humeral Internal Rotation (think of the humeral head rolling inward in the shoulder socket) Humeral Horizontal Abduction (think rear-delt flye)

Now, before I go any further, I'm going to show the picture from above again. I want you to look at the significant cross sectional area and multiple muscle attachments of the lat. Now consider the four functions that our "classic" anatomy textbook definition gives us. If the tech guys could insert some Jeopardy music here, they would.

Anybody see where I'm going with this? Hopefully, you'll realize that all these anatomy books are confining their coverage to what goes on at the humeral attachment, but they're altogether ignoring what's happening along the entire rest of a really big muscle. Let's look at the muscle's points of attachment:

Vertebral: T6 all the way down to the sacrum Pelvic (in addition to the sacrum): posterior aspect of the iliac crest Ribs: last 3-4 ribs Scapula: inferior scapular border Humeral: intertubercular groove of the humerus

Note: Part or all of #1 and #2 above are via the thoracolumbar fascia, which is incredibly important. We'll address this later.

If you got one out of five correct back in high school, did you pass the test? Or did you get a book deal from a publisher to create an anatomy book that would teach others your "20% wisdom" of the human body?

Before I finish up this functional anatomy diatribe, please take a quick glance at the fiber orientation of the lats. Notice how it's not perfectly "horizontal" (as we see with the pecs) or "longitudinal" (as we see with the biceps or hamstrings). We've got a nice blend of both with a diagonal fiber orientation, which accommodates a lot more complex movement and stability demands.

So, we know we've got a muscle that a) has a huge cross-sectional area, b) has a broad spectrum of attachments, and c) has a unique fiber orientation that accommodates diverse movements.

The Obvious: Getting Bigger

Most folks in the gym wouldn't mind packing some size on their lats, and it goes without saying that a muscle with so much natural cross sectional area obviously has a lot more potential for growth than a serratus anterior or piriformis. Everyone knows that it's tough to beat chin-ups for lat development, but you'll also see tremendous improvements with deadlifts as a complementary exercise.

In order to keep the bar close to you during the pull, your lats are acting isometrically in humeral extension – and with a lot of weight. If you're not pulling, don't expect to have big lats. It goes beyond just isometric action in humeral extension, though.

Deadlifts and pull-ups have been good to Ronnie.

Chad Waterbury has done a great job of discussing the importance of training specific regions more frequently in order to build muscle mass more rapidly. The nice thing about the lats is that they have so many different functions that you're literally training them relatively heavily every time you're in the gym. The secret is to just know how to use them correctly.

Building a Big Squat and Deadlift –

and Keeping the Lower Back and Hips Healthy

Ever been in a canoe? If so, have you ever tried to shoot a cannon out of it? Probably not, and not just because you don't own a cannon!

The fact of the matter is that stability is a prerequisite for any kind of strength and power movements. Specific to the squat and deadlift, we know that the overwhelming majority of the force is developed in the lower body. And it should come as no surprise that most programs you see that are written to improve the squat and deadlift focus on building leg strength.

However, think about where the resistance you're trying to move is located on these two exercises. On the squat, it's on your upper back. On the deadlift, it's in your hands. The force you generate has to get to the upper extremities in some fashion, and the lats are an important part of that process.

The force we generate crosses the pelvis into the thoracolumbar fascia, a large bunch of connective tissue onto which the lats (along with several other muscles) attach. The lats work with the other core stabilizers to transfer that force to the bar. If they're weak, some of the force escapes, and you can't move the kind of weights you ought to be able to move.

It works in the other direction, too. Your lats are actually powerful stabilizers of the lumbar spine. As Stuart McGill has discussed in Ultimate Back Fitness and Performance and his seminars, core stability is about the synergistic contribution of several muscles that all fire simultaneously to stabilize our spine. Through its attachment on the thoracolumbar fascia, the lats have an important influence on ensuring multi-directional stability at the lumbar spine. If you need to be told that lumbar spine stability is a prerequisite for a big squat or deadlift, you probably ought to take up crocheting.

And, indirectly, we can keep our hips healthy by keeping our lumbar spine stable. If we're stable in the lumbar spine, it's easier for us to develop hip mobility. Since Mike Robertson and I have been proclaimed "The Mobility Guys" since our Magnificent Mobility DVD came out, I can pretty much promise you that it's all related. Stabilize your spine and you won't see as many hamstring, hip flexor, and adductor strains; anterior hip pain; adhesions in the piriformis and gluteus medius; or any of a host of other problems.

So what's the secret to using the lats on a squat? Regardless of the width of your grip, pull the bar down into your upper back and tuck the elbows in tight (isometric extension and adduction, respectively). You'll also notice that this will pop your chest up, making it easier to stay upright for the lift.

As a little aside, not being able to use the lats as much is one of the reasons that people are traditionally weaker on the front squat. By elevating the upper arms, you're taking the lats out of the picture to some degree. They can't fire as much when they're lengthened.

The deadlift isn't quite as easy. Your best bet is just to make sure that two of the last cues you give yourself in the set-up are "bar close to shins" and "shoulder blades pulled down."

Driving up the Bench Press

Back in August of 2005, I started training with the crew at South Side gym in Stratford, CT. In the crew is a guy named Vincent Dizenzo, who has an 800-pound shirted bench and 600-pound raw bench under his belt. One of my major problems was poor leg drive, and I never realized what it was until I saw Vincent bench.

He told me that once I got leg drive down, my bench would go up 10%. Long story short, my leg drive has gotten better, and I've gone from a 340 bencher to a 420 bencher in about fifteen months. Vincent knows his stuff.

So how does leg drive relate to the lats? Just like we saw with the squat and deadlift, the force from the heels driving into the floor has to get to the bar somehow, and the lats are one avenue through which this force has to travel.

How can we ensure that our lats are engaged appropriately when we bench? First, it's imperative that we ditch the "bodybuilder-style," elbows-flared style and replace it with a more elbows-tucked style of benching. I went into great detail on the difference between the two in Shoulder Savers Part I . There are some videos included, so check it out.

As you watch those videos, consider the diagonal fiber orientation of the lats. You'll see that the elbows-tucked style increases lat recruitment dramatically, especially as you learn to increase activation intentionally by pulling the bar down to you. And, as we'll discuss now, it'll actually increase scapular stability and protect your shoulders and upper back from injury.

Keeping the Shoulders and Upper Back Healthy

People tend to overlook the effect of the lats on the position of the scapulae. The lat not only influences the scapulae indirectly via its effects on humeral motion, it's also directly (albeit somewhat weakly) involved in some important scapular motions via its "subtle" attachments on the scapulae as it travels to the humerus.

As one of the scapular depressors, the lat works to counteract the upper trapezius and levator scapulae, both scapular elevators. Anyone who knows anything about posture can tell you that the upper trap and levator scapulae are huge problems with respect to forward head posture, chronic headaches, neck pain, and pain along the medial scapular border. By making the lats stronger, we can help to reposition the scapulae.

Levator Scapulae

Along these same lines, the lats are weak scapular retractors, meaning that they assist the entire trapezius complex and rhomboids in pulling the shoulder blades together (and down, in the case of the lats – a nice little perk). This retraction helps to counteract the shortness virtually everyone has in their pecs from benching six days per week.

Third, the lats help the levator scapulae, rhomboids, and pectoralis minor out in downward rotation. This interaction is more of a gray area for the lats. If they're short, they'll contribute to a common problem: scapular downward rotation syndrome – meaning you're tight in these muscles and you can't upwardly rotate properly.

Inadequate Lat ROM

The easiest length test for the lats is done in the supine position. On your back, bend your knees to 90 degrees and keep your feet on the floor, which will flatten out your lower back (eliminates the rectus abdominus from being the limiting factor in ROM). Try to extend your arms overhead and to the floor behind you without bending the elbows.

Foam Rolling the Lats

If you make it, you pass. Keep hammering the lats hard. If you can't get your arms to the floor – or you start arching your back like crazy just so that you can – you fail. You need a lot of soft tissue work and flexibility training. Start foam rolling your lats and incorporate both static and dynamic flexibility work.

Running Faster

Earlier, I alluded to the thoracolumbar fascia (TLF), a dense collection of connective tissue at the lower back. This fascia serves as an attachment point through which several muscles can exert their desired effects.

Source: http://anatomy.med.umich.edu/

In the image above, you can see the attachment of the latissimus dorsi (2) onto the thoracolumbar fascia (1). The serratus posterior inferior (2) is a respiratory muscle that demonstrates the TLF's role in breathing, and the Iliocostalis thoracic (4: thoracic erectors) shows how the fascia also helps to transfer forces in a more vertical manner (in contrast to the diagonal approach of the lats).

Speaking of diagonals, check this out:

Source: http://anatomy.med.umich.edu/

You can easily recognize the TLF (1) and lat (3), but look at the way that the gluteus maximus' fibers are oriented. Consider the line of pull on the left-side lat in this diagram. If those forces are transferred across that TLF, they go right into the "wheelhouse" of the gluteus maximus.

In other words, they work synergistically, linking one shoulder with the opposite hip. This is known as the "serape effect" and is readily apparent in virtually every athletic endeavor. Look at the sprinters below:

In both cases, their right arms are extended (lats shortened) while their left femurs (thighs) are extended (glutes shortened). The lats are directly related to how fast these sprinters move. In fact, many coaches – myself included – use chin-up numbers as one indicator of whether what we're doing is working when the goal is to make athletes faster.

And, to take it a step further, in Anatomy Trains, Thomas Myers discusses the spiral line, a fascial connection between the shoulder and opposite leg, from the hip to the ankle. If you have restrictions in the spiral line, both ends of the line will be negatively affected.

This is one reason why I almost always see poor flexibility in the opposite ankle and hip in anyone who has a shoulder problem that involves tightness of some sort in the shoulder girdle. Yes, ankle and hip mobility training can actually help to fix shoulder problems!

Breathing Correctly

Believe it or not, the latissimus dorsi actually plays a crucial role in breathing. While the anterior fibers impact expiration, the posterior fibers assist in inspiration. Let's apply this to the bench press example. Imagine you're taking a heavy single.

The first thing you're going to do (hopefully) as you unrack the weight is get a huge belly full of air in order to stabilize your spine with increased intra-abdominal pressure. The lats help not only build this pressure and stability, but also help to transfer the force generated further down up to the bar. Get your air, tuck your elbows, and move big weights.

Take-Home Points

There was some science, some anatomy, some theory, and some recommendations here, so let's take a moment to bring the practical applications together:

1. Most people need to pay more attention to vertical pulling movements, as doing so will increase squat, deadlift, and bench press poundages; improve shoulder, upper back/neck, hip, and lower back health; enhance running speed; and wallop loads of quality mass on the upper back.

The only exception to this rule would be the individual who fails the test of latissimus dorsi ROM. He'll need to work on tissue length and quality before he can "get after it."

2. In addition, people need to appreciate that the lat is doing a lot more than just working on the humerus; it's probably the single-most influential muscle in the entire body, if you really think about it.

Learning to activate it isometrically in the squat and deadlift will enhance lumbar spine stability. Learning to pull the bar down on the eccentric component of the bench press will enhance stability, improve leg drive transfer, and help the lifter breath correctly during the lift.

3. Don't overlook the role of the fascial system in human function. Specific to this discussion, pay close attention to the spiral line (shoulder to opposite hip and ankle) and thoracolumbar fascia, both of which are intimately related to the latissimus dorsi. Regular soft-tissue work can make a big difference in how you feel and perform.

And you thought the lats only came into play during the pulldown...