Okay, tough guy, so you want to write your own training programs, eh? You think you've got what it takes?

I went over a lot of the basics in a previous article, Program Design 101, which covered topics such as sets and reps, time under tension, rest periods, and other training variables. However, every person who writes his own training programs should have at least a rudimentary knowledge of functional anatomy. Can you tell me what joints the hamstrings span? How to preferentially recruit the long head of the biceps? The difference between anterior and posterior?

If so, great! But I'd be willing to bet that you'll still learn a thing or two here. With a little bit of anatomy knowledge, the next time you write your own program you'll be more educated on how the body works and how to balance your training properly.

Throughout the course of this article, I'm really going to try and get you to focus on how muscles work, not only in isolation, but in integrated movements as well. In fact, it's often very difficult to isolate any muscle; instead, most movements simply emphasize or prioritize a certain muscle (or group of muscles) over another. Regardless, for ease of reading, I'll use the term "isolation" throughout.

Before we get into all the muscles and their movements, we need a basic primer on the anatomical position and planes of movement. Now, I'm going to warn you up front: there's no way I'm going to cover every single muscle group in the body! My goal here is to give you a quick synopsis of the biggest and baddest muscle groups, how they work, and how to effectively train them.

The Anatomical Position

You may have heard of the anatomical position, which is based on DaVinci's Anatomical Man.

The most important item to note here is that in the anatomical position, our model's arms are externally rotated, e.g. his palms are facing forward and alongside the body. Nothing else too exciting here, but you need to know where we're starting from to figure out where we're going!

Planes of Movement

The first and easiest plane to remember is the median or sagittal plane. This is where most of our weight training movements come from. Basically, this plane divides your body into symmetrical right and left sides.

The two basic movements we have in the sagittal plane are flexion and extension. Flexion takes a part of the body forward from the anatomical position (think bringing your knee to your chest for hip flexion), while extension takes a part of the body backward from the anatomical position (think letting your head relax back).

Now of course there are exceptions to every rule: the flexion exceptions are knee flexion and flexion of the ankle (also known as dorsiflexion). Don't worry too much about these for now.

The second plane we'll discuss is the coronal or frontal plane. This plane divides your body into a front and a back (anterior and posterior for you biomechanics tough-guys out there!).  Our primary movements in this plane are AB-duction (a movement which takes any part of the body away from the midline of the body), and AD-duction (a movement which takes any part of the body toward the midline of the body).

Again, there are some exceptions to this rule. Side bending of the neck/torso is called lateral flexion, while movements about the hand/foot are referenced from the midline of each.

The third and final plane is the transverse or horizontal plane, which divides your body into top and bottom (superior and inferior) parts. Movement that takes part of the body outward is called lateral or external rotation, while movement that takes part of the body inward is called medial or internal rotation. (I'll use medial and lateral throughout the course of this article.)

Just to be nice, I've included a picture to help you out. If you're thoroughly confused, read over this section again while referencing the picture.

Reference Terms

Now that we've discussed the planes of movement, let's briefly go over how we describe different positions on the body.

Medial and Lateral

If you look at the median/sagittal plane, it divides our body into symmetrical right and left sides. If we're talking about something closer to the medial (mid) line, then we'd use the term medial. If we're discussing something that's farther away from the medial (mid) line, we'd use the term lateral. Typically, we're discussing two separate points of reference and their relation to each other, so here's an example:

"In the anatomical position, the pinky is medial when compared to the more laterally sitting thumb."

If you have trouble, just remember that medial is toward the middle of your body and you should be fine!

Anterior and Posterior

This one is typically a lot easier to remember. If we're talking about something on the anterior part of the body, we're talking about something on the front of the body. If we're talking about something posterior, we're discussing the back side of the body. Here's a quote I'm sure will help (while discussing Vida Guerra's booty):

"She had the greatest posterior I'd ever seen!"

Superior and Inferior

This is another one that should be fairly easy to remember. Superior basically discusses points that are closer to the head, while inferior discusses points that are farther away from the head. Keeping with our examples, here's another quote:

"In the anatomical position, the shoulder is superior to the elbow."

How Muscles Work

When you contract a muscle and move it in a concentric fashion, you're shortening the muscle (bringing its starting and ending points closer together). Now, throughout this you'll notice that we discuss several points of reference for each muscle: the origin, the insertion, and the actions those muscles produce. Here are a few things you'll need to know:

• The origin is the starting point of a muscle, and usually starts either proximally and/or medially to the insertion.

• The insertion is where the muscle ends.

• The actions are all the specific movements or roles that muscle contributes to.

One thing I want you to keep in mind here is that when we're talking about the actions of a specific muscle, we're talking about when that muscle contributes as a prime mover or synergist. All this means is that when you curl a dumbbell or barbell, the biceps are a prime mover, so they're noted in that muscle action. On the flip side, the triceps are also active in an eccentric role, but since they're not a prime mover or synergist they aren't listed.

Hopefully this clears up any confusion. We can get pretty geeky with this stuff, but my goal is to give you a basic overview, not write an expansive anatomy text. Once you feel comfortable with all the reference terms, you'll be that much closer to writing superior training programs.

Now, finally, let's dig into how these muscles work. For each section, I'll provide you a table that outlines the origin, insertion, and various muscle actions of said muscle group. Next, you'll get a written description of the various muscle actions, along with some key points I feel are important to consider when writing programs.

Finally, I'll provide some "parting thoughts" that should help you take your programming to the next level!

Muscles of the Upper Torso

Muscle

Pectoralis Major

Latissimus Dorsi

Deltoid

Trapezius

Origin

Medial 1/3 of clavicle

Anterior aspect of manubrium and length of body sternum

Cartilaginous attachments of upper 6 ribs

External oblique's aponeurosis

Spinous processes of T7-L5

Upper 2-3 sacral ligaments

Iliac crest

Lower 3 or 4 ribs

Lateral, anterior 1/3 of distal clavicle

Lateral border of the acromion

Scapular spine

External occipital protuberance

Along the medial sides of the superior nuchal line

Ligamentum nuchae (surrounding the cervical spinous processes)

Spinous processes of C1-T12

Insertion

Lateral lip of bicipital groove next to crest of the greater tubercle

Clavicular fibers insert more distally; sternal fibers more proximally

Lateral lip of the intertubercular groove

Deltoid tuberosity of humerus

Posterior, lateral 1/3 of clavicle

Acromion

Superior spine of scapula

Action(s)

Adducts humerus

Internally rotates humerus

Flexion of arm from extension (clavicular portion)

Adduction of the humerus

Internal rotation of the humerus

Extension from flexed position

Downward rotation of the scapula

Abducts arm

Flexion and internal rotation of humerus (anterior portion)

Extension and external rotation of humerus (posterior portion)

Elevates scapula

Upward rotation of the scapula (upper fibers)

Downward rotation of the scapula (lower fibers)

Retracts scapula (middle fibers, all fibers co-contracting)

Let's get right into the meat of this article. These four muscle groups are what I'd consider the Four Horsemen of the Upper Torso (and no I'm not talking about "The Nature Boy"  Ric Flair, Arn Anderson, Ole Anderson, and Tully Blanchard!). Not only are these the biggest muscles in the upper torso, but they also contribute to a variety of movements.

Pectoralis Major

When you first step into a gym, chances are you wanted to bench and get a bigger chest. And why not? The pecs are heavily involved in horizontal pressing. However, the angle of the bench can play a significant role in whether you utilize the sternal or clavicular portion of the pecs. Please note that I didn't say the upper, lower, inner, or outer pecs! If we're going to be biomechanics geeks, we need to go all the way.

For instance, an incline press (increased flexion at the shoulder) promotes greater utilization of the clavicular portion of the pecs and anterior deltoids, while a decline press (decreased flexion at the shoulder) will prioritize the sternal portion of the pecs.

While we're at it, we can always argue the pros and cons of using exercises that utilize heavy weights versus those that "isolate" muscles. The classic example is using the bench press (where the pecs are called upon along with the triceps and anterior deltoids), versus a dumbbell flye which better isolates the pecs and uses them in their most optimal line of fire (via humeral adduction). While I wouldn't base an entire program around flyes, they can play a role in development and hypertrophy of the pecs.

Training Implications:

• If your only goal is pec development and hypertrophy, find a healthy balance between integration and isolation exercises. Please note that I don't consider a 50/50 balance acceptable. Something more like 80-90% heavy integration exercises and 10-20% isolation should suffice.

• Mix up the angle at which you press to preferentially recruit various portions of the pecs (incline, flat, decline, and everything in between.)

• If you're a powerlifter, why the hell are you doing flyes anyway?

Latissimus Dorsi

The latissimus dorsi are what strength athletes are talking about when they refer to the width of their back or their "wings." If you check out the primary roles of the latissimus dorsi, you'll see that they're very similar to those of the pecs (internal rotation and adduction of the humerus). This might seem strange since they're on opposite sides of the body, but you need to know where the muscle attaches to see how this works.

The picture below isn't the best to prove my point, but it'll help show how the lats actually insert on the anterior portion of the humerus, making their role as an internal rotator indisputable.

Now, an exercise that many old-time bodybuilders swore by was the pullover. Sure, they were mistaken about it expanding the ribcage, but if you're looking for an isolation exercise that will rip your lats up, this may be one to try.

However, if you're looking for a more integrated approach, chin-ups and pull-ups are probably the best lat-developers known to man. Chins, with their supinated grip, tend to place a greater emphasis on the mid-arm musculature, while the pronated grip pull-up takes the arms out of the movement, increasing the loading on the lats (and making the exercise more difficult!).

Training Implications:

• Again, if your only goal is lat development and hypertrophy, find a healthy balance between integration and isolation exercises. The above ratio should work fine.

• Don't get too caught up in using a certain grip width or hand position when doing chin-ups and pull-ups; the best position is a variety of them. Variables could include grip width (wide, medium, narrow), as well as hand position (pronated, neutral, supinated).

• While they aren't as good at developing the lats as chin-ups or pull-ups, please don't overlook the importance of rowing variations in your back development. More on this in the rhomboid section.

• Whenever possible, use chin-ups or pull-ups versus the pulldown machine. If I have to explain why, you need more help than this article can provide.

Trapezius

Wanna know a secret? Anatomists are lazy. They want things to be easy so you can remember them. Here's the secret to the traps: they have a trapezoidal shape. Brilliant!

The trapezius is one of those showy muscles that really separates someone who works out from someone who doesn't. It's also known in strength circles as the "yoke." Typically, when people think of the trapezius, they focus solely on the upper trapezius and their role –  elevation of the scapula. But we're smarter than most, so let's focus on the other two areas: the middle and lower trapezius fibers.

The middle fibers are important in scapular retraction, or the action of pinching your shoulder blades back together. Just as an aside, if all the various fibers contracted at once (upper, middle, and lower) you'd get a net movement of scapular retraction as well.

The lower fibers are the most often neglected, and most people have a very hard time getting them to work at all! The lower fibers depress the scapula (think moving straight down, the opposite of elevation) as well as downward rotation.

The best movement I've found to train this is the scapular wall slide; it really focuses on both the depression and downward rotation of the scapula. It's funny, but three sets of ten performed correctly on this exercise will have you wondering the next day what the hell happened to your mid-back!

I'm not going to break the traps up into isolated vs. integrated exercises; instead, I'll just give you a few exercises that hit all the different fiber angles.

Training Implications:

• The upper traps (in most trainees) are overdeveloped, especially when compared to the middle and lower fibers. If you're going to train the upper traps, please work on the other areas as well. Your body will thank you!

• The best exercises for developing the upper traps are deadlifts, Olympic pulls, and rack pulls.

Deltoids

Just like the trapezius, the deltoids have three distinct sub-sections: the anterior, middle, and posterior heads. It's funny, too, because there are a lot of parallels between these muscle groups. Let me explain.

The anterior head is basically the "twin" of the clavicular portion of the pecs: it internally rotates and flexes the humerus. This is why you'll hear a lot of powerlifters and bodybuilders say they do no direct anterior delt work, especially if they're doing a ton of horizontal pressing in their programs. In other words, just like the upper traps are typically overactive and overtrained, so are the anterior delts.

The middle deltoid is very similar to the middle trapezius fibers: it gets used in quite a few movements, but it's typically more indirectly involved rather than the focal point of training. However, if you're doing a ton of overhead pressing and/or lateral raises, chances are you're getting more than enough middle deltoid work.

Finally, the posterior deltoid, like the lower trapezius fibers, is like the red-headed stepchild of the group. Couple the fact that you can't see it with the fact that it's typically hard to train, and you have a reason for it to be all but forgotten!

Listen, the fact that it's an external rotator automatically places it in the "must train"  category. Bentover laterals, band pull-aparts and (gasp!) the posterior delt machine are all good choices for developing this often under-developed muscle group.

Training Implications:

• Much like the traps, most trainees have huge muscle imbalances around the deltoids. As well, remember that every horizontal press you perform recruits the anterior delt to some degree, so be sure to balance that with plenty of posterior delt work.

• With the exception of the posterior delt, most people get more than enough anterior and middle delt work with horizontal and vertical pressing exercises. In other words, unless you're seriously lagging in the development of these areas, extra isolation work probably isn't necessary.

The Rotator Cuff

Muscle

Supraspinatus

Infraspinatus

Teres Minor

Subscapularis

Origin

Supraspinous fossa

Muscle fascia

Infraspinous fossa

Muscle fascia

Middle half of scapula's lateral margin

Subscapular fossa

Insertion

Uppermost of three facets on the greater tubercle of the humerus

Middle facet of greater tubercle of humerus

Lowest of three facets of the greater tubercle of the humerus

Lesser tubercle of humerus

Action(s)

Abducts arm through initial 15-20 degrees of ROM

Stabilizes the glenohumeral (GH) joint

External rotation of humerus

Stabilizes GH joint

External rotation of humerus

Stabilizes GH joint

Internal rotation of the humerus

Stabilizes GH joint

I was going to leave this out, simply because this is supposed to only cover the major muscles of the body. However, I can't sleep with a clear conscience knowing that I didn't educate you on the anatomy and importance of the rotator cuff.

How many times have you heard this quote on SportsCenter: "[insert name] tore his rotator cuff and is out for the year." But here's the money question: How many of you know all the muscles of the rotator cuff and their function? If you don't, you need to learn! I assume that most T-Nation readers desire more than a casual knowledge of the musculature involved, so here goes.

The easiest way to remember the muscles of the rotator cuff is to use the acronym SITS. Therefore, the muscles of the rotator cuff go like this (along with their primary functions):

Right Shoulder, Posterior View. Source: Sports Injury Management: 2nd Edition

Supraspinatus

In a normal, healthy shoulder, the supraspinatus is the first muscle to abduct the humerus. This is important because not everyone's shoulders are healthy! Once you get past the first 15-20 degrees though, the middle deltoid takes over.

Infraspinatus and teres minor

These guys are the primary external rotators of the shoulders (the posterior deltoid contributes as well, but not as significantly as these two). Quite often these muscles are overpowered and imbalanced when compared their internally rotating counterparts (subscapularis, pectoralis major, and latissimus dorsi).

Exercises: Cuban press, L-lateral raise, shoulder horn, poor man's shoulder horn

The poor man's shoulder horn

Subscapularis

The internal rotator of the bunch, the subscapularis, is not only very strong/overactive, but quite often filled with adhesions in those with shoulder issues. Unfortunately, your average massage therapist is never going to get to this muscle, so here's reason #5287 to find a good ART therapist in your area.

Training Implications:

• If you value your shoulder health, you'd be well served to incorporate external rotations into your program. As well, make sure to perform external rotation movements with both the arm adducted (by the side) and abducted to 90 degrees.

• Unless you have some sort of specific shoulder pathology, it's rare that you need to include training for the supraspinatus or subscapularis in your program.

Muscles of the Upper Back

Muscle

Rhomboid Major

Rhomboid Minor

Origin

Spinous processes of T2-T5

Spinous process of C7 & T1

Ligamentum nuchae

Supaspinous ligament

Insertion

Medial scapula from the scapular spine to the inferior angle

Medial margin of the scapula at the medial angle

Action(s)

Retract scapula

Retract scapula

Sorry people, for the most part, these muscles aren't all that sexy. We'll give them their props then move on!

Rhomboids major and minor

Just like the middle trapezius, the rhomboids typically don't get enough work, especially when you consider the lustful relationship most of us have with the bench press. The primary role of the rhomboids is to retract the scapula, so if you want to use them, get to rowing! I wrote an entire article on rowing variations called Wanna Grow? Gotta Row!, so check it out and jump on the upper back bandwagon.

Training Implications:

• Again, if you value your shoulder health, you better be including a ton of rowing into your workouts. In reality, a 1:1 ratio of horizontal pulling:horizontal pressing isn't acceptable since most of us are so far out of whack to begin with. Unless you've been doing a ton of rowing since you started training, a 2:1 ratio is much better.

• Doing a ton of vertical pulling (pull-ups and pulldowns), too? This isn't as bad as the former, but I'd still say that for most, a 1:1 ratio of horizontal pulling:vertical pulling is a good start. Remember, the lats are internal rotators, too.

Sound like a lot of rowing? It is! However, most peoples' programs are so far outta whack from day one that no matter how long they've been training, they have some pretty significant imbalances going on around the shoulder. Fix it now before it becomes an issue!

Muscles of the Upper Arm

Muscle

Triceps Brachii

Biceps Brachii

Brachialis

Origin

Long head – Infraglenoid tubercle of the scapula

Lateral head – Upper half of the posterior surface of the shaft of the humerus, and the upper part of the lateral intermuscular septum

Medial head – Posterior shaft of humerus distal to radial groove and both the medial and lateral intermuscular septum (deep to the long & lateral heads)

Long head – Supraglenoid tubercle and glenohumeral labrum

Short head – Tip of the coracoid process of the scapula

Lower 1/2 of anterior humerus

Both intermuscular septa

Insertion

Posterior surface of the olecranon process of the ulna

Deep fascia of the antebrachium

Radial tuberosity

Bicipital aponeurosis

Ulnar tuberosity

Coronoid process of ulna

Action(s)

Long – Adducts the arm, extends at the shoulder, and forearm extension

Lateral – Extends the forearm at the elbow

Medial – Extends the forearm at the elbow

Flexes the forearm at the elbow

Supinates forearm from neutral

Stabilizes anterior aspect of shoulder

Flexes shoulder (weak, if at all)

Elbow flexion

Hopefully none of you just skipped to this section. If you did, shame on you!

Obviously the big dogs here are the triceps and biceps, but the brachialis plays a critical role in the integration of movements between the shoulder and elbow. As well, let's examine how subtle changes in body position can preferentially recruit different portions of said muscles.

Triceps

The primary function of the triceps is extension of the forearm, but the long head also extends the shoulder.

There are thousands of triceps exercises out there, but if for some reason you want to preferentially recruit the long head of the triceps, you need to take the shoulder into extension (e.g. overhead dumbbell extensions, EZ-bar overhead extensions). While it shouldn't make up the bulk of your training, this little tip can help lead to more balanced triceps development in the future.

Training Implications:

The triceps are best developed using heavy loads. For that reason alone, close-grip benches, board presses, and rack lockouts should be staples in your programming. If it weren't for some shoulder issues associated with them, I'd put dips in this category, too. To preferentially recruit the long head of the triceps, try overhead variations.

Biceps

The biceps perform several movements, the most obvious of which are flexion and supination of the forearm. Now, for those of you that get pronation and supination confused, here's a few ways to help you remember:

To hold a cup of soup, you need to be supinated.

You're supinated (palms facing forward) in the anatomical position.

If you rotate your forearms so that your palms are facing backwards, you have pronated.

As well, I'm sure some of you are wondering why people waste their time with dumbbell curls on an incline bench. With the biceps being weak shoulder flexors, if we take the shoulders into extension, we get an increased stretch in the bottom position and therefore increased recruitment of the long head of the biceps. Just a little nugget I thought you might like to know!

Training Implications:

• To fully develop the biceps, use a variety of exercises, hand positions, and upper arm positions (in front of the torso, next to the torso, and behind the torso).

• To preferentially recruit the long head of the biceps, try curling while lying on an incline bench.

• The best tips for bigger arms? Increase your squat and deadlift, put on some weight, and quit curling so damn much!

Brachialis

Finally, the brachialis serves the same primary function as the biceps (forearm flexion). However, to preferentially recruit the brachialis, we need to pronate the forearm. This pronation places the biceps in a somewhat ineffective line of pull, which thereby places more stress on the brachialis. This is also why you can't use nearly as much weight in pronated grip curls as you can in supinated grip curls.

Training Implications:

• Total upper arm development means training your brachialis. Reverse grip exercises decrease the mechanical advantage of the biceps and place a great load on the brachialis.

Summary

Now that I've thoroughly overwhelmed you, I'm going to give you a day to reflect on all this info. In Part II, we'll discuss the muscles of the core and the lower extremity, as well as give you some pointers on how to incorporate all this into your programming to take it to the next level!