My good friend, Physical Therapist Gray Cook, has a gift for simplifying complex topics. I envy his ability to succinctly take a complicated thought process and make the idea appear simple. In a recent conversation about the effect of training on the body, Cook displayed one of the most lucid thought processes I'vc ever heard.

Gray and I were discussing the findings from his Functional Movement Screen evaluation system. For those who are unfamiliar, the Functional Movement Screen is a system used to evaluate the mobility and stability of the body.

If you train athletes other than yourself, I'd strongly recommend you visit the site and familiarize yourself with the screen. The tests can help to identify the needs of the different joints of the body and how the function of the joints relates to the execution of the lifts.

One of the beauties of the Functional Movement Screen is that the screen allows us to distinguish between issues of stability and issues of mobility. Cook's thoughts were simple and led me to realize that the future of training and of corrective exercise may be on a joint-by-joint approach rather than a movement-based approach.

Cook's analysis of the body was a straightforward one. In his mind, the body is just a stack of joints. Each joint or series of joints has a specific function and is prone to specific, predictable levels of dysfunction. As a result, each joint has specific training needs. The table below looks at the body on a joint-by-joint basis from the bottom up:

Joint Primary Training Needs

Ankle mobility (particularly sagittal)

Knee stability

Hip mobility (multi-planar)

Lumbar Spine stability

T-Spine mobility

Gleno-humeral stability

The first thing you should notice as you read the above table is the joints simply alternate between the need for mobility and stability as we move up the chain. The ankle needs increased mobility, and the knee needs increased stability.

As we move up the body, it becomes apparent that the hip needs mobility. And so the process goes up the chain: a simple, alternating series of joints.

You're probably asking yourself, "What does this have to do with lifting?" Can it make me squat more? Yes, absolutely.

The basic fact is that over the past twenty years the average gym-goer has progressed from the bodybuilding approach of training by body part to a potentially more intelligent approach of training by movement pattern.

In fact, in the sports world, the phrase "movements not muscles," has almost become an overused one and, frankly, that's progress. I think most good lifters have given up on the old chest-shoulder-triceps muscle mag thought process and moved forward to a push-pull-anterior chain- posterior chain thought process.

I think the injuries we see and technical problems we encounter with many lifters relate closely to proper joint function or more appropriately to joint dysfunction. Confused? Let me try to explain. In simplest terms, problems at one joint usually show themselves as pain or a problem in the joint above or below.

The simplest illustration is in the squat. As a former Powerlifter, we know that the big issue in the squat is depth. If you had trouble getting deep, the first thing the old school gurus did was recommend that you elevate the heels.

We may not have understood the difference between mobility and stability as it related to the ankle, but we did know that squatting in work boots allowed us to get depth easier. In simple terms, heeled shoes (work boots in this case) compensate for poor ankle mobility. So the take home lesson is work on ankle mobility if you have depth issues in the squat.

How many people do you know who can no longer squat due to back pain. My theory of the cause? Loss of hip mobility.

Loss of function in the joint below (in the case of the low back, the hip) seems to affect the joint or joints above (lumbar spine). In other words, if the hip can't move, the lumbar spine will.

The problem is that the hip is built for mobility, and the lumbar spine is built for stability. When the supposedly mobile joint (in this case the hip) becomes immobile, the stable joint ( the lumbar spine or lumboscaral joint) is forced to move as compensation, becoming less stable and subsequently painful. In other words, if you lack hip mobility or ankle mobility, you'll lean forward in the squat and shift stress to the back.

The process is simple:

Lose ankle mobility, get knee pain.

Lose hip mobility, get low back pain.

Lose thoracic mobility, get neck and shoulder pain (or low back pain).

The Ankle (Mobility)

Looking at the body on a joint-by-joint basis beginning with the ankle, this thought process seems to make sense. In jumping sports an immobile ankle causes the stress of landing to be transferred to the joint above: the knee.

In fact, I think there's a direct correlation between the stiffness of the basketball shoe and the amount of taping and bracing that correlates with the high incidence of patella-femoral syndromes in basketball players and other frequent jumpers. (ADD Anterior Knee Pain Link)

Our desire to protect the potentially unstable ankle comes with a high cost. We've found many of our athletes with knee pain have corresponding ankle mobility issues. Many times this follows an ankle sprain and subsequent bracing and taping.

In lifting, as we noted above, poor ankle mobility results in a need to lean into the squat and attempt to use the hip extensors to a greater degree. You can tell if you have an ankle mobility issue by taking the FMS Overhead Squat Test.

Perform an overhead squat. If the arms fall forward (technically, the arms can fall forward but must stay in line with the trunk angle), then add a heel lift.

If the heel lift solves the problem, the problem is primarily in the ankle. How do you know it's a mobility issue versus a flexibility issue? Take a simple test. Assume a calf stretch position. Do you feel a huge stretch or a do you feel "stuck" in front?

If you feel a big stretch, you have a flexibility issue and calf stretching will help. If you feel "stuck" or a pinch, you have a mobility issue. Flexibility issues are cured by stretching, mobility issues are cured or cleared by mobilizing the joint. If you think there's no difference, you need a little more studying

The Knee (Stability)

The knee itself is simple and straight-forward. Knees need stability. They are hinges with minimal rotary components. Think squats and straight leg deadlifts. Old school. Call it anterior chain and posterior chain if you want, but it's not complicated.

McGill, in both his books, emphasizes that most back pain sufferers don't have a weak back. In fact McGill's research is very clear. Those with a bad back generally have stronger back extensors than those with a weak back.

Yes, that's what I said and more importantly, what McGill states in all his writings and lectures. Back pain is not about a weak back. Back pain is about overuse, primarily from flexion forces. Guess what. Heavy squats and deadlifts produce flexion forces. Look at the research on my website under McBride research.

The Hip (Mobility)

The exception to our mobility/ stability rule seems to be at the hip. My friend Jason Ferrugia has been ranting about hip mobility lately. Jason thinks all hip mobility work is a waste of time.

I wrote to him and disagreed. In fact, I think in strength development hip mobility is key. As I stated above, good hip mobility allows us to use multi-joint exercises to strengthen the lower body.

Jason writes that mobility and flexibility were synonyms. In reality, they aren't. Flexibility applies to muscles and is indicative of length. Mobility applies to joints and is used to describe motion.

To be honest, the hip is incredibly complicated and merits great attention. I wrote an entire article on Understanding Hip Flexion and am working on one on Understanding Adduction.

The hip, much like its upper body counterpart, the shoulder, can be simultaneously immobile and unstable; immobile because of lack of flexibility and lack of motion, and unstable due to weakness, too much reliance on double leg strength exercises, or too much reliance on machine based training.

The result can be knee pain from the instability (a weak hip will allow internal rotation and adduction of the femur) or back pain from the immobility and accompanying forward lean. How a joint can be both immobile and unstable is the interesting question.

Both weakness and/ or immobility of the hip in either flexion or extension causes a corresponding compensatory action at the lumbar spine. This is the problem in squatting. In our joint above/ joint below concept, the lack of hip motion compromises the low back in squatting.

As the spine moves to compensate for the lack of strength and mobility of the hip, the hip loses more mobility. It appears that lack of strength at the hip leads to immobility, and immobility in turn leads to compensatory motion at the spine. The end result is a kind of conundrum: a joint that needs both strength and mobility in multiple planes.

Let's look further at the interrelationships. The weakness of the hip in preventing adduction causes stress at the knee. We've oversimplified this to a glute medius weakness, however the weakness often extends to the glute max and the hip rotator group.

In this case we need frontal plane control to prevent patella femoral problems, IT band issues, etc. In the sagittal plane, poor psoas and iliacus strength and/or activation will cause a pattern of lumbar flexion as a substitute for hip flexion.

Poor strength and/or activation of the glutes will cause a compensatory extension pattern of the lumbar spine that attempts to replace the motion of hip extension. In other words, if you can't move your knee up (i.e flex the hip), you'll flex the lumbar spine to achieve a motion that appears similar.

The Lumbar Spine (Stability)

The lumbar spine is even more interesting. The low back is clearly a series of joints in need of stability, as evidenced by all the work in recent years in the area of core stability.

Strangely enough, the biggest mistake I believe we've made in training over the last ten years is engaging in an active attempt to increase the static and active ROM of an area that obviously craves stability.

In other words folks, you don't need to stretch your low back. Trust me, I know what you're going to say. "It feels good to rotate." It does feel good when I do that stretch.

Do you know what I tell coaches and trainers when they tell me "it feels good when I do X," I tell them scratching a scab on a cut also feels good. However, the result is bleeding and scar formation.

This is how I feel about rotational stretches for the low back. They're like scratching a scab. I believe that most if not all of the many rotary exercises done for the lumbar spine were misdirected. Both Sahrmann "Diagnosis and Treatment of Movement Impairment Syndromes" and Porterfield and DeRosa "Mechanical Low Back Pain: Perspectives in Functional Anatomy indicate that attempting to increase lumbar spine ROM isn't recommended and potentially dangerous.

I believe our lack of understanding of thoracic mobility has caused us to try to gain lumbar rotary ROM and this is a huge mistake. So let's get back to lifting.

The lesson here is, never, and I mean never use any kind of rotary torso machine. Eliminate all the trunk twists, Scorpions, etc. that you do to "warm-up" your low back. As McGill says, "Spare the spine."

All this talk over the past ten years has been about core stability, not core mobility. The lumbar spine needs to be stable, not mobile. Squat tall with the bar high; deadlift with a flat back. If you have a history of low back pain, go single leg.

Thoracic Spine (Mobility)

The thoracic spine is the area about which we seem to know least. Many physical therapists seem to recommend increasing thoracic mobility, though few seem to have exercises designed specifically for thoracic mobility.

The approach seems to be "we know you need it, but we're not sure how to get it." I think over the next few years we'll see an increase in exercises designed to increase thoracic mobility. Interestingly enough in SAHRMAN Diagnosis and Treatment of Movement Impairment Syndromes, physical therapist Shirley Sahrmann advocated the development of thoracic mobility and the limitation of lumbar mobility.

We've added a simple thoracic spine mobility drill to our warm-up to try to get the thoracic vertebrae to regain lost motion.

From a lifters point of view, thoracic mobility may seem less important, but if you suffer from low back pain or from neck pain, thoracic mobility work will spare both the lumbar and cervical spine.

The Scapulo-Thoracic Joint (Stability)

As we continue up the kinetic chain, we get to the scapulo-thoracic joint, which is the transfer station to the upper body. This is the interface of the shoulder blade and torso and also the key to a healthy shoulder.

Logic dictates that this is a joint that needs stability. As a lifter, this is the key to the health of the rotator cuff. As we all know, our fascination with supine pressing has made rotator cuff tendonitis almost a badge of honor in the lifting world.

Charles Poliquin has frequently talked about lower trapezius strength and its relationship to shoulder health. Bottom line. The scapulo-thoracic joint is usually weak and under worked. Most strength athletes don't do nearly enough back work and, rarely do mid-back work like rows.

If they do row, they like the bent row, which often compromises the lumbar spine as it attempts to work the scapula stabilizers. Most, if not all, lifters need more rows for the scapulo-thoracic joint as well as isolated exercises for the scapula-thoracic joint.

Low trap raises as well as exercises that have become know as Y's, T's, W's, and L's or U's all directly target the scapula stabilizers

Take a quick test. Try a max set of inverted rows.

Can you do 10? Most "strong" guys can't get 10 reps where they touch their chest to the bar without cheating. As soon as they fail they immediately go into the excuse book. Excuse one is that their incredible size keeps them from touching their chest to the bar.

My next question. Why does your incredible size allow you to bench? That's when they usually just shut up and acknowledge their weakness. Work to stabilize the scapula and at the same time, to develop the strength of the retractors like the rhomboids and lower traps. Just because you can't see them in the mirror doesn't mean they're not important.

The Shoulder

The gleno-humeral joint is similar to the hip. The gleno-humeral joint is designed for mobility yet frequently becomes immobile.

The shoulder is a complex system in that the gleno-humeral joint is strongly interrelated with the scapulo-thoracic joint. I like the "You can't shoot a cannon from a canoe" analogy here.

The scapulo-thoracic joint is the stable base that allows a mobile shoulder to work. We need to be able to lock the shoulders in place in a retracted and depressed position with the scapula stabilizers for the gleno-humeral joint to function properly.

The bottom line is that a stable shoulder complex will make for a healthy shoulder complex. The best exercise to feed this interrelationship is what we call Wall Slides. Wall slides can best be described as an active range of motion exercise for the gleno-humeral joint, combined with a stability exercise for the scapulo-thoracic joint.

The key to the Wall Slide is that the shoulder blades remain retracted and depressed while the gleno-humeral joint attempts to move the arms overhead. They are the "air guitar" of overhead pressing.

Many beginners will actually cramp in the lower trap/ rhomboid area as they attempt this exercise. The key is that the forearms must slide up in contact with the wall while the shoulder blades stay down and back.

Don't be surprised if you can't do it. It'll take some time. Only lift the arms overhead as far as pain free ROM allows. Initially this may be a small range, but trust me, it'll improve.

From a lifter's standpoint, the important take-away is that good shoulder health is all about what you can't see. I think most lifters should stay away from heavy overhead work until they master the wall slide.

I also think the need for a combination of stability and mobility in the gleno-humeral joint presents a great case for exercises like Stability Ball and BOSU Push-ups as well as unilateral dumbbell work.

The inability of joints to function normally places stress on the joints above or below. In the book "Ultra Prevention" (actually a great nutrition book, too), the authors describe our current method of reaction to injury perfectly. Their analogy is simple; our response to injury is like hearing the smoke detector go off and running to pull out the battery.

The pain, like the sound, is a warning of some other problem. Icing a sore knee without examining the ankle or hip is like pulling the battery out of the smoke detector.

What we need to realize is that "We get old too soon and smart too late." Oscar Wilde said, "I am not young enough to know everything."

Every day, I learn more and more about the body. What I learn allows me to be a better coach and a better educator. Often, what I learn contradicts what I formerly believed. Just remember, the world was once thought to be flat.