If you are not yet familiar with the joint-by-joint theory, be prepared to take a quantum leap in thought process.

One beauty of the FMS is that it allows the screener to distinguish between issues of stability and those of mobility, in relation to joint function.  Visualize the body as a stack of joints where each joint or series of joints has a specific function and is prone to predictable levels of dysfunction.  As a result, each joint will have particular training needs.

The list below looks at the body on a joint-by-joint basis from the bottom up:

Joint                                      Primary Need

Foot                                      Stability

Ankle                                   Mobility (sagittal)

Knee                                     Stability

Hip                                       Mobility (multi-planar)

Lumbar Spine                    Stability

Thoracic Spine                   Mobility

Scapula                                Stability

Gleno-humeral                   Mobility

Cervical C7-C3                     Stability

Cervical C2, C1                    Mobility

The first thing to notice is the joints alternate between mobility and stability as we move up the body.

Over the past 30-years, we have progressed from the approach of training by body part to a more intelligent approach of training by movement pattern.  In fact, the phrase ‘movements, not muscles’ has almost become an overused one, and frankly, that’s progress.  Most good coaches and trainers have given up on the old ‘chest-shoulders-triceps’ method and moved to the push-pull, hip-extend, knee-extend programs.

Still, the movement-not-muscles philosophy should have gone a step further.  Injuries relate closely to proper joint function, or more appropriately, to joint dysfunction.   Problems at one joint usually show up as pain in the joint above or below.

The primary illustration is in the lower back.  It’s clear that we need core stability, and it’s also obvious that many people suffer from back pain.  The intriguing part lies in the new theory of the cause: loss of hip mobility.

Loss of function in the joint below…in the case of the lumbar spine…seems to affect the joint or joints above.  In other words if the hips can’t move, the lumbar spine will.  The problem is the hips are designed for mobility, and the lumbar spine for stability.  When the intended mobile joint becomes immobile, the stable joint is forced to move as compensation, becoming less stable and subsequently painful.

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

Now take this idea a step further:

What is the primary loss with an injury or lack of use?  Ankles lose mobility, knees lose stability, hips lose mobility.

The hip is a bit of an exception in that the hip can be both immobile and unstable, resulting in knee pain from instability (a weak hip will allow internal rotation and adduction of the femur) or back pain from immobility.

Weakness of the hip in either flexion or extension causes compensatory action at the lumbar spine, while weakness in abduction, or, more accurately prevention of adduction causes stress at the knee.

Poor psoas and illiacus strength or activation will cause patterns of lumbar flexion as a substitute for hip flexion.  Poor strength or low activation of the glutes will cause a compensatory extension pattern in the lumbar spine to replace the motion of hip extension.

This fuels a vicious cycle.  As the spine moves to compensate for the lack of strength and mobility of the hip, the hip loses more mobility.  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.

Excerped from, Advances in Functional Training, by Mike Boyle.