The joint-by-joint idea came about as a result of an off-hand conversation. Physical therapist Gray Cook and I were discussing the results we had seen in his Functional Movement Screen. I noted that difficulty in squatting always seemed to be related to limited ankle mobility. Cook’s answer and subsequent analysis of the body was a straightforward one. In Cook’s mind, the body is a 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. Table 5.1 looks at the body on a joint-by-joint basis from the bottom up.
Note that the joints alternate between the need for mobility and stability as you move up the body. The ankle joint needs to be mobile, while the knee joint needs to be stable. The hip also needs to be mobile. As you follow the chain up, a simple, alternating series of joints appears.
When designing a functional workout, think about what joint the movement targets. The mobile joints need to be addressed during the warm-up sequence with rolling, stretching, and mobility work, while the stable joints are addressed during strength workouts. In essence, the joint-by-joint approach gives us targets to aim for in specific aspects of functional training.
It should be clear that injuries relate closely to proper joint function, or more appropriately to joint dysfunction. The most important concept to understand is that problems at one joint usually show up as pain in the joint above or below.
The simplest example is the lower back. It seems obvious based on the advances of the past decade that we need core stability, and it also should be obvious that many people suffer from back pain. But why do we have low back pain? Is the back weak? Stuart McGill has frequently said at seminars that people with back pain actually have stronger backs than people without back pain, so weakness is not the culprit.
In the past back pain has been blamed on a weak core. There is no strong evidence for that case, either. I believe low back pain is primarily the result of loss of hip mobility. Loss of function in the joint below (in the case of the lumbar spine, the hip) affects the joint or joints above (lumbar spine). In other words, if the hip can’t move effectively, the lumbar spine will compensate. We know the hip is built for mobility and the lumbar spine is designed for stability. When the supposedly 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).
Looking at the body on a joint-by-joint basis beginning with the ankle, this thought process seems to make sense. An immobile ankle causes the stress of landing to be transferred to the joint above: the knee. In fact, I think there is a direct correlation between the stiffness of the basketball shoe and the amount of taping and bracing that correlates with the high incidence of patellofemoral syndromes in basketball players. Our desire to protect the unstable ankle comes with a high cost. Many of our athletes with knee pain have corresponding ankle mobility issues. This knee pain often follows an ankle sprain and subsequent bracing and taping.
The exception to the rule seems to be at the hip. The hip can be both immobile and unstable, resulting in knee pain from the instability (a weak hip will allow internal rotation and adduction of the femur) or back pain from the immobility. How a joint can be both immobile and unstable is the interesting question. It seems that weakness of the hip in either flexion or extension causes compensatory action at the lumbar spine, while the weakness in abduction and external rotation (or, more accurately, prevention of adduction and internal rotation) causes stress at the knee.
Poor psoas and iliacus strength or function will cause patterns of lumbar flexion as a substitute for hip flexion (see figure 5.12). Poor strength or activation of the glutes will cause a compensatory extension pattern of the lumbar spine that attempts to replace the motion of hip extension.
Figure 5.12 Poor psoas and iliacus strength or function will cause patterns of lumbar flexion as a
substitute for hip flexion.
Interestingly enough, this fuels a vicious cycle. As the spine moves to compensate for the lack of strength and mobility of the hip, the hip loses 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.
The lumbar spine is even more interesting. The lumbar spine is clearly a series of joints in need of stability, as evidenced by all the work in the area of core stability. Strangely enough, the biggest mistake I believe we have made in training over the last 10 years is engaging in an active attempt to increase the static and active range of motion of an area that obviously craves stability. I believe most if not all of the many rotary exercises done for the lumbar spine were misdirected. Both Sahrmann (2002) and Porterfield and DeRosa (1998) indicate that attempting to increase range of motion in the lumbar spine is not recommended and potentially dangerous. Sahrmann states: “Rotation of the lumbar spine is more dangerous than beneficial and rotation of the pelvis and lower extremities to one side while the trunk remains stable or is rotated to the other side is particularly dangerous” (72).
I believe our lack of understanding of thoracic mobility has caused us to try to gain lumbar rotary range of motion, a huge mistake. The thoracic spine is the area we seem to know least about. Many physical therapists seem to recommend increasing thoracic mobility, and I think we will continue to see an increase in exercises designed to increase thoracic mobility. Interestingly enough, Sahrmann advocated the development of thoracic mobility and the limitation of lumbar mobility.
The glenohumeral joint is similar to the hip, meaning it is designed for mobility and therefore needs to be trained for stability. The need for stability in the glenohumeral joint presents a great case for exercises such as stability ball and BOSU ball push-ups as well as unilateral dumbbell work.
Hyman and Liponis (2005) perfectly describe our current medical system’s method of reaction to injury. Icing a sore knee without examining the ankle or hip is like pulling the battery out of the smoke detector to silence it. Pain, like the sound of a smoke detector, is a warning of some other problem.