Practical Science on Movement and Pain
Practical Science on Movement and Pain
This post is about using awareness of your skeleton as an aid to finding the most efficient movement patterns. In the Feldenkrais Method, students are encouraged to develop skeletal awareness by visualizing their actions in terms of the movement of the bones. In Z-Health, students are instructed to perform exercises while attending to “bone rhythm” as opposed to muscular contraction. One reason I find this interesting is that it tends to conflict with postural and movement advice we see from many mainstream experts, who often teach movement in muscular terms by asking students to, for example, suck in the navel, brace the abs, tighten the core, squeeze the glutes, etc. So why is it better to visualize movement in terms of the skeleton as opposed to the muscles?
Before addressing that, let’s go over a few points about how the skeleton functions in efficient movement. Bones have at least two important qualities. First, they can do “work” with no energy expenditure required. Just as blocks that are well stacked can resist gravity from pulling them down, bones that are well aligned can hold us up with minimum effort. This work is “for free” because it does not require muscular energy. So, if you stand with your knees straight, that is, the femur stacked right over the tibia, the force of gravity that is pulling you downward can be counteracted with a minimum of muscular effort, because the bones are stacked. However, if the knee is bent and the bones are at an angle, the tensional forces of the quadriceps muscles must be used to prevent a collapse.
The second thing that bones can do is transfer compressive or pushing forces from one part of the body to the other. This is useful for generating power. Imagine trying to throw a medicine ball as high as possible into the air. Of course you would use your legs to generate power, but how do they help? The lower leg extends and pushes into the femur, which also extends and pushes the pelvis upward, which pushes the spine upwards, which pushes the shoulder up which helps elevate the arms upward into the ball. If you did not have a spine connecting the upper and lower halves of the body, there would be no way for the forces generated in the lower half to reach the upper half. So, bones are better than soft tissues for accurately and efficiently transferring pushing forces, which is why you would rather play pool with a femur than a chicken breast.
Of course, the bones will only effectively communicate forces through the body if they are well aligned. Let’s say you want to transfer force from your legs to your hand. There is a certain angle that the femur must push into the pelvis that will cause the pelvis to push into the spine. Similarly, the spine needs to be angled properly to push the shoulder to its target. Imagine flexing at the ankles to lean your weight into a straight arm to push open a heavy door. If the boney alignment is correct, the door will open with very little muscular effort, because the skeleton will transfer forces from the feet all the way to the door. The action will be perceived as smooth and effortless. By contrast, if you do not lean forward, and bend your elbow while pushing, the potential forces generated from the body weight and pelvis are lost, and you must use a significant muscular force in the triceps and/or pectorals to open the door. The action will be perceived as strained and awkward.
From these examples we can see that the alignment of the skeleton determines how much muscular force is necessary to perform a certain action. Therefore, an optimally aligned skeleton is essential for efficient movement.
Optimal alignment of the bones is also necessary to prevent wear and tear and injury. Imagine throwing a punch into a heavy bag, which will cause a reaction force to be delivered up your arm to the shoulder. If the bones are well aligned at impact, the force travels safely through the wrist, up the arm, and through the shoulder socket and scapula, and then to the spine and down to the pelvis and feet. What happens if the upper arm is poorly aligned in the shoulder socket? All the force will be absorbed in the shoulder joint instead of moving through the joint, and the joint will probably be injured. Imagine the horrible clanking feeling of a golf club in your hands when you hit the ball off center. You failed to transfer your force into a powerful movement of the ball, so the force was dispersed by movement of the golf club, causing it to vibrate in your hands in a uniquely humiliating way. On the other hand, if you really connect with the golf ball you feel almost no impact in your hands at all, because all the force has passed through to the ball. The same principles apply when you align your bones properly and deliver forces through your bones and out into the environment instead of leaving some of the forces in your soft tissues to rip them up.
It should also be noted that unlike the soft tissues, bones benefit from having compression forces pass through them. This strengthens them up and keeps them healthy. Astronauts who get out of the field of gravity and don’t experience compression forces in their bones get osteoporosis very quickly. Inefficient movement that does not use the bones for their proper purpose will have the same effect in the longer term.
So, the basic principle is simply this – your skeleton is capable of doing lots of work for free, that is, with minimal muscular work required. The more work the skeleton does, the less work needs to be done with the muscles, the less wear and tear on the joints, and the healthier the bones. Therefore, visualizing the position and orientation of the bones as you move will assist in proper skeletal alignment, which will assist in movement efficiency and health. By contrast, focusing attention on the contraction of certain muscles while moving will tend to put you in the mind of creating excess muscular effort to move, which is contrary to the goal of increasing efficiency. In efficient movement, the sense of effort tends to disappear, even when the forces generated are high. Trying to feel the contraction of a certain muscle during movement is counter to this goal.
Let’s take a few examples. People are often instructed to suck in their abs for better posture. Although the abs must certainly be active to a certain degree to have good posture, so does every other muscle in the body. Singling out the abs for attention will likely cause more tension than is necessary in this area, which will make breathing and smooth movement harder. How can you cue posture from a skeletal perspective? You could imagine stacking the vertebrae one on top of the other and lengthening the spine from the tailbone through to the crown of the head. This action will necessarily tone the abs, but no more so than necessary to create the result. It will also appropriately relax and/or tone every other muscle in the spine, instead of just focusing on the abs.
Muscular visualization is even more problematic in the context of movement, because the complexity of muscular action during any movement is mind boggling. For example, what is the first muscle to fire when the arm is lifted straight in front on the body? The deltoid? One of the rotator cuff muscles? No, it’s the soleus, located in the calf! The soleus needs to fire to prevent you from falling forward when the arm unbalances the body by moving out in front of the center of gravity. The point here is that muscular contractions are so fabulously complex and often counterintuitive, that hoping to visualize or understand movement in these terms is hopelessly confusing. By contrast, a skeletal description of this movement is simple. Lifting the arm to the front requires flexing at the shoulder joint so that the arm moves from a vertical to a horizontal position. That’s it, I have (almost) completely defined the movement with one variable. If I was to fully describe this movement in terms of the force, length, timing and sequence of muscular actions, it would be a PHD project.
So how would we imagine squatting in terms of the movement of the skeleton? You can pay attention to the movement of the pelvis (back, down, and tilting forward), or tibia (vertical to about 30 degrees forward) or femurs (vertical to horizontal). Visualizing the movement of the femurs is probably easiest. They start in a vertical position and rotate until they are about horizontal. The axis of rotation is near the middle of the bone. There is a smooth rolling motion at the hip and knee that allows the femurs to move with respect to the pelvis and tibia.
Try squatting while imagining the movement of the femurs. Are they both doing the same thing? Does one femur roll in the hip better than the other? Does one femur move outward or inward or forward or back more than the other? Asking these questions about bone position will give you more information about the quality of your squatting than trying to determine which muscles are firing when. After a few reps paying attention to the movement of the bones, see whether the action feels smoother, more clear and efficient than your habitual way. Feel any better? When did your glutes fire? Who cares? As long as you took your bones where they were supposed to go in a smooth motion, the glutes did what they were supposed to do.