The bicycle wheel and postural tone

Let’s see how far I can stretch this analogy…

Imagine a bicycle wheel, in perfect true with its evenly tensioned spokes. Over-tightening one spoke will deform the entire wheel in three dimensions. But, if one simply loosens that spoke, the wheel will tend to return to true. Tightening all of the other spokes will also return the wheel to “true”, but it will be a less flexible “true”. A similar thing can be said to occur in human posture. In good posture, there is adaptable tension in all muscles, and all muscles interact to balance the body in movement; the work that muscles do in all actions and responses will be distributed reflexively throughout the system. In the body, there are cases in which, if there is one habitually shortened muscle, the whole system is affected, as one tight spoke affects a wheel. Unlike in the wheel, however, in human posture, when we notice imbalance, we don’t usually ferret out the tight muscle causing it and learn how to release it. If we do anything, we usually tighten other muscles to try to balance the already overused muscle – if our shoulders are rounded forward, we try to pull them back, rather than learning to not pull them forward.

Abdominal muscles as spokes

Look at an obvious example: abdominal muscles. When there is undue tension in the neck (there usually is), the body loses the ability to micro-adjust the head’s considerable weight to control balance. Hip flexors and extensors will then tend to compensate by over-working to control balance, and these muscles will, in effect, disconnect abdominal muscles, which would ordinarily work constantly to balance the action of posterior spinal muscles. But the contraction of iliopsoas muscles against glutes and hamstrings causes over-stabilization of the hip joints, and prevents the abdominal muscles from interacting optimally with their antagonists. The abdominal muscles are than no longer fully interactive within the muscular system, and they become weak. Strengthening them, at this point, will not make them effective – they will be like fat bicycle spokes with no pull placed upon them, or, worse, they can simply be tightened to the level of the tight muscles around them, and there will be further decreased mobility in the lower trunk and legs.

Note how, in the example of the bicycle wheel, an over tightened spoke will take on the work of other nearby spokes on the same side of the wheel. Those neighboring spokes will do no work. If the over-tightened spoke is loosened, the slack spokes will again be loaded, and will function as they should. However, when this happens in the body, the under-used muscles weaken, and then, when the tight muscles usurping their function are released and the under-used muscles are called into action, they are initially too weak for the task demanded of them.

Barefoot running

The new barefoot runner, even if he is doing everything well, is likely to suffer from the underused muscles called into play because of changing conditions. In particular, in the runner transitioning from heel to forefoot strike, calf muscles and tendons will take time to strengthen, especially in the already fit athlete, who will have strong muscles in the upper legs attempting to deliver their force through the weakened lower leg muscles. The tendency we see among converts to barefoot running is to attempt to circumvent the use of weak and underused muscles and tendons – they shorten their strides, avoiding both full extension of the leg at the ankle, and full forward recovery. Or, their muscles may be strong enough for a powerful extension, but not supple enough to progressively accept the body’s weight during foot-strike. If one jumps vertically, in order to get maximum height, one straightens the legs maximally. Then, in landing from the height attained, there could be no benefit to drawing the legs up so that one lands with bent knees. Nor can there be any advantage to flexing the ankles to land on the heels, even if the jumper is wearing big-heeled, cushioned running shoes. On the contrary, the more the leg remains lengthened for descent, ankles and knees fully extended, the more the impact of landing can be distributed over time, and thus, the less abrupt and potentially damaging can be the landing.

Over-stretching the metaphor

Of course, the marvel of the spokes of human posture is that they are constantly dynamic, and respond to the tension of their antagonists. To create movement at a joint, one spoke can shorten, while its antagonist lengthens. This means that the body can change shape, without losing balance in muscular tone. It is possible, though, for the brain to impose limits on the reduction of tone required for easy movement. There can be a failure of inhibition, and thus lengthening, of a muscle in order to allow for excitation, and thus shortening of its antagonist.

Now, I fear that I have entirely over-stretched and exhausted the bicycle wheel analogy, so I’ll leave it… Happy running!

The Alexander Technique is a method for learning to loosen the over-tightened spoke.

F.M. Alexander stated, “Sometimes, if you don’t do the wrong thing, the right thing does itself.”

Montreal Center for the Alexander Technique