There will always be someone who is more flexible; there will always be another stage of a pose that is inaccessible to you because you are not flexible enough. Do you see the pathology here? Do you see the dysfunction? "Function" is a funny word. It's relatively neutral when used to mean "an activity or purpose natural to or intended for a person or thing." But "function" is mostly used with "dys" in the front to denote some kind of abnormality or impairment. After all, we rarely say, "I am in a functioning relationship." It's almost as if "function" is redundant. We only think of function or its perceived/desired effects when we notice that it has become dysfunction. (For more on this, you might want to check out Drew Leder's Absent Body.) When someone says they would like to increase their flexibility, they are most likely saying that they are experiencing some kind of dysfunction such as low back pain or inability to tie their shoelaces without feeling humiliated and hamstrung, or something to that effect.
Further, practicing with the flexibility paradigm means that we (perhaps inadvertently) practice to get to a sensation of stretching. If you have above average flexibility, this means you are probably routinely going beyond what's reasonable from the point of view of the health of your joints and ligaments (especially over the long term). If you are below or averagely flexible, what you are probably feeling is not a muscle stretching but a muscle contracting, a muscle that's being pulled and telling you it's too much. What's more is that practicing in this context means that you need to practice constantly with ever-increasing levels of intensity to maintain (and potentially increase) the level of flexibility you think you need, usually at the expense of stability and well-knittedness.
Research discussed here indicates that static stretching led to increased range of motion (ROM) due to an increase in stretch tolerance (ability to withstand more stretching force), not extensibility (increased muscle length). Similar findings are discussed here. A review of this latter study asks a very important question, which many are trying to answer:
"...[I]f there is a reduction in sensation at a given joint angle without modification of the mechanical properties of the material [i.e., increased muscle length], this may imply that the joint ROM between the point of onset of pain and the point at which the muscle tears from being overextended is reduced. This joint ROM might be described as a “safety margin” during which the individual is aware of a strong sensation of pain and acts to reduce this pain. Reducing the size of this safety margin could potentially be detrimental to the risk of injury in certain sports, although studies are needed to assess this hypothesis."The implications of this for long-term asana practice (focused on defining progress as the ability to execute more advanced postures) invite the need for serious consideration and reflection on the part of both yoga pedagogy and practice.
When we practice with the idea of creating space in the flesh, the mathematical meaning of function makes the most sense: "a relationship or expression involving one or more variables." In this case, making flexibility the main or only variable in our practice negates the very meaning of function, because the human body is not a function with only one variable.
Concentrating on flexibility also encourages us to think linearly, almost unimaginatively, such as for example, "increasing the distance between point A and point B leads to stretching leads to flexibility." The human body does not work linearly. We are like a Pollock painting inside and not like a Mondrian poster.
Promoting flexibility as a virtue in yoga or a goal of one's practice gets our mirror neurons in overdrive at the expense of pausing to allow for perception and paying attention to the flesh kinesthetically (in space) and proprioceptively (felt sense of internal movements). Perception to our internal and external environment, in essence orienting ourselves, is a sort of pre-movement itself and as such is essential for movement education in asana practice, or dance and other similar activities. The flexibility ideal encourages a focus on a form, a shape, a pose, a snapshot in time.
Practicing yoga to create space promotes function, movement, connection within and without. As Matthew Remski recently taught in his excellent Ayurveda course (that I am currently taking), (paraphrasing) "Virtually every therapeutic action involves the addition or sculpting of spaciousness in the spine, joints, sensory, organs, etc." Further, it is "in perception [that] space conjoins."
It is in perception that we contain and can make sense of the infinite spaciousness within, and in perception that we realize that space contains us.
