From Job's Body, Chapter 8, "The Sense of Effort" we continue to see anatomical descriptions that shed light on the sensations that are felt during tai chi movement.
   Tai chi principles can seem to be obscure directives lacking any concrete basis.  First the translations from Chinese to English are lacking in full meaning.  Use Intent rather than Force, Seek Quiescence, Balance Inner and Outer Energy may have meaning, but are open to a great dal of interpretation.  Each Grand Master's description or experts interpretation may expand the concept or narrow the focus randomly.  I will use just one such interpretation to illustrate the obscurity and then suggest that the bodies "Sense of Effort" is integral to all.

The sensory feedback that comes from the musculature is below the level of consciousness.  See pages 248-250 for full examples of how the muscle spindles and golgi tendon organs, along with the cerebellum and brain stem ganglia, create a sense of effort that is the essence of our reality of time, space and self.

I have moved on with the reading so will just summarize by saying how strongly the tai chi principles are supported by the fact that the sensory cortex is responsible for organizing the muscle memory that allows us to be so precise in repeating learned movement.  It would seem that the muscle cortex would do this job, but in fact, the muscle cortex takes its cues from the sensory cortex and just carries out how we feel when we move.
The Taijquan principles of:"Use intent rather than force," "balance inner and outer energy", and "seek quiescence" all are indicative of the sense of feel that initiates movement, coordinates it and allows for its smooth execution.

The case to eliminate the very concept of "STRETCHING"

Everything I read adds to my belief that "stretching" for whatever reason is not a beneficial practice.  Certainly some individuals can do stretches that feel good, but, I am convinced that there is little benefit to extensive stretching for the following purposes.
---increased range of motion
---injury prevention
---enhanced performance
---life enhancing practice

I will offer instead that one should increase functional range of motion only by enhancing stable
bio-mechanically efficient alignment.  What this means is that you need to first be in alignment, then have the strength to maintain that alignment as you move through the desired range of motion.


Supple Leopard presents a full description of concepts and movements that maximize alignment and mechanical efficiency, while releasing tension blocks at the joints through mobility enhancement.   "Bracing" as presented in "Supple Leopard" is integral to maximizing mechanical efficiency, without the use of stretching, as it is known in the old paradigm.

Tai Chi Chuan, as a movement system, is, at its core, a health practice that enhances strength in alignment and release of tension through movements that are designed to "extend to engage and open, rotate to release and loosen" all muscles, tendons and ligaments and other supporting connective tissue at the joints as well as throughout the myofascial sheath.
This is what stretching should be.  Visualize a cat rising from a nap, arching its back and undulating its torso, finishing with a quiver that extends outward through the legs and tail.  This "Cat Stretch" is what tai chi chuan is doing throughout the form.

The human body as a tensegrity devise responds to aligned movement with instant adaptation throughout the body.  The tai chi adage that "when one thing moves, everything moves" directly relates to tensegrity, in that, any force exerted, at any point, on a tensegrity devise is expressed everywhere throughout the devise, instantly.
In Job's Body, in the chapter on "Muscle as a Sense Organ", is a description of the change in muscle tonus, throughout the body, in response to any movement.  Clearly understandable in imagining the change in balance when raising an arm to the side, it is less obvious when considering the changes throughout the body as a result of a shifting of the gaze.
I am using this description of tensegrity and muscle tonus adaptation to support the notion that stretching should be nothing more that a full body adaptation to the changes that take place during movement, and particularly beneficial when the movement is in alignment.
When movement is out of alignment, tension must take place to prevent damage to the bodies support structure (muscles, joints, tendons, ligaments, and other connective tissue).  Extreme tension results in "faults" as defined in Supple Leopard, with traumatic injury or long term wear and tear the eventual result.
On the other hand, movement in alignment with the necessary supporting strength, can result in a loosening of the support structures and removal of blockages of circulation of all bodily systems needed for supporting a health life.

How does Yoga fit into the definition of stretching?  I am no yoga expert and would welcome hearing from one, as to how yoga accomplishes the positive definition of stretching.  I know enough to know that one of the health objectives of yoga is to enhance the free flow of Prana (qi) through the body.  Asanas are meant to create the ideal environment for this to happen, by releasing tension and removing blockages, much as described above with tai chi chuan.
Like any movement system, including tai chi chuan, incorrect application of the system eliminates the maximum benefit and can be counter productive, even causing injury.  My belief is that yoga asanas should never exceed functional range of motion with correct alignment.  At that point, the focus should be on release of tension, in alignment and never taken beyond that.  Over time, the functional range of motion should increase.  Trying to imitate the extreme position of the advance yoga practitioner, is counter productive and dangerous.  This is also true of tai chi chuan in trying to imitate the low movements of the advanced teacher or the Grand Master.

The Alexander Technique to a case study in bio-mechanical efficiency.  The "Use of the Body" written by F.M. Alexander defines the a way of reaching functional efficiency through proper biomechanics.  The release of tension that accompanies the natural realignment of the body can then be seen as path to correcting a wide range of afflictions ranging from muscular and structural pain to mental dysfunctions.  Nowhere in this system have I seen any mention of stretching as an aid to this process.

Just because it is fun to do, I will throw in my word play regarding stretching:
---We stretch the truth, when we lie.
---We stretch our budgets, when we are short of funds
---We get stretch marks, "whenever".
---Our clothes can get stretched and then do not fit anymore
---You stretch a rubber band and it snaps back