Pandiculation and Muscle Repositioning

Pandiculation and Muscle Repositioning: Pandiculation is the name given to the behavior of yawn and stretch. Some studies were done on this subject, whose functions still remain unclear. Interestingly, the tonic activity that we detected by electromyography during MR maneuvers has been accompanied by a subjective experience similar to pandiculation-type of stretch. In addition, some clients have reported the resumption of the habit of pandiculating in the morning, behavior that had unconsciously been abandoned. Furthermore, such behavior was associated with a state of well-being and had helped in improving the pain of which they reported.
A possible function of pandiculation: The hypothesis that we raise from these observations is that the ubiquitous behavior of pandiculating helps maintain the integrative function of the fascial system by: (a) mechanical signaling the connective tissue metabolism (mechanotransduction) to reinforce the collagen links that unites the segments to one another, as when one pandiculates, (b) the redistribution of free water (water that can flow) in the extracellular matrix. This latter effect stabilizes the joints and thus also increases the degree of integration, among other hypothetical mechanisms. Noteworthy is the difference between the pandiculation-type stretch, which arises spontaneously, is pleasurable and increases joint stability, with the regular stretching, which is produced by a volitional action, may produce displeasure and joint instability (because of this, stretching has been contraindicated before physical activity).
Pandiculation, evolution and musculoskeletal disorders: Pandiculation occurs in almost all animal kingdom, even in fish. It is believed to have a role in the development and maintenance of the musculoskeletal system ([1], [2], [3]). Human fetuses are already moving in this way in the womb and children continue to do so. But as we become adults we tend to pandiculate less and less frequently. Would culture and education be responsible for the progressive abolishment of this behavior? If so, could this inhibition be related to the high frequency of functional musculoskeletal disorders in humans?

references:

[1] Fraser AF The phenomenon of pandiculation in the kinetic behaviour of the sheep fetus. Appl Anim. Behav. Sci, 24:169-182, 1989.

[2] Fraser AF Pandiculation: the comparative phenomenon of systematic stretching. Appl Anim Behav Sci, 23:263-268, 1989.

[3] Walusinski, O. Neurofisiologia del bostezar y estirarse: su ontogenia y filogenia. Electroneurobiología, 14 (4):175-202, 2006.