Those who seek to understand how things work ask:
What effect does yoga have on one's physicality? When one assumes and holds a yoga posture, this act of stretching and bending at the joints facilitates feedback to the central nervous system. This is done by means of beds of proprioceptive nerve endings located within the joints and muscles. Proprioceptors provide information about position, direction and rate of movement as well as the amount of muscle tension in a locality.
Yoga causes the central nervous system to respond with appropriate self-regulatory measures by promoting proper bio- mechanical use.
Self-regulation and self-healing are the physiological responses of the living body. The central nervous system takes the input from the proprioceptive nerve endings and by relaxing and tightening muscles in an organized fashion allows one to hold that posture. Changing balance of any one portion of the spine requires compensatory adjustments throughout it. Muscles respond automatically to stimuli from the nervous system which controls and integrates the activity of the whole body.
Flexibility is the proper and full range of motion within the joints of the body. This is brought about by the coordination of muscle tension and muscle relaxation via the nervous ystem.
Slowly moving into a proper postural stance and holding it provides for proprioceptive feedback that allows the nervous system to coordinate muscle action. Stretching slowly protects muscle fibers and their tendons from strain while resistance set up by holding the posture increases muscle strength. Improved muscle strength and stretch provides stability, flexibility and protection to the joints.
Stimulating the proprioceptive system or massaging the nervous system is but one of yoga's benefits. The encouragement and development of proper structural alignment reduces strain on muscles, ligaments, and tendons. Proper alignment allows for better functioning of the organ systems.
Structure determines function. If body cavities are distorted, so too are the contents within. Distortion caused by poor posture changes the relationship of tissues within organs, leading to the dysfunctioning of the system. Stress, a product of the distortion, reduces circulation throughout the area.
By improving posture, yoga supports the proper functioning of internal organs by maintaining structural integrity of these systems. Proper position and relaxation of tension improves circulation. Nutrition to the whole system is encouraged by the fluctuating internal pressures generated by the different asanas. This fluctuation in pressure enhances cellular diffusion and osmosis.
Simply, motion is life! By moving us through bio-mechanically sound postures, yoga promotes a healthier life. To say that yoga only affects us physically would be denying the larger reality of our existence. However, it is the profound effect that it has on our physicality which frees us to experience the depths of our existence.