“Spine is like a windmill generating electricity.” – Sperry
Postural Yoga (i.e. the practice of physical postures and breathing exercises) in the world of therapy often tends to be viewed narrowly as a physical therapy aimed to improve muscle tone, coordination and flexibility. However, this perspective is changing. For example, Yoga is becoming popular as an effective therapeutic tool in trauma treatment. van der Kolk gives an excellent account of this.
Those who practice Yoga in its true spirit know that it has an “integral” effect on body and mind spanning cognitive, behavioural and emotional planes. Evidence from evolutionary neurobiology seem to shed light on how some of these effects come about.
Nervous system evolved bottom-up along with purposeful movement. Complexity and size of nervous system, in particular the brain, appears to be correlated with the complexity of movement. Even apparently simple movement like walking is quite complex given the possible combinations of muscle groups involved. Planning ability required by execution of such movements possibly evolved into higher cognitive functions. Llinas outlines this beautifully here.
Stimulation is essential for the health of nerve cells. Deprivation of stimulation results in degeneration of nerve cells. One source of stimulation that is always present is gravitational force. The mere act of standing up forces us to deal with gravity and in turn, stimulates the brain. Movement in general stimulates the brain through sensory receptors in muscles and joints. Interestingly, the receptors are not evenly distributed in the muscles and joints. Greatest concentration of receptors for muscles and joints are found along the spine and even here, the density of receptors increase closer to the top of the spine, making it an important conduit to stimulate the brain. Therefore, it is not an exaggeration to say that spine is like a windmill generating electricity. Melillo and Leisman’s book provide a comprehensive account of the evolutionary neurobiological evidence and their possible relation to neurobiological disorders.
Spinal health occupies a central role in Yoga. In fact, postural Yoga is obsessed with spine. A well constructed, balanced Yoga practice would involve spinal mobilisation in all possible planes of functional movement e.g. forward bending, backward bending, lateral bending and twisting. These movements could be done in standing, seated or supine configurations. This leads to many possible configurations of a sequence of postures depending upon the health and competency of the practitioner. AG Mohan’s book and Sonia Sumar’s book are valuable sources if you want to explore further.
Benefits of exercise, in particular aerobic exercise, are undisputed. Exercise positively affects on immune, endocrine, cardiovascular and cognitive systems. While we do not know the exact mechanics of this influence, the general stimulation of the brain from movement could be a fundamental reason. However, in practice, a safe and controlled aerobic exercise regimen is quite challenging to implement for people on autism spectrum. This is where advantages of Yoga are many. The availability of hundreds of Postures makes it easier to design a sequence that is appropriate for the individual. The sequence can be adjusted to provide progressive adaptation. The sequence can also adjusted for the time in hand. A short 10 minute practice every 2 hours is easy to implement during the day. This is a distinct advantage given that a stimulation needs to be frequent to be effective. Yoga teacher can also manually assist the individual in performing postures that are challenging and need assistance. This makes it accessible to people with low muscle tone.