I have started learning Yoga from Desmond Dunne’s 1961 classic Yoga Made Easy – and discover that the exercise I recommend on the Bad Back page is, in fact, a pose called The Cobra (Bhujangasana):
“An exercise to make the spine amazingly supple and flexible, at the same time it revitalises abdominal muscles. Kidney, liver and pancreas are stimulated so that appetite improves and bodily heat increases. This asana is of great value to persons who do a great deal of stooping – sedentary workers and women overburdened with housework – and all who suffer from habitual backache.
“Caution: If your spine is stiff, proceed cautiously. Remember that whereas a smooth, slow stretch will benefit you, a wrench may be painful or even harmful.”
There you are. I said I’d learned it from someone else…