The semi-supine active resting position gives optimum support to your whole back – and to your spine in particular. Alexander Technique teachers recommend it as a daily practice. Do it once a day if possible for up to twenty minutes. As well as easing your posture it is particularly calming and centering. Youtube video clips, picture and written instructions are below…
It only requires a firm and warm surface, such as a blanket on the floor, and a few paperback books to serve as a headrest. It will help you to let go of excessive muscular tension in your body as a whole. It allows your torso to widen and your spine to release into its optimum resting length. It eases and reduces pressure on the inter-vertebral discs by placing the spine in a position of maximum mechanical support.
Most people need somewhere between 1 – 3 inches of books underneath the back of the skull. The head-rest encourages release in the muscles that join the back of the neck to the base of your skull. It should be neither too high (or your chin will compress your throat) nor too low (or your chin will stick up in the air). This gives maximum support to your spine. Your feet are flat on the floor, knees pointing up to the ceiling about shoulder-width apart and your hands can rest gently on your torso. It’s the ideal pre-cursor to some voice-work. No wonder my ex-drama students continue to practice it daily decades after being introduced to it!
Over the next ten minutes or so you will simply develop your relationship to the floor and head rest… Imagine the four ‘corners’ of your back–head, shoulders and tail bone– spreading and lengthening and widening away from each other and on to the floor. Let go of trying and forcing. Let it be effortless. Leave it up to gravity and muscular release. Look at the video several times to get a general idea of how to get into the semi-supine position. The main thing to remember about getting into the semi-supine position is to do it mindfully, quite slowly and with awareness. The same thing goes for returning to your feet again. I’ll go into a bit more detail in future postings.
Alan Mars - coaching in Brighton & Hove 
Won’t the books hurt the head a bit, especially at the edges? Can we use something else to rest our head upon?
Apologies for slow reply. Try it out and see! The vast majority of people find it very comfortable. If necessary simply fold up some fabric, like a scarf, and lay it on the books. This way you will get a firm supportive headrest that isn’t too hard. High density foam rubber blocks are also popular.
Not necessarily- but it’s fine to put something soft on top of the books such as a soft scarf or a thin layer of foam.