The fish pose is a pose in supine (face up) where one initially leans on the elbows to allow the shoulders to roll inwards underneath the back. Slowly the hands slide lower towards the buttocks and move centrally. When more advanced the hands can be placed on top of each other (hand palms down). The shoulders are challenged to roll in internal rotation and are encouraged to depress and retract:. The rhomboids work, the trapezius is relaxed and stretched. The cervical spine appears more than ever, with the muscles on the front stretched completely. These are all positions which are beneficial for extension and straightening of the back.
From a physiotherapy point of view I like this pose, because it stimulates the client to extends the back in both a longitudinal way (along the spine) as well as in a transverse way. It is the active brother in relation to the passive sister pose, backwards over the Swiss ball and stretch completely relaxed. The spine extensors are a big group of muscles which love to bend all three ways, even sideways. We move three dimensional.
Our thoracic spine is the most immobile part of our spine because the ribs form the protective cage around our heart, vital organs and part of the intestines. The cervical spine is most mobile followed by the lumbar spine. We still need to move it all directions, so it is a nice treat for your body to counteract the rounded shape which we tend to create in our thoracic spine when we work, bike-ride, sit in the car, behind a computer or stand.
So after we have positioned the arms and shoulders we are going to lift ourselves up through the sternum. This stretches our Pectoralis muscles and opens up the chest by pulling it up and lifting the ribs. This semi inversion tips the chest over to the top of us. The rib cage automatically lifts up, and we can focus on letting the breath happen deep in our abdomen. The Psoas muscle works through the lift of the hips. In variations w also lift the legs and come into a V-shape.
We then tip the head back and lean on the top so the position becomes most effortless. The anterior part of the neck stretches out. If you find the pose too strenuous and you need to ease yourself into this, try lying on a bed or table and position a chair or bench on the top-end so you can let your head hang down supported. You can roll up and towel and place this between your shoulders LENGTHWISE OR TRANSVERSE. This pose is slightly more passively done, but a good start to get yourself used to the active one.
The fish pose id usually done in the end of a yoga session and might or might not be accompanied by a big sigh out to stimulate the Ujayi breath. This can be perceived as weird, but it is a freeing move and worth a try. Our facial muscles love to be re-positioned and I often think yoga for the face is more beneficial than having a pot of night creme, Botox or other expensive short lasting remedy.
Nothing wrong with being a bit fishy now and then. Enjoy.