The reason for that is that bolsters are on the equipment list B.
SIyengar has recommended for safe practice.
There are literally numerous ways to use your bolster to enhance your ability and safety in practice, not even mentioning making you feel more free and easy-going while going into postures.
Doing your yoga postures leisurely will allow you to put more concentration on your breathing and muscle awareness, giving you the best conditions to get deeper into your practice.
One of the main fear-blocks people have with yoga is head stands.
In this position, that demands stamina, strength, balance and concentration, the yoga bolster-comes to our aid.
Placing your bolster on the wall, using it as a pillow to lean on when entering the pose takes away some of the fear some of us feel when thinking about standing on our hands.
It allows a comfortable leaning area, that goes along the entire spine, and helps us with our balance.
It also allows us to gradually leave the wall, as we hold our mulabandha (our lower stomach belt) and stretch our legs up to the sky, while breathing calmly and keeping our backs straight.
Using the bolster for this position is an excellent way to start practicing head-stands without fear and in a safe way.
Another reason to use a bolster is for shoulder stands.
One of the shortest muscles group we have is our neck muscles.
In most people, the back of the neck is nothing but flexible, and the pressure we put on it while doing a shoulder stand (Sarvangasana) is sometimes dangerous to the spine, especially C7-T1 segment of the spine, which is where the neck meets the back.
Using a bolster correctly, allowing our shoulders some leverage, will greatly lower our chances of injuries.
These spinal injuries usually happen with time, as with each shoulder stand we put more pressure on the vertebrae, slowly damaging it.
It is highly recommended to use a yoga bolster in this position, regardless of you being a beginner or a yoga teacher.
People tend to hold their trouble in the shoulders and their neck, and so even if you are very flexible, these areas tend to get stressed and hard to move around freely.
Having a bolster is important and healthy, but it is also good outside the studio and of your yoga mat.
You can use a bolster as a pillow, when you relax at home, reading a book or meditating.
It is easy to wash and keep clean, as most bolsters could be empties from their content within a few seconds, and washed in the machine.
You can use it in the sweaty yoga studio, or practicing at home, yet keep it clean for leisure time.
For safe practice, and for your well-being, use a yoga bolster.
Don't be shy to use it even if you are the only one in the studio putting it against the wall.
You will be a role model the health and safe practice, knowing that by giving your body the protection and support it needs, you are loving it, and it will serve you for a long and healthy life.