Do you say that in class?
If you do I’m not saying it’s wrong, but I’d like to offer you a different perspective.
Unless you’re teaching a group of super fit, flexie, young yogis and yoginis, then you have students in your class that probably don’t need to engage in more extreme neck extension.
Many people have a forward head carriage. They jut their head forward of their shoulders to the detriment of the health of the cervical vertebrae (C1-C7). This tends to happen when we drive, text and sit at computers hours a day.
The C1 and C2 vertebrae are blessed with unique functions: C1 is the Atlas - it holds the weight of our skull. C2 is the Axis - its job is to foster the turn of the head from side to side. These very important vertebrae have very important ligament structures protecting them.
When there is chronic forward head carriage there is often chronic calcification of the ligament structure as well. This calcification can cause reduced mobility, neck pain, headaches, insomnia, even hormonal imbalance.
Students suspected of having this structural misalignment should be encouraged to do jhalandara bhanda - drawing the chin in and lengthening the back of the neck instead of lifting the chin and shortening the back of the neck. This may help to elongate the cervical spine, encourage greater prana flow, and reduce calcification.