There are various ways to strengthen the neck in yoga but it’s important for women to bear in mind that they have relatively small upper bodies and their necks are often not as strong as men’s are, so they are more prone to neck injury – this does not mean that women cannot develop upper body and neck strength, only that they need to be patient and practise neck and shoulder strengthening regularly. A gung-ho attitude on the part of students or teachers will lead to injury.
The front of the neck is strengthened in abdominal exercises which lift the head and shoulders. If you do this kind of abdominal exercise, the back of the neck needs strengthening as well. Bridging is often done after ab-work and the back of the neck can be strengthened by bridging on your head, as in Matsyasana. The correct way to do this is by lifting into it with your hips and legs, NOT by attempting to lift your shoulders up with your neck. This is a good preparation for Setu Bandhasana.
Matsyasana and similar variations all strengthen the neck but Sirsasana is better for shoulders and neck and is the starting point for Mukhta Hasta Sirsasana variations and Pincha Mayurasana, etc.
The muscles at the back of the neck are usually stretched in Salamba Sarvangasana, Halasana, Pindasana, etc. but it is also useful to stretch the neck to the side as well as turning the head 45 degrees to the side and bending it forward, to stretch Scalenes and upper Traps. These kinds of stretches are always done upright, never in inversions such as Halasana, Salamba Sarvangasana. It is also better to stretch the front of the neck by turning the head to the side, rather than by rotating the head backwards – this puts pressure on the facet joints of the vertebrae.
Kim, 2004, Ultimate Flexibility
Sharkey, 2008, The Concise Book of Neuromuscular Techniques
Neil-Asher, 2005, The Concise Book of Trigger Points