Your spine if very precious and important! Don’t risk injuring it with neck bridges.
Bridges are traditionally used by wrestlers and boxers to develop strength in their neck. A strong neck can help to reduce the risk of concussion and also reduce the risk of an injury to the neck during competition.
Neck bridges certainly work for developing huge neck muscles, but they also compress the discs in the cervical spine. This can lead to acute, and/or chronic injuries to the neck including prolapsed (or herniated) discs – which can literally lead to constant pain for the rest of your life. No joke, if you ‘pop’ one of the discs in your neck, it can cause all type of nerve problems, often meaning that you lose strength in one of your arms.
Bas Rutten & Kurt angle had neck problems, that caused one of their arms to pretty much waste away due to nerve issues.
Using bands or even manual resistance (i.e. your own hand) can be a great alternative to neck bridges.
For example, you can simply place both hands on your forehead, and push back and forth (slowly) as you nod your head backwards and forwards against the resistance of your own hands. This can also work well with a band.
You can then repeat this exercise but with a lateral-flexion – i.e. moving your right ear towards your right shoulder and then your left ear towards your left shoulder.
Isometrics are also safer than neck bridges. Push against your hands or even a wall with your forehead for 20 seconds. Start with your head already against the wall, you shouldn’t move at all, just push against it without actually moving!
If you still really want to bridge, there are a few modifications which make it a bit safer. For example you could use a bench, or even a stability ball (this is still not ideal and still risky):
The other weird thing people do is bite on a towel and hang weights on it, and then flex and extend the neck. If you can afford the dentist and a gym, it might have some merit. Anthony Joshua is doing this below – it should be more slow and controlled, the weight is too heavy and he is risking an unneccessary injury:
The Iron Neck is probably the safest way to strengthen the neck: