If you do your Abdominal crunches correctly with proper form, there is no reason to suffer from neck pain or sore neck.
One of the biggest mistakes that people make is that involve there neck muscles while doing these exercises- that is a NO-NO. Bringing your head and neck forward puts unnecessary pressure on the neck and it is not healthy. So when you do your abdominal crunch look at the ceiling. In fact pick a spot on the ceiling and concentrate on that. If you keep this position you will keep your neck spine neutral, with no added pull on the neck muscles. There is no reason to be lifing your head and bringing your chin to your chest.
Also, your hand position is important. Many people interlock their fingers and place them behind the neck- change this immediately. This makes it more possible that you will involve your neck muscles. Instead place your fingers LIGHTLY behind your ears or cross your arms and hands in front of your chest. Remember to continue looking at the ceiling and not forward. If you utilize this position of your hands, you won???t pull on your neck while doing abs- and hopefully avoid neck pain
Another good point is to focus your thinking on your abs while doing these exercises. This will actually give you a better work out. Finally, don???t forget to breathe. This is very important while exercising.
Before you begin exercises, it is a good idea to do some neck exercises - some simple neck flexion extension, lateral flexion and rotation exercises will loosen you up and also prevent any neck soreness after exercise. These will help to increase mobility and range of motion in the cervical spine- decreasing the chances of get injured. -NJ