I never thought my neck muscles were spasmy either, until my PT was able to loosen them up. The issue is sometimes a matter of balance between right and left.

I would try to feel my neck or shoulder muscles and find nothing out of the ordinary. Then, she would see me and her first touch would put me in agony for a few seconds. Only spasmed muscles respond like that. My chiro who used kinesiology, could do a similar thing. After getting the muscles to relax, he could do wonder to the joints.

Seeing, or more likely feeling is believing. There are many believers on this forum.