What are sublaxations? especially in neck? can sublaxation affect muscles etc..?

Subluxations: "subluxation" means that the joints are not articulating properly and there is a slight shift in the joint alignment, but they are not dislocated. Subluxations can be a consequence of arthritis, which would cause muscle stiffness in the neck.

Subluxation: Subluxation is abnormal forward backward motion of spinal alignment. It can occur after trauma or from degeneration. Local pain is the usual presentation although if severe enough, spinal cord compression can lead to extremity weakness and numbness.