He secondary is developed as a maladaptive behavior in response to stuttering. When you're stuck you try things to get the word out and random things like head ticks, blinking, or arm movements may work at the time. They don't work reliably. But since they have sometimes worked in the past, you keep doing them because you never know and boom, you're stuck with a new unnatural behavior that is unproductive. So, it does have to do with stuttering because it was developed as a reaction to stuttering, but it is not native to the condition of stuttering.