What causes slow dilation during labor? Being tense is one of the cause?

Every woman's dilation speed is different. Some women don't even dilate enough for natural birth so they have to undergo c sect. But we can try to make it easier for our bodies to dilate faster by relaxing more, getting up to walk around slowly or sitting upright , listen to music. I think the moving around or changing position helps although for some of us it will be impossible to walk around with iv drip, epidural and inducing drip stick on us.