What Causes Goose Bumps Across The Shoulders After A Neck Injury?

Hi, i am 30 and a few days ago i jarred my neck and was in some amount of pain for a couple of days. The pain is easing off now but i have developed a goosebump effect across my shoulders that has been permanantely there for a couple of days now.

Do you know what this could be?

Thanks

Nikki