My Right Shoulder Started Hurting Like I Overworked It That

My right shoulder started hurting like i overworked it that was right after i started getting crazy spasms in my lower back and down my legs. the spasms have eased but my shoulder hurts all the time-i thought it was dislocated so i went to er they said no its just overstrained,that was at least 3 weeks ago and now i notice on both shoulders it looks dark like bruised and on the right arm by the elbow its bruised and swollen a little as though i had blood taken from a new nurse or inexperienced nurse. What would cause this?