How long does it usually take for neck/back/shoulder pain from whiplash to go away?

2-8 weeks. If there are no structural injuries symptoms should resolve with stretching & strenghening exercises in 2 to 8 weeks depending o degree.
6 weeks. Book answerf or acute neck painmuscular but whiplash lasts longer ive seen it last years try everything avoid narcotics early.
Whiplash pain. There is no way to predict, how long the pain lasts depend on the extent of the injuries and responce to the treatment.So it may be a week in some cases to months in other even after meds and physical therapy.
May not without help. The time table for a whiplash type of pain can vary based upon the duration, type of injury, severity of the injury and the individual. Also depends on the therapies that you are having to try and calm everything down. Need to talk to a doctor who deals with this type of injury. Could also be a tmj/tmd issue.
6, 4, nerver. 6 months with NSAID meds, alone; 4 months with pain med, muscle relaxer, NSAID and physical therapy; never if not treated in any way.