Hi Physiofi,
Through my experience with patients I think they may be some link between hypermobility and whiplash associated disability. Below is just my thoughts on this, feel free to disagree or discuss.
Whiplash can be messy to recover from and seems more strongly affect those who are more mobile in the neck.
Why?
-Possibly because if there is more movement to control at each joint, the muscles have a harder time maintaining postural control and are thus more susceptible to trigger points and muscle fatigue.
-Related to this point- joint pain can occur when muscle control is suboptimal and there is joint subluxation or excess end of range loading.
-Another thought is that the whiplash itself may have increased your cervical mobility through the accident itself, through stretched or torn ligaments. If ligaments and muscles are damaged from the accident, this is decrease your sense of proprioception through altered joint and muscle receptors and make it easier to take joints past their natural comfortable limit resulting in abnormal loading(think of a sprained ankle).
So with these points in mind, probably the most important thing to improve is your postural control. Improved postural control will decrease abnormal muscle and joint loading and pain signals going into the brain and hopefully break the pain cycle.
Pay close attention to head, neck and shoulder posture as well as making sure that the whole body posture is good. Pay very close attention to your posture throughout the day and see if you can find any links to tasks and your pain-there are usually more than you would think.
Do proprioception exercises for your neck eg writing letters with your nose, doing deep neck flexors exercises. Trigger points and muscle releases are good- especially infraspinatus and subscapularis however don't forget to strengthen appropriate muscles as well or the trigger points are likely to return.
Hope this helps