It can take as long as 12 months for the healing process of injured soft tissues to become complete.
(Medicine and Science in Sports and Exercise, 1986)

 
• The average time for an appropriately treated whiplash-injured patient to achieve maximum improvement is 7 months 1 week. (Spine, 1994)
 
• Some whiplash-injured patients take 2 years to stabilize and to reach their maximum improvement.

(Canadian Family Physician, 1986)
(Pain, 1994)
(Spine, 1994)
(Injury, 2005)