Much is known about the injury mechanisms of concussion injuries in the acute phase, but there is little evidence to support many of the theories regarding postconcussion syndrome (PCS). A potential, and very treatable, cause of this chronic condition is cervical spine dysfunction due to co-existing whiplash-type injury. Based on previously established tissue injury thresholds, acceleration/deceleration of the head and neck sufficient to cause traumatic brain injury is also likely to cause injury to the joints and soft tissues of the neck. It has also been well established that injury and/or dysfunction of the cervical spine can result in numerous signs and symptoms synonymous with concussion, including headaches, dizziness, cognitive as well as visual dysfunction. Given our current level of evidence, skilled, manual therapy-related assessment and rehabilitation of cervical spine dysfunction should be considered for chronic symptoms following concussion injuries.