Final answer:
Adjusting the head restraint to be level with the top of the ears is important in reducing the risk of soft tissue neck and back injuries during a rear-end crash.
Step-by-step explanation:
Adjusting your head restraint so that it is at least level with the top of your ears is important in reducing the risk of soft tissue neck and back injuries during a rear-end crash. When a rear-end crash occurs, the headrest helps to support and align the head with the spine, preventing excessive backward movement and reducing the impact on the neck. This positioning helps to protect the anterior longitudinal ligament and reduces the chances of whiplash injuries.