This ALL occurs in less than 500 milliseconds. You cannot voluntarily contract your muscles this fast, which means even if you had time to prepare yourself for the impact, you can’t stop the whiplash effect!
It’s been found that muscles in the front of the neck contract first at about 100 ms, which is 25 ms too late to prevent ligament or muscle damage, and they reach their peak stretch at 150ms (see 3rd from the left picture above). The muscles in the back of the neck start contracting soon thereafter but are injured more than the muscles in the front of the neck around the 300ms point. The reason for this is because as the head rebounds forwards, the muscles in the back of the neck are in the process of tightening up or shortening at the same time they are being stretched (your body's attempt to protect itself under normal forces) but NOT a good combination under the excessive G-Forces experienced during a car crash.
This is one reason why many people injured in MVAs often complain of greater intensity of neck pain in the back of the neck than in the front of the neck. Patients often present to our office following a car accident with neck pain in the front, sides, and back of the neck, and in more severe cases the pain will radiate into the shoulders, arms and even to the hands and fingers, indicating injury to the deeper spinal nerves.
This also helps explain why headaches are common symptoms associated with whiplash as the upper 3 nerves that exit the top of the spine in the neck go into the head/scalp and are compressed or squeezed by the tight muscles in the back of the neck when they are injured which results in headaches. The spinal discs can also be injured by whiplash, requiring proper diagnostic studies such as an MRI.
Whiplash and Whiplash Associated Disorders (WAD) can be quite serious and debilitating. They should be taken seriously and anyone suffering from auto accident related injuries should be seen by a physician who specializes in such injuries. Too often, a primary care doctor will simply prescribe pain medication and some rest, ignoring the potential severity of their patient's symptoms following an accident, neglecting import treatment that could save the patient from future pain and disability.