Whiplash & Chiropractic
SOURCE: ACA News
Whiplash is an enigmatic injury. We spend billions of dollars each year to treat it. Yet many lawyers, legislators, and medical doctors deny its existence. It affects millions of people around the world, yet research is severely under-funded. It is a largely preventable injury, yet we do little to prevent it. Fortunately, times are changing as whiplash enters a new phase of research and understanding.
“We now have a completely new model of whiplash,” says Dr. Arthur Croft, researcher and co-author of the well-respected textbook, Whiplash Injuries: The Cervical Acceleration/Deceleration Syndrome. “Back in 1982, when I started practice, we had an extremely simplistic view of whiplash-you got hit from the rear; your head snapped back, which may have caused damage to ligaments, muscles, and tendons; your head snapped forward, which may have caused some additional damage; and then you had symptoms. We weren’t very sophisticated in terms of what we knew, because there hadn’t been much research.”
Researchers now believe that during a rear-end collision, the lower neck goes into hyperextension, while the upper goes into flexion. “That means the bottom and top parts of the neck are going in opposite directions during the initial phase of a whiplash, which forms the letter ‘S,’” explains ACA member Dan Murphy, DC, who teaches whiplash throughout the world, including a 120-hour certification course on spine trauma. “This sequence of events has been captured with cineradiography, which lets us look at the movement of each joint of the spine with motion x-ray. It’s remarkable what it shows-especially in the lower neck where people seem to have the most complaints and most findings on examination. In a 6.5g impact, for example, the motion between C7 and T1 is supposed to be about two degrees, but researchers are finding that the joint is moving about 20 degrees – or 10 times more than it is supposed to.”
Researchers initially captured this information by using human cadavers in cars, but those who thought live humans would respond differently were skeptical. Researchers counter-argued that it made no difference because maximum injury occurs in less than one-tenth of a second. “The injuries happen so fast they beat the dynamic of the muscles that would normally protect the joints,” Dr. Murphy explains. “For the muscles to kick in to protect the joints, you need approximately two-tenths of a second.”
There are more articles like this @ our:
The criticism remained until 1999 when researchers in Japan began using live volunteers. Although researchers have used live volunteers for decades, they had not done so in this situation because of the threat of exposure to ionizing radiation from cineradiography. When changes in technology reduced that threat, ten volunteers participated in research that substantiated the earlier findings.
“The neck’s S-shaped configuration puts great stress on the facet-joint capsules and the annulus of the disc,” Dr. Murphy says. “Chiropractors treat facet-joint capsules and treat the disc biomechanically when they do spinal adjusting. We have always known that chiropractors are effective with whiplash, but there were lots of theories as to why. Now, it appears that by the very nature of what we do, chiropractors are most effectively treating the tissues injured during the accident.”