The Los Angeles Dodgers reported that their pitcher Hiroki Kuroda is back on the roster after being benched for a neck injury. A couple of months ago he was running in the outfield when he was struck down by what Kuroda called “pain I’ve never felt before.” He was taken out of the game and doctors diagnosed him with a small herniated disc in his cervical spine. He had reportedly been feeling some “tightness and discomfort” on the left side of his neck and upper back since he was beaned in the right side of his head by a baseball on August 15.

If you watch the video of the game where Kuroda is hit by the ball (see link below) you will see him pitch a ball that comes back at high speed and hits him on the right side of his head. He falls to the ground on this left and there is a brief moment where his head can be seen ricocheting toward the ground and back. This is likely where his neck injury started. This moment is an example of a side-impact “whiplash.” “Whiplash” itself is not an official diagnosis, but a term used when the head is flung too far in any one direction, and too abruptly. This most often occurs in an auto accident, but also when you get hit in the head by a ball going 90 miles per hour. This kind of injury, not uncommonly, leads to a herniated disc in the neck. Why does this happen? That requires a brief description of what a disc is and what does it mean when it herniates.

Our neck (or cervical spine) has seven bones called vertebrae stacked on top of each other. In between these bones is a cushion we call the disc. The disc is kind of like a stale jelly doughnut. It is firm on the outside and gooey in the center. This makes it great for shock absorption. When you tilt your head to the left, for example, you are putting more pressure on the left side of the disc. Now if you do it like Kuroda did, really really really fast, imagine how much more force is going to go into the disc. Probably more force than it can handle and it is likely to be damaged. So, what happens when the outside of a jelly doughnut, gets damaged? The jelly oozes out. That is essentially what a herniation is. This can be very painful when it puts pressure on the large spinal nerve root nearby.

Why, then, was it weeks later, while running, that Kuroda suffered such intense neck pain? A likely scenario is that the disc was damaged significantly when he was hit by the baseball but didn’t completely rupture. Not until, the bobbing of his head while running, last-straw-like finished it off.

Treatment for this injury varies depending on severity. Some times simple rest is recommended, other times Physical Therapy is prescribed and when conservative treatment fails, surgery can be done. Luckily for Kuroda, he is young, his disc injury was small, and he is back in the game.

To learn more about Herniated Discs, how they are diagnosed and treated click this link: http://www.cumc.columbia.edu/dept/nsg/ct/hidd.html.

Read the USA Today article: Kuroda hit by Line Drive

Photo by Ross D. Fanklin, AP

Here is a great Animated Video about the Cervical

Spine. You can see that as the head rocks side to side pressure on the disc shifts from right to left.