Narrator: This is Science Today. Heavy loads on the spine may actually alter the physical structure and biologic activity of the discs, which are gel-filled cushions between bones and the spine. Jeffrey Lotz, director of orthopedic surgery at the University of California, San Francisco, found there's a correlation between heavy lifting and cell death in the disc.
Lotz: Just that observation is interesting because it might allow us in the future to design lifting regimens which minimize the toxicity to the spine.
Narrator: Disc degeneration is one of the most common causes for low back pain and occurs when the discs - which normally attract water - become dehydrated and lose the ability to sufficiently support forces in the spine.
Lotz: A good analogy is that in the spine, the forces are really carried by pressure just like with a tire, the weight of your car is carried by air pressure. And so if you deflate a tire, the only thing that's left to carry the loading is the outside of the tire and the same thing happens in the disc.
Narrator: Lotz says future studies may eventually lead to re-inflating these discs through biologic repair strategies. For Science Today, I'm Larissa Branin.