FRIDAY, Aug. 22 (HealthDay News) -- Twelve hours of rest is sufficient for an intervertebral disc to largely recover its dynamic properties following fatigue loading, according to research published in the Aug. 1 issue of Spine.
Jaw-Lin Wang, Ph.D., of National Taiwan University in Taipei and colleagues, analyzed data from experiments using intervertebral discs from six-month-old pigs. The researchers used a vibrating motor to create fatigue loading and a drop-tower apparatus for impulse testing.
The investigators found that a 12-hour saline bath could fully restore the disc's dynamic properties after a half-hour of fatigue loading. This rest period could also restore disc dynamic properties after two hours of fatigue loading; however, during a following fatigue loading, the loss of dynamic properties was accelerated compared to the previous loading, the researchers report.
"In conclusion, the dynamic properties of intervertebral disc depend on the degree of disc hydration and integrity. During the short-term fatigue loading, the fatigue loading squeeze out the fluid within the disc, and attenuate the disc properties. After the rehydration, the disc properties can be recovered to the original status. During the long-term loading, the fatigue loading not only squeeze the fluid out, but also may have damaged the disc integrity. Therefore, although the disc properties recovered to the original status after rest because of the rehydration, the rate of attenuation disc properties during the second fatigue loading is faster than the one during first fatigue loading because of the damaged disc," the authors write.
Abstract
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