Effect of lumbar protective belt on prevention of low back fatigue in personnel during simulated driving / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe low back fatigue of subjects before and after simulated driving, and to study the role of the belt used in prevention of low back fatigue of drivers during driving.</p><p><b>METHODS</b>To assess the changes in median frequency (MF), mean power frequency (MPF) of surface electromyogram (SEMG), and flicker frequency, visuognosis persistence of drivers with and without protective belt in simulated driving.</p><p><b>RESULTS</b>There were significant differences in MF [(47.35 +/- 6.07), (39.26 +/- 5.79), (47.21 +/- 6.02), (43.44 +/- 6.26) Hz respectively], MPF [(69.86 +/- 7.08), (59.12 +/- 7.19), (69.86 +/- 7.08), (63.88 +/- 7.49) Hz respectively] between before and after simulated driving without or with the special belt (P < 0.01). But no differences in MF or MPF between without and with the belt before simulated driving were found (P > 0.05). The flicker frequency [(35.64 +/- 2.82), (42.31 +/- 4.68), (35.96 +/- 3.05), (39.79 +/- 3.36) Hz], visuognosis persistence (65.77% +/- 3.94%, 56.83% +/- 5.68%, 65.88% +/- 3.92%, 62.27% +/- 2.91%) had some changes too.</p><p><b>CONCLUSION</b>Simulated diving could induce fatigue of back muscle in drivers. However, the protective belt can effectively prevent low back fatigue of drivers in simulated driving.</p>

Mechanism of radiculopathy induced by experimentally herniated nucleus pulposus in rats / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the effects of the autologous nucleus pulposus on the pain-related behaviors of hind paws in rats.</p><p><b>METHODS</b>The nucleus pulposus harvested from autologous coccygeal vertebra was applied beside the unilateral L4 and L5 nerve roots without compression. The mechanical withdrawal threshold of both paws were measured in different times after surgery. And hematoxylin and eosin (HE) staining was applied to observe the changes of nucleus pulposus and nerve roots.</p><p><b>RESULTS</b>Mechanical sensitivity of the operated side in paws obviously increased after application of autologous nucleus pulposus beside the lumbar nerve roots without compression. And HE staining showed obviously inflammatory changes in the nucleus pulposus and vacuolation in the nerve roots.</p><p><b>CONCLUSIONS</b>Inflammation resulted from nucleus pulposus may contribute to the development of mechanical hyperalgesia. The results suggest that in addition to mechanical compression, inflammation may be an important factor in the pathogenesis of sciatica.</p>