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Objective: To investigate the influencing factors and population attributable risk percent (PAR%) of low back pain in automobile assemblers. Methods: A total of 634 assemblers from 11 automobile manufacturers in Shiyan City, Hubei Province were chosen as research subjects using judgment sampling method. The prevalence of low back pain in the past one year was investigated using Musculoskeletal Disorders Questionnaire. PAR% was used to analyze the contribution of influencing factors to low back pain. Results: The annual prevalence of low back pain was 68.8%. The results of multivariate logistics regression showed that length of service>15 years, high school or secondary college education or above, standing most of the time, sitting most of the time, the proportion of cumulative time of poor posture in work shift time ≥1/8, and bending for insufficient height of working space were the risk factors for low back pain (all P<0.05). The PAR% of the proportion of cumulative time of poor posture in work shift time ≥1/8 was 43.0%, 37.8% for standing most of the time, and 12.8% for bending for insufficient height of working space. Conclusion: The annual prevalence of low back pain was higher in automobile assemblers. The influencing factors included individual factors and occupational factors. The proportion of cumulative time of poor posture in work shift time ≥1/8, standing most of the time and bending for insufficient height of working space should be taken as the priority intervention factors to reduce the prevalence of low back pain among assemblers in this enterprise.
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OBJECTIVE: To explore the prevalence of work-related low back musculoskeletal disorders(WMSDs) among electric welders in an automobile factory and to analyze its individual influence factors. METHODS: A total of 754 electric welders with a service length ≥1.0 years from an automobile factory in Shiyan City were selected using judgment sampling method. The Musculoskeletal Disorders Standard Questionnaire was used to collect the information of low back WMSDs. RESULTS: The annual prevalence of low back WMSDs among electric welders was 65.9%(497/754). The prevalence in females was higher than that in males(78.4% vs 63.1%, P<0.01). The prevalence of WMSDs had a rising tendency with age, educational level and service length(P<0.01). The multivariate logistic regression analysis results showed that the risk factors for low back WMSDs were age, gender, and educational level(P<0.05).CONCLUSION: The prevalence of low back WMSDs of electric welders in the automobile factory is high. Gender, age and educational level are the main risk factors affecting low back WMSDs.
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<p><b>OBJECTIVE</b>To observe the effects of different frequencies of electroacupuncture (EA) at "Baihui (GV 20)" and "Shenshu(BL 23)" for the learning and memory ability as well as glycogen synthase kinase-3β (GSK-3β) and growth associated protein-43 (GAP-43) in hippocampal tissue of rats with Alzheimer's disease(AD), so as to explore the mechanism of different frequencies of EA for the prevention and treatment of AD.</p><p><b>METHODS</b>One hundred and twelve healthy Wistar male rats were divided into seven groups by random number table, namely a normal group, a sham operation group, a model group, an acupuncture group, a 2 Hz EA group, a 30 Hz EA group, and a 50 Hz EA group, 16 rats in each one. The rats in the normal group were conventionally raised in the laboratory without any treatment. 0.9% NaCl solution was injected into bilateral dentate convolution of hippocampus in rats of the sham operation group. AD model was established by β-amyloid protein1-42 (Aβ1-42) injected into bilateral dentate convolution of hippocampus in the other groups. 15 days after establishment, no treatment was applied in the model and sham operation groups, and EA with corresponding frequencies at "Baihui (GV 20)" and "Shenshu (BL 23)" was used in the three EA groups for 2 sessions, once a day and 7 times as one session. There was 1 day between the two sessions. The same acupoints were adopted in the acupuncture group, without electrical connection. The escape latency, the first spanning platform time, and the number of crossing platform were tested in the Morris water maze immediately after treatment. The expressions of GSK-3β and GAP-43 were examined by immunohistochemistry and Western blot.</p><p><b>RESULTS</b>①Morris water maze tests showed that the escape latency and the first spanning platform time significantly increased in the model group compared with those in the normal group (both<0.01), and the number of crossing platform decreased (<0.01). Compared with the model group, the escape latency and the first spanning platform times decreased in the acupuncture and three EA groups (all<0.01), and the numbers of crossing platform increased (<0.01). Compared with the acupuncture and 2 Hz, 30 Hz EA groups, the escape latency decreased in the 50 Hz EA group (<0.01,<0.05); the first spanning platform time reduced (all<0.01); the number of crossing platform increased (<0.01,<0.05). ②The expressions of GSK-3β and GAP-43 of the model group increased compared with those of the normal group(both<0.01). The expressions of GSK-3β in the acupuncture and three EA groups decreased compared with that in the model group (all<0.01), and the expressions of GAP-43 increased (all<0.01). The expressions of GSK-3β decreased and GAP-43 increases in the 50 Hz EA group compared with those in the acupuncture group and 2 Hz, 30 Hz groups (all<0.01).</p><p><b>CONCLUSIONS</b>EA may promote synaptic damage rehabilitation by down regulating GSK-3β and up regulating GAP-43 to improve learning and memory ability of AD rats. The effect of 50 Hz EA is better than those of 30 Hz and 2 Hz EA and acupuncture.</p>
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Objective To observe the effect of electroacupuncture with different frequencies on learning and memory ability, synaptic morphology and synaptic density in the hippocampus of Alzheimer's disease rats. Methods Forty-eight healthy Wistar rats were randomly di-vided into normal group, sham operation group, model group, 2 Hz, 30 Hz and 50 Hz electroacupuncture groups with 8 cases in each group. The Alzheimer's disease model was established by injecting Aβ1-42 into two sides of lateral cerebral ventricle. The sham operation group was injected with normal saline instead. The electroacupuncture groups received electroacupuncture at Baihui (DU20) and Shenshu (BL23) acu-points. The learning and memory ability was evaluated with Morris water maze test, and the morphology and density of synapse were ob-served by electron microscope. Results Compared with the model group, the latency was shorter, the time of crossing the platform was short-er and the number of crossing the platform was more in the electroacupuncture groups (P<0.01), especially in the 50 Hz electroacupuncture group (P<0.01). The number of synapse and the synaptic density were more in the electroacupuncture groups than in the model group (P<0.01), especially in the 50 Hz electroacupuncture group (P<0.01). Conclusion Electroacupuncture could improve learning and memory abili-ty and increase synaptic density in rats with Alzheimer's disease, especially with high frequency.