Physical work load between 1970 and 1993 - did it change?
研究1970至1993年间城市和郊区居民体力工作负荷的变化，发现男性体力负荷下降而女性上升，且性别差异随年龄变化，对理解肌肉骨骼疾病有参考价值。
OBJECTIVES: This study investigates changes in self-reported and expert-evaluated physical work loads between 1970 and 1993 in relation to calendar year, birth cohort, and gender in an urban and suburban population sample (232 men and 252 women) born between 1935 and 1952. METHODS: A self-administered questionnaire was answered in 1993 concerning different aspects of physical work loads between 1970 and 1993. With the use of a classification matrix, the objective physical work load on different body regions was also assessed. RESULTS: Between 1970 and 1993 the fraction of subjects in blue-collar occupations and the physical work loads decreased among the men, but they both increased among the women. Physical work loads were, in general, higher among the men than among the women at younger ages (below 30 years), but less so at higher ages. Expert evaluations of the musculoskeletal load showed a pattern similar to that of self-reported work loads. CONCLUSIONS: The gender difference in work load development with age may have implications for the development of musculoskeletal disorders.