Anthropometric criteria for the design of tractor cabs and protection frames.

Improved human-tractor interface designs, such as well-accommodated operator enclosures (i.e. cabs and protection frames) can enhance operator productivity, comfort and safety. This study investigated farm-worker anthropometry and determined the critical anthropometric measures and 3-D feature envelopes of body landmarks for the design of tractor operator enclosures. One hundred agriculture workers participated in the study. Their body size and shape information was registered, using a 3-D full-body laser scanner. Knee height (sitting) and another eight parameters were found to affect the cab-enclosure accommodation rating and multiple anthropometric dimensions interactively affected the steering wheel and gear-handle impediment. A principal component analysis has identified 15 representative human body models for digitally assessing tractor-cab accommodation. A set of centroid coordinates of 34 body landmarks and the 95% confidence semi-axis-length for each landmark location were developed to guide tractor designers in their placement of tractor control components in order to best accommodate the user population. Finally, the vertical clearance (90 cm) for agriculture tractor enclosure in the current SAE International J2194 standard appeared to be too short as compared to the 99th percentile sitting height of male farm workers in this study (100.6 cm) and in the 1994 National Health and Nutrition Examination Survey III database (99.9 cm) and of the male civilian population in the 2002 Civilian American and European Surface Anthropometric Resource database (100.4 cm).

Anthropometry of an aging work force.

Faced with an aging labor force, industrial planners are worried about the possible need to redesign jobs and workspaces in the future. One area of concern is the changes that occur in body size characteristics as people age. Although no true database for the anthropometry of the American worker exists, available surveys and studies that include older individuals (40 to 70 years), and errors associated with these studies, are discussed. Using sample mean values from selected cross-sectional and longitudinal studies, the changes in weight and selected body dimensions are traced from the third to the eighth decade of life. As a practical exercise, age-associated changes in a number of workspace dimensions are tested against recommended design values for seated work stations. While acknowledging the need for flexibility in future workplace designs the authors conclude that age-related changes in body size are insufficient in themselves to justify the resizing of existing ergonomically-designed workplaces.

Effects of burning on human bone microstructure: a preliminary study.

The microscopic determination of age at death in human bone is a widely used technique in forensic anthropology. Despite its use, little attention has been given to the reliability of microscopic aging when the subject has been burned, either at the time of death, or after death. This preliminary report examines some of the variables of the burning process that may affect the age estimates. Preliminary conclusions are: (1) bone burned at 600 degrees C retains all of the structures necessary for microscopic aging and (2) bone shrinkage, widely reported in the literature, does not appear to have significant effect on the age estimate. A research plan is outlined that will address some of the questions left unanswerable in the present report.

Mortality of pregnant females in Arikara villages: osteological evidence.

High infant mortality and high mortality for late adolescent and young adult females suggest that obstetrical hazards may be one explanation for differences in male and female mortality curves. This possibility is investigated in Arikara skeletal series by determining the frequency of females who died with fetal remains in utero. Two females (0.9%) were so identified. Examination of the females and the fetal remains do not provide evidence that stress of childbearing was the cause of death in these cases.