Research to improve extension ladder angular positioning.

A leading cause for extension ladder fall incidents is a slide-out event usually related to suboptimal ladder inclination. An improved ladder positioning method or procedure could reduce the risk of ladder stability failure and the related fall injury. The objective of the study was to comparatively evaluate the effectiveness of a multimodal angle indicator with other existing methods for extension ladder angular positioning. Twenty experienced and 20 inexperienced ladder users participated in the study. Four ladder positioning methods were tested in a controlled laboratory environment with 4.88 m (16 ft) and 7.32 m (24 ft) ladders in extended and retracted positions. The positioning methods included a no-instruction method, the current standard anthropometric method, and two instrumental methods - a bubble level indicator, and a multimodal indicator providing direct feedback with visual and sound signals. Performance measures included positioning angle and time. The results indicated that the anthropometric method was effective in improving the extension ladder positioning angle (p < 0.001); however, it was associated with considerable variability and required 50% more time than no-instruction. The bubble level indicator was an accurate positioning method (with very low variability), but required more than double the time of the no-instruction method (p < 0.001). The multimodal indicator improved the ladder angle setting as compared to the no-instruction and anthropometry methods (p < 0.001) and required the least time for ladder positioning among the tested methods (p < 0.001). An indicator with direct multimodal feedback is a viable approach for quick and accurate ladder positioning. The main advantage of the new multimodal method is that it provides continuous feedback on the angle of the device and hence does not require repositioning of the ladder. Furthermore, this indicator can be a valuable tool for training ladder users to correctly apply the current ANSI A14 standard anthropometric method in ladder angular positioning. The multimodal indicator concept has been further developed to become a hand-held tool in the form of a smart phone application.

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).

Prostate-specific antigen in a community screening program.

BACKGROUND: This study was designed to determine who participates in community-based prostate-specific antigen (PSA) screening programs and what serum PSA levels can be expected. METHODS: A descriptive analysis of men who participated in an annual community health screening program was used to compare men who chose PSA screening with those who did not. The relationship of demographic variables to PSA level was evaluated by multivariate regression analysis. Data were available on 5548 men, 6% of whom were black. RESULTS: The population of PSA screening participants included proportionately more middle-aged white men with higher median income, as compared with men who did not participate. Those who did not participate in the screening were more likely to be either very old or very young. PSA levels increased with age, and the percentage of men with elevated PSA levels increased with age. One tenth (9.6%) of all participants had PSAs between 4 ng/mL and 10 ng/mL, and 1.9% had levels greater than 10 ng/mL. Within 1 year of the screening, 1.7% of the screened participants had a diagnosis of prostate cancer. The mean PSA in this group was 15.9 ng/mL. CONCLUSIONS: These data confirm the need for age-specific PSA reference ranges. It is likely that the same reference range can be used for all racial ethnic populations.

Effect of age and race on the survival of men with prostate cancer in the Metropolitan Detroit tricounty area, 1973 to 1987.

OBJECTIVES: Reports have demonstrated that African Americans diagnosed with prostate cancer have a poor survival compared with whites. We examined the impact of age, race, and stage of disease on survival for men diagnosed with prostate cancer. METHODS: A retrospective analysis was made of men diagnosed with prostate cancer utilizing the Surveillance, Epidemiology, and End Results Program (SEER) database. A total of 12,907 men (9339 white, 3568 black) diagnosed from January 1, 1973 through December 31, 1987 were included in the study. For each stage of disease, survival experience was examined using Kaplan-Meier and life table methods, followed by analysis using Cox's proportional hazard model. RESULTS: African-American men have a poorer survival than whites for all stages of prostate cancer when the cancer is diagnosed at younger ages. These differences in survival were not demonstrated for men diagnosed with prostate cancer after age 70. CONCLUSIONS: Age and race should be taken into account when assessing the survival of patients with prostate cancer.

Increasing incidence of cancer of the prostate. The experience of black and white men in the Detroit metropolitan area.

BACKGROUND: Prostate cancer mortality and incidence rates have been gradually increasing for decades in the United States, with an accelerated increase in incidence noted in the past several years. This study explores in detail the occurrence of prostate cancer in southeast Michigan from 1973 through 1991. METHODS: Data from the National Cancer Institute Surveillance, Epidemiology, and End Results program are analyzed with emphasis on time trends by race, age, stage, and treatment. RESULTS: Population-based rates for prostate cancer increased by 70% between 1988 and 1991. Increases are most pronounced for early stage disease and among whites compared with blacks. Corresponding increases in treatment with radical prostatectomy are also observed. CONCLUSION: Increased incidence of prostate cancer is likely a result of widespread use of prostate-specific antigen.

Trends in cervical cancer incidence among young black and white women in metropolitan Detroit.

BACKGROUND: Although the overall incidence of invasive cervical cancer in the United States has declined over the past several decades, recent studies suggest that rates for both invasive and in situ cervical cancer are rising among younger women. METHODS: Trends in cervical cancer incidence among females between the ages of 15 and 39 years were evaluated using data from the Metropolitan Detroit Cancer Surveillance System, a population-based registry and founding participant in the SEER Program of the National Cancer Institute. Age-adjusted and age-specific rates for all black and white women in this age group were evaluated as well as rates for married and single women for the period 1973-1991. RESULTS: Incidence trends vary by race and marital status. A nonlinear increasing trend was evident (P < 0.01), for in situ cervical cancer among white women, with rates for single white women exhibiting the largest increase. Rates among black women for in situ cervical cancer exhibited a nonlinear decreasing trend (P < 0.01), with rates for married black women declining by 75%. Among single white women, invasive cervical cancer exhibited an increasing linear trend (P < 0.01), although the number of cases was small. CONCLUSIONS: Differences in trends among black and white women may reflect a combination of greater exposure to risk factors associated with cervical carcinoma as well as differential access to diagnostic and treatment services. Appropriate groups should be targeted for educational, screening, and follow-up services.