Educational level and its relationship with body height and popliteal height in Chilean male workers

Effects of aircraft tray table height and neck posture on passenger comfort: A study of the economy class cabin

BACKGROUND

The tray table in economy class air travel may cause excessive neck flexion and discomfort in passengers.

OBJECTIVE

The purpose of this study is to examine the influence of different tray table heights on the neck posture and discomfort perception of passengers.

METHODS

A passenger experience survey was used to determine the passengers' view that the tray table was not high enough, and that most passengers were dissatisfied with the overall comfort evaluation of the tray table, especially passengers with obesity. Three head-neck angles and discomfort perceptions of six body parts in 58 participants were recorded by neck posture 3D scanning and perceived level of discomfort assessment, respectively.

RESULTS

Tray tables at the original height (68 cm) caused unnatural neck posture and discomfort in participants. Raising the tray table can improve the neck posture of participants and reduce discomfort. However, raising the tray table too high will cause more shoulder discomfort in participants. Based on the results, 78 (±2) cm is suggested as the suitable thresholds range of tray tables for economy class air travel.

CONCLUSION

The results and findings of this study could provide a theoretical base for the optimization of tray table design.

Growing taller unequally? Adult height and socioeconomic status in Spain (Cohorts 1940–1994)

Socioeconomic inequalities and their evolution in different historical contexts have been widely studied. However, some of their dimensions remain relatively unexplored, such as the role played by socioeconomic status in the trajectory of biological living standards, especially net nutritional status. The main objective of this article is to analyze whether the power of socioeconomic status (SES) to explain differences in the biological dimensions of human well-being (in this case, adult height, a reliable metric for health and nutritional status) has increased or diminished over time. Educational attainment and occupational category have been used as two different proxies for the SES of Spanish men and women born between 1940 and 1994, thus covering a historical period in Spain characterized by remarkable socioeconomic development and a marked increase in mean adult height. Our data is drawn from nine waves of the Spanish National Health Survey and the Spanish sample of two waves of the European Health Interview Survey (ENSE) for the period 1987 to 2017 (N = 73,699 citizens aged 23–47). A multivariate regression analysis has been conducted, showing that, as a whole, height differentials by educational attainment have diminished over time, whereas differences by occupational category of household heads have largely persisted. These results indicate the need for further qualification when describing the process of convergence in biological well-being indicators across social groups. For instance, the progressive enrollment of a greater proportion of the population into higher educational levels may lead us to underestimate the real differences between socioeconomic groups, while other proxies of SES still point to the persistence of such differences.

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Different SES impact on nutritional status according to SES operationalization.

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Significant reduction in height differentials by educational attainment over time.

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Height differentials largely persist by social class over time.

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Evidence is provided on recent halt of upward intergenerational growth in Spain.

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Mean cohort height stagnation not due to increases in social groups' differentials.

Secular trends in Javanese adult height: the roles of environment and educational attainment

Background

Since its independence in 1945, Indonesia has undergone rapid socioeconomic development. The fastest changes occurred in Java, which is the main island where more than half of the Indonesian population lives.

Objective

This study aimed to analyze the secular trend in the height of adults living in Java born between 1953 and 1995 by comparing their residence (rural, small city, or large city) and considering factors that contribute to adult height.

Methods

The analysis used the following data: birth year, body height, weight, body mass index, sex, educational attainment, share of household food expenditures, and residence of 20- to 40-year-old men and women collected by the Indonesia Family Life Survey (IFLS) waves 1 to 5. Multiple linear regression was conducted to analyze several factors that influence adult height. Significance was set at p < 0.05 with a 95% confidence interval (CI).

Results

The study included 30,656 measurements of individuals born between 1953 and 1995 (54.9% female). Positive secular trends (95% CI) were observed for men and women: 1.3 (1.1–1.4) cm and 0.9 (0.8–1.0) cm per decade, respectively. Multiple linear regression analyses showed that, in addition to the year of birth, the adult height of both males and females was independently associated with level of education and share of household food expenditure. Stratifying the data into residence in rural areas, small cities, and large cities showed that education levels influenced the adult height of men and women living in all regions, whereas the influence of birth year and share of household food expenditure differed between areas and genders.

Conclusions

We observed positive secular trends in the height of adults living in Java who were born between 1953 and 1995. The birth year, educational attainment, and share of household food expenditure significantly influenced adult height. A higher education level was consistently associated with taller adult height in both men and women living in rural areas, small cities, and large cities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13144-6.

Height of Male Prisoners in Santiago de Chile during the Nitrate Era: The Penalty of being Unskilled, Illiterate, Illegitimate and Mapuche

This article contributes to the study of inequality in the biological welfare of Chile’s adult population during the nitrate era, ca. 1880s–1930s, and in particular focuses on the impact of socioeconomic variables on height, making use of a sample of over 20,000 male inmates of the capital’s main jail. It shows that inmates with a university degree were taller than the rest; that those born legitimate were taller in adulthood; that those (Chilean born) whose surnames were Northern European were also taller than the rest, and in particular than those with Mapuche background; and that those able to read and write were also taller than illiterate inmates. Conditional regression analysis, examining both correlates at the mean and correlates across the height distribution, supports these findings. We show that there was more height inequality in the population according to socioeconomic status and human capital than previously thought, while also confirming the importance of socioeconomic influences during childhood on physical growth.