Physical Development of the Population

PHYSICAL DEVELOPMENT OF THE POPULATION is an important indicator of the sanitary condition of human collectives. A number of fields of medical activity are connected with the characterization of physical development: examination of those called up for military service and re-examination of military contingents; medical control over mass physical culture; occupational consultation; medical control over the development of children of various ages—newborns, nursery children, preschoolers, schoolchildren; recording the results of the stay of children's and adult masses of the population in summer camps, rest homes, sanatoriums, etc. In relation to a patient, the characterization of physical development can also often be of importance for elucidating the pathological complex, therapy, and prognosis. In all the enumerated fields, two tasks are inextricably linked: the evaluation of the physical development of a) the individual and b) the group. Practically, the first task usually predominates: it is necessary to determine the level of physical development of such-and-such a conscript to determine the degree of his fitness for military service; it is necessary to decide the question of the level of physical development of a given child from the standpoint of the priority of sending him to a forest school, etc. But without a summary characterization of the group's physical development, it is impossible to give a justified evaluation of the development of the individual entering this group, and without data on individual individuals, it is impossible to find the summary typical values characterizing the given group. The physical development of a person is complex and diverse; it includes such an extensive complex of diverse traits that their exhaustive characterization is hardly possible. From the entire diversity of these traits, one has to choose a certain minimum of the most important ones that are at the same time as far as possible amenable to quantitative objective recording and require relatively simple apparatus; this refers in particular to mass studies of practically healthy people. A number of American, German, and other practical and scientific-practical works are limited to determining body length and weight; other works, including the work of Erisman and his pupils, include the measurement of chest circumferences; the Moscow Commission on the Standardization of Anthropometric Research (under the direction of Bunak) included in the program of mass research of physical development, in addition, sitting height (the distance from the crown to the level of the seat), from descriptive traits—the development of muscles, the fat layer, from physiometric traits—vital lung capacity (optional). Without exhausting the characteristics of physical development completely, these traits reflect a number of its essential aspects and, in combination with other data on the state of health, are of importance for assessing the sanitary condition of the group and the health of the individual (for details of the methodology of collecting and processing the corresponding materials, see Anthropometry, Variation Statistics, Indices of Physical Development). While the methodology of mass research of the morphological side of physical development is more or less developed, the methodology of mass accounting of functional features is in an embryonic state. Summary data on physical development—in close combination with data on mortality, morbidity, etc.—can be and have been used to assess the statics and dynamics of the sanitary condition of a given group. A typical example of the use of data on physical development as a sanitary-diagnostic tool is the classic work of Levitsky, "On the Physical Condition of the Population of Podolsk Uyezd" (1901), in which, according to the fair remark of Kurkin, "sanitary statistics, local sanitary research, and practical sanitary-economic measures constituted a coherent and complete whole." On the basis of data on the height, chest circumference, and weight of conscripts, the author singled out as the most disadvantaged in terms of physical development the Kdenovo volost, in which the hat-making cottage industry was concentrated. Having reinforced the data on the lag in physical development of this group with indicators of child mortality and survival to pre-conscription age and having detailedly investigated the sanitary conditions of the Kdenovo volost and the hat industry in it, Levitsky developed, proposed, and achieved the implementation of a number of measures to improve this industry. Table 1. a) Indicators of physical development¹ Professions Age 20-39 y. Workers processing non-woven substances... Workers processing fibrous substances..... Hatters........... 80.5* 80.00 Age 40-59 y. 30.5i 30.98 30.53 b) Mortality of population Districts Total At age 20-40 y. 33.5 36.75 8.9 5.5 ¹ V. A. Levitsky uses for a combined assessment of physical development the index: weight multiplied by chest girth and divided by height, with weight expressed in kg, height and chest girth in m. The historical work on the sanitary investigation of factory establishments of Moscow Governorate by Erisman and his collaborators (1879-1885) contained a description of the sanitary-technical conditions of production, living conditions of the working mass, data on the health status of workers, and a measuring characteristic of their physical development (height and chest circumference, partly weight and muscle strength). In total, over 100,000 workers (64,820 men and 36,102 women) originating from central Russia and engaged predominantly in industries processing fibrous substances were subjected to anthropometric research. Having verified on this huge material some general regularities of the course of growth depending on age and sex, Erisman divided the studied workers into several groups (spinners, carders, artisans, dyers, day laborers, etc.) and came to the conclusion that "the influence of the occupation and the lifestyle associated with it is predominant in relation to physical development." "Spinners are small in stature, with a narrow chest, the circumference of which only in the 22nd year of life reaches half of the height and in adults exceeds it by only 1.5-3 cm; conversely, day laborers are tall, with a well-developed chest, and its circumference already at the age of 18 gets a noticeable advantage over half-height and in adults exceeds it by 4-5 cm...". "Even if the origin of the workers (from one locality or another) is not without influence on their bodily development and the research results are in some dependence on the natural selection of workers by individual types of work, nevertheless the most essential reason for the significant differences observed in the physical development of individual groups of workers lies in the very nature of work and in everything that has relation to the latter... including here the living relations of a social and economic nature conditioned by the nature of labor." Height, chest circumference, and a number of other dimensions are determined to a significant degree by endogenous moments and in particular heredity; but a certain amplitude of fluctuations in the average values of these traits in a given group (taking into account age, sex, national, and other features) still depends on the impact of the environment and first of all on nutrition conditions in the decisive periods of ontogenetic development. In this sense, average data on height, weight, chest circumference, etc. and their ratios are an indicator of the sanitary state of a given group and reflect to a certain extent the socio-economic conditions in which this group is located. Niceforo gathered in his work "Anthropology of the Destitute Classes" extensive material illustrating this proposition. Telling is the comparison of the height of conscripts in individual quarters of Paris with the average apartment rent of the corresponding district. Table 3. Body length and average apartment rent (according to materials of statistical yearbooks of Paris of the beginning of the 20th century). Groups of quarters Average height of conscripts in cm Average apartment rent in fr. I. Quarters VIII, VI, VII, XVI...... II. Quarters I, XVII, II, IX ....... III. Quarters V, XII, XIII, XIX..... IV. Quarters XVIII, XIV, X, III ... . V. Quarters XV, IV, XI, XX....... 165.5 164.8 164.4 164.1 163.8 413 302.5 96.0 139.0 103.5 Some violation of the correspondence between height and well-being in the third group of quarters is explained by the special selection of the proletariat of this area—many porters, loaders, and butchers live here. Weissenberg, Schlesinger, Dikansky, and others came to similar conclusions, having gathered solid material on the physical development of children of various classes of population (see Body Weight, Height). There are further known differences between the physical development of urban and rural children. The proletarian child of school age in factory cities and settlements (Moscow, Noginsk) is somewhat taller in height and somewhat narrower in chest circumference than the peasant child (Volokolamsk district) (the survey of the physical development of Glukhovo schoolchildren in 1927 and 1934 was carried out by the same qualified forces according to a unified methodology for collecting and processing material (Table 4, diagram on pp. 727-728). Table 4. Height (in cm) ! Weight (in kg) Chest circumference (in cm) Age Erisman Syrkin Syrkin Erisman Syrkin Syrkin Erisman Syrkin Syrkin (1885) (1927) (1934) (1885) (1927) (1934) (1885) (1927) (1934) m. m.

These differences are relatively small and recede into the background before the significant positive shifts characterizing the dynamics of physical development of broad masses of children and adults in the USSR. The physical development of this group vividly reflects the shifts in the conditions of human existence and development. A clear example can be provided by the height and weight curves of Stuttgart school-age children from 1913 to 1925, which reflect with striking clarity the course of historical events in Germany during this period—the war, the food blockade, and inflation. Table 3, Dynamics of physical development of Stuttgart schoolchildren according to Gastpar (age 9¹/₂-10 years). Years, Weight (in kg), Height (in cm). For economy of space, only one age is given. Acute starvation in 1921-1922 in certain regions of the USSR as a result of intervention, the civil war, and crop failure had a sharp impact on physical development (works of Shtefko, Nikolayev, A. A. Ivanovsky), but the consequences of this starvation were quickly overcome. Pessimistic predictions by certain authors regarding changes in the anthropological type itself (A. A. Ivanovsky), regarding "degeneration," were not justified: with the growth of the material well-being of the broad masses of working people, the physical development of the population of the Soviet Union also rapidly improved, in full accordance with the improvement of all other indicators of the sanitary condition. These shifts can be illustrated by the given tables characterizing the dynamics of physical development of schoolchildren. From the extensive material on the dynamics of physical development of preschoolers, schoolchildren, and adolescents, the data given below stand out by the fact that they relate to a comparatively low-paid group of textile workers living in a factory settlement, the population turnover of which is relatively small. It is especially important that, along with reflecting long-term shifts, data on physical development can serve as a valuable indicator of the results of shorter health-improving influences on individual population groups. The effect of a stay in sanatoriums, pioneer camps, etc., on the state of health can be partially expressed in the numerical indicators of physical development. Such are, for example, the data of the Moscow Department of Health on changes in the weight of pioneers during their stay in camps near Moscow in 1933, or a more complex assessment of the results of a stay at resorts of the Institute of Health Resorts (based on data on the height-weight index, hemoglobin, dynamometry, spirometry, and functional cardiovascular tests before departure for the resort, shortly after return, and during subsequent repeat examinations). To assess the physical development of an individual, it is most correct to compare the numerical data on individual signs of his development with summary typical values for a given group, with the so-called standards of physical development. The deviation of individual values from typical averages, expressed in conventional criteria ("standard deviation"), gives a clear and distinct characteristic of the physical development of a given individual. The indices of physical development widespread in medical and adjacent literature have only a relative and rather limited significance (see Indices of physical development). The most substantiated assessment of the combination of individual signs (the combination of a given height with a given weight and chest circumference, etc.) is given using correlation and regression coefficients (see). At the same time, it should be kept in mind that the assessment of individual physical development is a complex task, that "in individual cases, relatively unfavorable anthropometric data may correspond to a relatively good state of health" (Prinzing). The individual assessment of physical development must be based on numerical anthropometric data, on the characteristics of the so-called descriptive signs, on taking into account constitution, and on medical examination as a whole. Only such a comprehensive conclusion can be taken into account in the most serious complex conclusions about the degree of "suitability" of a given individual for military service or for a certain profession, etc. It must be remembered that the "norms" with which a given individual is compared, and the standards of physical development themselves, are different for persons of different ages, sexes, nationalities, and social positions. In pathological cases (dwarfism, eunuchoidism, dropsy, acromegaly, achondroplasia, etc.), the deviation from usual norms is extremely significant, often going beyond the limits of three or more standard deviations from the average height, weight, etc. In individual cases of internal secretion disorders, the nature of the deviation of physical development from the typical, the features of the ratio of body parts ("body proportions") serve as an important diagnostic aid. Especially important for individual branches of practical medicine is the dynamics of the physical development of the individual: the general course of the growth and weight curve in a child, weight shifts in tuberculosis patients, in patients with chronic digestive disorders, in cancer patients and all diseases associated with cachexia, convalescents, etc., changes in body proportions and total length in patients with a significant group of internal secretion disorders—such is the far from exhaustive list of those cases when the study of the course of physical development in its individual elements and as a whole is a necessary component of medical work in the field of diagnosis and prognosis and accounting for treatment results (see also Anthropometry, Variation statistics, Indices of physical development, Body weight, Height, etc.).