Body Position

Body Position during work can be a cause of health disorders and constitutes a professional hazard in cases where it is forced (i.e., inevitably connected with the requirements of the production or labor process), prolonged, and monotonous. In these cases, it is associated with overstrain of individual muscle groups and areas of the locomotor apparatus, with disruption of their normal nutrition, with stagnant phenomena in certain organs and systems, etc. The standing position is most common in the production environment. As a professional hazard in non-mechanized production, it is often associated with increased muscular load, especially with lifting and carrying heavy loads (porters, bakers, etc.). And often the pathological results attributed to standing body position depend to a large extent simultaneously (or even primarily) on excessively intense muscular strain. Various authors associate standing body positions with the following diseases: flatfoot, varicose veins, kyphoses and kyphoscolioses, genu valgum and genu varum (so-called "baker's legs"), coxa valga ("peasant's foot"), enteroptosis, retroversio, retroflexio and descensus uteri, etc. Undoubtedly, the Soviet statistics available in this field from the first post-revolutionary years (especially of Moscow workers grouped around the Obukh Institute) significantly aggravate the pathogenetic significance of this professional hazard, since even very minor deviations from the "norm" ("pathological involvement") are interpreted as diseases in it. At the same time, however, it is undoubtedly true that, in addition to possible influence on the development of certain diseases, prolonged standing position (especially when it is truly monotonous, i.e., regular movement from place to place, walking or various other movements is excluded) causes significant static tension of a large number of muscles in a state of contraction, which in turn is associated with a significant additional expenditure of energy (according to experiments with determination of oxygen exchange - by 10-25%) and a significant increase in muscle fatigue. The sitting position of the body, if it continues for a long time without interruption, and especially if the work process requires a bent position at the same time, also contributes to a certain extent to a number of health disorders. These usually include compression of the chest cavity, deterioration of blood supply to the lungs and early ossification of the costal cartilages, which promotes the development of tuberculosis, especially in adolescence (however, it should be emphasized here that the corresponding statistical data usually refer to capitalist countries under conditions when the growing organism worked an excessively long working day, under conditions of malnutrition, lack of sleep, and unfavorable housing conditions, a classic example of which were teenage seamstresses, and that therefore the decisive improvement of these socio-hygienic factors in the USSR should be attributed a very important, if not decisive, role in the sharp reduction of tuberculosis in these professions); scolioses and kyphoscolioses; anemia due to weakening of oxidative processes; digestive disorders; hemorrhoids; increased intra-abdominal pressure and the associated change in the position of internal sexual organs in a woman, and mainly their hyperemia and on this basis dysmenorrhea, metrorrhagia, intensification of inflammatory processes in the uterus, tubes, ovaries, pelvic cellular tissue, etc. In addition to standing and sitting body positions, the work of some professions is associated with the most diverse other incorrect body positions: lying on the back or side (in mines and quarries, when working in pipes, boilers, tanks, when repairing various large objects, during minor current repairs of cars, etc.), on the knees (parquet floorers, weeders, etc.), bent over (e.g., molders in foundries), etc. In all these cases, increased pressure on certain parts of the body can occur with consequences in the form of calluses, bursitis, inflammations of the joint capsules, etc., and mainly disruption of the normal nutrition of individual muscle groups or internal organs. However, it must be taken into account that in this case, a prolonged monotonous body position outside a correct posture is very rare, and therefore its consequences rarely manifest themselves in any serious professional diseases. When evaluating body position as a professional hazard in general, it is impermissible to consider it in isolation from other working and living conditions, as bourgeois professional hygienists usually do. When assessing this problem in Soviet conditions, it must be pointed out that it loses much of its acuteness in the environment of a 7-hour working day, 5- and 6-day work week, and extensive mechanization of production, "first of all heavy and harmful work" (from the resolution of the XVI Party Conference). However, it would be wrong to assume that this question is completely "resolved". The possibility of eliminating even minor sources of professional diseases is currently receiving serious attention from the entire system of organs of the People's Commissariat of Health and the People's Commissariat of Labor. It should be especially emphasized that in this case the close connection between protection, organization and labor productivity is particularly clearly manifested. For example, recently chairs from the Institute of Labor Protection have been subjected to serious tests in the production environment in a number of places. The best worker-shock workers, who regularly exceeded the production norm by 12-50% even before this, were taken under observation. Observations were made for an average of 16 days on the old seat and 10 days on the universal wooden chair of the Institute of Labor Protection. All the workers transferred to the new chairs of the IOT design showed a significant increase in productivity, expressed in an increase in daily output and a reduction in the time spent per unit of product, which is clearly seen from the following table:

Daily

I ^TimeSpent ^{on 1} «^unit of

product (in pieces)

^time per 1 piece (in sec.) (in pieces)

_{(in sec-}on-_ds) On old seat Upholsterer (5 l.) .... 1 3 877

10,91 Universal chair Upholsterer (5 l.)' - . 1

2 232,5 4,09 15,62 10,08 Thus, these experiments showed that the time spent per unit of product decreased by 10-19.6%, and the daily output increased by 10.7-22.97%. Basic preventive measures. In relation to standing professions, the main requirement of labor hygiene is to create conditions that allow for the possibility of switching to sitting work. Sometimes this is associated with reconstruction of equipment, more often with much less complex measures: replanning of the workshop, freeing up space for chairs or work seats; individual adaptation of the work seat to the features of the machine; creation of mobile or folding seats, etc. In the event that it is still temporarily impossible to ensure work is done sitting down, workers should be given the opportunity to sit down regularly during short breaks, promoting among them the slogan "you work standing - rest sitting, you work sitting - rest standing". In relation to sitting professions, the rational design of the work seat is of paramount importance. In the USSR at present, the Central Institute of Labor Protection has developed standard work chairs that meet all the main physiological and hygienic requirements. Furthermore, properly organized physical education (in particular, so-called physical culture minutes conducted in short breaks, approximately every hour of work, right in the workroom) can play a very large health-improving role here. Finally, for sitting work, the elimination of associated additional hazards is of great importance. For example, the Central Institute of Labor has developed designs of work seats on tractors and a number of other agricultural machines that minimize vibration. The elimination of the need to strain vision excessively to examine details, etc., is also of great importance for the hygienic rationalization of sitting work. In relation to work associated with improper body position, in cases where it is constant or frequently repeated and continues for a sufficiently long time, the issue should be about a fundamental reconstruction of the production process or its complete mechanization, which completely eliminates this body position.