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Preliminary statistical analysis of anthropometrics data in related to sitting posture among college students at east coast Malaysia

Ibrahim M.H., Ishak N.F., Mukhtar N.Z., Basir M.H., Said N.A., Mohamed K.A., Awang M.E.

Archives of Materials Science and Engineering

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2022

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Vol. 116, nr 2

81--85

EN

Purpose: To statistically analyse sitting posture using anthropometrics data among college students in Malaysia. Design/methodology/approach: This study was conducted among 52 college students consisting of males and females. Data were analysed using a common statistical tool which is the Statistical Package of Sosial Science (SPSS). Findings: Preliminary analysis of data indicated that there are wider differences in standard deviation of eye sitting height compared to the previous study conducted. Research limitations/implications: This study was conducted at only one higher learning institution/college located at East Cost of Malaysia. Practical implications: The larger value of standard deviation discovered as statistical analysis performed using combined data among male and female participants suggested that data should be segregated. Originality/value: Result obtained could be used as a preliminary guideline to design any related item in related to sitting posture.

2

A sitting or standing position – which one exerts more loads on the musculoskeletal system of the lumbar spine? Comparative tests based on the methods of mathematical modeling

Zadoń Hanna, Nowakowska-Lipiec Katarzyna, Michnik Robert

Acta of Bioengineering and Biomechanics

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2021

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Vol. 23, no. 1

113--120

EN

Purpose: The work aimed to assess the functioning of the musculoskeletal system within the lumbar spine in relation to everyday postures of sitting and standing. Methods: The comparative analysis was based both on experimental tests and computer simulations performed in the AnyBody Modeling System environment. Input data used to prepare models were based on the information obtained in experimental tests. The test participants were tasked with adopting two postures: 1) standing position and 2) sitting position. Kinematics measurements were performed using the Zebris ultrasonic system. During sitting position, the tests additionally involved the use of a dynamometric platform measuring reaction forces occurring between buttocks and the seat. Results: The comparative analysis included measurements of the trunk inclination angle and the pelvic inclination angle as well as results of computer simulations. The sitting posture is responsible for increased trunk inclination and a change in the position of the pelvis. In terms of the sitting position, it was possible to observe an increase in the loads affecting individual intervertebral joints of the lumbar spine by 155–184% in comparison with the standing posture (100%). Simulations revealed an increased muscle activity of the erector spinae, abdominal internal oblique muscles and abdominal external oblique muscles. Conclusions: Adopting a sitting position increases the loads on the lumbar spine and increases the activity of the erector spinae and abdominal muscles compared to the standing position, which is caused by change in the position of the pelvis and the curvature of the lumbar region.

3

A computational evaluation of sedentary lifestyle effects on carotid hemodynamics and atherosclerotic events incidence

Caruso M. V., Serra R., Perri P., Buffone G., Calio F. G., Franciscis S., Fragomeni G.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 3

43--52

EN

Purpose: Hemodynamics has a key role in the atheropathogenesis. Indeed, atherosclerotic phenomena occur in vessels characterized by complex geometry and flow pattern, like the carotid bifurcation. Moreover, the lifestyle is a significant risk factor. The aim of this study is to evaluate the hemodynamic effects due to two sedentary lifestyles -sitting and standing positions- in the carotid bifurcation in order to identify the worst condition and to investigate the atherosclerosis incidence. Methods: The computational fluid dynamics (CFD) was chosen to carry out the analysis, in which in-vivo non-invasive measurements were used as boundary conditions. Furthermore, to compare the two conditions, one patient-specific 3D model of a carotid bifurcation was reconstructed starting from computer tomography. Different mechanical indicators, correlated with atherosclerosis incidence, were calculated in addition to flow pattern and pressure distribution: the time average wall shear stress (TAWSS), the oscillatory shear index (OSI) and the relative residence time (RRT). Results: The results have highlighted that the bulb and the external carotid artery emergence are the most probable regions in which atherosclerotic events could happen. Indeed, low velocity and WSS values, high OSI and, as a consequence, areas with chaotic-swirling flow, with stasis (high RRT), occur. Moreover, the sitting position is the worst condition: considering a cardiac cycle, TAWSS is less than 17.2% and OSI and RRT are greater than 17.5% and 21.2%, respectively. Conclusions: This study suggests that if a person spends much time in the sitting position, a high risk of plaque formation and, consequently, of stenosis could happen.

4

An experimental study to evaluate musculoskeletal disorders and postural stress of female craftworkers adopting different sitting postures

Maity P., De S., Pal A., Dhara P. C.

International Journal of Occupational Safety and Ergonomics

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2016

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Vol. 22, No. 2

257--266

EN

This study aimed to evaluate musculoskeletal disorders (MSDs) and postural stress among female craftworkers. The study was carried out on 75 adult female craftworkers in different districts of West Bengal. The prevalence of MSDs, body part discomfort (BPD) rating and body joint angles of the workers were evaluated with standard methods. Electromyography (EMG) of the shoulder and back muscles was recorded with the BIOPAC system. The prevalence of MSDs, BPD rating and deviation of joint angle were comparatively lower in the case of sitting on the floor with folded legs than squatting and sitting on the floor with stretched legs postures. The EMG and rms values of the shoulder and back muscles were comparatively lower in this posture. Therefore, it was concluded that sitting on the floor with folded legs was less hazardous and it imposed less postural stress in comparison to other sitting postures.

5

Respiratory chest movement measurement as a chair quality indicator – preliminary observations

Szczygieł E., Zielonka K., Mazur T., Mętel S., Golec J.

International Journal of Occupational Safety and Ergonomics

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2015

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Vol. 21, No. 2

207--212

EN

Regardless of the constantly increasing time man is spending in a sitting position, there is still a lack of objective chair quality assessment criteria. The aim of this paper is to find the answer to whether respiratory chest movement measurements can be a chair quality indicator. The study included 34 participants (mean 34.7 years ± 5.2). Their chest movements were assessed using respiratory inductive plethysmography while sitting on two subsequent chairs. Significant differences in chest movements depending on chair type were observed concerning the breathing duct (upper and lower) and breathing movement amplitude. The amplitude of the upper respiratory track in the first chair was higher (239.4 mV) compared with the second seat (207.3 mV) (p = .018). The analyzed parameters of respiratory chest movement may become a helpful indicator for design and selection of chairs which enable people to both work and relax in the most ergonomic conditions.

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Przewlekła niewydolność żylna kończyn dolnych - schorzenie związane z rodzajem wykonywanej pracy

Łastowiecka-Moras E.

Bezpieczeństwo Pracy : nauka i praktyka

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2015

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nr 6

16-19

PL

Przewlekła niewydolność żylna (PNŻ) jest najczęściej występującym u ludzi zespołem chorobowym naczyń kończyn dolnych, wywołanym niewydolnością zastawek żylnych. Gdy zastawki są uszkodzone, krew cofa się i zaczyna napierać na ściany naczyń Naczynia poszerzają się i z biegiem lal zalegająca krew żylna wywołuje zmiany chorobowe w otaczających tkankach. Objawy choroby mogą mieć charakter zmian skórnych lub naczyniowych PNZ jest chorobą o etiologii wieloczynnikowej, a jednym z czynników mogących mieć wpływ na pojawienie się jej objawów jest charakter wykonywanej pracy. Długotrwała praca w pozycji stojącej lub siedzącej może prowadzić do zastoju krwi w naczyniach żylnych kończyn dolnych, dlatego należy odpowiednio zadbać o swoje stanowisko pracy. Dla osób pracujących w pozycji siedzącej poleca się krzesła z pochylonym oparciem i podnóżki pod stopy oraz regularne przerwy, w czasie których następuje zmiana pozycji ciała. Z kolei pracownikom wykonującym głównie pracę stojącą zaleca się częste przerwy na krótkotrwały spacer. Najlepszym sprzymierzeńcem w walce z PNZ, niezależnie od rodzaju wykonywanej pracy jest aktywność.

EN

Chronic venous insufficiency (CVI) is the most common human disorder of the lower limbs; it is by venous valvular insufficiency. When the valve does not close properly, blood backs up and begins to push against the walls of the blood vessels. Vessels extend and over the years residual venous blood causes lesions in the surrounding tissues. Symptoms of the disease may be cutaneus or vascular. CVI is a disease of multifactional etiology and the nature of work may be a factor that leads to symptoms of CVI Prolonged standing or sitting can lead to stagnation of blood in the veins of the lower limbs; therefore, workers doing this kind of work must take care of their workstation. For people working in a sitting posture, chairs with a sloping backrest and a footrest, and regular breaks are recommended. For workers working in a standing posture, short walks during frequent breaks are recommended. Physical activity is best in fighting against CVI, regardless of the type of work.

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Ocena pozycji siedzącej u niemowląt w wieku 9 miesięcy przy użyciu stanowiska podoskopowego „PodoBaby”

Adamska M., Wójtowicz D., Ostrowska B.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2013

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Vol. 19, nr 1

49--54

PL

Pozycja siedząca jest wyrazem prawidłowego rozwoju dziecka i powinna być utrzymywana przez krótki czas już w 6-tym miesiącu życia, natomiast w 9-tym miesiącu powinna być przyjmowana samodzielnie i w pełni opanowana. Dzieje się tak wtedy, gdy ośrodkowy układ nerwowy rozwija się bez zakłóceń. Dzięki temu możliwe jest prawidłowe kształtowanie się mechanizmów podporowo-wyprostnych i rozkład napięcia mięśniowego, umożliwiając tym samym utrzymywanie tej pozycji przez coraz dłuższy czas. Ocena symetrii pozycji siedzącej jest ważną informacją o funkcjonowaniu ośrodkowego układu nerwowego, rozkładzie napięcia mięśniowego i jakości wzorca ruchowego dziecka. Celem pracy była ocena pozycji siedzącej w siadzie prostym niemowląt w dziewiątym miesiącu życia za pomocą stanowiska podoskopowego PodoBaby. Badaniami objęto grupę 6 dzieci w 9 miesiącu życia. Ocenie poddano ogólną powierzchnię przylegania ciała dziecka do podłoża oraz powierzchnię przylegania prawego i lewego pośladka wraz z kończynami dolnymi. Wyniki podano w wartościach procentowych. U pięcioro dzieci stwierdzono niewielką mieszcząca się w granicach normy (< 10%) asymetrię pozycji siedzącej. Tylko u jednego dziecka asymetria przekraczała 10%, co może wskazywać na zaburzenia i wymagać interwencji terapeutycznej. Urządzenie PodoBaby może wspomagać diagnostykę neurorozwojową w zakresie motoryki spontanicznej dziecka.

EN

The sitting position is an expression of the proper development of the child and it should be kept for a short time starting from the age of 6 months and in the 9 months old babies it should be taken alone and fully controlled by a child. This occurs when the nervous system develops without any problems. The correct development of both supporting and extension mechanisms, as well as the spread of muscle tension allows to maintain the sitting position for longer time. The measurement of symmetry in sitting position provides an important information about the functioning of the central nervous system, muscle tension and the quality of the child's motor pattern. The aim of the study was the evaluation of the sitting position among the 9 month old babies with the use of PodoBaby system. The study was conducted on a group of 6 children. The total area of the child's body adhesion to the surface and of the right and left buttock with the lower limbs, were evaluated. Five children had small (< 10%) asymmetry in the sitting position. Only one child’s asymmetry exceeded 10%, which may indicate disorders and require the therapeutic consultation. PodoBaby may be used for the diagnosis of the neuro-developmental motility of a child.

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The influence of trunk inclination on muscle activity during sitting on forward inclined seats

Mastalerz A., Palczewska I.

Acta of Bioengineering and Biomechanics

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2010

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Vol. 12, no. 4

19-24

EN

The aim of the study was to estimate the influence of trunk inclination on muscle activity during sitting on forward inclined seats without backrest. The group consisting of thirteen healthy women was examined. Based on anthropometrical data two types of sitting position were adopted with two different angles between thighs and trunk: 120 and 135 degrees. Bioelectrical activity of five muscles was recorded. There was observed statistical influence of the trunk inclination on erector spinae, gastrocnemius lat. and tibialis anterior ( p < 0.05). Especially, the inclination of seat pan influenced tibialis anterior activity (10%), although EMG measured during sitting did not exceed 20% of MVC.

9

Isometric Pull-Push Strengths in Workspace. 2, Analysis of Spatial Factors

Das B., Wang Y.

International Journal of Occupational Safety and Ergonomics

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2004

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Vol. 10, No. 1

59--64

EN

The effect of reach levels, horizontal angles and vertical angles on isometric pull and push strengths of males and females in standing and seated positions was determined. The effect of reach levels on strength varied as a consequence of force direction, working position and gender. Reach level has a significant effect on women's pull strength in the seated position and on push strength in the standing position. The strength value was significantly greater in the extreme reach than in maximum or normal reach. Vertical angle ö had a significant effect on strength consistently in all cases. Strength values increased significantly with the increase of ö angles from 0º to 45º to 90º. The horizontal angle è had a significant influence only on the pull strength of standing and seated men and standing women (not seated woman). The maximum strength was significantly greater at è = 90º.

10

Isometric Pull-Push Strengths in Workspace. 1, Strength Profiles

Das B., Wang Y.

International Journal of Occupational Safety and Ergonomics

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2004

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Vol. 10, No. 1

43--58

EN

The isometric pull and push strength profiles of males and females were determined in seated and standing positions in the workspace. The strongest pull strength location was at extreme reach vertically above the shoulder for both males and females. The greatest pull strength of 400 Newtons (N) for males was recorded in the seated and standing positions. Females. pull strengths in the seated and standing positions were 222 and 244 N, respectively. The strongest push strength was always at the maximum reach at the overhead location. Males. maximum push strength was 227 N in the seated position and 251 N in the standing position. Females’ maximum push strength was 96 N in the seated position and 140 N in the standing position. On the average the strength in the standing position was 79% of the seated position. The push strength was 71% of the pull strength and females were 56% as strong as males.

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Sitting Posture, Postural Discomfort, and Visual Performance: A Critical View on the Interdependence of Cognitive and Anthropometric Factors in the VDU Workplace

Ziefle M.

International Journal of Occupational Safety and Ergonomics

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2003

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Vol. 9, No. 4

503--514

EN

The study focuses on individual and standard visual display unit (VDU) workplaces with respect to performance and muscular load. Three different work settings were realized: The workplace was either adjusted to individual preferences or to the European standard. The third condition mirrored exactly the individual setting, however participants were told that it was set according to another standard. Dependent variables were visual performance in a search task, the rated muscular load, and individual preferences. Results show that both individual work settings yielded a superior performance as compared to the standard. However, performance and muscular comfort improved when participants knew they had adjusted the workplace. Apparently, VDU users follow a intuitive rationale adjusting their work setting minimizing muscular load and optimizing performance.

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Dolegliwości kręgosłupa przyczyny i sposoby ochrony

Kamińska J., Liu D.

Bezpieczeństwo Pracy : nauka i praktyka

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2000

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nr 4

16-19