A quatitative approach for establishing safe weight of lift

The objective of this work was to formulate a mathematical model for predicting a safe weight of lift. Considering the intratruncal pressure, post-work height shrinkage of the worker and strain energy of the intervertebral disc, the SWL function was derived in terms of the Young Modulus of elasticity (E) of the articular cartilage (endplate of the disc); velocity of lift (u); acceleration due to gravity (g); vertical location of the load (V); horizontal length of the load from the ankles (H); vertical displacement of the load (D); the angle of lift ("theta") and the lifter’s anthropometric dimensions. To evaluate the function for a particular individual, the value of the length of the spine from the first thoracic to the last lumbar vertebrae, the heights just before the start and after the close of work were measured to determine the height shrinkage. Additionally, the breadth and depth of the trunk were measured. A range of values of the function parameters: V, H and D were adopted from National Institute for Occupational Safety and Health (NIOSH), while E and U were also taken from the literature. SWL values were computed and compared to those of the Recommended Weight Limit (RWL) of NIOSH and Maximum Acceptable Weight of Lift (MAWL) from the literature. At an average height shrinkage of 0.014 m and a maximum permissible shrinkage of 0.21 m, the SWL and SWLMax values were significantly different (at 95% level confidence) from the corresponding RWL and the MAWL values

A quatitative approach for establishing safe weight of lift

The objective of this work was to formulate a mathematical model for predicting a safe weight of lift. Considering the intratruncal pressure, post-work height shrinkage of the worker and strain energy of the intervertebral disc, the SWL function was derived in terms of the Young Modulus of elasticity (E) of the articular cartilage (endplate of the disc); velocity of lift (u); acceleration due to gravity (g); vertical location of the load (V); horizontal length of the load from the ankles (H); vertical displacement of the load (D); the angle of lift ("theta") and the lifter’s anthropometric dimensions. To evaluate the function for a particular individual, the value of the length of the spine from the first thoracic to the last lumbar vertebrae, the heights just before the start and after the close of work were measured to determine the height shrinkage. Additionally, the breadth and depth of the trunk were measured. A range of values of the function parameters: V, H and D were adopted from National Institute for Occupational Safety and Health (NIOSH), while E and U were also taken from the literature. SWL values were computed and compared to those of the Recommended Weight Limit (RWL) of NIOSH and Maximum Acceptable Weight of Lift (MAWL) from the literature. At an average height shrinkage of 0.014 m and a maximum permissible shrinkage of 0.21 m, the SWL and SWLMax values were significantly different (at 95% level confidence) from the corresponding RWL and the MAWL values

Anthropometric design of furniture for use in tertiary institutions in Abeokuta, South-western Nigeria

Students sit for most of the time on school furniturein the classroom. However, the design of schoolfurniture in Nigeria using the anthropometric dataof the users has yet to be given adequate attention.This study was carried out to obtainanthropometric data of students in higherinstitutions of learning in Nigeria for the design ofergonomics chairs and tables for use by students inthose institutions. Seven hundred and twenty (720)students in three selected institutions participatedin the study. Various body dimensions (sittingelbow height, shoulder height, knee height,popliteal height, buttock-popliteal length, statureand body weight) of the students were measuredusing standard anthropometer and 5 th, 50th, and95 th percentiles of the data obtained werecomputed using a SPSS 16.0 statistical package.The existing furniture dimensions in the selectedinstitutions were also measured. Based on theobtained anthropometric data, this paper proposesfurniture design dimensions for seat height, seatdepth, seat width, backrest height (upper), armrestand desk height for students in the selected tertiaryinstitutions. The present study may be a pointer tothe effect that in the design of tables and chairs foruse in higher institutions, the anthropometric dataof the Nigerian students were not considered. It ishereby recommended that similar study should becarried out in other sections of the country

Analysis and Modeling of Physiologic Equivalent Temperature of an Outdoor Environment

This study developed a model that depicts the relationship, strength, and direction of the causality between the predictor variables (microclimatic variables) and a response variable (ambient temperature) interpreted for the physiologic equivalent temperature of an environment. Data collected were microclimatic variables which include air circulation, relative humidity, mean radiant and ambient temperatures over land cover materials namely tarmac, grass, soil and concrete at the premises of Federal University Wukari, Taraba state of Nigeria at a guided height of 1.1 m. The data was collected using physical measurements with respect to time of the day; morning (8:00 – 9:00 am), afternoon (1:00 – 2:00 pm) and evening (6:00 – 7:00 pm) and season of the year; dry (November – March) and wet (April – October) from April 2016 to March 2017. Comparative analysis of the data obtained from the survey and that of the developed model gave percentage variation range of 0.5 – 6.8%. However, in both cases there is an association between the microclimatic variables and the ambient temperature on each of the considered materials, season and measurement intervals. The ranges of the physiological equivalent temperature for different grades of thermal sensation and physiological stress on the land cover materials in this study was 30.2 – 43.3 °C which of intense thermal range. The physiologic equivalent temperature analysis for the land cover materials showed that there was variation in the mean radiant temperature with intense thermal effect in season and measurement intervals. This study depicted that combined use of several land cover materials in a particular area has impact on the mean radiant temperature. This necessitate that the design of the land surface environment should be with due consideration to the convective heat exchange between the outdoor workers and the ambient environment for their thermal comfort and occupational heat stress

Anthropometric studies for designing to fit gari-frying workers

 Work system and product design require anthropometric data of the user population relevant to the facility in order to have safe operation in service as well as increase user satisfaction and efficiency. Designing to fit gari-frying workers in each of the southwestern states in Nigeria is geared towards this end. The age, weight and twenty-five body dimensions of 120 gari-frying workers in Lagos, Ogun, Oyo, Osun, Ondo and Ekiti, selected by random sampling, were measured. The body dimensions include stature, shoulder height, sitting height, eye height, forward grip reach, buttock-popliteal height, buttock-knee length, knee height, thigh clearance, forearm-to-forearm breadth, waist depth, elbow rest height, knuckle height, elbow grip length, hip breadth, hand length, hand breadth, hand thickness, grip span and lumbar height. SPSS 20 software was used to perform statistical analysis to determine the mean, standard deviation, minimum and maximum values, 2nd, 5th, 25th, 50th, 75th and 95th percentiles for each state. Ogun state was used as a control, against which means of body dimension data, collected from other states, were compared using paired sample t-test. The results revealed that some of the body dimensions showed significant difference across the states at P≤0.05 with Oyo having more anthropometric parameters that differ from that of Ogun and Ondo having the least. Between 11.42% and 24.25% difference in the mean age, weight and lumbar height was observed in all the states. Osun state has the highest mean BMI and BSA values of 32.38 kg/m2 and 1.82 m2, respectively. These results are the required data for the design of facility and products for gari-frying workers as well as in similar women workspaces, especially in processing centres

AN ERGONOMICS ASSESSMENT OF PASSENGER SEATS IN BUSES IN SOUTH WESTERN NIGERIA

SAŽETAK: Cilj ovoga rada bio je doći do antropometrijskih podataka o korisnicima putničkih autobusa i ispitati moguću neprilagođenost sjedala antropometrijskim mjerama. U istraživanju je sudjelovalo 200 ispitanika između 20 i 55 godina starosti. Provedeno je jedanaest antropometrijskih mjerenja, a izmjerene su i dimenzije sjedala u 30 Toyotinih autobusa koji se koriste u javnome prijevozu. Izračunate su srednje vrijednosti, standardne devijacije, te peti, pedeseti i devedesetpeti postotak. Uspoređene su tjelesne mjere putnika i dimenzije sjedala. Rezultati pokazuju određenu neprilagođenost dimenzija sjedala tjelesnim mjerama. Zaključak je da se pri izradi autobusnih sjedala nisu koristili antropometrijskim podacima za tu populaciju. Iz ovoga se može zaključiti da se u cijeloj zemlji antropometrijski podaci nisu koristili pri izradi autobusnih sjedala.The objective of the study was to survey and obtain the anthropometric data of users of passenger buses and examine the possible mismatch between their relevant dimensions and the seats they sit on when in these buses. Two hundred passengers participated in the study with ages ranging from 20 years to 55 years. Eleven anthropometric measurements were taken. Also, the dimensions of the locally fabricated seats in 30 Toyota Hiace buses were measured. The means, standard deviations, fifth, fiftieth and ninety fifth percentiles were calculated. Moreover, the passengers’ body dimensions and seat dimensions were compared. The results showed a degree of mismatch between the passengers\u27 bodily dimensions and the seat dimensions. It was thus concluded that the anthropometric data of the Nigerian passengers was not employed in the manufacture of the seats in the buses. This may be an indication that seats in the buses and passengers’ anthropometric dimensions are at variant nationwide

AN ERGONOMICS ASSESSMENT OF PASSENGER SEATS IN BUSES IN SOUTH WESTERN NIGERIA

SAŽETAK: Cilj ovoga rada bio je doći do antropometrijskih podataka o korisnicima putničkih autobusa i ispitati moguću neprilagođenost sjedala antropometrijskim mjerama. U istraživanju je sudjelovalo 200 ispitanika između 20 i 55 godina starosti. Provedeno je jedanaest antropometrijskih mjerenja, a izmjerene su i dimenzije sjedala u 30 Toyotinih autobusa koji se koriste u javnome prijevozu. Izračunate su srednje vrijednosti, standardne devijacije, te peti, pedeseti i devedesetpeti postotak. Uspoređene su tjelesne mjere putnika i dimenzije sjedala. Rezultati pokazuju određenu neprilagođenost dimenzija sjedala tjelesnim mjerama. Zaključak je da se pri izradi autobusnih sjedala nisu koristili antropometrijskim podacima za tu populaciju. Iz ovoga se može zaključiti da se u cijeloj zemlji antropometrijski podaci nisu koristili pri izradi autobusnih sjedala.The objective of the study was to survey and obtain the anthropometric data of users of passenger buses and examine the possible mismatch between their relevant dimensions and the seats they sit on when in these buses. Two hundred passengers participated in the study with ages ranging from 20 years to 55 years. Eleven anthropometric measurements were taken. Also, the dimensions of the locally fabricated seats in 30 Toyota Hiace buses were measured. The means, standard deviations, fifth, fiftieth and ninety fifth percentiles were calculated. Moreover, the passengers’ body dimensions and seat dimensions were compared. The results showed a degree of mismatch between the passengers\u27 bodily dimensions and the seat dimensions. It was thus concluded that the anthropometric data of the Nigerian passengers was not employed in the manufacture of the seats in the buses. This may be an indication that seats in the buses and passengers’ anthropometric dimensions are at variant nationwide

Safe Backpack Mass for Students in Tertiary Institutions

Abstract Load carrying using backpacks is common among students from primary schools to tertiary institutions in Nigeria. Backpacks are used for carrying books and other school materials. The aim of this study is to determine the mass of backpack that students in tertiary institutions using strain energy principles of the spine. Ten students in a selected tertiary institution participated in the study. A model was developed using strain energy in terms of chest width, chest depth, Young Modulus of Elasticity of articular cartilage, maximum permissible spinal shrinkage, length of spine and body height of the students. The 5 th , 50 th, ands 95 th percentiles of the data obtained were computed using a SPSS 16.0 statistical package. The study confirmed that the model is valid and showed that the maximum backpack load limit for students in tertiary institutions should be 12% of body mass. Similar studies were recommended to be carried out in primary and secondary schools