Occupational Ergonomics - Volume 11, issue 1

Authors: Reilly, Tara | Olinek, Simone

Article Type: Research Article

Abstract: Background: Recent observations and feedback from military operations demonstrated the need to reassess the validity of a fireman's carry (FC) as an assessment of casualty evacuation ability in the Canadian land forces command physical fitness standard. Objective: The objective of this research was to determine: (1) the most common methods of casualty evacuation employed by the Canadian land forces (LF), (2) performance of land forces personnel on casualty evacuation abilities, and (3) potential predictive fitness tests (PFT) for performance on a casualty evacuation task. Methods: Task analysis, interviews, observations, and subject matter experts were used to …identify the common casualty evacuation methods. Simulations of these methods were developed and validated. LF members performed these evacuation methods and 7 PFT to their maximum ability (N=118). These data were analyzed using step-wise regression analysis, ANOVA and Pearson product moment correlations. Results: Casualty drag (CD) and vehicle extrication (VE) were found to be the most common methods of casualty evacuation. Males performed significantly better on VE and CD compared to females. CD predicted VE, and the addition of grip strength and static squat performance improved the prediction by 26% to account for 65% of the variability in VE. Of the LF members tested, 88% were able to drag an 82 kg casualty 25 m and 83% succeeded in extricating an 82 kg casualty from a light armored vehicle. Conclusions: It is recommended that the FC be replaced by a 25 m CD. It is not recommended that VE be tested, as it is expected that VE of an 82 kg casualty could be performed by two soldiers; all subjects capable of dragging an 82 kg casualty could also extricate 41 kg. Show more

Keywords: Military, casualty, fitness standard

DOI: 10.3233/OER-130203

Citation: Occupational Ergonomics, vol. 11, no. 1, pp. 1-9, 2013

Authors: Kuruganti, Usha | Albert, Wayne J.

Article Type: Research Article

Abstract: Background: The aquaculture industry is growing in Canada and is particularly strong in Atlantic Canada. Workers in the fish processing industry are required to complete a variety of tasks in a typical day and there is concern for musculoskeletal disorder. Objective: The purpose of this study was to examine the daily operations of fish processing workers to determine any musculoskeletal concerns. Methods: The ergonomic assessment consisted of several plant visits to observe the processing line and the requirements of the workers. Video recordings were made of each stage of the assembly lines. The video data was …analyzed to determine high-risk jobs and to identify areas of concern. Cumulative loading was assessed using posture matching software and the video data. A Job Strain Index (JSI), Rapid Upper Limb Assessment (RULA) and the revised NIOSH lifting equation were used to identify high-risk tasks. Results: The data showed that six tasks were considered high risk; sorting fish, removal of fish bones, trimming of fish, pallet loading/conveyor operation, fish processing and cleaning of the trim machine. In addition, four categories of occupational health and safety (OHS) hazard concerns were identified (physical, chemical, biological, and psychosocial). Each category was then broken into their causative agents and potential health effects on the worker. Conclusions: Several areas for improvement were identified at this seafood processing plant. Six jobs were identified as high risk and in need of intervention. Changes in pace of work, workstation height, and new equipment would also help reduce the number of musculoskeletal injuries. The issue of job rotation should also be examined to determine its impact on musculoskeletal health. Implementation of strategies to reduce musculoskeletal disorders will help to improve the health of these workers. Show more

Keywords: Aquaculture, fish processing, ergonomics, musculoskeletal disorders

DOI: 10.3233/OER-130204

Citation: Occupational Ergonomics, vol. 11, no. 1, pp. 11-19, 2013

Authors: Antle, David M. | Vézina, Nicole | Messing, Karen | Côté, Julie N.

Article Type: Research Article

Abstract: Background: Some proposed mechanisms for the development of back discomfort and musculoskeletal disorders relate to fatigue of trunk musculature, but these phenomena require further investigation. Hydrostatic pressure changes in vascular tissue are thought to drive development of lower limb discomfort and vascular disorders; however, specific vascular outcomes during standing work have not been investigated experimentally. Objectives: The goals of this experiment were to evaluate the effects of standing work on indicators of discomfort and on biological variables related to risk for trunk musculoskeletal andlower limb vascular disorders. Methods: Ten university-aged female volunteers, who did …not work in jobs requiring prolonged standing, moved small objects between two containers for 32 minutes while standing. Electromyography from the erector spinae and rectus abdominis, lower limb blood flow data, brachial and ankle blood pressure, heart rate, and discomfort ratings were collected every 4 minutes. Results: There were no significant changes in electromyography outcomes for either muscle group. Foot and soleus blood flow (p < 0.05) and ankle blood pressure (p < 0.05) increased over time. There were strong correlations (> 0.8) between lower limb discomfort (feet and knees) and blood flow in the foot and soleus. Conclusions: Blood pooling may explain the discomfort associated with the simulated standing work evaluated here, and this vascular indicator should be tracked when attempting to alleviate lower limb symptoms in various working postures. Additional work is needed to determine which musculoskeletal indicators might explain back discomfort during standing. Show more

Keywords: Prolonged standing work, ergonomics, discomfort, blood flow, electromyography

DOI: 10.3233/OER-130205

Citation: Occupational Ergonomics, vol. 11, no. 1, pp. 21-33, 2013

Authors: Ismaila, Salami Olasunkanmi | Oriolowo, Kolawole Taofik | Akanbi, Olusegun Gabriel

Article Type: Research Article

Abstract: Background Many ways have been adopted in measuring workers', responses to manual tasks in order to appraise the incompatibility of work demands to the capabilities of the workers. Heart rate is commonly used to estimate the energy expenditure or physical strain in physically demanding job. Objective: The main purpose of this study was to build a prediction model using the neural network to reflect the effects of age, body height, body mass, and resting heart rate on the working heart rate (HWorking ) and % relative heart rate (%RHR) of bricklayers. Methods: A neural network …in SPSS 16.0 was applied to identify the importance of the inputs (age, body height, body mass, resting heart rate) in predicting the outputs (working heart rate and % RHR) of a function. Results: The results show that the mean % relative heart rate (RHR) was 57.4%. The mean working heart rate was 120.8 bpm and that of resting heart rate was 68.6 bpm. It was also shown that the neural network could be trained to predict HWorking and % RHR. This also demonstrates that there is a non-linear relationship between the age, body height, body mass, resting heart rate, working heart rate and % RHR. The neural network results for the HWorking and % RHR were dominated by resting heart rate, followed by body mass, age and body height in that order. The predicted values of % RHR and HWorking did not differ significantly from the actual values though the relationships were non-linear. Conclusions: The neural network might be used to predict the % RHR and HWorking of bricklayers in Nigeria given age, body height, body mass and resting heart rate. Show more

Keywords: Relative heart rate, working heart rate, neural network, bricklayers

DOI: 10.3233/OER-130207

Citation: Occupational Ergonomics, vol. 11, no. 1, pp. 35-43, 2013

Authors: Spyropoulos, Elias | Chroni, Elisabeth | Katsakiori, Panagiota | Athanassiou, George

Article Type: Research Article

Abstract: Background: Fatigue is a timely topic that has been studied in a laboratory setting, yet still remains difficult to apply in an industrial setting. Objective: The aim of the present study was to define possible indicators of fatigue accumulation for an over shoulder level repetitive lifting work while performing lifting in two different ranges (LR1, LR2) in a supermarket. Methods: Video-based kinematics parameters were estimated and surface electromyography (EMG) of the anterior deltoid muscle was analyzed for nine healthy female subjects. A static biomechanical model to assess the effect of LRs on fatigue and a new …fatigue index to allow for the estimation of substantial fatigue onset time (TSFO) were developed. Results: The data showed that fatigue accumulation strongly depends on the LRs. According to TSFO (time to substantial fatigue onset), shoulder muscle fatigue was unexpectedly lower when performing LR1 than LR2. Conclusions: The study shows a holistic analysis approach, suitable for the design of work/rest ratios in the occupational ergonomics field. Show more

Keywords: Shoulder fatigue, musculoskeletal disorders, electromyography

DOI: 10.3233/OER-130206

Citation: Occupational Ergonomics, vol. 11, no. 1, pp. 45-57, 2013