Occupational Ergonomics - Volume 13, issue 2

Authors: Chander, Harish | Garner, John C. | Wade, Chip

Article Type: Research Article

Abstract: BACKGROUND: Slip induced falls have been identified as a major causative factor for injuries in workplace. Firefighter's boots play a critical role in personal safety and affects postural stability. OBJECTIVE: The purpose of the study was to examine slip severity in firefighters while wearing rubber and leather boots. METHODS: Thirty professional firefighters were tested on two separate days with a rubber boot and a randomly chosen leather boot. Firefighters performed a three minute simulated stair climb wearing a full set personal protective equipment (PPE). Following this, they performed normal walking trials and a …slip trial without the knowledge of the slippery floor. After a brief rest, they repeated the stair climb and walking trials followed by another slip trial with the knowledge of the slippery floor. RESULTS: Significant differences were found in slip parameters between boot and slip types. Significantly greater slip parameters were seen in rubber boots and during unexpected slips. CONCLUSIONS: These results suggest that rubber boots elicit greater slip severity indicating a 2.67 to 4.8 times and 2.49 to 3.6 times greater chance of a hazardous slip during unexpected and expected slips respectively, compared to leather boots. These findings provide practical information on firefighting work practices and PPE usage decisions. Show more

Keywords: Firefighter, slips, non-hazardous and hazardous slips, rubber and leather boots

DOI: 10.3233/OER-160241

Citation: Occupational Ergonomics, vol. 13, no. 2, pp. 67-77, 2016

Authors: Torres, Yaniel | Nadeau, Sylvie | Morency, François

Article Type: Research Article

Abstract: BACKGROUND: Fatigue and workload experienced by aircraft de-icing personnel have been largely neglected in occupational health and safety research. OBJECTIVE: To provide an initial assessment of fatigue and workload among de-icing ground crews. METHODS: Company records were used to reveal possible relationships between different variables (age, seniority, truck type, and work shift). A group of 20 volunteer participants (17 men and 3 women) rated their level of fatigue before and after one shift using the Samn-Perelli fatigue scale. Workload was evaluated using the NASA-TLX method at the end of the shift. …RESULTS: The average fatigue experienced by de-icing worker was significantly greater (P = 0.043) for the technicians in open-basket trucks than for the ones in trucks with a cabin (4.43 vs 3.37). Furthermore, there was a significant age difference (P= 0.048) in the perceived level of fatigue (4.1 vs 3.1), with younger workers (< 30 years) reporting a higher level than older workers (≥ 30 years). Overall NASA-TLX score were not significant (P> 0.05) for any of the factors tested: type of truck, shift and age. CONCLUSIONS: The results suggest that particular attention should be paid to young technicians and technicians working in open-basket trucks, since the fatigue levels reported in association with these factors were higher. Show more

Keywords: Aircraft de-icing, fatigue, workload

DOI: 10.3233/OER-160240

Citation: Occupational Ergonomics, vol. 13, no. 2, pp. 79-90, 2016

Authors: Cutlip, Kasey | Nimbarte, Ashish D.

Article Type: Research Article

Abstract: BACKGROUND: The shoulder complex possesses sufficient strength to exert forces in multiple directions. Little is known about the maximum strength and perceived discomfort while performing multidirectional force exertions using shoulder complex. In this study, maximum strengths and perceived discomfort was studied for the exertions performed in the six anatomical directions. METHODS: Eight healthy, right-hand dominant, male participants were recruited for the research. A custom-build device was used to measure shoulder strength at Maximum Voluntary Contraction (MVC). The MVC strength was measured in the six anatomical directions: 1) anterior (+X), 2) superior (+Y), 3) lateral (+Z), 4) …posterior (-X), 5) inferior (-Y), and 6) medial (-Z). In addition, isometric exertions were performed in the six anatomical directions at 20 N, 40 N, and 60 N force levels and the ratings of perceived discomfort were used to quantify the workload placed on the shoulder. RESULTS: The highest MVC strength was observed in the -Y, +X directions, followed by -X, -Z directions. The lowest MVC strength was observed in the +Y, +Z directions. High discomfort was perceived while performing isometric exertions in +Z and -Z directions. Low discomfort was perceived while performing isometric exertions in +X and -X directions. CONCLUSION: The results of this study conclude that the MVC strength and perceived discomfort for the shoulder complex is direction dependent. The exertions performed in the mediolateral direction impose higher workload on the shoulder complex compared to the other directions. Show more

Keywords: Shoulder, MVC strength, perceived discomfort

DOI: 10.3233/OER-160243

Citation: Occupational Ergonomics, vol. 13, no. 2, pp. 91-99, 2016

Authors: Shakouri, Mahmoud | Aghazadeh, Fereydoun | Ikuma, Laura H.

Article Type: Research Article

Abstract: BACKGROUND: Driver workload is an important cognitive factor that can be associated with frustration and unsafe driving behavior. Extensive research has shown the impacts of external factors on driving workload. However, little is known about the influence of individual differences on driver workload. OBJECTIVE: The objectives of this simulation based study are to (a) examine the associations between individual differences and perceived driving workload, and (b) identify the variables that significantly contribute to driver workload within construction work zones. METHODS: Thirty college students (23 males and seven females) navigated through two different work …zone configurations in two levels of traffic density. Demographic variables such as gender, years of driving experience, previous traffic offense and type A personality along with driving behavior questionnaire (DBQ) and driving anger expression inventory (DAX) were used as fixed factors in this study. Self-reported measures of NASA TLX were used to collect subjective workload measurement. RESULTS: The results showed that the best predictors of regression analysis were lapses, adaptive behavior, traffic, gender, work zone layout and vehicular aggressiveness. CONCLUSIONS: There are significant associations among individual differences and driver workload suggesting the need to consider these differences when designing for road safety. Show more

Keywords: Workload, individual differences, work zone safety, NASA-TLX, driving simulator

DOI: 10.3233/OER-160244

Citation: Occupational Ergonomics, vol. 13, no. 2, pp. 101-117, 2016