ABSTRACT
@#The involvement of ageing drivers in traffic accidents were reported but little cited on the severity of auditory driving distractions. Driving distraction contributes to increases in reaction time which can lead to safety traffic risks. Thus, in this study, hand and foot reaction times were measured in response to different distractions within the identical simulated driving route. The task varies in a controlled setting where soundless distractions were present, Comfortable Loudness Level (CLL), Uncomfortable Loudness Level (ULL) auditory distractions, and phone call distraction. Participants were among 40 Malaysian driving license holders consists of 57.5% males and 42.5% females with age mean, (M=51.83, SD=14.058). Results indicated that both hand and foot reaction time were shortest for CLL and longest during phone call. Ageing male scored shortest hand reaction time of 1.15s during CLL distraction. For foot reaction time, ageing male scores shortest of 0.92s for both CLL and no distractions. Pearson’s coefficient of correlation shows r>0.5. The results indicated hand reaction time was affected by foot reaction time (r=0.665), was significantly more for foot when compared with hand, could be because of difference in nerve conduction velocity and movement time of the hand when compared with that of foot.
ABSTRACT
@#An investigation on ablution workstations design for person with disabilities has been carried out in this study. The focused were on wheelchair user or person with lower-limb impairment in Malaysia. The objective of this research is to determine the most suitable ablution workstation for person with disabilities. One hundred wheelchair users which include 74 males and 26 females participated in the study. The findings highlighted that the most suitable and preferred ablution workstation for person with disabilities is a separate design for washing hands and legs. The results also indicated that the noteworthy body parts that should be enhanced are arms, neck, trunk, and legs. Therefore, it can be concluded that it is important to design an ablution workstation with correct anthropometric dimensions referring to the population under investigation taking into account their preferences and disabilities limitation. Thus, the innovation will bring equality between people with disabilities and physically normal people in future facilities design. The workstation will become one of the worthy social contributions to the population of Muslim disabilities especially in Malaysia.
ABSTRACT
It is known that lifting tasks are one of the risk factors of musculoskeletal disorders in the automotive industry. Extensive research has been carried out over the years to develop guidelines and determine safe limits in which an individual can lift. For this reason, the objective of this study is to determine the significant risk factors of musculoskeletal discomfort among manual lifting task workers in the automotive industry, and propose a methodological framework for future research on manual lifting tasks. The subjects of this study comprise 211 manual material handling workers from the automotive industry. The subjects completed a set of questionnaires which are used to elicit information on their demographic characteristics, as well as physical factors and the prevalence of musculoskeletal discomfort. The Chi-Square test was used to determine the relationship between the risk factors and musculoskeletal discomfort. The findings of the study show that the following postures (trunk bent slightly forwards, hands above the knee level (p < 0.05), trunk twisted (over 45o) and bent sideways (p < 0.05) are the significant risk factors of musculoskeletal discomfort among manual lifting task workers in the automotive industry. A methodological framework on manual lifting task in the automotive industry is proposed based on the findings of this study. The framework is developed based on the need to model human lifting capabilities so that task demands can be designed to fit the workers’ capacity when performing lifting tasks.
ABSTRACT
Extensive research has been carried out over the years to determine the maximum acceptable weight that a worker is capable of lifting in a given situation among the Occidental populations in the Europe and US. At present, there is a scarcity of studies in which lifting frequency is used as the measuring variable, especially in developing countries such as Malaysia. Therefore, the objective of this study is to determine the effects of lifting loads on the maximum acceptable frequency limit (MAFL), physiological response (muscle activity) and rating of perceived exertion (RPE) for asymmetric lifting and lowering tasks of Malaysian males.Ten male subjects are recruited in this study and they perform asymmetric lifting and lowering tasks repetitively for 30 minutes. Two lifting loads are considered (1) 1 kg and (2) 5 kg. Each of the subjects adjusts his frequency of lifting using a psychophysical approach. The subjects are instructed to perform the lifting and lowering task as fast as they could over duration of 30 minutes without exhausting themselves or becoming overheated. Electromyography (EMG) signals are recorded from four muscles (Right Erector Spinae (RES), Left Erector Spinae (LES), Right Trapezius p Descendenz (RTD) and Left Trapezius p Descendenz (LTD) and analysed in terms of the normalized MVC during asymmetric lifting and lowering tasks. The ratings of perceived exertion (RPE) for four body parts (arms, lower back, shoulders and entire body) are also collected after the subjects have completed the lifting and lowering task. The mean frequency of the lifting and lowering task obtained from the experiment is 13.41 and 9.66 times/minute for a lifting load of 1 and 5 kg, respectively. The results of the independent sample t-test show that load has a statistically significant effect on the maximum acceptable frequency limit (p 0.05). The percentage decrease in the maximum acceptable frequency for Malaysian males is higher than the Occidental populations for both of the loads investigated in this study.
ABSTRACT
It was suggested by most researchers that train drivers’ workload and alertness levels attribute to train accidents. The main objective of this study is to determine the significant patterns of mental workload and alertness levels of train drivers with respect to the conditions. The data are collected from simulation experiments on 15 professional train drivers. The simulation experiments are performed under three driving conditions (i.e. daytime, rainy daytime and rainy night) using a train driving simulator set. Electroencephalogram (EEG) signals are collected from six significant points on the body of the subjects. It is found that the mental workload of the train drivers tends to be high during rainy night driving condition and sleepiness occurs which is indicative of low vigilance. The beta amplitude increases under rainy night driving condition which may be attributed to viewing difficulties while driving in the dark. The results reveal that there is a significant different between each session (p = 0.042) especially with the pattern for rainy night driving. It is also observed that there is lower mental workload among the train drivers, which indicates that the train drivers are detached from their work.
ABSTRACT
Most studies have examined the association of ergonomic risk factors and musculoskeletal discomfort in developed countries. Meanwhile the data are still lacking in developing countries such as Malaysia. The aim of this study was to determine the relation between risk factors and musculoskeletal discomfort among manual material handling workers in Malaysian automotive industries. A total of211 manual material handling workers from automotive industries completed a set of questionnaire on the individual, physical and environmental factors and the prevalence of musculoskeletal discomfort. The Chi-Square test and logistics regression analysis were used to determine the relationship of the risk factors and musculoskeletal. The findings highlighted that job tenure was significantly correlated with musculoskeletal discomfort among the workers (OR=2.33-5.56). The most significant physical risk factor that was associated with musculoskeletal discomfort was bending the trunk forward slightly, hands above knee level, which was significantly related to lower back discomfort (OR=5.13, 95%CI=1.56-16.8), thigh discomfort (OR=5.1, 95%CI=1.01-25.53) and wrist discomfort (OR=3.65, 95%CI=1.06-12.53). Twisting of the trunk (over 45o) and bending sideways were significantly associated to lower back discomfort (OR=4.04, 95%CI=1.44-14.44), and thigh discomfort (OR=4.3, 95%CI=1.29-8.50). The findings also highlighted that environmental factors was associated with musculoskeletal discomfort (p < 0.05. Musculoskeletal discomfort can be reduced by lowering work-related risk factors among automotive manual material handling workers, particularly by focusing on significant factors, including job tenure, bending or twisting postures and environmental factors.