Driving posture is important to determine the comfortability of the driver. The purpose of this study is to investigate the muscle response in car pedal operation. To evaluate this response, 11 volunteers involved in simulated driving experiment using an electrical impedance myography to detect the muscle contraction of the lower leg, particularly at Gastrocnemius medial (GM). The driver requires to perform different pedal actions. The results depict that GM muscle shows different reaction according to pedal actions. According to these results, different degree of ankle angle lead to different muscle response. These findings help us to understand the effect of physical attribute related to muscle response and joint angle on driver during monotonous driving task.
The main objective of the study is to determine the noise level emitted by the machinery and equipment used at a Liquefied Petroleum Gas in Melaka, Malaysia. The study also aims to determine the exposure level of noise to the employees. The machinery and equipment noise level was measured using a calibrated sound level meter. Noise level of each source was measured by pointing the sound level meter microphone at normal working distance to the source. Personal noise exposure was conducted at the shoulder of the personnel and as close as possible to the personnel’s ear. From a total of 154 noise sources points identified at three work areas surveyed, 122 points were above Action Level of 85 dBA of which 57 points had exceeded the Permissible Exposure Limit of 90 dBA. For the personal exposure monitoring, ten out of fourteen had exceeded the Action Level of 85 dBA for those working for 8 hours and 82 dBA for those working for twelve hours and one of them had exceeded the Permissible Exposure Limit of 87 dBA for those working for twelve hours. The monitored personnel have exceeded the Maximum Level and the Peak Level limit of 115 dBA and 140 dB respectively. From the study, it is concluded that further noise monitoring is needed especially when there are changes to the work process and equipment used. Also the requirement to notify the selected workers on the personal noise exposure result, actions to reduce noise level at the workplace through engineering control methods and administrative controls.
Discomfort and pain issue at the body part are common complaints reported by car drivers. It is due to driving task
require physical demands and need to maintain and adapt several postures in a constrained space while controlling
the car. Hence, this study aims to determine the pattern of shoulder activation muscle consisting of the Trapezius
muscle in two different driving posture. Respondents were required to grasp the steering wheel at 8 and 4 hand
position. The Surface Electromyography was used to get the reading for left muscle’s Trapezius Descendent (TD) at
two different positions; i) closest distant from steering wheel and ii) far distant from the steering wheel. Then,
Temporal Analysis was used to evaluate the pattern of the driving action. From the experiment, it shows the
different value of muscle activation occurred while driving according to turning action. The far seated position
depicted greater activation on driving action compared to the closer seated to the steering wheel. In conclusion, the
driving posture effects the activation of shoulder and arm’s muscles as early as after 20 seconds of driving activity.
Hence, choosing the correct driving posture allowed a comfortable driving environment for the driver.
Motorcyclists are particularly vulnerable when compared to large vehicles on the road. This study was conducted to gather feedbacks from motorcycle deliveryman regarding their riding conditions. A self-rated questionnaire was used to determine prevalence of riding symptom and its association with Whole Body Vibration and other associated factors among motorcycle deliveryman in Malaysia. A set of questionnaire was developed, pilot tested for its reliability and validity and distributed to 100 respondents. An interview was conducted after gathering the data from the respondents through the questionnaire. Survey findings show majority of the respondents preferred to ride according to the standard riding posture. Large majority of them agreed handlebar and foot peg/rest exposed them directly to the vibration. In addition, majority of them felt discomfort at the lower back and felt fatigue after long hours of riding. These findings are in-line with past studies regarding the road users.
Proper driving requires a proper posture to bring comfort to drivers. A problem that commonly exists in driving is incorrect driving posture which can cause discomfort to the driver, especially when interacting with automotive pedals. Research on contraction of tibialis anterior (TA) muscle on driver's posture based on the knee angle less than 101º in a position of pressing and releasing a pedal was conducted to investigate and overcome this problem. This is a field experiment study and surface electromyography (sEMG) is used in collecting data on the TA muscle. The procedure of collecting data on the TA muscle before and after experiments follows the Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles (SENIAM) recommendations. The result of the experiment shows that there is a strong negative relationship between driver's postures in nature based on the angle of the knee with TA muscle contractions, where the Pearson correlation coefficient (r) is - .993. While the temporal analysis measurements based on Maximum Voluntary Isometric Contraction (MVIC) 60% in a position of releasing a pedal exceeding rms μV 39.38, are 39.71 and 40.25 respectively. On the other hand, MVIC 2% rms μV values: 1.19 and 1.2 are obtained in the position of pressing the pedal. The knee angle with TA muscle contractions is significant [F (1, 10) = 660, p
Introduction : Shift work is practised in manufacturing industry to increase production capacity up to three times compared to the normal daily eight hours working system and able to optimize the utilization of machine and equipment. However, shift work has negatif effects on human social interaction, health and safety.
Methodology : The study was conducted to evaluate production workers’ perception on the effects of working at night shift. The respondents of the study were production workers in Company X in Kuala Lumpur. The Data was collected using self administered questionnaires. The study objectives was to study the work schedule design, to find out their perceptions on the effects of night shift and to study on personal factors, employees’ level of acceptance on the work schedule design and personal factors that cause safety and health disruption.
Result : A total of 200 production workers participated in the study. The result of the study shows 61% of production workers took sick leave and 43.5% were absent between 1 and 2 times a month. In terms of health and safety disruption, 77% of respondents agreed that they faced lack of focus with family and friends, 75.5% of them did not have enough sleep and 76.5% felt sleepy during working time. Regarding the work schedule and workstation design, 81.5% said they felt uncomfortable because they were required to stand during working and 77% felt that the resting period provided by the factory was too short and inadequate. More than 70% of the respondents proposed the rest period should be extended from the current 40 minutes to one hour. More than 80% of respondents agreed they would feel comfortable if standing at work is changed to sitting work system.
Conclusion : To minimize the unwanted effect of night shift among the production.
Prolonged sitting is one of the factors for back discomfort. Sitting in the same position for long periods of time is worse.
This experimental based study was conducted to achieve three objectives. There were to 1) identify whether is there any
differences between perceived body discomfort among respondents before and after upright sitting, 2) identify whether
is there any differences between perceived body discomfort among respondents before and after slump sitting and 3)
compare the level of perceived body discomfort among respondents after two sitting postures. Thirty young and healthy
adults were recruited as study respondents. Each respondent was asked to sit in a posture either upright or slump for 30
minutes. Respondents were then rated their body discomfort using Borg CR-10 scale before and after sitting. Another
sitting posture was carried out after one day interval. There is a significant difference between perceived body
discomfort among respondents before and after upright and slump sitting. Body discomfort of upright sitting was shown
significantly greater than slump sitting. Although, slump sitting caused less discomfort than upright, but it proven by
previous studies did not provide benefit to occupational safety and health practice in preventing occupational health
related disease.
Measuring discomfort towardthe car seat is important as the act of driving requires a driver to remain at the car seat
while controlling the car. The seat condition, including sitting position as well as the driver’s posture can lead to
discomfort and fatigue. The objective of this study is to investigate a driver’s pressure distribution in static and
dynamic circumstances for two types of cars; the sedan and compact car. This study involved both subjective and
objective evaluations of 12 respondents. For the subjective evaluation, the Visual Analog Scales (VAS) were used to
obtain respondents' perception of discomfort. For the objective evaluation, pressure distribution readings of the seat
interface were obtained using piezo capacitive sensors. The findings showed that the highest pressure was recorded
for the compact car. Furthermore, the static circumstance showed greater pressure compared to the dynamic state.
Subjective evaluation indicated that the right buttocks and the lower back (lumbar)experience the highest discomfort
for both types of seats.The type of seat found to contribute to the value of different pressure. Thus, it can be
concluded that appropriate seat selection can reduce pressure as well as discomfort.
Safe driving requires an ideal posture to bring comfort to drivers. A problem that commonly exists in driving is nonideal
driving posture, which can cause discomfort to the driver, especially when interacting with automotive pedals.
Research on contraction of Soleus muscle on driver's posture based on the knee angle more than 144º in a position of
pressing and releasing a pedal was conducted to investigate and overcome this problem. This is a field experimental
study and surface electromyography (sEMG) is used in collecting data on the Soleus muscle. The procedure of
collecting data on the Soleus muscle before and after experiments follows the Surface Electromyography for the
Non-Invasive Assessment of Muscles (SENIAM) recommendations. The result from the experiment shows that there is
a strong positive relationship between driver's postures in nature based upon the angle at the knee with Soleus
muscle contraction, where the Pearson correlation coefficient (r) is .990. While the temporal analysis measurements
based on Maximum Voluntary Isometric Contraction (MVIC) 60% in a position of pressing a pedal exceeding rms µV
25.34, and 25.47 respectively. On the other hand, MVIC 3% rms µV values: 1.18, 1.21 and 1.26 are obtained from the
position of releasing the pedal. The knee angle with Soleus muscle contractions is significant [F (1, 10) = 38.06,
p
Proper driving requires a proper posture to bring comfort to drivers. A problem that commonly exists in driving is
incorrect driving posture which can cause discomfort to the driver, especially when interacting with automotive
pedals. Research on fatigue of Soleus muscle on driver's posture based on the knee angle more than 144º in a
position of pressing and releasing a pedal was conducted to investigate and overcome this problem. This is a field
experiment study and surface electromyography (sEMG) is used in collecting data on the Soleus muscle. The
procedure of collecting data on the Soleus muscle before and after experiments follows the Surface
Electromyography for the Non-Invasive Assessment of Muscles (SENIAM) recommendation. The result of the
experiments shows that there is a strong positive relationship between driver's postures in nature based on the angle
of the knee with Soleus muscle contraction, where the Pearson correlation coefficient (r) is .890. While the muscle
fatigue index based on value MDF (MNF) in position of pressing a pedal. The results show that the Soleus muscle
fatigue occurs when the foot pressing a pedal on MVC-normalized 60%. This is because the value of MDF (MNF) there
is displacement of decrease of frequency MDF (MNF), from 130.21 Hz (313.42 Hz) to 127.60 Hz (312.49 Hz). The
increase in the knee angle will directly provide discomfort to the driver while interacting with the pedal; and this is
due to Soleus muscle fatigue.
Posture is one of the most important factor that need to be considered in any postural analysis. Awkward, extreme,
and repetitive postures can increase the risk of musculoskeletal disorders (MSDs). As observational methods are more
widely used than instrumentation-based methods to assess postural problems, this study reviews and assesses the
scientific literature of observational methods and focused on pen and paper based specifically. In order to identify the
published methods, a list of English or Malay articles dating as far back as 1990 was compiled from PubMed, Science
Direct and Google Scholar. The keywords were ergo*, posture*, method*, observational*, postural problems*, pen and
paper*, posture analysis*, indirect* and macro-ergo*. In addition, a secondary search was also performed using
bibliography of retrieved articles so that additional papers for conducting review and evaluations can be collected. A
total of 121 articles that assessed postural problems in working activities were found. However, after intensive
screening process only 6 articles were selected to be further analyzed. Posture of upper arms/shoulder, lower arms/
elbow, wrist, neck, back/trunk and leg were highlighted in this study. The limitations and the strengths of the
published pen and paper based observational method focusing on those postures were also discussed. The finding of
this review will benefit researchers in the process of understanding unsafe posture in workplace. It could also provide
to researcher on how to improve the current pen and paper based observational method for assessing postural
problems.
While driving, a driver is required to control the steering wheel to change direction. The driver’s muscles of the upper
limbs and shoulders are involved in such a task. Therefore, an assessment of the driver’s physiology according to
certain condition is necessary to improve driving comfort and safety. This study aims to investigate the driver’s
Deltoid Anterior (DA) muscle activity while operating the steering wheel. Eleven test subjects were recruited for an
experiment using a car simulator. They were required to remain in the car seat and perform the task of steering the
wheel. Surface electromyography (SEMG) was used to record each subject’s muscle contraction while turning the
steering wheel to the right and left by several degrees. According to the findings, 45 degrees turning recorded the
highest Root mean Square (RMS) value for DA. In addition, DA muscle activation increased with more degrees turning.
This An Ergonomic hazard often exists in any industry. However, majority of the employees are not aware of practicing good body posture until the MSDs symptoms become permanent and chronic. The main objective of this study is to determine the manual handling problems among workers at an electronic component manufacturing company. The scope of this study focused on the study entire body disorders among workers on electronic manufacturing company using the Rapid Entire Body Assessment (REBA). A cross sectional study involving observation of the workplace, the work task and the working environment, photographs and videos taken during the observation. Later, a survey questionnaire was given to the respondents to obtain their socio-demography information, work activity and health problems. Rapid Entire Body Assessment (REBA) was conducted on all respondents to determined REBA scores in different work positions. The study was conducted at an electronic component manufacturing company located in Klang Valley, Selangor. A total of 124 workers were surveyed and REBA assessment was performed on 20 workers at Company X production area. It includes 5 categories of position at Company X, such as:loading steel bar into casing; pushing the steel bar, turning movement while adjusting the steel bar, adjusting steel bar into the loading area, unloading steel bar from casing into the machine. The study found that turning section has the highest MSDs problems regarding manual handling because majority of the respondents in the turning department felt the pain while performing their work. This is due to their job demand, which they need to handle with tools weighing from 200 to 400 kg. The REBA scores showed that17 out of 20 respondents performing turning operations, moving and pushing the steel bar recorded the highest score of 11 or more which are categorize in the very high risk group. The position of pushing and turning steel bar while moving the steel bar has higher risk that contributed to the ergonomics risk factor, which in-turn can contribute to Muscular Skeletal Disorders (MSDs). More detailed investigation and remedial measures should be taken immediately, especially for the workers performing the manual handlings activities.