This study was conducted to analyses the Biceps Brachii (BB) muscle contraction during different driving postures. Drivers’ posture is one of the factors that contribute to driving fatigue that eventually may lead to road accident and injuries. The experiment conducted for this study is using the surface electromyography (SEMG) method for objective evaluation of muscle involved in driving activities. A total of 14 participants are involved in the experiment. The experiment was done on three different posture based on comfortable angles published by previous research. From the results analysis, the RMS value for activity left turn is lower than activity for right turn for all three postures and results also shows that posture B with elbow angle of 134° is perceived as most comfortable based on the lowest value of muscle contraction with a value of 15.67μV. The outcomes from this study are hoped to benefit both manufactures and also car users in ensuring better and optimum driving postures that can avoid fatigue and injuries.
comfort ; seat design ; surface electromyography ; driving posture ; muscle contraction

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.
Trapezius ; steering wheel ; SEMG ; driver ; temporal analysis ; driving posture

In this paper, a biodynamic model of human upper-body in the seated posture is developed. Based on d'Alembert's principle, the non-linear biodynamic equation of the modelling is derivated. Furthermore, the function of frequency and amplitude of modelling is obtained by employing the KB method in the non-linear theory. The response of realistic human parameters and the external stimulus on the modelling is simulated by MATLAB. The results show that the modelling presents a plenty of non-linear characteristics. The parameters identified and the stable areas to keep the stabilization of upper-body in the seated posture are discussed. These data can be used to explain and estimate the mechanism for the maintenance of stable trunk posture due to the mechanical shocks transmitted through the vehicle seat.
Automobile Driving ; Biomechanical Phenomena ; Humans ; Low Back Pain ; etiology ; Models, Biological ; Nonlinear Dynamics ; Posture ; physiology ; Spine ; physiology ; Vibration

OBJECTIVETo evaluate the effects of different vibration frequency on the back muscle fatigue during simulated driving.

METHODSThirty-six subjects performed three simulated driving experiments under three vertical vibration frequencies which were 1.8, 4.0, 6.0 Hz respectively and the driving time was 90 minutes. At the same time the electromyography of low back was recorded.

RESULTSThe median frequencies calculated from the power spectrum were decreased exponentially under three vertical vibration frequencies, especially under 4.0 Hz vibration frequency.

CONCLUSIONThe 4.0 Hz vibration frequency has the most important effect on the back muscle fatigue under simulated driving condition.

Adult ; Automobile Driving ; Electromyography ; methods ; Humans ; Low Back Pain ; etiology ; physiopathology ; Male ; Models, Biological ; Muscle Fatigue ; physiology ; Muscles ; physiology ; Posture ; physiology

OBJECTIVETo observe low back fatigue of subjects before and after simulated driving, and to study the role of the belt used in prevention of low back fatigue of drivers during driving.

METHODSTo assess the changes in median frequency (MF), mean power frequency (MPF) of surface electromyogram (SEMG), and flicker frequency, visuognosis persistence of drivers with and without protective belt in simulated driving.

RESULTSThere were significant differences in MF [(47.35 +/- 6.07), (39.26 +/- 5.79), (47.21 +/- 6.02), (43.44 +/- 6.26) Hz respectively], MPF [(69.86 +/- 7.08), (59.12 +/- 7.19), (69.86 +/- 7.08), (63.88 +/- 7.49) Hz respectively] between before and after simulated driving without or with the special belt (P < 0.01). But no differences in MF or MPF between without and with the belt before simulated driving were found (P > 0.05). The flicker frequency [(35.64 +/- 2.82), (42.31 +/- 4.68), (35.96 +/- 3.05), (39.79 +/- 3.36) Hz], visuognosis persistence (65.77% +/- 3.94%, 56.83% +/- 5.68%, 65.88% +/- 3.92%, 62.27% +/- 2.91%) had some changes too.

CONCLUSIONSimulated diving could induce fatigue of back muscle in drivers. However, the protective belt can effectively prevent low back fatigue of drivers in simulated driving.

Adult ; Automobile Driving ; Electromyography ; Humans ; Low Back Pain ; etiology ; physiopathology ; prevention & control ; Lumbosacral Region ; Male ; Muscle Fatigue ; physiology ; Muscle, Skeletal ; physiology ; Posture ; physiology ; Protective Devices