Lumbar Flexion During Driving: Establishing a Methodology for Characterising Real-Time Posture Data Collected by Innovative Technology

Objective To determine a methodology for the analysis of real-time driving posture data in the low back pain population. Background The strength of the relationship between driving posture and low back pain is yet to be defined due to the lack of studies in the field using validated and repeatable posture measurement tools. Reliable and validated real-time measurement tools are now available, yet reliable methods of analysis of these data are yet to be established. Method Ten occupational drivers completed a typical work shift while wearing an inertial motion sensor system (dorsaVi ViMove). Real-time lumbar flexion data were extracted, with test–retest reliability of mean lumbar flexion, peak lumbar flexion, and standard deviation of lumbar flexion analysed at different times across a work shift, and in different sections within a drive. Results Mean lumbar flexion was highly repeatable over numerous drives in one day, with greater test–retest reliability if the first five minutes of driving data were excluded. Peak lumbar flexion had acceptable test-retest reliability over numerous drives in one day, while standard deviation of lumbar flexion was not a repeatable measure. Conclusion Mean lumbar flexion was a reliable outcome for characterising driving posture in drivers with low back pain. Peak lumbar flexion may be used if appropriate to the individual study. Standard deviation of lumbar flexion is not a reliable posture outcome. Application This paper provides a reliable methodology for analysis of real-time driving posture data in occupational drivers with low back pain.

Research on comfortable driving posture of car drivers based on muscle biomechanics

This paper aims to solve the problem of optimal design on a comfortable human-machine arrangement of car drivers with different physical signs under dynamic manipulation. Based on the biomechanical characteristic of human skeletal muscle and Hill muscle mechanics model, this paper constructs the human seat musculoskeletal model of 5th, 50th, and 95th percentile physical signs of Chinese car drivers under dynamic manipulation. The six-degree-of-freedom flexible test bench was set up and the center composite method was used to optimize the number of experiments. The consistency and relevance analysis of the actual measurement and dynamic manipulation simulation was carried out to comprehensively analyze the human-machine arrangement parameters such as vehicle seat, pedal, and steering wheel, so as to realize the optimization design of the hard point size of comfortable driving posture and verify the rationality and applicability of the test results through the vehicle road test.

Neck Braces and Driving Posture Affect Neck Mobility on Powered Two-Wheelers

Cervical spine injuries are a major concern for motorcyclists in traffic accidents and racing competitions. Neck braces aim to prevent cervical spine injuries during accidents by reducing the neck range of motion, and keeping it under physiological limits. This work aims to evaluate the ability of neck braces to reduce neck mobility for two driving postures associated with PTW configurations. The neck mobility of twelve volunteer subjects testing four neck braces on two powered two-wheelers (scooter and racing motorbike) is measured using an optoelectronic motion capture system. With the tested neck braces worn, neck mobility is significantly reduced as compared to the physiological range of motion in all degrees of freedom. However, only flexion/extension is reduced by all neck braces tested. This suggests that these brace designs do not provide protection against all the cervical spine loading directions that may occur in a trauma. Furthermore, specific type of each powered two-wheeler considered significantly affects the neck mobility in axial rotation, as well as the postero-anterior and caudo-cranial translations, thus underscoring the need to consider the driving posture when evaluating neck brace devices.

Comparison of bus driving posture in USA and India

The aim of this project is to compare driving postures in India and the USA in order to develop seat designs to improve driver posture. The postures of 14 bus drivers from the USA and 9 from India were evaluated by RULA (Rapid Upper Limb Assessment) analysis, and various seat dimensions from India ware collected and compared with standard dimension in the USA. For both countries, low posture occurred most frequently, showing a RULA score of 3, indicating a need for posture change and further investigations. Among drivers who exhibited high posture, posture in American drivers displayed a RULA score of 4, and posture in Indian drivers showed a RULA score of 6. Furthermore, the component ratio of the high posture group in India was about 10 times higher than that of the high posture group in the USA.

MUSCLE CONTRACTION DURING MANEUVERING STEERING WHEEL USING SURFACE ELECTROMYOGRAPYHY

Driving posture is one of the factors that need to be emphasized in ensuring driver’s comfort and to avoid road accidents and injuries. Meanwhile, fatigue has a strong relationship with comfortable posture and it contributes 15.7% of the total road accidents in Malaysia. Fatigue can reduce driving concentration and performances, thus increases the risk of road accidents and injuries. In order to determine the driver’s comfort, this study had measured muscle contraction using the objective measurement for comfortable and optimum driving posture angles. The equipment used for conducting objective measurement on 14 respondents was sEMG. The researcher had used sEMG equipment to evaluate muscles activities at upper extremities, which comprises of Biceps Brachii (BB), Deltoid Anterior (DA) and Trapezious Upper (TU) that were involved during controlling the car steering. It involves three driving postures parameters according to the fixed elbow and shoulder angles. The results from this study showed the BB muscle increased positively when turning the steering wheel to the right within 3 to 6 times value increased. Meanwhile, DA and TU muscles experience a contraction in the opposite direction with steering wheel turning action, which shows higher right side DA and TU muscle contraction when the driver turn the steering to the left with around 80% decrease for DA and within 60% to 80% decrease value for TU. BB muscle also shows an increasing value of muscle contraction with higher elbow flexion, meanwhile DA and TU muscles contraction also show an increment in-line with greater shoulder abduction. The results showed that posture B with elbow angle at 36° and shoulder angle at 134° are the most comfortable driving postures, hence the lowest muscle contraction value of 15.67μV (BB), 19.31μV (DA) and 12.36μV (TU) compared to the other two measured postures. The results of muscle contraction from this study is capable of assisting researchers and car manufacturers to understand the relationship of steering maneuvering when developing more comfortable and suitable vehicle’s driver seat compartment.