Original Research
Occupational Ergonomics & Vehicle Safety

The Enhancement of Driver Seat Comfort for Small Size Car: A Preliminary Study

Background and Context

Driving comfort is a significant public health concern that intersects ergonomics, transportation safety, and musculoskeletal health. As urbanisation accelerates across Malaysia and commuting distances increase, the time spent behind the wheel has grown substantially. For many Malaysians, daily commutes of one to two hours each way are commonplace, particularly in the Klang Valley and other major urban corridors. This prolonged seated exposure in a confined space places considerable demands on the musculoskeletal system, particularly when the vehicle seat is not optimally designed for the driver’s body dimensions.

Small-sized cars, commonly referred to as mini cars, occupy a substantial segment of the Malaysian automotive market. Their popularity is driven by economic factors including lower purchase prices, reduced fuel consumption, and lower road tax rates. However, the compact dimensions of these vehicles often necessitate compromises in seat design and cabin ergonomics, potentially exposing drivers to elevated musculoskeletal risk.

This preliminary study, published in the Malaysian Journal of Public Health Medicine, sought to develop and validate a survey instrument for assessing driver seat comfort, and to identify the body regions most affected by discomfort during and after driving sessions in small-sized cars. The findings provide a foundation for subsequent ergonomic intervention studies aimed at enhancing seat design for this vehicle category.

Study Design and Participants

The researchers developed a structured questionnaire designed to assess subjective comfort perceptions and identify areas of bodily discomfort associated with driving. The reliability of the questionnaire was evaluated using Cronbach’s Alpha, a statistical measure of internal consistency. The instrument achieved an alpha coefficient of 0.887, well above the generally accepted threshold of 0.7, indicating strong reliability and internal consistency.

The survey was administered to 30 students at Universiti Malaysia Pahang, comprising 20 males and 10 females. All participants held valid driving licences and had experience driving small-sized or mini cars. This selection criterion ensured that respondents could provide informed assessments based on actual driving experience with the vehicle category under investigation.

Participants were asked to rate their perceived discomfort across various body regions both during driving sessions and after completing driving periods. This temporal distinction is important because some musculoskeletal symptoms may not manifest during the activity itself but emerge or intensify in the post-driving recovery period.

Key Findings on Body Discomfort

The results revealed a consistent pattern of discomfort concentrated in the spinal column and its supporting structures. The neck region emerged as the most commonly reported site of discomfort, followed closely by the upper back and lumbar (lower back) regions. These findings are consistent with the biomechanical demands of driving, which requires sustained static postures with the neck in slight flexion to view the road and instruments, the upper back supporting the weight of the arms on the steering wheel, and the lumbar spine bearing the compressive loads of seated posture.

The persistence of discomfort after driving sessions is particularly noteworthy from a public health perspective. Drivers who experience ongoing neck and back discomfort after driving may carry these symptoms into other activities, potentially affecting work performance, sleep quality, and overall quality of life. For professional drivers or individuals with long daily commutes, the cumulative effect of repeated exposure to these discomfort patterns may contribute to chronic musculoskeletal conditions.

Malaysian Anthropometric Considerations

A critical dimension of this research is its recognition that Malaysian drivers have anthropometric characteristics that differ significantly from those of populations in countries where most automotive seats are designed. International automotive seat standards are typically based on anthropometric data from North American, European, or Japanese populations, which differ in average stature, sitting height, hip breadth, and limb proportions compared to the Malaysian population.

Previous research has established recommended dimensions for Malaysian driver car seats, including a back seat width of 480 mm, back seat height of 417 mm, cushion width of 503 mm, and cushion length of 381.4 mm. When small car manufacturers design seats based on international standards without adapting to local anthropometric data, the resulting mismatch between seat geometry and driver body dimensions can contribute to postural compromise and discomfort.

The compact cabin dimensions of small cars compound this issue by limiting the range of seat adjustment available. Smaller vehicles typically offer less fore-aft travel, less recline range, and may have fixed headrest positions, reducing the driver’s ability to optimise their seating position. This constrained adjustability means that seat design itself must be more carefully optimised to accommodate the target population.

Broader Ergonomic Literature Context

This study’s findings are consistent with the broader literature on driving-related musculoskeletal disorders. Research conducted internationally has consistently identified the neck and lower back as the most commonly affected regions in drivers, with risk factors including prolonged static posture, whole-body vibration transmitted through the seat, and suboptimal seat design. Studies across diverse contexts — from long-haul truck drivers to urban commuters — have demonstrated similar patterns of spinal discomfort.

In the Malaysian context, this study complements other research published in MJPHM on occupational ergonomics in various industries. The oil palm plantation sector, manufacturing, and now the driving population have all been subjects of ergonomic assessment studies highlighting the prevalence and consequences of musculoskeletal disorders in the Malaysian workforce. Together, these studies paint a picture of a working population facing significant ergonomic challenges across multiple occupational domains.

Recommendations for Seat Design Enhancement

The researchers recommend that automotive manufacturers producing small cars for the Malaysian market should incorporate Malaysian anthropometric data into the seat design process. Specific design features that could enhance comfort include adjustable lumbar support systems, headrests that can be positioned to support the natural cervical curve, seat cushions of appropriate length and inclination for Malaysian leg dimensions, and materials that provide adequate pressure distribution while managing the thermal comfort demands of Malaysia’s tropical climate.

Beyond design, the study implicitly supports the role of ergonomic education for drivers. Many drivers are unaware of how to optimise their seat position, adjust mirrors to reduce neck strain, or take breaks during long drives. Public health messaging that addresses driving ergonomics could complement design improvements in reducing the burden of driving-related musculoskeletal complaints.

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