# Ergonomics Study of Musculoskeletal Disorders Among Tram Drivers
## 1 Introduction  
Ergonomics, also called human factors, is an interdisciplinary scientific discipline focused on the interaction between people and their environment. In the study of ergonomics, a scientific approach is applied including theory, principles, data, and design methods to optimize human well-being and overall system performance [1]. Therefore, ergonomics can be defined as a discipline that offers both the skills and approaches necessary for analyzing work and professional tasks. The scientific literature shows that ergonomics can provide new perspectives on workplace well-being, which are connected to the social dimension of sustainability [2, 3, 4, 5]. The main goal of ergonomics is to adapt the job to the individual, rather than forcing the individual to adapt to the job [6]. The work environment, job demands, and level of control all influence the mental and physical condition of the worker. An ergonomically inadequate workplace can contribute to both physical and emotional stress. Ultimately, both types of stress are associated with reduced productivity and lower quality of work [6]. Several theoretical approaches within the work pressure framework emphasize the importance of designing healthy working conditions [7]. Ignoring ergonomic principles--guidelines for designing work environments, tools, and tasks to enhance comfort and efficiency--can result in pain and, eventually, injury. Most of this pain is related to musculoskeletal disorders (MSDs), which include a set of injuries and symptoms affecting the osteomuscular system and associated structures [8]. Symptoms of work-related MSDs (WMSDs) are typically expressed as pain in one or more regions of the body. Accumulated microtraumas caused by prolonged and repetitive work-related loading are considered a key cause of WMSDs [6]. Thus, working conditions, including the environment, tools used, and immediate surroundings, contribute to the type and frequency of musculoskeletal disorders. However, organizational factors and health outcomes are still insufficiently investigated [9; 10; 11]. Work-related musculoskeletal disorders (WMSDs) are injuries or conditions related to job demands that place the whole body or specific body parts in positions that lead to pain in spinal disks, as well as surrounding nerves, joints, muscles, tendons, and the circulatory system [12]. WMSDs are further aggravated by psychosocial factors [13; 14], although the mechanisms are more complex [13]. These disorders can lead to pain, stiffness, and reduced mobility, all of which affect daily activities and quality of life. The most influential causes and risk factors include repetitive motion, poor posture, age, obesity, and genetic predisposition. Almost half of the causes stem from the type of work and the work environment itself. Many WMSDs are directly linked to job performance in physically demanding roles [12]. By taking a proactive approach to health and well-being, individuals can better manage symptoms and maintain an active, fulfilling lifestyle. Globally, low back pain caused by WMSDs is a leading cause of disability, with a rising prevalence in low- and middle-income countries in recent years [15; 16]. Workers who spend prolonged hours sitting, such as drivers, often suffer from low back pain due to constrained positions, along with vibrations and jolts experienced while driving [15; 16]. It is important to emphasize that WMSDs rank among the most common occupational disorders across various industries [13]. Biomechanically, prolonged seated posture increases compressive and shear forces at the lumbosacral junction, particularly at the L4/L5 and L5/S1 segments. Reduced spinal mobility, combined with static muscle activation, leads to higher intradiscal pressure and accelerates degenerative changes. In response to pain, drivers often adopt asymmetrical or guarded postures, which further disrupt spinal alignment and increase muscular fatigue.