Edelweiss Applied Science and Technology ISSN: 2576-8484 Vol. 9, No. 3, 2982-2986 2025 Publisher: Learning Gate DOI: 10.55214/25768484.v9i3.5897 © 2025 by the author; licensee Learning Gate © 2025 by the author; licensee Learning Gate History: Received: 23 January 2025; Revised: 19 March 2025; Accepted: 24 March 2025; Published: 29 March 2025 * Correspondence: smmo@osan.ac.kr Suggestion of ergonomic evaluation index for agricultural ladders considering human-machine interaction Seung-Min Mo1* 1Department of Occupational Safety and Health Management, Osan University, 45 Cheonghak-ro, Osan-si, Gyeonggi-do 18119, Republic of Korea; smmo@osan.ac.kr (S.M.M.). Abstract: The purpose of this study is to suggest an ergonomic evaluation index, considering human- machine interaction, to ensure the fundamental safety of ergonomic equipment. To systematically investigate and analyze accident cases involving ladder-related injuries among agricultural workers, which is one of the most frequently used equipment in agricultural work, the 'Agricultural Safety 365' database, operated by the Rural Development Administration of Republic of Korea, was utilized. This study conducted two focus group interviews (FGI) for consulting on the ergonomic evaluation index of agricultural ladders: one group consisting of agricultural safety experts and the other of agricultural workers. The causes of ladder-related accidents were classified into seven types, with most accidents occurring due to unstable floor conditions in agricultural work environments. As for the mechanical/equipment/tool related causes, accidents involving ladders (type A) were frequently found to occur due to the failure or absence of the device that secures the ladder's extension. This study suggested the ergonomic evaluation index focusing on safety and usability indicators to consider human-machine interaction. The evaluation indices were derived using criteria such as accident probability, stability, effectiveness, and comfort, including factors like step anti-slip features, ease of ascension, anti-leg spreading devices, and the height/width between steps. Based on the results of this study, it can ensure fundamental safety from the design and production stages of ergonomic equipment and contribute to the creation of a safer agricultural work environment. Keywords: Accident, Agriculture, Ergonomics, Evaluation index, Human-machine interaction, Ladder. 1. Introduction Agriculture is a key sector that drives the economy of nations worldwide. However, compared to industrial workplaces, agricultural workers are exposed to relatively complex risk factors [1]. The incidence of injuries and fatal accidents during work is high [2]. Agricultural workers often perform tasks such as planting, irrigation, soil management, pruning, harvesting, cleaning, sorting, packaging, and transportation, which involve awkward postures and repetitive motions, increasing the risk of musculoskeletal disorders. Due to the nature of agricultural work, workers are often exposed to unpredictable weather conditions, and a high proportion of tasks are carried out in outdoor environments. Additionally, irregular tasks are frequent, and during peak seasons such as the harvest period, work is concentrated over long hours, leading to high cumulative physical strain, which further weakens safety [3]. In general, ergonomic equipment for agricultural work is used to reduce the workload of agricultural workers and improve productivity. However, agricultural accidents are often caused by the use of machinery and tools. For example, in Bangladesh and India, a significant portion of injuries occur due to agricultural machinery and small tools, and machinery-related accidents also account for a significant proportion in countries like New Zealand and Canada [4]. In South Korea, more than half of 2983 Edelweiss Applied Science and Technology ISSN: 2576-8484 Vol. 9, No. 3: 2982-2986, 2025 DOI: 10.55214/25768484.v9i3.5897 © 2025 by the author; licensee Learning Gate agricultural accidents are similarly linked to the use of machinery and small tools. Agricultural accidents often result in fatal injuries, lead to permanent disabilities, and incur high economic costs [5]. Although injuries and accidents caused by small tools during agricultural work may have lower severity, their frequency is high, and they could potentially be a source of fatal accidents in the future. Previous studies have been conducted to improve the safety of agricultural tools and machinery. Son and Shin [6] classified agricultural tools and proposed safety guidelines for ergonomic design, including control panels, steering levers, frame size, and shape, necessary for ergonomic equipment. Kee, et al. [7] reported key indicators for the improvement of agricultural ergonomic equipment and reported that ergonomic design could enhance safety. Benos, et al. [8] found that ergonomic agricultural equipment can economically improve repetitive manual material handling and reduce the physical strain of long- duration work, thereby enhancing safety and comfort. The use of ergonomic equipment in agricultural work is expected to continue to increase, and the design of such equipment, considering usability for the prevention of musculoskeletal disorders and improvement of safety, is becoming increasingly important [9]. Therefore, the purpose of this study is to suggest an ergonomic evaluation index, considering human-machine interaction, to ensure the fundamental safety of ergonomic equipment. It could improve the safety of frequently used ergonomic equipment in agricultural work environments and contribute to the creation of a safer agricultural workplace. 2. Materials and Methods 2.1. Accident Case To systematically investigate and analyze accident cases involving ladder-related injuries among agricultural workers, which is one of the most frequently used equipment in agricultural work, the 'Agricultural Safety 365' database, operated by the Rural Development Administration (Republic of Korea), was utilized. The search period for accident cases was from 'before 2000 to 2019,' and the search was limited to 'ladders' as the type of agricultural equipment. For the accident cases involving agricultural workers collected in this study, the accident scenarios were reconstructed by reviewing items such as the accident overview, details, and injury severity, based on the detailed information provided by the database. The collected accident scenarios were analyzed using the 4M approach, focusing on human (man), machine/equipment/tools (machine), environmental (media), and management (management) factors, to analyze the causes, contributing factors, and agents involved in the accidents from multiple perspectives. 2.2. Focus Group Interview This study conducted two focus group interviews (FGI) for consulting on the ergonomic evaluation index of agricultural ladders: one group consisting of agricultural safety experts and the other of agricultural workers. The agricultural safety expert FGI group was composed of six experts in agricultural safety, health, hygiene, ergonomics, and machinery. The agricultural worker FGI group consisted of ten agricultural workers with more than 30 years of farming experience. 2984 Edelweiss Applied Science and Technology ISSN: 2576-8484 Vol. 9, No. 3: 2982-2986, 2025 DOI: 10.55214/25768484.v9i3.5897 © 2025 by the author; licensee Learning Gate Figure 1. Example of focus group interview. 2.3. Evaluation Criteria This study developed evaluation sheets focusing on safety and usability indicators to consider human-machine interaction. Based on previous research by Mo [10] evaluation indicators were derived using criteria such as accident probability, stability, effectiveness, and comfort. Interviews were conducted with the FGI groups to assess the necessity, appropriateness, and reliability of the derived evaluation indicators. Table 1. Evaluation index sheet. Criteria Evaluation index Content Usability Effectiveness Anti-slip for steps, Irregular ground adaptation Ease of control Reinforced step Comfortness Ease of transport (portability) Safety (Accident) Probability Anti-leg spreading device, Ladder weight capacity (Accident) Severity Ladder leg slip prevention, Step height spacing Stability Safety bar 3. Results and Discussion 3.1. Accident Case The causes of ladder-related accidents were classified into seven types, with most accidents occurring due to unstable floor conditions in agricultural work environments (Media), such as sloped or irregular surfaces, which are primarily influenced by environmental characteristics (Figure 2). As for the mechanical/equipment/tool (Machine) related causes, accidents involving ladders (type A) were frequently found to occur due to the failure or absence of the device that secures the ladder's extension. Also, accidents where workers fell while working at the top of the ladder were also analyzed, often resulting from unsafe behaviors and non-compliance with proper work procedures due to human error. In addition, accidents were analyzed where ladders were improperly used for tasks, or where workers slipped and fell while climbing or descending a ladder due to worn-out shoe soles. 2985 Edelweiss Applied Science and Technology ISSN: 2576-8484 Vol. 9, No. 3: 2982-2986, 2025 DOI: 10.55214/25768484.v9i3.5897 © 2025 by the author; licensee Learning Gate Figure 2. Proportion of causes of ladder accidents in agricultural work. 3.2. Focus Group Interview According to the FGI results, the key indicators for evaluating the usability of ladders in agricultural work were found to be anti-slip for steps, the presence of sharp edges, and ease of mobility and elevation. For evaluating the safety of ladders, important indicators included devices to prevent ladder leg spread, anti-slip features on the ladder legs, and the height/width between the steps. 3.3. Ergonomic Evaluation Index By combining the analysis of agricultural ladder accident cases and the FGI results, an ergonomic evaluation index and protocol were suggested, as shown in Table 2. The evaluation indices were derived using criteria such as accident probability, stability, effectiveness, and comfort, including factors like step anti-slip features, ease of ascension, anti-leg spreading devices, and the height/width between steps. Table 2. Ergonomic evaluation index for agricultural ladders. Criteria Evaluation index Content Protocol Usability Effectiveness Anti-slip for steps Has the surface of the steps been treated with an anti-slip coating? Ease of control Sharp edges Are there any sharp edges in areas that could come into contact with the body or clothing? Comfortness Ease of ascension Is the angle of the climbing surface (θ) less than or equal to 75°? Safety (Accident) Probability Anti-leg spreading device Is there a ladder leg spreading prevention device made from a non-elastic and durable material that is not easily damaged? (Accident) Severity Slip resistance for ladder legs and steps Has the ladder leg been treated to prevent slipping on the floor surface? (e.g., spikes, surface treatment, rubber materials, etc.) Has the surface of the steps been treated with anti-slip coating? Stability Height/Width between steps (Height) Does the height between steps meet the following criteria?" - 1st step: ≤ 350mm - 2nd step and above: 180–350mm (Difference between maximum and minimum height: less than 5mm) (Width) Is the width (front-to-back depth) of the steps at least 30mm? 2986 Edelweiss Applied Science and Technology ISSN: 2576-8484 Vol. 9, No. 3: 2982-2986, 2025 DOI: 10.55214/25768484.v9i3.5897 © 2025 by the author; licensee Learning Gate 4. Conclusion Rural areas are already experiencing rapid aging, and the risk of accidents is increasing due to the climate crisis. Therefore, to ensure agricultural work safety, the physical risk factors in ergonomic equipment and work environments should be prioritized for improvement. As accidents involving ladder use are frequent in agricultural work, a design that ensures safety based on ergonomic evaluation indicators is necessary. Based on the results of this study, it can ensure fundamental safety from the design and production stages of ergonomic equipment and contribute to the creation of a safer agricultural work environment. In the future, as agricultural work becomes more dependent on machinery, it is hoped that the ergonomic evaluation index for ergonomic equipment will be legislated to prevent safety accidents. Funding: This work was carried out with the support of “Cooperative Research Program for Agriculture Science and Technology Development (Grant Number: PJ01709903)” Rural Development Administration, Republic of Korea. Transparency: The author confirms that the manuscript is an honest, accurate, and transparent account of the study; that no vital features of the study have been omitted; and that any discrepancies from the study as planned have been explained. This study followed all ethical practices during writing. Copyright: © 2025 by the authors. 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