Influences Of Tactile Sensation On Pinch Force Under Loaded And Unloaded Conditions

Although researchers have studied various parameters that affect grip force, few studies investigate the effects of tactile sensation on pinch force. This study aims to determine the influences of tactile sensation on pinch force with a special emphasis on screw knobs under loaded and unloaded conditions. The participants included 32 manual workers who were required to pinch and turn the knobs to generate pinch force under reduced and increased sensations simulated using cotton and nitrile gloves. The data were analysed using the analysis of variance via Minitab 16. Results show that the pinch force exerted for reduced sensations is higher than that of increased sensations because the reduced friction increased skin-object slippages, which caused participants to spontaneously increase their force to prevent slippages. This study serves as a guideline to potentially improve the design of objects operated with pinch grips to be safe and suitable for manual, sedentary or general tasks

The effect pfoffice equipment familiarity in reducing human errors and accidents

Although the advancement of technology can provide a better and safer working environment to people, sometimes, overconfidence in technology can lead to unavoidable accidents and human errors in the workplace. This study aims to determine the effects of familiarity with office equipment on human errors and accidents in the workplace. A total of 150 surveys were collected and analysed with correlations analysis usingSPSS software version 19.0. The results show that although familiarity can reduce the occurrence of human errors, it cannot reduce the occurrence of accidents in the workplace. While it is now understood that improving one's familiarity with office equipment can potentially reduce their mistakes at work, companies should still be observant of other factors that can potentially reduce accidents in the workplace. This study sheds light on potential possibilities to improve the occupational safety, health and environment of organizations

Design and Development of an Ergonomic Milling Machine Control Knob using TRIZ Principles

TRIZ, a Russian abbreviation known as the Theory of Inventive Problem Solving, refers to a methodology for problem-solving rooted in logic and data rather than intuition. It promotes the ability to solve problems creatively. Using TRIZ tools for problem-solving such as the cause-effect-chain analysis and engineering contradiction, a new ergonomic milling machine control knob was developed for improved musculoskeletal comfort. The major improvisations from the original milling machine knob included its spherical shape design, the indentations to accommodate a lateral pinch and the addition of a rubbery material for increased sensation. In the validation test, it was found that this new and improved ergonomic milling machine control knob was able to reduce the amount of pinch force by about 72% for males and 55% for females compared to the original knob, hence potentially eliminating risks of overexertion in pinch grips. This solution potentially reduces occupational injuries and cumulative trauma disorders. An implicit benefit is that the quality of machined parts using the milling machine can be potentially enhanced due to better control of the machine knobs that could eventually lead to the reduction of rejects and reworks, which also translates to improved productivity

The mechanics, conceptualization and design of an ergonomic clockwise directional screwdriver

Studies concluded that clockwise torque directions secure and improve grip force compared to counter-clockwise torque directions. However, it appears that there is no study on the design and development of an ergonomic screwdriver to address the difficulty of manually unfastening screws. In this study, a screwdriver concept was developed with clockwise directional input and ergonomic features. Previous studies found that the ergonomic design recommendations involved in designing the handles of hand tools were diameter, shape and material. The planetary gear system was proposed in the design concept as a solution to change the screwdriver input direction inwards for unfastening tasks. Ergonomics design factors such as handle diameter, shape and surface material were also taken into consideration for a more secure grip. With lower force requirements and ergonomic features, this screwdriver can potentially benefit manual workers towards decreasing risks of sustaining CTDs and accidents, and eventually improve efficiency in precision tasks

Usability Validation of an Ergonomic Inward Directional Screwdriver for Enhanced Musculoskeletal Comfort

Previous studies suggested that the use of inward torque direction in hand-related manual activities not only increases the total normal force and torque capacity but also reduces grip force. This means lesser effort is required to perform the task, which prevents overexertion and hand injuries. Manual screwdrivers are the most common hand tools used in the industry and daily life. However, due to the difficulty users face when unfastening screws, it can also be a hand tool that potentially leads to the development of cumulative trauma disorders. In this study, 50 subjects participated in a psychophysical testing of an ergonomic inward directional screwdriver and a normal manual screwdriver. The comparative study involved the perceptions of grip, comfort and ease-of-twist for both normal and ergonomic manual screwdrivers. The data was analysed using the analysis of variance via Minitab 16. The results showed that grip, comfort and ease-of-twist are significantly affected by torque direction and ergonomics features. Further observations on participant justifications also suggested that participants rated the inward screwdriver as a better tool to be used compared to the normal screwdriver

Development of Ergonomics Guidelines for Improved Sitting Postures in the Classroom among Malaysian University Students

PLIBEL stands for Plan for Identifiering av Belastnings faktorer, which is a Sweedish acronym describing a method for identification of ergonomics hazards. Using a modified PLIBEL checklist, this study aimed to identify the relationships among musculoskeletal risk factors and the classroom sitting conditions among Malaysian university students. A survey questionnaire was developed based on the modified PLIBEL checklist. A total of 142 responses were retrieved. The data was managed with SPSS version 21 and analysed using reliability analysis, normality analysis and analysis of variance (ANOVA). The results suggested that there was little correlation between the perception of the table and chair arrangements and stress factors by general repetitive movements, repetitive upper extremity movements and space/support of the workplace. Since static sitting postures were typical, students faced risks of developing common musculoskeletal disorders, especially on the lower back and upper back. A list of guidelines was recommended based on the findings to prevent potential musculoskeletal disorder symptoms