Ergonomics evaluation of user-hand tool interaction.

BACKGROUND: An in-depth evaluation of user hand tool interaction aids to derive strenuous areas for redesigning. OBJECTIVE: In this paper, we examined user perception about the hand tool features and derived features that exert an influence on human system. This nature of study aids to reduce the risk and enhance the comfort. METHODS: Workers from six occupational groups participated in the study. Ergonomic checkpoints pertaining tool features and a general health questionnaire that included musculoskeletal discomforts, stress symptoms and general health complaints were administered to check user's interaction with hand tools. RESULTS: Risk estimates identified varied factors such as weight of tool, improperly designed handle and sharp edges associated with workers risk to pain in upper extremities, anxiety and injury. The workers' response indicated that handle redesign and protection against sharp-edged tools are crucial for improving comfort. CONCLUSION: The study aims to provide an approach to examine the characteristics of tools for redesign and increase user's comfort and safety.

Occupational health scenario of Indian informal sector.

Workers in the Indian informal sector are engaged with different occupations. These occupations involve varied work related hazards. These occupational hazards are a consequent risk to health. The study aimed to determine occupational health scenario in the Indian Informal sector. One thousand eleven hundred twenty two workers from five different occupations namely weaving (handloom and power loom), construction, transportation, tobacco processing and fish processing were assessed by interviewer administered health questionnaire. Workers suffered from musculo-skeletal complaints, respiratory health hazards, eye problems and skin related complaints. There was a high prevalence of self-reported occupational health problems in the selected sectors. The study finds that workers have occupational exposures to multiple hazards. The absence of protective guards aggrevate their health condition. The study attempts to draws an immediate attention on the existing health scenario of the Indian Informal sector.

Occupation, participation, inclusion, work role postural control in different load handling tasks.

BACKGROUND: Manual material handling has been attributed as a major risk to human musculoskeletal system. Workers postural stability in these tasks is influenced by holding method, time and weight being handled. OBJECTIVES: The study attempts to investigate postural balance in five different commonly adopted load handling methods amongst female volunteers. METHODS: Ten women subjects performed manual material handling tasks by lifting 9 kg load in five different ways. Lifting tasks included (1) Upfront in palms (2) on head (3) sideways (left) (4) sideways (right) and (5) in bag at back. Normalized electromyography signals (back and leg) and center of pressure displacements parameters were investigated as measures of postural control. RESULT: An increase in the medio-lateral and anterio-posterior center of pressure displacements and activity of back muscles was reported when subjects lifted the weight directionally. CONCLUSION: There was a significant influence of load position on center of pressure displacements and muscle activity and thereby on postural stability. KEYWORDS: Balance; center of pressure; electromyography.

Disparity of a seat cushion and its influence on postural control.

Properties of supporting surfaces of a seat have an influence on postural control. Centre of pressure (COP) displacement parameters reflect both the balance controlling process and movements of the centre of a mass of entire body. The subjects of the study were 9 healthy men. A seat cushion was examined with a 2-force platform setup. Force exertion at a seat pan and feet and COP displacement at a seat pan were measured to analyse postural control. Analysis of variance determined the differences in postural control depending on a cushion type among the subjects. Significant differences in COP displacement parameters were in COP trajectory length, medio-lateral COP displacement and COP velocity. The results of the study showed that foam cushion ensures better postural control.

Postural stability of sitting women.

The study examined the utility of stabilometric dimensions and explored whether the changes in sitting postures were manifested in functional measures of postural control. Eleven women participated in the study, which used 11 chair sitting postures: arms on laps or arms right angled; armrest at a height of 17, 20 and 23 cm; with or without backrest; slouch or straight back; legs right angled at knees or crossed legs. The backrest and armrest shifted 16.3% of body weight from a seat pan. The characteristics of stabilometric dimensions evaluated the influence of seat components and sitting behaviour on postural balance. The study attempted to evaluate stability and its application in human-seat interface design.

Risk factors and musculoskeletal disorders among women workers performing fish processing.

BACKGROUND: The study examined the prevalence of musculoskeletal pain and discomfort (MSD) among workers engaged in fish processing activities and identified the occupational, environmental, and psychosocial factors contributing to the MSDs. METHODS: An ergonomics checklist and questionnaire on general health and psycho-social issues were administered to women workers (N = 450). The relative risk for MSDs due to demographic factors, stress symptoms, and task variables were estimated. RESULTS: Nearly 71% of the women (age 23.0 ± 6.4 years) reported MSDs, chiefly in upper back (54%), lower back (33%), knee (35%), and shoulders (27%). Workers engaged in mixed task (OR 13.8; CI 8.7-22.0), ring cutting (OR 18.3; CI 11.8-24.7), having job experience <3 years (OR1.9; CI1.3-2.9), being married (OR 1.5; CI 1.1-2.2), BMI18-25 (OR 1.7; CI 1.1-2.8) had increased risk of MSDs in the upper back. The severity of pain was high among the workers with elevated co-morbidity (pain in two or more regions). One third of the workers perceived the work environment to be cause of their MSDs. Multivariate analysis using binary logistic regression model indicated that highly specialized job (OR 13.0; CI 4.7-14.2), high physical activity (OR 11.7; CI 4.6-12.7), improperly designed tools (OR 8.1; CI 3.5-9.5), poor training (OR 7.0; CI 3.3-7.5), and poor job satisfaction (OR 1.5; CI 1.1-4.8) significantly increased the risk of MSDs. Almost all the psychosocial and work stress factors were associated with lower back MSD. CONCLUSION: A cold and humid environment, awkward standing work posture for long hours, high physical activities, poor task clarity, and high mental overload are important risk factors for the development of MSDs.

Occupational injuries in automobile repair workers.

Mechanics are exposed to varied work stressors such as hot noisy environments, strenuous postures, improperly designed tools and machinery and poor psycho-social environments which may exert an influence on their health and safety. The study aimed to examine the occupational injury patterns and identify work stressors associated with injury amongst automobile mechanics. A descriptive ergonomic checklist and questionnaire on general health and psycho-social issues were administered to male workers (N=153). The relative risk factors and correlation statistics were used to identify the work stressors associated with occupational injury. 63% of the workers reported injuries. Cuts were the chief injuries being reported. Poor work environment, machinery and tool characteristics, suffering from poor health and psycho-social stressors were associated with injury occurrence amongst automobile repair workers.