Anjali Nag

Influence of arm and wrist support on forearm and back muscle activity in computer keyboard operation

The effects of forearm and wrist supports on the upper extremity postures in computer keying tasks and associated EMG activity of arm and back muscles were examined (N = 8). Four positions were forearms unsupported (floating) and supported, wrists supported by bead packed (WR1) and gel-filled (WR2) wrist rest. The right and left elbow extensions were 65 degrees and 68 degrees , respectively, in unsupported forearms. Bilateral elbow extension increased with the forearm/wrist supports and mostly, the elbow was maintained at around 90 degrees or greater. The wrist extension decreased with forearm/wrist supports over the unsupported condition. The forearm support significantly reduced the activity of forearm extensor digitorum, i.e., right (F((1, 47)) = 12.19, p < 0.01) and left (F((1, 47)) = 5.38, p < 0.05) and upper trapezius muscles over the floating posture. Wrist rests, however, increased load on the upper trapezius; the activities of flexor digitorum superficialis and erector spinae were close to the resting EMG activity for both forearm and/or wrist support. The type of wrist rests was a concern and this study indicated that the gel filled wrist rest was advantageous in reducing the forearm muscle load, in comparison to the bead packed cushions.

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 injury proneness in Indian women: A survey in fish processing industries

A cross sectional survey was initiated to understand the frequency of occupational injury occurrence and the associated factors in the fish processing industries of western India involving 185 randomly selected women subjects. All the subjects were interviewed with the help of an interviewer-administered questionnaire to collect information regarding their personal, occupational and work related morbidity details (including details of occupational injuries). Logistic regression method was used to analyze the data in order to obtain the contribution of individual factors on occupational injuries. This study has shown that work related morbidity like blanching of hand (OR; 2.30, 95%CI; 1.12–4.74) and nature of job like grading (OR; 3.99, 95%CI; 1.41–11.27) and packing (OR; 5.68, 95%CI; 1.65–19.57) had a significant impact on injury causation. This study eventually concludes that apart from nature of job of fish processing workers occupational hazards prevailing in the work environment contribute significantly to the occurrence of work related injuries and prevention of such occupational hazards may help in protecting workers from occupational injuries also.

HEAT STRESS OF WOMEN DOING MANIPULATIVE WORK

Six women were exposed to nine environmental conditions, ranging from 26.0 to 35.8 degrees C effective temperature (ET), in a climatic chamber. They were involved in manipulative work in a seated position for a duration of 3 hr. The O2 uptake, heart rate, deep body (Tc) and skin temperature (Tsk), sweat loss, and perception of thermal comfort were noted. The O2 uptake increased with the time of exposure at different heat levels. The work energy demand, which was 19% of VO2max at 26 degree C ET, increased to 35% of VO2max at 35.8 degrees C ET. However, the work output declined with the increase in ET. Thus, the elevated metabolic demands were the results of the thermal stimuli. The Tsk was greatly influenced by the environmental heat; the Tc changes were gradual. The highest mean Tsk attained was 37.3 degrees C at 33.8 degrees C ET when the gradient of Tc-Tsk was only 0.5 degrees C. The rate of change in mean Tsk for 31.6 to 33.8 degrees C ET was much faster compared to the range between 26.0 and 31.6 degrees C ET. From 32.1 degrees C ET onward the Tc and heart rates rose rapidly, while the sweating rate tended to fall, indicating some hindrance for evaporative cooling. Also, thermal sensations were noted as extremely hot for the conditions 32.1 to 35.8 degrees C ET with the increase in exposure duration.

EMG analysis of sitting work postures in women.

Based on EMG analysis on six middle-aged women, seven sitting work postures were compared with reference to relaxed standing position. The muscles included in the investigation are pectoralis major, levator scapulae, deltoideus, latissimus dorsi, upper fibres of the trapezius, erector spinae, vastus medialis and lateralis, rectus femoris and gastrocnemius muscles. The commoner sitting postures examined were sitting on the floor with crossed legs, sitting on the floor with right leg bent at the knee, sitting on the floor with left leg bent at the knee, squatting with both legs bent at the knee without any back support, sitting on a plank of 10 cm height with both legs bent at the knee, sitting on the floor with legs extended, and sitting upright on a stool of 40 cm height. The relative load on the muscles was highest in the case of sitting on the floor with the right leg bent at the knee. However, less muscle activity was noted when sitting on the floor with the legs extended, a posture commonly adopted by women performing various domestic and other activities.

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.

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.

Influence of footwear on stabilometric dimensions and muscle activity

Background: Properties of footwear exert an influence on centre of pressure (CoP) displacement parameters, muscle activity and users postural control. Thereby, selection of footwear aid to manage postural stability and fall problems. Objective: The study applies stabilometry, force exertion and electromyography when women stood and walked by donning footwear with different characteristics and in barefoot. Method: Women volunteers aged (30.2 ± 5.6 year), and having BMI (27.6 ± 7.4) participated in the study. The footwear included in the study were of four different designs, laced shoe (2.5 cm heel), flat heeled (9 cm heel), and pointed heel (7 cm and 13 cm heel). Female subjects (N = 15) stood and walked after putting on footwear and in bare feet. Results: The weighted force (kgf) distribution derived as the square root of the sum of squares of three forces at x, y and z coordinates was minimal in laced shoes, suggesting the relative stability in comparison to bare feet and other footwear. ANOVA showed that the footwear had discernible effect on the medio-lateral CoP displacement and CoP speed during standing, and anterior posterior CoP range while walking. The leg muscle activity, both soleus and tibaials anterior, was significantly higher in pointed heel (13 cm heel) while standing, suggesting that heels exert an influence on leg muscle activity and postural control mechanism. Conclusion: Laced shoes gave relatively better postural stability to the wearer. Potential implications: This work gives a valuable insight to consideration of biomechanical parameters for footwear manufacturers and wearers.

945 Influence of industrial safety shoe characteristics on postural stability

Introduction Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. Slip, Trip and fall accidents in the industrial setting range from trivial falls to life- threatening fatalities and injuries which could be as a compromised of postural stability. Safety shoe has different characteristic features but in what way these characteristics interact with each other and influence postural stability is uncertain. The study elucidates the influence of industrial safety shoes characteristic on different stabilometric dimensions that are the indicators of postural stability. The purpose of the current study effect is to explore the contribution of specific characteristics of safety shoe used in industries along with the individual characteristics in Static and dynamic postural conditions. Methods Twenty-five male subjects performed the task of standing and walking on the piezoelectric force platform (Kistler, Switzerland, model 9268AA) with industrial safety footwear and centre of pressure displacements parameters were investigated as measures of postural stability. Results Multiple ANOVA results showed the significant influence of shoe characteristics (toe cap, sole of shoe, weight of the shoe and ankle type) and their interaction on the centre of pressure displacement determinants. Conclusion The role of individual characteristics preponderate the impact of safety shoe characteristics on postural stability. This work gives a valuable insight to consideration of footwear characteristics for manufacturers and employers to put a check on Slip, Trip and Fall injuries which can improve the productive life of labour with more work efficiency.

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.