Amitabha De

Evaluation of the working posture and prevalence of musculoskeletal symptoms among medical laboratory technicians

BACKGROUND Technological advancement in the medical laboratories has exposed the laboratory technicians to various ergonomic hazards due to nature of their work. OBJECTIVE The study aimed to analyze the working postures, to find out the prevalence of work related musculoskeletal disorders and to investigate the relationship between musculoskeletal disorders with individual factors, work characteristics and the working postures. METHODS The study was conducted among 60 medical laboratory technicians. Nordic Musculoskeletal Questionnaire (NMQ), Visual Analogue Scale (VAS) and RULA were used for this study. RESULTS Mean and SD of age, BMI and work experience of the technicians were 28.6 ± 9.04 years, 22.07 ± 4.5 and 7.1 ± 8.2 years respectively. The overall prevalence of musculoskeletal problems experienced by the technicians was 73.3% and the major affected areas were trunk, knees, neck and ankles/feet. Statistical analysis shows significant associations between musculoskeletal symptoms and VAS scores. Also a significant difference was found between the means of pre and post work shift scores of neck, low back and knee pain. Postural analysis showed that the subjects mean Score A, B and Grand Score were found to be 3.98 ± 0.8, 4.95 ± 1.6 and 6 ± 1.02 respectively. The final RULA score 6 ± 1.02 emphasizes on poor workstation design which resulted in unnatural posture. CONCLUSIONS The study highlighted the prevalence of postural and musculoskeletal problems among medical laboratory technicians. Intervention of administrative and engineering controls can significantly reduce ergonomic hazards.

Study on lumbar kinematics and the risk of low back disorder in female university students by using shoes of different heel heights

The study was taken up to investigate the effects of heel heights on lumbar kinematics and the risk of Low Back Disorder (LBD) in females. Nineteen female university students (24.5 ± 3.36 yrs) volunteered in the study. Lumbar kinematics was measured by using Industrial Lumbar Motion Monitor (iLMM). The volunteers were asked to walk for a distance of 50 meters in 3 different given conditions i.e bare foot (Heel 0), with flat heels (Heel 1) and with high heels (Heel 2). Heights of Heel 1 and Heel 2 were 1.5 ± 0.84 cm and 5.5 ± 1.70 cm respectively. The Lumbar kinematic parameters studied were- Average Twisting Velocity (ATV), Maximum Sagital Flexion (MSF) and Maximum Lateral Velocity (MLV). It was observed that all the above mentioned Lumbar kinematics - ATV, MSF and MLV increases with increase of heel heights, which in turn increases the risk of LBD. As a result of increase in Lumbar kinematic values with increase in heel heights, LBD risk has also increased. Mean and SD of the LBD risk with Heel 0, Heel 1 and Heel 2 were 16.79 ± 6.04%, 19.00 ± 7.38% and 22.11 ± 6.98% respectively. Lower stature with high heels showed higher risk of LBD than the higher stature with high heels.

Work related musculoskeletal disorders among medical laboratory technicians

Medical laboratory technicians are a unique group of healthcare professionals who are at risk for developing work related musculoskeletal symptoms. The study was conducted using 49 laboratory technicians working in the department of laboratory medicine in Mumbai hospitals. Several measures were obtained: Quick Exposure Checklist (QEC), Nordic Musculoskeletal Questionnaire (NMQ), Visual Analogue Scale (VAS), RULA and REBA. Results show that the most prevalent body regions were lower back (30.61%), upper back, knees (20.40%) and neck (18.36%). The QEC analysis showed that the neck (93.4%) has the highest level of exertion followed by the wrist (69.1%), back (62.7%) and shoulder (54.3%). The analysis of Visual Analogue Scale (VAS) revealed significant differences in the morning and evening scores for neck (p<0.005), low back (p<0.012) and knees (p<0.023). A significant difference was also found in hand grip measurements before and after the 8 hour shift, similar as for pinch grip measurements. RULA and REBA scores for various activities varied from 4 to 7 and 5 to 12 respectively. Scores of RULA and REBA indicated that risk was very high and further investigations were required. The subjective evaluation of workstations revealed that 22.4% felt the workstation height was inappropriate and an objective evaluation showed that the dimensions of the laboratory work benches were not appropriate. Stress and pain were evident from the findings of NMQ and QEC. Ergonomics intervention was recommended to reduce WRMSDs for the medical laboratory technicians.

Relationship of Heart Rate with Oxygen Consumption of adult male workers from Service and Manufacturing Sectors

The purpose of the present study was to find a relationship between Heart Rate (HR) and Oxygen Consumption of industrial workers. HR and Oxygen Consumption of 135 adult males from service sector and 49 adult male from manufacturing sector in the age group of 40-50 years were measured by direct (breath-by-breath technique using Cortex Metamax 3B) measurement using computerized Bi-cycale ergometer. The correlation coefficients of HR with oxygen consumption of Service and Manufacturing sectors were 0.82 and 0.81 and Mean Square Error were 24.02 and 29.54. These two group were merged (135+49=185) and an Experimental group was formed (Phase I). In Phase II Prediction equation for oxygen consumption was developed from the regression analysis. The correlation coefficient of HR with oxygen consumption was 0.82 and Mean Square Error (MSE) was 24.27. In Phase III 100 new subjects (Validation group) were chosen at random from service and manufacturing sector. There oxygen consumption was determined by using laboratory technique and also by prediction equation developed in phase II. Test-retest correlation values showed high correlation coefficient 0.85 and MSE 16.24. The higher correlation value shows the accuracy of the prediction equation developed in the present study.

A study of subjective visual disturbances in jewellery manufacturing.

Subjective Visual Disturbances are silent adversaries that appear over a period of continued exposure and arise when the visual demands of the tasks exceed the visual abilities of the user. Jewellery manufacturing activity involves precision designs, setting the metal and stones, polishing and filing which requires higher visual demand. Therefore, it is expected that the jewellery manufacturing workers may experience subjective visual disturbances. This study was taken up with the following objectives 1) To study the presence of subjective visual disturbances among jewellery manufacturing workers and compare the same with VDT operators 2) To study the effect of work exposures on subjective visual disturbances and 3) to ascertain whether subjective visual disturbances have any permanent vision related problems. The study was carried out on jewellery manufacturing workers, VDT operators and on graduate students. The symptoms of subjective visual disturbances were identified using a questionnaire developed by Sheedy (2003). Viewing distances were measured and visual angles were calculated. The eye check--ups were also carried out. The subjective visual disturbances were higher in jewellery manufacturing workers. The findings suggest that work exposure has an impact on the causation of subjective visual disturbances. No pathological conditions of the eyes were observed.

Duration of Exposure (Working Hours) and Musculoskeletal Discomfort/Pain

Indian traditional jewellery manufacturing plays an important role in the national economy. There are several studies which discuss about various hazards especially chemicals, among jewellery manufacturing workers in India. But studies related to evaluation of musculoskeletal disorders and its causal effect have not been evaluated in any of such studies. This study has been carried out to identify one of the causal factor (duration of exposure) of the development of work-related Musculoskeletal Disorders (WRMSD) and its association with prevalence rate. Prevalence of musculoskeletal disorders was recorded using Nordic Musculoskeletal Discomfort Questionnaire (NMQ). Data related to duration of exposure to jewellery manufacturing were collected using diary method and direct observation. Statistical analysis of the data revelled that there was a significant correlation between duration of exposure and the prevalence of low-back pain. Whereas the correlation was absent with knee and neck pain.

Characteristics of Gait Variability Among Healthy Indian Construction Workers During Different Load Carrying Modes

Compared to work-related musculoskeletal disorders of the upper extremity and lower back area, much less investigative focus has been found on the prevention of lower limb musculoskeletal disorders and injury (LLD) in the workplace. A higher incidence of musculoskeletal injuries in lower extremities when carrying a heavy load during daily activities was found among Indian construction workers. The objective of this study was to examine the changes in temporal and distal gait parameters of healthy Indian men and women construction workers with different modes of load carriage. Five healthy male and five female construction workers were selected to walk at self-selected speed along a 7 m walkway, crossing two Kistler force platforms with unloaded and different loaded (15 kg) conditions. Indian males and females displayed significantly different gait patterns under all load conditions while the changes were relatively small in males. The results also indicated that the walking patterns of both the male and female subjects among the Indian construction labours were affected while carrying loads in different modes. It was found that due to differences in the ability to carry heavy loads in different modes, females are more prone to injuries compared to males and so considering the biological differences load carriage task should be assigned carefully to the female labours.