The process of work and the operators working in the work stations has been observed thoroughly and critically during the period of study.
Work station analysis:
Anthropometric dimensions of the work station were measured, working heights, reaches and work surface have been recorded. In critical and hazardous areas this was not possible.
Ergonomic Risk factors :
Ergonomic Risk factors have been evaluated through application of Rapid Upper Limb analysis techniques (RULA), Rapid Entire Body assessment (REBA), and calculation of Lifting Index using the NIOSH revised equation at all pre-selected areas of specialized sections like material handling operations, maintenance operations, store operations and shipping.
- RULA [Annexure 1] (Rapid Upper Limb Assessment)was developed by McAtamney and Corlett, in 1993(RULA: a survey method for the investigation of work-related upper limb disorders, Lynn McAtamney and E Nigel Corlett, Applied Ergonomics 1993, 24(2). 91-99) to evaluate the exposure of individual workers to ergonomic risk factors associated with upper extremity MSD. The RULA ergonomic assessment tool considers biomechanical and postural load requirements of job tasks/demands on the neck, trunk and upper extremities.
- The Rapid Entire Body Assessment worksheet (REBA) [Annexure 2] was designed by Hignett and McAtamney in 2000 for easy use without need for an advanced degree in ergonomics or expensive equipment. After the data for each region is collected and scored, tables on the form are then used to compile the risk factor variables, generating a single score that represents the level of Musculo-Skeletal Disorder (MSD) risk.
- The lifting index [Annexure 3] was calculated through NIOSH revised equation to assess severity of risk in manual materials handling job. The NIOSH Lifting Equation is a tool used by occupational health and safety professionals to assess the manual material handling risks associated with lifting and lowering tasks in the workplace. This equation considers job task variables to determine safe lifting practices and guidelines. The 1991 equation for manual lifting is a revised version of the original lifting equation published in 1981. The primary product of the NIOSH lifting equation is the Recommended Weight Limit (RWL), which defines the maximum acceptable weight (load) that nearly all healthy employees could lift over the course of an 8 hour shift without increasing the risk of Musculo Skeletal Disorders (MSD) to the lower back. In addition, a Lifting Index (LI) is calculated to provide a relative estimate of the level of physical stress and MSD risk associated with the manual lifting tasks evaluated.
Other physiological measurements
Other physiological measurements like Hand Grip evaluation, Heart rate, Noise levels, anthropometric measurements and lighting levels can be measured in situations where needed.
Photographs and video clippings of the work station as well as the working postures of the operators in the work station can be taken elaborately during the field collection of data to analyze the postural stress.