Assessment of working postures and physical loading in advanced order picking tasks: A case study of human interaction with automated warehouse goods-to-picker systems

An ergonomic evaluation of workers in the winding section of the pump manufacturing industry

BACKGROUND: Work-related musculoskeletal disorders (WMSDs) are prevalent and have an impact across occupations. However, there are very few studies that document the prevalence of WMSDs in the pump industry. In manufacturing industries, the common issue for WMSDs and physiological stress among the workers is caused by poor working posture. OBJECTIVE: To investigate the occupational risks at the winding station in the pump manufacturing industry. In addition, this study examined the influence of work-study on mitigating occupational risks. METHODS: Workers who were involved in circular coil winding and insulation testing were considered for the study. Awkward postures adopted while performing these tasks cause fatigue, injuries and WMSDs. Tasks were evaluated as per the National Institute for Occupational Safety and Health (NIOSH) standards. A work-study was conducted to better understand the workflow. Virtual ergonomic postural evaluation (Rapid Upper Limb Assessment, RULA) was used to identify the occupational risks. RESULTS: Time taken for making circular windings and insulation testing (7.5 Hp submersible motor) was found to be 4.04 minutes and 0.95 minutes, respectively. A CAD model was used for ergonomic evaluation in the virtual environment. The RULA final score of 2 and 3 is attributed to coil winding and insulation testing. CONCLUSION: For further studies, the whole pump manufacturing process should be taken into account. The ergonomic tools used in this study will considerably reduce the occupation risks at the winding station in the pump manufacturing industry.

Evaluation of musculoskeletal workload of manual operating tasks using a hydraulic jack based on ergonomic postural analysis and electromyography: A case study of non-professional young male users

BACKGROUND:

Manual operations of the hydraulic jack device can become ergonomic stressors for the musculoskeletal system because of the required operational forces, muscle activities, or working postures. However, the usability of the hydraulic jack has not been fully explored for non-professional personnel.

OBJECTIVES:

To evaluate the musculoskeletal loads during manual operations of a hydraulic jack based on the ergonomic postural analysis and electromyography

METHODS:

Nine men operated the lever of a hydraulic jack with three positions: parallel to and near (P-N), parallel to and far from (P-F), and orthogonal to the jack lever (O). Postural loads were evaluated by Loading on the Upper Body Assessment (LUBA), an ergonomic observational method, and were classified into action categories. The surface electromyogram of eight muscles and the subjective sense of burden were also measured.

RESULTS:

The initial force for lever pushing reached 40–80 N and exceeded the recommended forces for the unusual postures. The overall assessment of LUBA showed that 31% of working postures observed in O position require immediate consideration and corrective action and the maximum holding time estimated was < 1 minute. The postural load increased due to the shoulder joint abduction in the P-F and O positions and due to the trunk rotation in O position.

CONCLUSIONS:

The results suggest that operating the hydraulic jack cause considerable postural loads and manual forces insufficient for several minutes of manual task. Therefore, improving working methods and tool designs are needed to improve usability and decrease the risk of musculoskeletal disorders during jack operations.