Mining Topic: Ergonomics and MSD Prevention

What is the health and safety problem?

Ergonomics is the science of designing tasks, equipment, tools, and work environments to accommodate the capabilities and limitations of the majority of the workforce. Ergonomics enhances human performance including the health, safety, and productivity. Ergonomics efforts in mining aim to prevent musculoskeletal disorders by reducing exposure to awkward postures, high force exertions, and task repetition. Outdoor and underground work environments exacerbate exposure and make ergonomics efforts more challenging than in other industry sectors.

What is the extent of the problem?

According to an OMSHR study comparing 1983–1984 and 2003–2004 MSHA data, the percentage of cumulative injuries was similar (37% and 33%), but many more work days were lost due to injury in 2003–2004. Cumulative back injuries decreased by 10%, potentially due to use of assist devices, but cumulative knee injuries increased by 8%, possibly a result of kneeling/crawling in low-seam mines.

How is OMSHR addressing this problem?

The Office of Mine Safety and Health Research’s recent and current research has been designed to provide tools to help mines identify risk factors and implement and audit ergonomics processes, as well as provide specific interventions to address ergonomics problems in mining. Two current projects involve developing ergonomics audits for specific types of operations (haul truck operation, bagging operations, and maintenance and repair in processing and preparation plants) and developing a knee pad for low-seam mining environments. These projects use a mix of laboratory and field investigations to assess the problems and develop guidelines for remediating ergonomics issues.

What are the significant findings?

Cumulative injuries are a major financial burden to the industry, but using NIOSH-developed tools for incorporating ergonomics in the workplace was shown to be a tremendous success, indicating that ergonomics can be used to reduce injuries and costs.

OMSHR has published two ICs on ergonomics processes and participatory methods for mines: Ergonomics Process and Risk Factor Awareness. Practical Demonstrations of Ergonomics Principles was developed to provide safety trainers with several demonstrations for teaching ergonomics principles to mine workers.

With attention focused on the knee, OMSHR published on preventing injury in Keeping Knees Healthy, and summarized experimental investigations of pressures and moments on the knee during different activities and while wearing different knee pads. It details stress distributions while wearing commonly-worn kneepads as well as physiological and biomechanical responses due to different postures and modes of locomotion.

What are the next steps?

Both the knee and audit projects are at the stage of finalizing development. Once the audits are finalized and the prototype knee pad is designed, the next steps will be field testing and validation. Certified Professional Ergonomists will test the reliability and validity of the audit modules so they can be modified, finalized, and prepared for computer-based use by the mining industry. For the prototype knee pad, the next step will be preliminary testing to determine if it is rugged enough to withstand the demands of underground low-seam mines.

Noteworthy Publications & Products

• Age Awareness Training for Miners (2012-09)
  The purpose of this training is to provide the information necessary to develop an appreciation of the changes that occur with age and an understanding of methods that can be used to reduce the injury risk that may result.
• An Analysis of the Potential of Roof Screening to Reduce Workers' Compensation Costs (2012-09)
  The goal of this study was to determine the potential saving in workers' compensation (WC) premiums that could be achieved due to a reduction in rock fall injuries after roof screening.
• Comparison of Whole-Body Vibration Exposures on Older and Newer Haulage Trucks at an Aggregate Stone Quarry Operation (2012-08)
  This testing monitored the performance of older and newer truck models relative to whole-body vibration (WBV) exposures as a means for determining when the vehicle (e.g., suspension system) and seats required maintenance or replacement.
• Ergonomic Interventions at Unimin (2012-08)
  This paper discusses ergonomic interventions that were successfully implemented at the Unimin Gleason, Tennessee operation using a participatory approach to reducing the risk of injury.
• Ergonomics Processes: Implementation Guide and Tools for the Mining Industry (2012-08)
  This paper describes how three mining companies partnered with the MSD Prevention Team at NIOSH to demonstrate that an ergonomics process could be systematically implemented and effectively integrated with existing safety and health programs.
• Forces and Moments on the Knee During Kneeling and Squatting (2012-08)
  For 10 subjects in four postures, euler angle decomposition and inverse dynamics were used to determine the knee angles, the net forces, and the moments applied to the tibia during kneeling and squatting with and without kneepads.
• Keeping Knees Healthy in Restricted Work Spaces: Applications in Low-Seam Mining (2012-08)
  NIOSH researchers developed a training package to educate the mining community about possible interventions beyond kneepads that may be used to help decrease knee injury rates. This document summarizes the training, including a glossary of terms.
• Pressure Distribution on the Anatomic Landmarks of the Knee and the Effect of Kneepads (2012-08)
  This study examines stress transmitted to anatomic landmarks of the knee (patella, combined patella tendon, and tibial tubercle) while in static kneeling postures without kneepads and while wearing two kneepads commonly used in the mining industry.
• Proceedings of the Second American Conference on Human Vibration (2012-03)
  Proceedings of the Second American Conference on Human Vibration held in Chicago, Illinois.
• Reducing Low Back Pain and Disability in Mining (2012-08)
  This report provides managers, supervisors, and safety and health professionals with information on low back pain (LBP) and low back disability. It also provides the latest LBP research and describes methods to address the problem.