Mining Topic: Manual Materials Handling

What is the health and safety problem?

Worker performing manual materials handling while palletizing 100 pound bags of sand.

Manual materials handling is performed by many types of workers in the mining industry, including maintenance workers, electricians, mechanics, laborers, and some equipment operators. Restricted workspaces common in underground mining and lack of proper workstation design in many plants and shops contribute to injury risk for workers performing tasks with manual materials handling components.

What is the extent of the problem?

Manual materials handling represents a critical and persistent source of injuries in many industries including mining and is commonly the largest category of nonfatal, lost time injuries. Injuries can affect more than just the back—shoulder injuries are also reported. A recent analysis found that shoulder strains resulted in lost work days with a median over five times that of back strains. Traditional workplace safety practices target the back and may neglect the impact of shoulder injuries, which are known to have an increased prevalence in older populations and require significant healing time. Additionally, when lifting in a kneeling posture, there are added risks for injury to the knee structures.

How is OMSHR addressing this problem?

One of the tenets of injury prevention is education and resources. The Office of Mine Safety and Health Research (OMSHR) has created several training packages to educate mine workers on ergonomic risk factors as they relate to mining workplace practices. Additionally, OMSHR also promotes the use of mechanical assist devices to reduce the necessary force application as well as lift tables and workstation redesign to promote improved posture when lifting.

What are the significant findings?

Research studies have been conducted to examine the impact of manual materials handling when in restricted postures, when working in workstations of varying heights, and when performing repetitive stacking tasks. Posture is a significant factor in manual materials handling. Even moderate weights can cause an increased risk for injury when lifted incorrectly. Posture can be influenced by several factors which can be personal as well as environmental. Restricted vertical heights require workers to stoop, squat, or kneel which reduces lifting capacity. Stacking on pallets located at floor level requires workers to fully flex their back. Stacking on pallets exceeding shoulder level requires shoulder flexion to access higher areas. Non-adjustable workstations may also require awkward postures for some workers.

What are the next steps?

Research will continue in this area with the hopes of providing better education on safe workplace practices and workstation design for manual materials handling and ensuring mining companies are aware of devices to improve worker safety when performing these tasks. Additionally, publications are available with recommendations to reduce injury risks associated with manual materials handling.

Noteworthy Publications & Products

• A Case Study of Roof Bolting Tasks to Identify Cumulative Trauma Exposure (2001-03)
  An analysis of roof bolting tasks was conducted at a mine to identify early warning signs of cumulative trauma. Health and safety risk factors were identified and recommendations to reduce cumulative trauma exposure were provided.
• Characteristics of the top five most frequent injuries in United States mining operations, 2003-2007 (2010-01)
  Many injuries common to all mines, mine locations and commodities can be identified and ranked by frequency. Such rankings can reveal general trends of mine injuries and classify them by nature, accident type and class.
• Ergonomics and Risk Factor Awareness Training for Miners (2008-07)
  This training will increase awareness of risk factors and encourage miners to take action to report and reduce their exposures to risk factors.
• External L5-S1 Joint Moments When Lifting Wire Mesh Screen Used to Prevent Rock Falls in Underground Mines (2009-09)
  This study uses biomechanical modeling to estimate external moments about L5-S1 for sixteen lifting tasks, using two sizes of wire mesh screens, and presents recommendations to reduce spine loading.
• Reducing Low Back Pain and Disability in Mining (2008-09)
  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.
• Solutions to Prevent Materials-Handling Injuries in Underground Coal Mines (2007-02)
  This paper describes three mechanical methods - the mobile manipulator, the in-mine hoist, and a cable-handling system - developed by NIOSH to reduce injuries related to handling supplies or material, loading and unloading, and moving power cables.

Additional Resources

• Back Belts - Do They Prevent Injury
  NIOSH pamphlet on preventing back injury.
• Ergonomic Guidelines for Manual Material Handling
  How best to use energy, equipment, and exertion to get the job done in the most efficient, effective, and effortless way possible.