Posts from Tom Albin
Risk Mitigation in Manual Materials Handling (MMH) Push-Pull Tasks
Over the past four years, Darcor’s Workplace Ergonomics and Caster Technology Blog has emphasized the utility of good cart design, especially with regard to careful consideration of the required operating forces. Failure to act to control risk or making poor decisions in the design of manual cart handling tasks or in the evaluation of risk during push and pull tasks incurs costs from injuries, productivity losses, and operational inefficiencies. To mitigate MMH risk from the start and ongoing, it is crucial to initially design the cart and task so that all operating forces are within safe limits and perform routine verification and maintenance to ensure that the operating forces remain within those recommended limits throughout the economic life of the cart.
Push / Pull Injuries Impact the Whole Body, Not Just the Back
When we talk about pushing and pulling as potential causes of manual material handling (MMH) injuries, we tend to focus on low-back injuries. This is not without good reason; back injuries and back pain are both prevalent and expensive. Shoulders and knees are also at risk of workplace injuries due to poorly designed carts. Although less frequent, shoulder and knee workplace injuries can cost companies the same or more than back injuries.
Workplace Ergonomics: Cumulative Stress & Back Injuries
Cumulative stress to the spine plays a key role in assessing risk of occupational back injuries. Back pain and back injuries cost companies in the US more than 100 billion US dollars per year, in terms of both treatment costs and in lower productivity. An effective ergonomics program that identifies and reduces all Manual Materials Handling (MMH) risk factors is a key component of any effort targeted at reducing the cost of injuries. Recently experts have suggested that, as employers recognize and reduce the risks associated with lifting, attention in MMH work has shifted towards reducing the risk associated with pushing and pulling activities. Key to the analysis of push and pull forces has been the determination of maximum acceptable forces, which have been determined by either psychophysical methods or biomechanical methods.
The Hidden Ergonomic Risks of Manual Material Handling Carts
By Tom Albin | Caster Problems, Continuous Improvement, Workplace Ergonomics | July 24th, 2018 | Comments (0)
In the management of manual material handling carts, a common hidden and unknown factor is the stability or consistency of operating forces over the life of the cart. Operating forces are those forces necessary to initiate and sustain movement of the cart. Those forces will change as carts and casters wear. This factor can mean risk of injury for the company as, if the operating forces change, the risk of injury to the worker increases substantially.
While we have good processes in place to measure the initial and sustained operating forces and to ensure that those forces are within safe limits, we are perhaps less accomplished in utilizing risk management processes to ensure that the required forces remain within safe limits over the course of time.
How can we assure ourselves that a cart’s long-term operating forces aren’t hidden and that they remain within the desired performance envelope six months or a year from now?
Current MMH Evaluations may Underestimate Risk from Push and Pull Forces
Current methods of assessing push pull forces in industrial ergonomics are useful, but they need further development as they likely overestimate the safety of push and pull task forces. Back injuries remain one of the most-costly of all occupational injuries. It is estimated that about 10 percent of adults experience back pain severe enough to limit their productivity 25 days or more per year and that workplace lost-time back injuries cost businesses about $460 per employee per year. The physical stresses created by Manual Materials Handling (MMH) are known to play a causal role in back pain and injury, and studies by Snook and Marras et al have shown that using ergonomic analyses of MMH stresses to design reduced-stress MMH jobs reduces the number of injuries that occur. MMH tasks such as manually moving carts are composites of multiple elements: starting movement, sustaining movement, turning, and stopping. Each element applies stress to the individual who exerts forces to perform the task. Risk analysis of MMH such as cart handling must consider the stress created by all the elements of a task, not just starting and sustaining movement. When all MMH elements of a task are considered, the safe forces are likely lower than current assessment techniques suggest.
New Methods for Assessing Risks Needed in Industrial Ergonomics
Identifying musculoskeletal injury risk factors associated with MMH is an important component of any industrial ergonomics program that targets the reduction of workplace injuries. MMH tasks are often compound tasks or aggregates of several different tasks. For example, an MMH task might consist of loading boxes onto a cart, pushing the cart to a first location, maneuvering the cart around corners, unloading a few boxes, pushing the cart to a second location, and unloading or loading boxes there. Compound MMH patterns of this type are routinely seen in industrial workplaces. Currently, separate tools are used to individually evaluate each simple component of MMH tasks, such as each instance of lifting, carrying, pushing, and pulling. Applying the tools to a compound task yields several separate risk assessments, e.g. one for the lifting component and another for the pushing component. How should the combination of these individual analyses be evaluated to estimate the risk of injury for the compound task which includes multiple tasks, e.g. both lifting and pushing?
Industrial Ergonomics: Best Practices for Cart Management
By Tom Albin | Caster Problems, Caster Technology, Workplace Ergonomics | January 9th, 2018 | Comments (0)
Manual material handling using carts is a prime example of an occupational push and pull task. Managing the risk associated with pushing, pulling and maneuvering carts in the workplace is a critical component of an industrial ergonomics program.
As most facilities or organizations have fleets of carts, a systematic approach is useful in managing and reducing the risks associated with cart handling. While such a system will vary to suit the idiosyncrasies of different operations, there are some common components to these ergonomics cart management programs.
So, what are some best practices for cart ergonomics?
Industrial Ergonomics Regulations around the World
Understanding manual material handling and cart ergonomics standards everywhere is the key to minimizing risk of injury. Injuries related to manual materials handling (MMH) tasks are a major concern in industrial ergonomics. 3 out of every 4 individuals whose jobs include MMH tasks suffer pain due to back injury at some time, accounting for about 1/3 of all lost work and more than 1/3 of all compensation costs. In addition, there are major productivity losses associated with back injuries. Pushing and pulling tasks can be a major contributor to back injury in MMH tasks. So, what is a safe level of push/pull force?
How Reliable is Your Measurement of Forces to Maneuver Carts?
Effective management of manual cart handling ergonomic programs relies on measuring the forces required to move carts manually. Forces that exceed acceptable levels are more likely to result in injury and may also adversely affect productivity. An accurate, reliable measurement of the force required to manually move carts is essential for the effective use of the Liberty Mutual Tables or any other tools that evaluate the acceptable level of the forces required to move carts. But, how reliable is your measurement of the forces exerted to maneuver carts in your facilities?Sign up for free updates about workplace ergonomics, caster technology, industry news & events, product updates and more.
