Companies are plagued by the increasing impact of employee overexertion injuries. The costs associated with overexertion injuries can be massive including insurance payouts, on-boarding replacement workers, low employee morale, and more.To combat these unwelcome outcomes, organizations are stepping up and implementing workplace ergonomics solutions. Liberty Mutual Research helps organizations by providing the resources necessary to make improvements.
Since the 1970’s, those in the material handling world have turned to Liberty Mutual for guidelines to help companies design material handling tasks for employees to reduce risk of overexertion injuries. The Liberty Mutual Research Institute is the go-to industry expert providing Snook and Ciriello tables. These tables show how both male and female populations can handle material handling tasks without overexertion. Some of the material handling tasks covered are:
- lifting
- lowering
- pushing
- pulling
- carrying
These tables were designed to keep material handling costs down. Material handling costs can be significant due to disability costs and reduced productivity and quality. For employers, these tables are indispensable as they provide the information needed to optimally design material handling tasks for efficiency while minimizing overexertion injuries to employees.
Material handling best practices indicate that tasks should be designed so that 75% of the female work population can achieve the task without overexertion. However, it may be difficult given a specific task, to accomplish this. So, these tables are also used to identify tasks that should be redesigned to create ergonomic solutions so that a company can achieve its ergonomic objectives.
The tables take into consideration a number of factors, depending on the type of material handling task including:
- object weight
- hand distance away from body
- hand height – at start and end
- task frequency
- distance
- initial pushing/pulling force
- sustained pushing/pulling force
- twisting
The recent edition of the Liberty Mutual Material Handling Guidelines includes a worksheet to record measurements to help evaluate the task.
Most companies rely on the Liberty Mutual Tables to assess and improve their material handling tasks as they highlight specific areas in the material handling process that need to be redesigned to accomplish workplace ergonomic goals.
Sometimes tasks can be redesigned simply by replacing the casters on the carts used in order to reduce the push/pull forces required to move heavy loads. A major impact can be made in reducing these forces by altering the caster wheel. Factors to consider include selecting the proper wheel diameter and material in relation to the environmental conditions. Our recent blog post, 5 Questions to Ask When Choosing a Caster, highlights some of the factors that may improve push/pull material handling tasks.
