Ergonomics and safety for Manual Material Handling (MMH)
Manual material handling (MMH) work contributes to a large percentage of musculoskeletal disorders reported annually in Europe and in the United States. Musculoskeletal disorders often involve strains and sprains to the lower back, shoulders, and upper limbs.
They can result in protracted pain, disability, medical treatment, and financial stress for those afflicted with them, and employers often find themselves paying the bill, either directly or through workers’ compensation insurance, at the same time they must cope with the loss of the full capacity of their workers.
Scientific evidence shows that effective ergonomic interventions can lower the physical demands of MMH work tasks, thereby lowering the incidence and severity of the musculoskeletal injuries they can cause. Their potential for reducing injury-related costs alone make ergonomic interventions a useful tool for improving acompany’s productivity, product quality, and overall business competitiveness.
Manual load handling and industrial manipulators (load balancers)
Industrial manipulators and load balancers have been introduced to answer a need for more ergonomics and safety in manual material handling and to comply with National standards and regulations (like for example the EU EN 1005-2 or the US OSHA and NIOSH standards related to ergonomics and safety.
All lift assist equipment have a positive impact on ergonomic safety, nevertheless conventional lifting equipment such as hoists (actuated by pressing buttons to control either pneumatic or fixed-speed electric devices) have not been associated with productivity improvements. For applications requiring rapid and accurate movement, they are awkward, slow and do not take advantage of the natural human ability to coordinate and control motions. Traditional pneumatic manipulators have a few non ergonomic features as well: they over-travel, bounce and require lots of little corrective movements to precisely position the load, thus causing strain and reducing productivity (see for example Woldstad, Chaffin – 1994 and Rossi, Bertoloni – 2013).
The lack of intuitive and responsive control may also both product damage and cumulative trauma injuries, especially when people force the equipment, or they get frustrated working with unresponsive equipment and put it aside.
To effectively improve operator wellness and achieve ergonomic safe handling operations, it is necessary that the manipulator not only eliminates the strain during load lifting (along vertical axis), but also the inertia during acceleration, braking or direction changes.
Only new generation electronic manipulators, better referred to as INDEVA® (Intelligent Devices for Handling) or IAD (Intelligent Assist Devices), comply with these ergonomics guidelines.
The results of a case study conducted by Rossi and Bertoloni of the Research Team at the University of Brescia and published on the International Journal of Industrial Ergonomics (2013), indicate that the use of an INDEVA® like the Liftronic® Easy by Scaglia Indeva®, may be preferable to manual material handling in situations in which the lifted weight is large (20kg) as well as those situations in which the weight of the load could not apparently justify the investment necessary for a manipulator (5kg). This study has also proved how the use of an INDEVA satisfies demand for more productivity as well together with improved ergonomics and safety.
A study carried out by Colombini and Fanti of the Italian Centre of Ergonomics (SIE) proved that an INDEVA satisfies requirements of ergonomics, combined with safety and productivity much more than a pneumatic manipulator and manual handling. Read more
Guidelines for ergonomic and safe manual load handling
You can read more about the International safety standards for Manual Material Handling like EN 1005 and OSHA and NIOSH regulations downloading the following documents.
Learn more about the work groups and the major standards issued by the CEN/TC122, the technical committee of the European Union in charge of economics standards:
Download a summary of major EU and US ergonomics principles and regulations
- Ergonomics principles and regulations
- Basic Ergonomics principles by the ILO (International Labour Organisation)
- UK manual handling handbook with reference to UK regulations (SI 1999 No.3242, SI 1992 No. 2793)
- NIOSH and Cal/OSHA MMH Booklet
- Calculate the Recommended Weight Limit (RWL) using the revised Niosh Equation
Download for case histories