Solution Summary: Powered Wheelbarrow
A powered wheelbarrow is an engineering control that reduces the stress of lifting, carrying, pulling, or pushing objects. Powered wheelbarrows allow maneuvering and unloading of large, heavy objects with minimal effort, and are smaller than traditional forklifts and trucks. When using a traditional wheelbarrow to move heavy loads, a worker must perform heavy lifting, pulling, or pushing. These movements can cause musculoskeletal disorders (MSDs).
Powered wheelbarrows are used for moving loads too heavy for traditional wheelbarrows. There are two main categories of powered wheelbarrows including gas and electric powered. Both types are navigated by hand controls on the back of the wheelbarrow and the user either walks behind or stands on a platform.
The gas powered models have engines between 5-15 hp (Figure 1). Different models offer 2 or 4-stroke engines, 2x4, or 4x4 drivetrains, and reverse. Loads up to 1500 lb can be hauled across a worksite and dumped or unloaded at a desired location.
Figure 1. Power Barrow® Rocky
There are numerous makes and models with various features to accommodate the needs of construction workers. For instance, flat beds can replace the bucket to accommodate large and awkward loads. Ball hitches can be attached to the bucket to pull trailers up to 1.5 tons. A forklift can be fitted to the front of a powered wheelbarrow to move ¼-pallets up to 800 lb. The forklift is powered by the wheelbarrow engine. Snow plows can be attached to the front of the powered wheelbarrow. The blade can be raised for maneuvering, or angled to move the snow in the desired direction.
The electric powered models typically use 24 volt batteries which maintain 4-7 hours of runtime per charge (Figure 2.). Different models offer 200-750 lb carrying capacity, 2x4, or 4x4 drivetrains, and reverse.
Figure 2. Granite Industries Hopper Dump Cart
Powered wheelbarrows are much narrower than traditional forklifts and trucks. This enables them to go around tight corners and fit through narrow doorways. Furthermore, most powered wheelbarrows have traction tires and four-wheel drive allowing them to navigate rough or uneven terrain. The wheels can be locked for dumping, and some models feature motorized dumping.
When using a traditional wheelbarrow to move heavy loads, a worker must perform heavy lifting, pulling, or pushing. Lifting, pulling, and pushing heavy objects can cause disc herniation, muscle strain, and other MSDs. A low back disc herniates when there are excessive loads are placed on the spine. Overworking the muscles can also result in strains. Use of powered wheelbarrows may reduce the risk of disc herniation, muscle strains, and other MSDs associated with lifting, pulling, and pushing.
How Risks are Reduced:
Powered wheelbarrows eliminate the lifting, carrying, pushing, and/or pulling that is required with traditional wheelbarrows. Instead, the wheelbarrow uses power from a small engine to move heavy loads.
Independent published studies report that there is strong evidence that lifting and carrying (manual material handling) puts workers at risk for musculoskeletal disorders of the low back and spine (Bernard et al. 1997). According to the National Academy of Sciences, there is a clear relationship between back disorders and manual material handling (National Research Council and the Institute of Medicine 2001). Furthermore, research has shown that repetitive heavy lifting predicted low back pain, and heavy pushing or pulling predicted lower limb pain (Andersen, Haahr, and Frost, 2007). Unlike traditional wheelbarrows, powered wheelbarrows require minimal repetitive heavy lifting, pushing, and/or pulling.
There have not been independent published studies measuring the effect of powered wheelbarrows on the incidence of low back disorders. However, studies have shown an association between manual materials handling and low back pain. (Kuiper et al. 1999; van der Molen et al. 2005). Powered wheelbarrows reduce the amount of manual materials handling and therefore may reduce the incidence of low back pain.
Joe Built Wheelbarrow LLC states that powered wheelbarrows “…will reduce your labor costs and work-related injuries,” and “overexertion injuries account for a significant number of all work-related back injuries to employees” (http://www.joebuiltwheelbarrow.com/).
Safety and health experts believe that powered wheelbarrows can require less lifting, pushing, and/or pulling than traditional wheelbarrows and therefore reduce the incidence of MSDs.
Effects on Productivity:
Powered wheelbarrows increase productivity on the worksite.
Motorized wheelbarrows would help those performing constant wheelbarrow tasks. However, powered wheelbarrows may not be cost-effective for a trade requiring occasional wheelbarrow tasks.
Using the ball hitch attachment to tow trailers may be problematic because the powered wheelbarrow can lose traction due to its relatively light weight compared to fully loaded trailers.
In addition, heavy lifting might be required to load motorized wheelbarrows. However, transport and dumping of the material will be easier.
Transporting motorized wheelbarrows between worksites might be difficult due to their relative size and weight.
Dan Anton, PT, PhD, ATC; and Kevin Wright, SPT – Eastern Washington University
Granite Industries/American Cart Equipment Dump Hopper (Electric)
To obtain information, visit http://www.americancartequipment.com or contact 1-877-447-2648
Acme Tools Electric Power Assist Wheelbarrow
To obtain information, visit http://www.acmetools.com or contact 1-877-345-2263