Solution Summary: Powered Hand Trucks
Powered hand trucks are engineering controls that enable one or two workers to move heavy loads with minimal effort and without awkward postures. These hand trucks can move loads vertically (e.g. stairs, or loading docks) or across worksites using self-propelled wheels.
There are many varieties of powered hand trucks available. Most have aluminum frames, are battery operated, weigh 120 to 170 pounds, and lift between 450 and 1500 lbs. Powered hand trucks can be used to carry heating and AC units, water heaters, drums, motors, transformers, refrigerators, and other appliances.
Powered hand trucks are for manual materials handling on level surfaces, up and down stairs, on and off trucks, between trucks and loading docks and over obstacles such as curbs and thresholds. They can be self-propelled for moving items on level surfaces or have motors for lifting up steps.
Many accessories for powered hand trucks are available: extension handles for more leverage or reducing the size for tight spaces, larger rough surface wheels, vacuum grip handles, and floor dollies for moving object while the hand truck is lying flat.
Most powered hand trucks take practice and proper training to use. Training is generally short and can be as little as 30 minutes.
Figure 1. An example of a powered hand truck
Heavy lifting and carrying and stooped postures can cause low back disorders, such as muscle strain or a disc herniation (“slipped disc”), which is bulging of disc material possibly pressing on the spinal cord or nerves that go into the leg. Powered hand trucks can help reduce stooped postures, heavy lifting, and carrying by moving loads using a powered machine.
How Risks are Reduced:
Exposure to lifting, carrying, and continuously stooped postures can cause low back disorders such as disc herniation or muscle strain, as well as other MSDs. An intervertebral disc herniates when there is an excessive loads on the spine that cause the disc to bulge onto a nearby spinal nerve, resulting in a variety of symptoms. Overexertion while lifting or carrying can result in muscle strains, which is characterized as partial tearing and separation of muscle fibers. Powered hand trucks reduce risks of disc herniation, muscle strains, and other MSDs associated with lifting, carrying, and continuously stooped posture.
Based on current research, the National Institute for Occupational Safety and Health has concluded that there is strong evidence that low back disorders are associated with work-related lifting and forceful movements (Bernard et al. 1997)
There have not been independent published studies measuring the effect of powered hand trucks 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)
According to the Advanced Manufacturing Institute, a research and development division of Kansas State University and manufacturer of powered hand trucks, the Power Dolly was developed to reduce strain on workers when handling heavy loads. Powermate Manufacturing states that a powered hand truck, “reduces [the] physical effort used to move heavy loads,” and “reduces the chance of personal injury.”
Effects on Productivity:
Powered hand trucks increase productivity.
Powered hand trucks are built for a large variety of uses and the purchaser should be careful to select one that is appropriate for their worksite. For example, choose rougher terrain tires for outside work and one that is lightweight if it has to be placed in a work truck. Many of the powered hand trucks available are too large and impractical for smaller jobs.
Dan Anton, PT, PhD, ATC; Zack Sinner, SPT; and Kevin Wright, SPT – Eastern Washington University
PowerMate Stair Climber
To obtain information, visit http://www.powermate.info or contact 1-800-697-6283