

Solution: Battery Backpacks

E-mail this Solution to a Friend


	Description:	The conversion from corded to cordless power tools eases mobility around a work site and decreases hazards, including trips, falls, and accidental electrocution. However, cordless power tools require the use of a portable battery. The battery adds extra weight to hand tools and increases the load placed on the shoulder, hand, and wrist. Battery holders worn on the torso help decrease the weight of cordless power tools. Battery holders come in two main styles: battery backpacks and battery belts (worn like a tool belt). Battery backpacks and belts allow power tools to have portable power sources without adding the extra weight of the battery to the hand. Stress on the hand, wrist, and shoulder is decreased, and the convenience of cordless tools is maintained. There are some tools available that currently use a battery backpack or belt. Paint sprayers, chemical sprayers, and metal detectors utilize a portable battery worn in a backpack or on the belt in order to decrease the amount of weight placed in the hand. Power tools, such as drills, saws, and nailers, are available in cordless models. Battery backpack options, however, are not currently available for these tools. More Detail
	Risks Addressed:	The weight of a hand-held tool can contribute to muskuloskeletal injuries associated with stressful hand and wrist activity.
	How Risks are Reduced:	Using a backpack or belt to hold the battery decreases the weight of the cordless power tool, which lowers the stress placed on the upper extremity while using the tool.
	Quality of Evidence (Risk Reduction):	Independent published studies have found a risk reduction. Safety and health experts believe there is a risk reduction.
	Quality of Evidence Explanation (Risk Reduction):	Work performed with power hand tools is often repetitive and requires physical force from the tool operator. Independent published studies have shown that repetition and force are two of the main factors that are associated with musculoskeletal disorders of the upper extremity. Adding extra weight to tools increases the stress placed on the hand and wrist in two main ways: 1) Extra weight in the hand requires increased muscle activation and results in early onset of fatigue. During overhead work, the extra weight can increase the stress placed on the shoulder and low back. 2) Extra weight can also lead to increased gripping forces. Increased grip strength combined with repetitive motions results in work injuries to the hand and wrist.
	Effects on Productivity:	Battery backpacks and belts increase productivity by decreasing the rate of fatigue of the hand, wrist, and shoulder.
	Quality of Evidence (Effects on Productivity):	Safety and health experts believe there is an increase in productivity.
	Quality of Evidence Explanation (Effects on Productivity):	Safety and health experts believe that decreasing the weight of hand tools slows the rate of fatigue of the muscles in the hand, wrist, and shoulder. Without fatigue, workers are able to work for longer periods of time and be more productive. Workers are also less likely to sustain injuries to the hand, wrist, and shoulder when the weight of the hand tool is decreased.
	Return on Investment:	To calculate the return on investment (ROI) for your specific application, please visit our Return on Investment Calculator. While a specific ROI example has not been developed for this particular solution, the ROI Calculator provides a useful tool and guidance on how to generate your own on investment analysis.
	Availability:	Chemical sprayers / paint sprayers Solo Tools www.solousa.com Rocket Spray www.rocketspray.com Battery backpacks/belts are currently not available for most cordless power tools.
	Contributors:	Dan Anton, PT, PhD, ATC, Cassie Malecha, DPT, and Michael Milanoski, SPT – Eastern Washington University