The predominant labor activities in which most roofers injure their lower backs involve lifting dead loads, twisting during transition and overreaching. It’s simply unreasonable to believe we can eliminate these motions during most roofing operations. It’s just the nature of the beast. There is one piece of personal protective equipment (PPE) designed to help your employees avoid serious musculoskeletal disorders during most of their normal roofing tasks. Unlike the old technology offered by the lifting (or abdominal) belt commonly used in warehouse operations, this aid actually reduces, in some cases, up to 50 percent of the eccentric strain associated with lifting heavy loads.
While most of the available ergonomic products on the market do not provide protection from injury by means of an engineering control method, some are actually capable of removing the hazard entirely, at specific times and locations. The extensive use of hand trucks, roofing carts, hoisting devices, ladder-elevators and deliver forklifts and cranes have all made significant reductions in load-carrying injures for roofers. Good housekeeping practices and slip-proof foot wear appropriate for the particular roofing surface have also reduced many of the indirect causes of ergonomic strains resulting from roof slips.
With Handi-Straps, the roofing contractor has a new weapon to use against those musculo-skeletal disorder (MSD) injuries nibbling at his profit margins every day. What is unique about this product is its engineering principle. I can best describe it as an engineering hazard control that is worn on the body as personal protective equipment. It is the product’s ability to actually remove the hazardous effects while lifting a load that sets this device apart from abdominal belts. There is no other device I’ve found on the marked which performs precisely as a lifting strength aid while preventing most of the indirect causes of MSDs in the lower back.
Handi-Straps are designed to take the application of any load which can be grasped by the hand (or hands) and transfer it to the mass of back muscles and bone without applying any debilitating lateral stresses to the lumbar vertebrae. It is feasible to use in almost every construction tasks requiring lifting or pulling. According to its inventor, Ron Komorowski, the product is a “historical breakthrough turning the human body into a more efficient machine, safely, determined only by the laws of physics.”
I undertook research on this product as a complete and utter skeptic. However, I underwent a conversion after just one day’s use. Each vertical arm strap is adjusted by slide buckle until the user cannot fully extend his arms down without the straps tightening first. As a result, during the lift the arms are totally free from any stress, avoiding wrist, elbow and shoulder injuries. If you have a shoulder or rib strain or injury, you may adjust the straps so that your dominant, uninjured shoulder receives more of the load. As the user slips four fingers of his hands into the hand loops (thumbs out), the red, rubberized extension straps hang comfortably in each palm. When a solid object is grasped, this friction strap increases the user’s grip strength and fully engages the load. When the load is lifted, the arms are loose and just slightly bent at the elbows. The dead load that would have been carried by the arms is diverted up and over the shoulders by the harness straps, distributing the weight over the entire back area, finally transferring the load vertically to the spinal column, pelvis and legs without any lumbar stress. The relief when compared to lifting, carrying and lowering the same object without using Handi-Straps is palpable.
Another benefit of Handi-Straps is that the arrangement of the harness straps necessitates the user to assume the correct posture for lifting: legs bent and back straight. The product is simply a lift-assist device, and as the manufacturer cautions, “This product will not enhance the overall load the body can manage.” As they will make the user feel much stronger, you should not attempt to use Handi-Straps to lift any object heavier than you would without their assistance. So only use it according to the manufacturer’s safe use instructions and warnings.
The light (less than 8 ounces) and unobtrusive (13/4 inches wide) woven nylon harness and cushioned shoulder straps conform closely to the body and are comfortable enough for all-day use, even when worn over any outer jacket or gear. They come in three basic sizes: small, medium, and large; the product’s sizing has nothing to do with the weights you plan to lift, but only in the dimensions of your torso and arms.
Material Handling Tests
While at work, our musculoskeletal system is exposed to a variety of forces which arise from just five basic material handling exercises: lifting, lowering, pushing, pulling and carrying dead loads. I evaluated Handi-Straps according to the five major categories involved with material handling tasks on the job: Lifting, lowering, pushing, pulling and carrying dead loads.
While far from totally inclusive or even scientific, the tests I conducted gave me the opportunity to evaluate the product’s ability to aid and assist in each typical construction task manipulating a load.
Lifting is the task that had the widest variety of successes, and I’d give Handi-Straps a grade of A in this category. Lifting objects of all sizes, shapes and weight, with or without full-grip surfaces of the handles, came quite easily. Obviously, it takes some getting used to, but a little practice and mental perseverance paid off. The good news is the center-postural design of the device actually assisted me in making the adjustments necessary to guide my vertebrae and muscles to the proper position.
There are lifting tasks which involve a “clean and jerk” technique required to raise the load above the waist, such as lifting a bundle of shingles onto the eaves from a ladder or scaffold. Once the load is transferred from the Handi-Straps back onto the arms, the device has no practical advantage and its use is nullified. That’s OK as long as the user knows the device’s limitations.
While Handi-Straps have both a right and left hand palm loop and grip strap, a single-handed lift is also greatly aided by its design.
When lowering items, just as during a lift, you must automatically assume a correct posture for the lower due to the product’s anatomical design. Because of the advantages I felt Handi-Straps offered me during lowers, I give it my highest grade: A-plus.
Carrying a load is a complex task and varies greatly according to the single or compound slope of the walking surface, whether you’re stepping up or down and the general shape of the load. If the load is an awkward shape, both arm straps should be properly adjusted to account for different hand elevations. There are so many more muscle groups involved with walking, climbing and descending, it’s hard to explain the aid which this device provides without trying it yourself. It is a matter of balance. I gave it a grade of A for carrying.
Although the overall scores for pulling were high, I must admit I would rather lift a load with Handi-Straps than pull one. The device was not very effective in a vertical pull down, such as hoisting a load to the roof or scaffold using a davit and single block pulley (at a 1:1 ratio). The only way that I could engage Handi-Straps in this configuration was to lean backwards, but as soon as I flexed my elbows I took stress off of the arm straps and the device was ineffective; I gave it a D grade in this application.
For a diagonal pull up, the grade was an A. When I added a second pulley block anchored to the scaffold leg base and ran the pulley line from the davit down through the second block and pulled up with a backward haul pull, the load lifted easily with no discernable spinal stress. Hauling items backward with a horizontal pull was effective, and I gave it a B. I dragged a 50-pound weight across a firm and level gravel grade by gripping the pull rope with the Handi-Straps and walking backwards, facing the load. Hauling items forward with a horizontal pull while facing away from the load resulted in an A grade.
Needless to say, the product can contribute absolutely nothing when pushing a load. The best recommendation I have is to consider the mechanics necessary to some way convert pushing into a pulling task. While not always physically possible, due to the work area or load configuration, this would simplify and amplify the worker’s ability to handle the task with much less effort.
Use Common Sense
I wanted to introduce the features of the Handi-Straps lifting aid to my readers because I think they provide unique and reproducible results. Handi-Straps have direct and beneficial material handling applications for roofers and laborers. It is a 100 percent American-made product, and at only $60 retail, it is certainly reasonably priced. It is rugged, and with adequate care, will certainly last for many decades. It meets (and almost defines) the K.I.S.S. (“Keep it simple, stupid”) method of safety.
The inventor has emphasized in his product literature and Web site that this device will not make you Superman. Don’t attempt to lift and carry any load that you would not attempt to lift without wearing the device. As Ron Komorowski notes in his caveat:
“Handi-Straps increases weight-bearing stability by distributing exertion to the entire upper body. This product is meant to assist the different tasks of lifting and pulling safely. This product will not enhance the overall load the body can manage.”
It is my opinion that this lifting aid device has surpassed and ultimately supplanted the 20th century lifting belt by introducing a safe and simple mechanical advantage to the lift when used properly according to instructions. Handi-Straps are manufactured and distributed by Web Devices, and the company’s Web sites (www.handi-straps.comandwww.webdevices-usa.com) provide amazing graphics and video clips of this lifting aid in use by people of all sizes, sexes, shapes and ages.