Abstract

Hand tools assist the hands in performing a task by increasing the output force, precision or efficiency of the hands/fingers. They can also help to protect the hands from injury, including cumulative trauma disorders (CTDs) if they are ergonomically designed. The meat hook is a tool that has become increasingly important to the meat packing industry as the economic demands of high speed lines and the consumer demands for cuts of boneless lean meat have converged. Various changes in the design of this tool’s handle, to better fit the human hand, have been developed. The rectangular handle of the mid- 70’s was gradually replaced by the cylindrical handle shape of the mid- 80’s and now by the custom moldable grip handle of the mid- 90’s. This latest handle design is an elliptical curve to fit the palm of the hand with a “brass knuckle” series of indentations for the fingers. The handle material not only resists slipping (important in this industry environment), but also has “recoil give” to soften the grip under heavy pulling force. Comfort of the tool has made it popular among industry employees and the reduction of CTD symptoms has made it recommended among physicians and therapists. The design of this handle was a joint venture between the material patent holder, the tool manufacturer and an industrial ergonomist. Both the design and handle material hold promise for tools in other industries as well.

Introduction and Statement of the Problem

The meat packing industry has experienced a significant drop in the incidence of CTDs due to its ergonomics emphasis in the 1990’s. The body segment that was most likely to develop a CTD was the fingers/hand/wrist. The majority of meat packers in the U.S. will hold a knife in one hand and a meat hook in the other. Therefore, the ergonomics of the fit between the handles of these tools and the hands is very important. The material patent holder, a hook manufacturer and an industrial ergonomist, therefore adapted the material and the design of a handle that could be customized for ergonomic fit.

Analysis

A meat hook is a desirable tool because it can eliminate a significant amount of pinch grip work with the fingers. It not only minimizes this CTD risk factor, but also decreases the chances of a knife cut by keeping the fingers further from the blade. The rectangular handle of the mid-70’s concentrated all the pulling pressure of the hook across a narrow band near the base of the fingers. The cylindrical handle of the mid- 80’s spread the pulling force of the hook more evenly across the fingers, but the hard plastic still put contact stress on the tendons as they were squeezed against the finger bones. Therefore, circulatory compromise, neuropathy and trigger finger CTD symptoms were more likely to develop over time. The need for a soft grip material was evident, and the ability to contour the handle to an individuals’ hand would be the ultimate in ergonomic design.

Problem Solving Process

The industrial ergonomist reviewed the historical data on hand/finger/wrist CTDs and discussed this with meat packing physical therapists and occupational physicians. It was agreed that the previously mentioned improvements to the meat hook would be beneficial to the reduction of CTDs to the fingers/hand/wrist. The ergonomist then contacted Barr Brothers, a hook manufacturer, to discuss the concept and need. The manufacturer’s search for an acceptable material (including USDA acceptability for food contact) led him to the patent holder of PersonaGrip (registered trademark). PersonaGrip is a material that can be applied to tool handles and heated for custom forming to an individual’s hand. This team then proceeded to work individually and collectively on the design and material blend of the new hook handle.

Alternatives and Solutions Selected

The first material blend for the hook handle was too soft to be durable and did not meet USDA approval beyond the trial period. A more durable and slightly harder material blend is presently used and still has a soft feel and give under pressure. Eight different ergonomic handle shapes (see Figure 1) were prototyped and distributed in the meat packing plants for testing by the meat packers. Ergonomics or training staff at the plants collected employee feedback on the various handle shapes. Dozens of employees, performing high pull force jobs, tried the various handle shapes and ranked them according to comfort and fit. The material patent holder, tool manufacturer and ergonomist selected the current design (see Figure 2) from the input. The handle design selected is an ellipse curve to fit the palm of the hand and a “brass knuckle” series of indentations for the fingers. Additionally, the handle can be heated (heat gun), and then grabbed by the individual’s soapy hand to custom form the tool to fit the hand. This process can be repeated if the tool is subsequently passed on to another individual. The tool is available industry-wide through Barr Brothers Corporation of Redding, CA.

Results

The acceptance of this tool among production meat packers has been exceptional. The most common comment is that “it feels good in my hand.” The handle material also resists slipping, an important consideration in the environment of this industry. Plant managers have been slower to accept the change due to the increased cost (50%), but are phasing them in. At an extra three dollars per tool, many could be purchased and cost less than a single doctor visit or surgical procedure, that it is designed to prevent. The occupational physicians and physical therapists are also routinely requesting the new hooks for their rehabilitation patients with trigger finger syndrome or similar CTD maladies.

Summary and Conclusion

This new hook with its handle’s customizing ability represents the pinnacle of ergonomic design. The comfort and fit make it a popular tool among production employees. This customizing ability has applicability to the development of handles for tools in other industries as well. The significant decline in CTD incidence rates in the meat packing industry, during the late 1990’s (BLS incident rate of 993 per 10,000 employees in 1998 versus 1,206 in 1995), is due to various ergonomic interventions. The ergonomic meat hook has been one of the significant changes that has helped to produce such results.

Dr. Greg Worrell, CPE

WORRELL CONSULTANTS, LLC

Health, Ergonomics, & Loss Prevention (HELP)

4816 West 5^th Street * Greeley, CO 80634

(970-353-4094); worrell.greg@juno.com

Hand-Held Meat Hook Evolution This tool offers ergonomic advantages to meat handlers
Ergonomically designed tools for the meatpacking industry will continue to grow in importance and demand. Several reasons are behind this. For one, the Occupational Safety and Health Administration is encouraging developments in this area in order to cut down on the amount of work force injuries. Meatpackers, too, are searching for every way possible to decrease injuries. This is being fueled, in large part, by escalating workman's comp costs. Ergonomic advantages One ergonomic tool used in a meatpacking plant that may often be taken for granted is the hand-held meat hook. The only alternative to using a meat hook is using the pinch grip of an employees fingers. One industry insider reports that meat handlers in some meat companies in Europe, as well as Australia - and possibly even in the United States - still prefer using the old-fashioned method of handling meat by hand as opposed to using meat hooks. "There is the mind-set that 'this is the way it has always been,'" says the president of a leading meat hook manufacturing company. "Times are changing." This supplier says his company has had success in recently introducing its ergonomic hooks to the European meat industry. The company has appointed its first distributors in France and Germany for this product line. Greg Worrell, a Certified Professional Ergonomist, is corporate ergonomics director for Greeley, CO based ConAgra Red Meat Cos. He has been working with this supplier on new hand-held meat hook designs for several years and says:	"Hand-held hooks have become increasingly popular. First, they were used in beef packing operations. And now, employees transferring from beef to pork packing operations are taking the hooks with them." A hand-held hook has many advantages over working meat by hand including: It extends the reach an extra several inches. The mechanical advantage gained in a heavy pull of using the whole hand in a power-grip position. Avoiding a pinch grip in pulling away a membrane or holding a small piece of meat. It may be used as a probe in small openings to separate meat and bone or muscle seams. All of the pre-mentioned may be useful in decreasing cumulative trauma disorder stressors. There is also the safety factor. Hooks physically remove the fingers several inches from the cutting surfaces of saws or knives. Hook evolution The meat hook company president says his company has been making meat hooks for more than 40 years. It first offered hooks with a wooden handle to fabricate meat "quick and easy." This flat handle had curves that went into a right angle. "There weren't a lot of design considerations for ergonomics at that time'" he adds. In the 1970s, wooden hook handles gave way to plastic ones. Soon, meat industry customers were asking for something better in meat hooks.	Cylindrical-shaped hammer handles were the next evolution, the manufacturer president says. "I've been working with ergonomic professionals at Monfort and IBP, primarily, to come up with better ergonomically-designed hooks." Thus, the open-grip hook was developed next. This hook has no steel going between one's fingers. It is "D" shaped; the hook comes out of the middle of the D. he round handle has ribs on it that keeps the hook from rotating in the hand. The open-grip hook also eliminates breakage of mesh safety gloves. "We wanted to develop a handle that would more evenly distribute the forces on the hand; spread it across a broader part of the hand and decrease contact stress on any portion of the fingers," Worrell says. In working with Worrell last year, the supplier also developed smaller diameter hooks for people who have smaller hands. Worrell notes that hand-held hooks should feature the following important design considerations: Rounded handles to reduce point contact and compression on the hand, and spread out the force as much as possible. Multiple handle sizes. A good grip pattern to rduce slip rotation and how tightly the hook must be gripped. The hook between the fingers should be as thin as possible to reduce contact pressure or use an open-handed design hook. Work is underway to design a USDA-approved comfort grip-hook and other futuristic designs.
Article taken from Meat Marketing and Technology, September 1995 issue

B a r r B r o t h e r s C o . Increase Productivity And Worker Safety In 1873 at Eugene, Oregon brothers William and Hugh Barr began making industrial cutlery under the name Barr Brothers.
Since its early beginnings, Barr Brothers has maintained a reputation for producing quality, American-made products which stand up under the most demanding use in the meat industry. In 1955, the first boning hooks - carbon steel with hardwood handles - were introduced as a safety aid for the US meat packing industry and the next 30 years saw a dramatic increase in demand. Stainless steal hooks hardened to a spring temper and plastic handles became the standard. Easily-visible bright orange handles from Barr Brothers became commonplace in large and small plants throughout the US.	The 1980s brought many challenges to the meat industry including ergonomics. Barr Brothers pioneered the idea of ergonomics in hand meat hooks with the introduction of the hammer handle design. It has worked with the ergonomics department of the largest mear packing plants in the US to develop the current product line. The hand held meat boning hooks are used in every meat packing plant and butcher shop in the United States, Canada and Mexico. The high production slaughtering environment can benefit from the use of hand held hooks,	versus the human hand, in the following ways: Extends reach by several inches; Mechanical advantage gained in a heavy pull of using the whole hand in a power grip position; Secure hold on slippery piece of meat; Avoids pinch gripping and may be used as a probe; Promotes safety by keeping hands away from blades; Decreases carpal Tunnel Disorder stressors.
Article taken from IFFA Focus 1995, Meat International Special Show Publication

What the Press has to Say

Abstract

Introduction and Statement of the Problem

Analysis

Problem Solving Process

Results