Industry Solutions

Running head: CONSTRUCTION PLIERS AND RODBUSTERS 1

MUSCULOSKELETAL DISORDERS

Work-Related Musculoskeletal Disorders

KEVIN P. MCGEE COLUMBIA SOUTHERN UNIVERSITY

CONSTRUCTION PLIERS AND RODBUSTERS 1

Contents

Definitions....................................................................................................................................... 2

Introduction ..................................................................................................................................... 3

Work Related Musculoskeletal Disorders ...................................................................................... 3

Literature Review............................................................................................................................ 4

Causation......................................................................................................................................... 4

Rodbusters....................................................................................................................................... 5

CTS ................................................................................................................................................. 5

Solutions ......................................................................................................................................... 5

Innovation ....................................................................................................................................... 6

Bridge Decks ................................................................................................................................... 6

Steel Contractors ............................................................................................................................. 7

Conclusions ..................................................................................................................................... 8

References ..................................................................................................................................... 10

Figures........................................................................................................................................... 12


Definitions

CT: Cumulative trauma

CTS: Carpal Tunnel Syndrome

EHSP: Environmental Health and Safety Plan

Ergonomics: the scientific study of human factors and their safe/healthy interaction with the

human environment.

IIPP: Injury and Illness Prevention Plan

NIOSH: National Institute for Occupational Safety and Health

OSHA: Occupational Safety and Health Administration

The power tool: MAX USA RB 392 rebar tying tool

Rebar: steel bars placed and secured in position to reinforce concrete structures

Resistance welding: welding method used to join two or more overlapping metals

RMI: Repetitive Motion Injury

Rodbuster: a field ironworker employed to place and tie rebar prior to concrete installation

STD: soft tissue damage

Tie: a short length of wire wrapped around two or more pieces of rebar to prevent movement

WMSD: work-related musculoskeletal disorders


Introduction

Work-Related Musculoskeletal Disorders (WMSD) account for the highest number of

days away from work behind; fall to lower level; transportation accidents; slip, trip, loss of

balance; assaults and violent acts by coworkers; and exposure to toxic chemicals (Figure 1)

(BLS, 2014). OSHA reports more than 3.1 million nonfatal workplace injuries and illnesses

among private industry employers in 2010. More than one-third of all serious occupational

injuries and illnesses stem from overexertion or repetition. The National Academy of Social

Insurance (NASI) reports (2014) these injuries cost business $15 to $20 billion annually in

workers' comp costs alone. Add indirect costs, and the total mounts as high as $60 billion.

Workers compensation costs increased from $61.0 billion in 2011 to $61.9 billion in 2012

(NASI, 2014).

Work Related Musculoskeletal Disorders

WMSDs occur at higher levels among construction workers. This research will focus on

the construction ironworker; and more specifically the rodbuster. Soft tissue damage to hands,

wrists, and fingers accounted for 47.8% of reported WMSDs (NIOSH, 2009). This research

focuses on the specific WMSDs of Rodbusters involved with placing and tying rebar on freeway

bridge decks. It will discuss current placing and tying methods and practices, as well as

ergonomic developments to reduce the incidents of WMSDs. Ergonomic efforts to lower

WMSDs among ironworkers will be synthesized to identify specific improvements and their

justification. The application of scientific principles, methods, and data to design and develop

systems that improve the human interface with work is the essential goal of Ergonomics.


Literature Review

The primary purpose of human factors and ergonomics is design (Helander, 2006, p. 3).

Man finds an interface that benefits man in order to satisfy a human desire to manipulate his

environment. From axe and stone to the height of a conveyor line in industry, ergonomics has

served to satisfy human need and desire. Human Factors Engineering (HFE) is a continuous

study in promoting this vital human purpose. Helander (2006) describes the history of

ergonomics as a struggle between productivity and health as a continuous effort to improve the

development of society (Helander, 2006). Ergonomics drives this struggle to adapt an external

environment to human input. The development of technological and industrial advancements

emphasizes the need for ongoing ergonomic studies.

Causation

The scientific method drives an interest in specific injuries and their causation. One

example of this interest focuses on the use of hand tools. Hand tools have been used to improve

mans ability to manipulate his environment. The use of hand tools required to perform specific

tasks requires appropriate tool design as well as user skill. On the other hand, hand tools are a

leading cause of soft tissue damage (STD), cumulative trauma (CT), and work-related

musculoskeletal disorders (WMSD). For example, a pair of pliers can produce useful results

when the pliers are used both skillfully and usefully. However, Dr. Barbara Plog identifies that

pliers can cause serious injuries to the hand, arm, or shoulder (Plog, 2012). Identifying pliers as a

cause of serious occupational injury is critical to understanding why plier-use causes injury.

Whether created by job design or unfriendly technologies, plier-use is recognized as harmful to

productivity, quality, and worker safety and health (Goetsch, 2011, p. 201). Researching the use


of pliers by rodbusters intends to better understand what can be improved with rodbuster-pliers

and how to control the STD done when they are used.

Rodbusters

Rodbusters are required to use pliers to tie rebar together prior to the placement of

concrete. Rebar must remain in engineered positions when concrete is placed around them.

Rodbusters assume a stooped position when bridge-deck, or slab construction occurs. Pliers are

used to secure bars with tie-wire. It is not uncommon for bridge-deck construction to require

making more than 2 million rebar ties (NIOSH, 2009). The National Institute of Occupational

Safety and Health (NIOSH) has studied the STD associated with the use of pliers by rodbusters.

NIOSH (2009) concluded that 16% of rodbuster work-related musculoskeletal disorders

(WMSD) were linked to hand-wrist activities (figure 2). Furthermore, NIOSH identified that

excessive hand, wrist, and forearm position and movements are linked to this disorder.

CTS

Carpal Tunnel Syndrome (CTS) related to excessive plier use is an ergonomic concern.

The hand, wrist and forearm position and movements required to place and tie reinforcing steel

increase the likelihood for CTS. According to NIOSH (2009), pliers use by rodbusters is a

significant source of CTS. Furthermore, this CTS is not isolated to hand and wrist movements.

Rodbuster CTS can manifest at 52.2% of low-back disorders (Publication No. 2010-103). Body

posture and forceful working methods among rodbusters creates an increased demand for

ergonomic solutions to plier use (Helander, 2006).

Solutions

Ergonomic solutions to plier-related CTS continue to change as ergonomic studies

develop. Current human adaptations include modifications to existing rodbuster pliers. For


example, plier handles are customarily coated with a plastic. This plastic is commonly removed

and replaced with an impact resistant rubber absorber (figure 3). This absorber not only reduces

shock from cutting ties, but improves grip capacity. In addition, rodbusters typically remove a

reflex spring that is designed to open the pliers once a cut is made. This spring returns the pliers

to an open position. However, force is required to overcome the spring action to make another

tie. Rodbusters remove this spring to remove unwanted energy. To compensate for the springs

absence, rodbusters place an index finger between the lever and the handle to open and close the

pliers digitally. Adaptation is not a product of ergonomics. Adaptation in this context is a product

of user pain. The rodbuster is adapting to the tool.

Innovation

To significantly reduce unnecessary stress and strain on the wrist, arm and shoulder a

MAX USA RB 392 device was designed. This device is a portable power-tool recommended

for tying flat level rebar (NIOSH, 2009). Figure 4 shows a rodbuster using the power tool (note

the straight wrist and arm). This device can be provided with an extension arm to assist

rodbusters lower back strain. The extension allows the rodbuster to stand erect while placing and

tying rebar. Rodbusters activities occur under various conditions. Activities vertical, diagonal,

horizontal and overhead create CTS potential. Other types of rodbuster ties in various positions

were not studied by NIOSH. These variations occur when rebar is tied in positions other than

flat.

Bridge Decks

According to Albers & Hudock (2007), bridge-decks requiring frequent or prolonged

exposure to rebar tying should use the MAX USA RB 392 to reduce worker exposure to

WMSDs. Freeway bridge deck construction can employ rodbusters in stooped positions for 8


hours per day, 40 hours per week. Flat tying occurs in phases as the deck progresses, however

the risk of WMSDs prevails throughout each project when rebar ties are made to vertical and

horizontal intersections. The hazardous positions rodbusters assume during the course of one

shift expose workers to potential WMSDs. According to Kroemer & Kroemer (2001) ergonomic

solutions can focus on seven conditions:

1. Activities with many repetitions.

2. Repetitive activities requiring more than about one-third of the operators static

muscular strength available for that activity.

3. Putting body segments in extreme positions.

4. Making a person maintain the same body posture for a long time.

5. Pressure from tools or work equipment on tissues, nerves or blood vessels.

6. A tool vibrating the body or a part of the body.

7. The exposure of working body segments to cold, including airflow from

pneumatic tools. (Kroemer, 2001, p. 391)

Steel Contractors

The stresses involved with tying rebar satisfy each of the above 7 criterion. Steel

contractors involved with bridge construction use ergonomic principles to help minimize the

damaging effects of WMSD. One example is DPR Construction. DPR is an international

construction contractor founded by Doug Woods, Peter Nosler and Ron Davidowski (DPR).

DPR developed and maintains a comprehensive environmental health and safety plan (EHSP)

designed in large part to minimize injury and illness to both employees and the environment.

This EHSP contains a section dedicated exclusively to Construction Ergonomics (DPR, 2007,

Sec. 3.0-4.2.3). DPR recognizes the demand for competitive quality in the workplace. They also


recognize the health and safety of its employees can depend on proper intervention. In other

words, the information contained in its EHSP is provided to enable interventions for existing

WMSDs and assist its subcontractors and vendors in identifying potential WMSDs. DPR adds to

Kroemer & Kroemers (2001) identification of seven specific conditions above which can lead to

WMSDs. In section 8.3.2 of its EHSP, DPR (2007) divides its construction ergonomics program

into six catagories:

Force or muscle effort

Awkward body postures

Repetitive work

Contact pressure

Vibration

Temperature (DPR, 2007)

The WMSDs related to the hand, wrist and arm of a rodbusters can be reduced when

tying rebar on flat freeway slab construction using the NIOSH recommended power tool.

Conclusions

Research identifies the current relationship between rodbusters pliers and WMSDs.

Rodbusters pliers are designed to increase delivery power to freeway slab construction when

rebar is placed and tied. The pliers are used during this process in a repetitive griping, twisting

and cutting motion. Rodbuster pliers use leads to WMSDs and ergonomic solutions to WMSDs

can be applied to rodbuster WMSDs. The rodbuster plier can be replaced with a NIOSH

recommended power tool. Ergonomics role addresses the hand, wrist, and arm damage

accumulated during one work shift. Nevertheless it is visibly apparent that the stooping posture

is of great concern to an ergonomist. The power-tool manufacture engineered an extension to


allow the rodbuster to remain vertical while tying a bridge deck. This WMSD is not addressed in

this research. In addition to the power-tool, another ergonomic consideration can help alleviate

WMSDs. A process yet to be designed involves a resistance type weld to connect latitudinal and

longitudinal rebar together. It is important to remember that rebar is tied with the sole purpose of

holding it in position until concrete is placed. There is no structural significance to a rebar tie.

The use of a resistance weld process would virtually eliminate WMSDs related to rodbuster

hands, arms, wrists and even backs. The stooped overburden position could be eliminated by the

use of a resistance weld process. This note encourages the use of a resistance welding process.

However, rebars structural integrity can be compromised during a welding process. My search

found no definitive study of concerns related to the tensile strength of rebar that has been

resistance welded. Nevertheless, this remains a potential process improvement to assist healthy

human production.

The introduction of a portable power tying-tool to rebar construction on freeways is a

landmark improvement to rod-work. This ergonomic development satisfies Helanders (2006)

criteria for an optimal hand tool; It must fit the task; fit the user and hand; and not create

injuries (p. 217). Ergonomic efforts to lower WMSDs among ironworkers surely succeed with

regard to this activity. It is interesting to note that this improvement has been in the mind of

every rodbuster who worked a bridge deck, including mine. I am an ironworker by trade. I laude

the successful design, development, and application of a tool to a trade that provided me with

real work-related musculoskeletal disorders.


References

Albers J.T., H. S. (2007). Biomechanical assessment of three rebar tying techniques.

International Journal of Occupational Safety Ergonomics, 13 (3): 227-237.

BLS. (2014). Repetitive motion results in longest work absences. Retrieved from:

http://www.bls.gov/opub/ted/2004/mar/wk5/art02.htm

DPR. (2007). Environmental health and safety plan rev. 7 sec. 8.3.0. DPR Construction

Company Inc.

Goetsch, D. L. (2011). Occupational safety and health for technologists, engineers, and

managers (7th ed.). Upper Saddle River, NJ: Prentice Hall.

Helander, M. (2006). A guide to human factors and ergonomics (2nd ed.). Boca Raton, FL:

Taylor & Francis Group, LLC.

Kroemer, K., Kroemer, H., & Kroemer-Elbert, K. (2001). Ergonomics: How to design for ease

and efficiency (2nd ed.). Upper Saddle River, NJ: Prentice Hall.

Manuele, F. A. (2008). Advanced safety management focusing on Z10 and serious injury

prevention. Hoboken, NJ: John Wiley & Sons, Inc.

NASI. (2014). REPORT: Workers' Compensation: Benefits, Coverage, and Costs, 2012 .

National Academy of Social Insurance. Retrieved from:

http://www.nasi.org/sites/default/files/research/NASI_Work_Comp_Year_2014.pdf

NIOSH. (2009). Workplace solutions: reducing work-related musculoskeletal disorders among

rodbusters. publication no. 2010-103. Department of Health and Human Services,

Centers for Disease Control and Prevention.

Plog, B. A. (2012). Fundamentals of industrial hygiene (6th edl). Itasca, IL: National Safety

Council.


Webster. (1994). New universal unabridged dictionary. New Jersey, NY: Random House Value

Publishing, Inc.


Figure 2. Rebar tying using pliers Figure 4. Rebar tying using a power tool

Figures

Figure 3. Field modified Rodbuster pliers.

Figure 1. Days away from work, by event or exposure.

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