ERGONOMIC RISKS IN THE WORKPLACE OF THE CENTRAL FRAME · ERGONOMIC RISKS IN THE WORKPLACE OF THE CENTRAL ... people involved in the central hardware (engineers, technicians, ... below

ERGONOMIC RISKS IN THE WORKPLACE OF THE

CENTRAL FRAME

Milene Menezes Rampinelli (UFSC)

[email protected]

Angela Regina Poletto (IFSC)

[email protected]

The job of the central frame is responsible for the preparation of armor by cutting, folding

and assembly of steel. The armor along with concrete, form the structural elements used in

buildings. This study aimed to evaluate the activities oof the jobs of the central frame in a

steel supply company benefited from the point of view ergonomic. An ergonomic work analy-

sis, following the method proposed by Guerin et al. (2001). We analyzed the activity of ma-

king the stirrups, rebar fabrication and assembly of armor. As a conclusion of EWA were ma-

de important recommendations regarding the postures adopted, adapted equipment and tools,

organization of the layout, use of PPE and packaging as well as the structuring of labor trai-

ning and education of workers.

Keywords: Central frame, ergonomic analysis of work, postures.

ICIEOM – CIO 2013 – Valladolid, Spain

2

1 Intoduction

The construction industry for its ability to create jobs is of economic importance to the country,

however, it presents issues regarding working conditions of the workers, low-skilled and high accident

rates. The data reveal that the construction of buildings is responsible for most accidents in the

construction industry due to the fact that the worker perform their activities outdoors, exposed to the

elements, use much physical strength and neglect of the use of equipment individual and collective

protection. In recent years, accidents have decreased gradually. In 2008 the Social Security reported

51,297 accidents, in 2010 the number dropped to 47,107 accidents (BRAZIL, 2012).

In medium to large it can be seen that the central frame are in the process of industrialization, from the

suppliers to perform the activity because it enables companies require more quality product due to the

possibility of greater control over the production process. So, besides being an alternative to

increasing productivity, can reduce resources by eliminating the step of cutting, bending and

assembling reinforcement of jobsites investing only in a small team to carry out the lease of the armor

within the elements structural.

The behavioral change is related to the highly competitive in the market, the reduction of financial

resources, increased awareness of consumers about the quality of service and the largest organization

of workers. In this context, the rationalization of the production process is characterized by a

coordinated action between the various aspects involved from conception to implementation, aiming

to improve the physical and economic performance of the product over its lifetime. During the phases

of production companies seek a balance between cost, time and quality, which depends basically

employing an efficient management in the production process.

According to he NR 17 (MTE, 2011), helps with ergonomics assessment tools to obtain work

organization through the adoption of ergonomic principles to improve the comfort and safety. The

ergonomic knowledge generates information that serve to guide the planning and implementation of

preventive measures of occupational accidents and occupational diseases, and reduce the physical

discomfort of the worker, thus increasing work efficiency.

Issues related to ergonomics and worker safety should not just be a legal obligation, while the

employer comply with existing legislation, providing adequate working conditions, resulting in worker

satisfaction with reflections on improving performance, reducing absenteeism and consequently

increase productivity. The aim of this study was to develop a job analysis study in central frame, from

the point of view ergonomic aiming to confront the work prescribed by engineering methods and

conditions for its execution of the work in order to diagnose the actual conditions and recommend

improvements to the transformation of the work situation.

2 Method

We collected information on the influence of ergonomics in the work of construction. The literature

review provided the basis for method development and understanding of the activities developed in

the steps of the central frame.

For the development of the research, we used the method of Ergonomic Work Analysis (EWA), which is

a form of ergonomic intervention used in studies that examine work activities (GUÉRIN et al., 2001).

The steps of EWA were developed through several techniques: observations, structured interviews and

semi-structured interviews, footage, audio recordings, photographs, questionnaires and verbalization

of workers. The observations were based on the activities of workers studied the station and the

people involved in the central hardware (engineers, technicians, master of works). We applied the

evaluation protocols and postural OWAS and MOORE and GARG on analysis of attitudes in key

activities.


3

The survey was conducted on a steel supplier received for the construction of buildings, located in the

southern region of Florianópolis. The company carries out the making of armor, by cutting, folding and

assembly of rebar and steel bars to be used for the construction of the structural elements of buildings.

Data were analyzed qualitatively and quantitatively. Qualitative analysis was performed by analysis of

content, in which they were created categories identified during the analysis of EWA. For quantitative

analysis we used measures of central tendency and variability.

3 Results

3.1 Analysis of the activities focus on postural

The company had twelve employees: three administrative (general production manager and two sales

managers) and nine production (two for cutting, bending and assembling, and installing a driver, one

for the manufacture and assembly of the stirrups and five for mounting) . All workers were males aged

between 20 and 64 years.

Regarding the workplace, in the production sector, the organization of work is performed by dividing

into three work teams comprising staff of rebar fabrication and assembly team and the team making

the stirrups. The driver and the officials in charge of undertaking the preparation of calipers and cut

and bend steel bars, to complete their activities, join the team assembling the armor.

The physical environment made available to the manufacturing sector comprises a covered area of

196m2 masonry brick coated with plaster and paint, cover metal frame with asbestos shingles and tiles

translucent polypropylene underlayment and the floor and smoothed area for preparation of stirrups

occupies 21 m2 built in masonry concrete block coated with paint and cover wooden structure with

ceramic tiles and translucent tiles and flooring with ceramic coating.

During the execution of work activities were observed postures in various situations. The workers

performer flexion, rotation and tilt of the trunk, wrist flexion and extension, knee flexion (squatting)

may cause injury. Therefore, we analyzed the attitudes of workers Durantes production activities of the

stirrups, cutting, folding and assembly of armor using ergonomic assessment tools in order to identify

the positions to be avoided or corrected.

3.1.1 Activity cutting and bending

The raw material arrives in the company and as the dimensions of the parts workers are performing the

lift, transport and deposition of charge on-site storage mechanically.

After storage of the raw material starts to step cutting and bending. As shown in Figure 1, the worker is

reading project and passing the information dimensions of the parts to be made for other workers who

derive the material to be used in place of storage manually (Figure 2) and deposited on the workbench.

It was observed that this procedure is performed throughout the workday, prompting the worker to

perform the twist and tilt of the trunk and squat successive times.


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Figure 1: Communication Figure 2: Selection of material

Workers place the materials on the workbench with the aid of bearings into position, perform the

alignment of the rods (Figure 3), with a measuring tape attached to the metallic bench, and held

marking the iron rod or rebar the site to be cut or folded (Figure 4). Positioning the material on the

guillotine for cutting the material (Figure 5), and then the material position to perform the bending.

After cutting and bending the part is identified by the label and sent manually to the storage location

near the mounting area. The label is set manually (Figure 6) and contains information on the size of the

part and of the features for mounting the armature, order number, customer name and shipping

address.

In evaluating Ergonomic these activities was observed that the worker bends the trunk whenever you

use the countertop cutting and bending.

Figure 3: Alignment Figure 4: Marking

Figure 5: Cut Figure 6: Identification


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In evaluating the job of cutting and bending there was the need for corrective actions exacerbated by

tilting and twisting the torso to recommend both the elevation of the cutting and folding to reduce or

eliminate the slope of the trunk and change layout of the installations so that is willing to machine

cutting and folding front of the manufacturing sector providing the elimination of the twisting

movement of the trunk.

The observations were validated by applying the tool OWAS postures observed in communication

activities, selection bars, alignment, marking, cutting and identification shown in Figures 1, 2, 3, 4, 5

and 6 which indicated the need for corrections in the future.

3.1.2 Activity the mounting

The mounting starts with removing the worker from the storage location of the mounting hardware

required for the manufacture of the armor (Figure 7), placing it on the easel, placing all the pieces

juxtaposed, checking the alignment and performing initial and final marking the spacing of the ties in

hardware longitudinal willing to stand with the aid of a metal measuring tape and chalk shown in

Figure 8, as established position in the structural project.

Figure 7: Selection Figure 8: Marking the spacing

The worker goes to the production area of the stirrups, finds the box with the stirrups as the desired

dimension and transports them manually to the assembly area. Figure 9 shows the posture adopted by

workers to remove from the box the stirrups to be used for mounting the workpiece. After removing

the brackets of the box, the workers have to separate them from each other because, as are dispersed

within the housing, the handle it stirrups parts intertwine (Figure 10).

Figure 9: Deinterlacing Figure 10: Selection the stirrups


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We observed the postures whose position the legs remain bent or kneeling for short periods that recur

throughout the work day. This position can provide the risk of spinal injury that warns of the need for

preventive measures.

We apply the tool to analyze OWAS postures observed in the activities of deinterlacing and selection

of calipers (Figures 9 and 10), which indicated the need for fixes as soon as possible.

For spinal injuries are avoided, it is recommended that the objects are placed within reach of the

worker, below shoulder height and above the knees in front or immediately adjacent to the worker. It is

necessary to install the assembly area near a workbench for the deposition of the steps, thus avoiding

that workers have to do constantly bending.

In the assembly of the reinforcement, the stirrups are inserted and distributed along the longitudinal

hardware until the markings position (Figure 11). Then comes the fixing of the stirrups with the

annealed wire. Easel is attached to a housing for storing the annealed wire to be used in mounting the

workpiece. The intertwining of the parts is done manually with double knot with the wire at the point

to be determined and with the aid of pliers to tighten the knot and cutting excess wire (Figure 12).

Figure 11: Positioning Figure 12: Tying

The completion of the activity with the head flexed (Figure 11) has a high risk of injury, is an example

of poor posture can cause problems in the cervical spine. During activities should observe the postures

and comfort of workers, it is important to increase the height of the trestles.

The analysis postures during activity-fixing stirrups (Figure 12), indicating the risk of wrist injury. The

handle has a significant role to control the length-tension relationship of multi-joint muscles of the

hand as they fit the various activities and ways to hold when subjected to overload the legwork cuff

tendons can damage causing pain, thus limiting the worker's movements. To minimize these effects

suggests that the mounting sector workers use appropriate tools compatible with the company's

productivity, such as the steel pincers for mooring. The risk of injury was validated by applying the tool

MOORE and GARG on risk analysis of development of muscle tendon dysfunction Posture and Hand

Grip.

Finishing the assembly, according to the characteristics set forth on the label, a southpaw stands label.

The label has two lefties, in which the rest will be withdrawn by the customer on receipt of the request

then the armors are manually transported and deposited in a temporary location until the delivery of

the application to the client (Figures 13 and 14).


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Figure 13: Transport Figure 14: Deposition of the armature

Analyzing repeated activities realization of transport and deposition of armature along the workday

observed bending of the legs while performing the squat for the deposition of the material as a point

to be improved to preventive maintenance. The result was validated by applying the tool OWAS for the

deposition of armature indicates the need for corrections in the future, for that we recommend for

pauses or mechanized activity.

3.1.3 Activity of making the stirrups

The making of the stirrups starts putting the steel coil on unwinder. The steel coil is hoisted by means

of a winch, where the floor is deposited until the unwinder. The transport is mechanized but has the

worker to assist in guiding the winch.

The worker program stirrup bending machine (Figure 15) that performs cutting the fold of material at

this stage is necessary that the machine assists the worker holding the tip material and pushing it

against the machine (Figure 16). All straps are made along the stirrup bending machine stored in

cardboard boxes and plastic as its dimensions and start the mounting activity of the armature the

mounting worker speaks to production area of the stirrups, finds the box with the brackets, as the

dimension desired and manually transported to the assembly area.

Figure 15: Programming the stirrup machine Figure 16: Production of stirrups

In the analysis performed during the construction of the steps, we can consider that much of the effort

exerted by the worker focuses on the upper limbs and so MOORE and GARG, was the tool that

indicated a high risk of injury due to hand-wrist posture and intensity of effort made which can be

minimized by performing intervals throughout the workday, caster with other activities, stretching or

replacement stirrups machine by providing the model worked exert effort against the machine.


8

As for collective protection equipment, it was observed that the stirrups machine presents unprotected

components that could compromise the safety of workers. During production of the stirrups operator

needs to position itself in front of stirrups machine at this time the component is close to the pectoral

region of the operator. It is recommended that to install a physical barrier in order to provide greater

operator safety in addition to performing the maintenance of the electrical machine on the ground

necessary for worker safety.

The postures more inadequate in central frame are performed in the production of stirrups for the

movement of the hand, wrist and efforts and in assembling the armor during the selection and

interlacing stirrups. Analyzing the position of the limbs and trunk along with movement of the hand,

wrist and efforts.

The employer provides the personal protective equipment but all workers found that not all use. To

ensure greater protection and safety for workers, it is suggested to replace the use of trousers and

shorts for the company to adopt a form for the registration of the personal protective equipment

delivery worker containing the rights and duties of the worker as well as make, model and Certificate

of Approval (CA) of the equipment provided to make constant the use of equipment and its

replacement when necessary.

Referring to the layout shown in Figure 17, we found that the organization of the physical space

interfere negatively on the work rate so it is recommended that modifications are performed as shown

in Figure 18, to prevent workers from moving on deposits, the cutting and bending machine is

positioned so that the operator is facing the manufacturing sector avoiding it has to do rotations,

changing the layout as well as the adequacy of NSCI (Santa Catarina, 1992) for the correct use of fire

fighting installation including preventive protection system for fire extinguishers, installation of

continuous handrails on both sides with guardrail, installation of signage on the walls indicating the

number of the corresponding pavement, signs and exit corridors considered escape routes.

Figure 17: Layout Figure 18: Modification of the layout

Relative to illumination it was found that the employment of the activity of cut and bend fittings have

natural daylight from the openings and the installation of translucent tiles in cloudy or rainy days,

when the front opening needs to be closed, triggers to artificial light so it is recommended that the

measurement field to identify whether levels of luminance minimum meet the requirements set by the

standard.

Regarding the noise has been found that emery, stirrups machine the countertop and bearings are


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sources of noise and should be given attention in order to minimize noise propagation. It was found

that only the worker's production of stirrups uses the shell-type hearing protectors during the

performance of activities too, do not feel uncomfortable with the noise so do not use their hearing

protectors. It is recommended to identify the noise level, since it was found that in some situations

may take concentration and impair the performance of the task. Fialho and Santos (1997) warn that 85

dB should not be a goal to be reached but a limit which should not be exceeded.

4 Conclusion

This paper carried out the analysis of the activities of the job of the central frame. With the knowledge

gained through observation and verbalization of workers had the opportunity to know how the activity

is performed and what factors affect positively or negatively the work process.

Confronting the information collected on the job with the bibliographic reference diagnose the

vulnerable points of the work process that affect the comfort, health, safety and achieving the main

purpose of this study. During the study, the contribution was made using scientific tools like OWAS

MOORE and GARG and for the analysis of postures observed EWA assisting in the central frame, as a

consequence, the work provided for the construction industry to identify the postures made in

conducting the activity.

On completion of the assembly of reinforcement identified the immediate need for the

implementation of improvements. As completion of the EWA important recommendations were made

regarding the adaptation of equipment and tools, organization of the layout, structuring the work,

improving safety as fire protection, use, handling and replacement of personal protection equipment

(PPE) . One should also emphasize the importance of diffusion through the implementation of the

recommendations, training and qualification of workers. Thus we recommend the development based

on ergonomic analysis of work a procedures manual for the job of central frame contemplating the

task and postural recommendations for its implementation.

It is recommended that a program of safety training and education to work to address broadly the

risks and behaviors necessary for safety and ergonomics, so that the workers can respond quickly and

appropriately to emergencies.

Parallel to the training is given to draft a signaling workplace as ergonomics, health and safety of

workers in order to guide the workers of the various risks inherent in their activities, leading them to

attitudes and preventive protection, reducing the risk accidents by calling attention, in a fast and

intelligible to objects and situations capable.

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ERGONOMIC RISKS IN THE WORKPLACE OF THE CENTRAL FRAME · ERGONOMIC RISKS IN THE WORKPLACE OF THE CENTRAL ... people involved in the central hardware (engineers, technicians, ... below