Dysergonomic Evaluation: Based on ISO 11226-2000, in Oil Production Operators

Introduction

When I studied applied ergonomics from my professional principles, I read many dialogical contexts about the study and concepts of Ergonomics, since then when I read the book, Ergonomics: what for, from the German psychologist [1]; a chain of interest and knowledge transcended me and led me to the development of research projects in the field of Applied Ergonomics in general. Through each paragraph in its pages, different studies are analyzed, both cognitive, practical and theoretical, creating a discipline that should be developed in all areas of work in the sciences of safety and health at work. Then, when analyzing the book, I was not in the nomological and competent, as to describe the integration towards other sciences of technical and scientific study, which addresses a more transcendental discipline in Ergonomics and its branches.

Before carrying out an ergonomic study or analysis of the dimensional conditions of one or several systems, it is necessary to consider the work methodologies that are or will be in the future; “if the methods are not considered optimal we must redesign them” [2].

According to the European Agency for Safety and Health at Work (EASH). The musculoskeletal disorder (MSD) of occupational origin, acquires a clinical picture in the health of workers both in Latin American countries and in the European Union, causing economic losses in all productive sectors and public organizations [3].

On the other hand, the SGRT-IESS-Ecuador, defines that, “the parts of the body that are most affected in work accidents are: the upper limb with 33.4% and the lower limb with 25.5%. In the case of the upper limb, the fingers of the left hand are most affected with 25.0% and the fingers of the right hand with 22.7%. The lower limb was most affected by the right ankle with 14.7% and the left with 11.6%. Five types of injuries were identified as the most representative: Superficial injuries, with 32.1%, fractures, with 20.2%, other injuries, with 20.0%, contusions and crushes, with 7.6% and finally sprains and strains, with 6.6%; the remaining injuries represented less than 5.0%. However, 5 types of injuries were identified as the most representative and they were Superficial trauma with 32.1%, fractures with 20.2%, other injuries with 20.0%, contusions and crushes with 7.6% and finally sprains and strains with 6.6%; the remaining injuries represented less than 5.0% [4].

Physical Ergonomics applied to the workforce of engineers, technicians or operators, who assume responsibility in production processes, shows that they are exposed to dysergonomic risks, which is why, “MSDs are, for years, one of the problems that affect massively all professional categories, causing significant economic losses in organizations. In view of this environment, it is necessary to focus efforts and provide instruments of adequate preventive control in the worker, to minimize the effective and decrease of occupational disease or accidents in the workplace [5].

MSDs cause clinical occupational symptoms that especially affect the back, shoulders, neck and in many cases the upper extremities. However, in several studies carried out on operators of crude oil production plants, they also affect the lower extremities, such as knee pain, achilles’ heel or the palm of the foot, producing pain in the short, medium or long term, according to the operator’s work cycles. Some MSDs, which can produce clinical occupational disease of origin such as carpal tunnel syndrome, their symptoms can become very sensitive to health considerations because of their constant exposure by repetition. Others may not be severe, as you may only have pain or fatigue with no clear symptoms due to a specific disorder.

In the study, approximately four out of six operators in the production plants claim to have repetitive movements in their hands and arms, while six out of four operators withstand the vibration of machines, motors and/or equipment in the production areas; These scenarios institute an important risk factor for the appearance of MSDs or SCIs (musculoskeletal injuries) of occupational origin, originating pathologies in the neck and upper extremities such as TMOLCES (Musculoskeletal Disorders of Occupational Origin). A large number of operators in the different areas tolerate this type of SCI or MSD, in the neck or upper extremities, which causes occupational pathologies related to the most common cycles of exposure to work in the production areas with 45% of all occupational diseases.

Results

In the evaluation of postures by work cycles, applying the method of ISO Standard 11226: 2000, several aspects of movement by postural biometry were established as a) Posture of the trunk: it is evaluated considering aspects of movement in the trunk. A symmetrical trunk posture implies that there is no axial rotation (or rotation), nor lateral flexion of the upper part of the trunk (thorax) with respect to the pelvis. However, the angle α is determined by the posture of the trunk during the performance of the task (continuous stroke) with respect to the reference posture (dotted line), as shown in Figure 2.

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Therefore, the convex curvature of the lumbar spine, this posture often occurs when: 1st to the lumbar spine, where it is not supported by a backrest, and 2nd, when a small hip angle is adopted, in table 3

b) Head position: For the evaluation of the head position the following procedure is followed: The head position must be evaluated considering both the angle inclination, β that, determines the accomplishment of the task (continuous line) with respect to the reference position (dotted line). Based on figure 2, in the case of the following figure, β has a positive sign. as well as the posture with respect to the posture of the trunk, see table 4: Assessment criteria for head posture:

c) Posture of the upper extremities: The posture of the shoulder and arm, should be evaluated by the posture of the shoulder and arm applying table 5; in figure 2, the retroflexion is represented (elbow behind the trunk, when we rotate the profile), the adduction (elbow not visible when looking from behind the trunk) and the extreme external rotation of the arm (the rotation of the shoulder outwards around the longitudinal axis of the arm). However, the angle determines the posture during the execution of the task (in line of posture) with respect to the reference postural biometry (dashed line).

d) Posture of the lower extremities: These postures of the lower extremities are evaluated according to the table 6. Item 3 of the table refers only to the standing position, except when a “foot support” is used (i.e., a device that allows part of the body’s weight to rest on a small seat while standing). Item 4 of the table refers only to the “sitting” position.

However, special attention should be paid to providing:

1. a balanced distribution of the body’s weight on both feet when standing or using a “stand”;
2. adequate support of the body by means of a stable seat, footrest, or “stand”, whichever is applied; and
3. a favourable position of the ankle and knee when operating a pedal while sitting, see table 6.

e) Postural Estimation by Exposure Cycles: In Image No. 3, and table No. 7: several aspects of assessment by postural biometry are correlated, based on the results of the ISO 11226: 2000 Standard Method, considering the pathological intensity by clinical picture with pain, in the last 6 months and during the 14 days per shift of work in the body area, in the application and analysis of the CN and the ECF, maintained the (n=411 operators).

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f) Most common dysergonomic symptomatologies due to posture: Poor posture at the time of the task, can contribute to a pathological clinical picture, affecting the spine, upper and lower extremities of operators, who spend most of their work cycles in front of an operating activity or the computer. In theory, every work cycle is established at eight hours a day, although in many cases in the oil sector, these cycles are prolonged in accordance with rest times, which is frequently the case with symptoms of MSDs or SCIs.

Other clinical occupational hobbies of operators are the hours without osteomuscular movement, where the joints can create an SCI such as spasms, numbness or tingling, causing problems in the nervous system, muscles and bones, which can be aggravated over time, if there is not adequate posture and spaces in the appropriate work cycles.

Conclusion

In the prevention of the dysergonomic risk factor by organizations, whether they are micro, small, medium or large enterprises, or whether they are public or private, the tools of the new technologies can bring about a change in the quality of life at work. The key to accepting change must come from good motivation and leadership in the entire work team, from the directors, managers, administrators and operational staff, who achieve the development of productivity in each of the organization’s processes. However, by accepting the change, we find ourselves immersed in different paradigms, where it has been indisputable in most of the operators of the crude oil production plants. Therefore, creating a culture of safety and prevention in ergonomics in the organization, is a responsibility and commitment of all those who do prevention. Likewise, when intervening with exaltation, the impact of some operators was uncertain because they used both electronic and manual resources, while in others they expressed some apprehension when they said that they did not master the equipment according to the movement by work cycles with mechanical aids. The results obtained from the method applied by the ISO 11226: 2000 Standard, gave rise to three aspects: a) to carry out epidemiological surveillance follow-up, with special medical examinations of x-rays, which are very advantageous for detecting occupational clinical pictures such as bone anomalies; it evaluates those bone areas that may present ailments, deformities or in many cases, suspicion of some pathology. Frequently, these X-rays or radiographs diagnose tumors, trauma, fractures, deformities and infections (such as hip dysplasia); b) implement mechanical aids, both manual and electrical, that allow operators to minimize forced postures during tasks in the work cycles; c) define an Ergonomics plan with emphasis on postural biometry, with active training and breaks in the short, medium and long term;

Finally, first of all, an information program should be implemented to raise awareness of the use of new technologies or electronic means among all plant personnel. In the second place, it is suggested to motivate the operators, in the business perspective, that allows a process of cognitive and organizational development as a tool, for the health and well-being of all the collaborators of the company.