Modelo conceptual de proceso de evaluación de factores ergonómicos en tareas con manipulación manual de carga dinámico asimétrica en el sector de la construcción
Authors:   , Cerda Díaz Eduardo Niels 
Published: October 2023

El objetivo de esta investigación es estudiar tareas, analizar variables y desarrollar modelo de evaluación para tareas con Manipulación Manual de Carga Dinámico-Asimétricas en el Sector Construcción. Los resultados describen la necesidad de desarrollar metodologías cuyo constructo sea adecuado para el estudio de este tipo de tareas, las variables de dinamismo y asimetría asociadas que determinan patrones
específicos en la ejecución de las mismas lo que finalmente orienta el desarrollo del Modelo. Este Modelo contempla en su constructo las siguientes etapas: Clasificación Sistemática Proceso, Levantamiento Información Técnica, Análisis Sistémico, Identificación de Variables, Análisis de Tarea, Determinación Índice Ergonómico Global - Parcial y Proceso Específico de Evaluación considerando las siguientes
variables específicas de análisis: Peso, Frecuencia, Técnicas y Posturas Combinadas, Agarre Combinado, Percepción de Esfuerzo y Dificultad de Manipulación. Se concluye con proyecciones y necesidades de investigación en la temática de Manipulación Manuales de Carga Dinámico-Asimétricas.

The Manual Material Handling is one of the most important physical risk factors in an Ergonomics context in the different productive processes. The current risk assessment models focus on methodologies that analyze the specific variables based on an atomized model. Some of these specific variables are: material characteristics, lumbar-hand distance, vertical distance, asymmetry of angle trunk, coupling and the frequency of manual material handling. In these models the independent variables in lifting (origin and destination) and carrying are analyzed . These traditional models do not take into account an integrated analysis of the risk factors assessment process in manual handling tasks performed in lifting and carrying.
The construction of current models has focused on the variables mentioned above. However, they do not ensure a proper application in the different productive sectors, such as the construction sector, due to the characteristic processes that have, as a common denominator, a poorly defined variable duty cycle, and several variable incidents.
Taking into consideration the concepts of ¿work related musculoskeletal disorders¿ and ¿physical load¿, there are three variables which are relevant to the development of a conceptual model in the risk ¿Ergonomics¿ assessment process. These variables are: range of motion, exposition time and force. For the "range of motion" and "time" variables there are technical agreements regarding the evaluation approach; however for the third variable studied, "the Force", there is no technical agreement in the assessment model.
The aim of this research is to study the tasks, analyze variables and develop a risk assessment proceses model in Manual Material Handling Dynamics and Asymmetrics in the Construction Sector. These model focus the analysis of specific variables related to ¿the Force¿.
This research concluded that it is necessary to develop models focused on the sectors where there are variables related to asymmetry and dynamism in manual material handling, and their associations and patterns of presentation. The incidence of variables such as handling techniques, handling posture, coupling and handling difficulties are relevant in a risk assessment model on manual material handling dynamics and asymmetrics. Each of these variables and their patterns of presentation are relevant in the assessment model and the task analysis. In manual material handling dynamics and asymmetrics there is a high incidence of these variables.
The model exposed defines the importance of several concepts; the first of them is the ¿production process classification¿ due to the importance of classifying (stage, operation, trades, task and activities) correctly and assessing critical conditions in a specific condition. The next relevants concepts are the task analysis and system analysis. In the conceptual model, it is relevant to execute the analysis from the macro to the specific aspects. This concept considered that the risk assessment is conditioned due to the interaction among the different elements in a specific system. Additionally, the risk assessment process model should follow a Decision Diagram and a Risk Assessment Model focused on Manual Material Handling Asymmetrics and Dynamics.