Have you ever wondered how many similar movements need to be made to represent a portrait in a drawing? How many times do you need to slide the pencil in the same position and for how long? It is a task that involves repeated movements, the ergonomic risk for Repetitive Movements.
These are those in which the same sequence of repeated movements takes place in more than 50% of the cycle or task that is carried out repeatedly. The number of actions carried out in each minute (speed), duration of the task, posture, intensity of force to be performed, the existence of pauses or recovery time and other additional factors such as the cold, the vibrations, the adequacy of Personal Protective Equipment to the dimensions of the individual, slip of what is held.
Perhaps it is easy to observe it in a repeated sequence of three movements, as it would be the three steps shown in the following drawing:
The drawing was carried out at ground level, with a spatula, given the need to adopt a forced dorsiflexion of the wrist, repeating the same sequence of movements and without rest intervals.
The movements that make up the cycles were performed quickly at a rate of 6 movements every 2 seconds.
The paper is wet, but following the same movements, to avoid monotony in the result of the work. Beyond a work where only lines in the same direction are visualized, it is necessary to value those others where the repetitiveness of movements is not intuited but are there, reason why recovery pauses and exercises as stretching ones, are necessary.
Pencil drawing. 2017.