124 prisms of withered pine tree wood with dimensions 20x18x18 cm will be carved from 9 logs of 300x20x20 cm at Aserrío San Ignacio Ltda. production plant, located in Soacha, Cundinamarca. Given it is an industrial process of chainsaw cutting and wood planing, a quality control will be implemented consisting of verification of prism stability while lying on the floor, and the mean height in millimeters of every prism will also be measured and registered. Unsteady products or those with atypical mean heights, defined as a height either exceeding percentile 75 + 1,5 times interquartile range or below percentile 25 - 1,5 times interquartile range, will be discarded and not used during the study. After exclusion of defective prisms, n groups of wooden prism pairs according to mean height in millimeters will be formed and every group will be given a random digit generated by computer. Afterwards, every random digit of prism groups will be sequentially assigned to a consecutive HBE-allocated patient number, in such a way that every consecutive patient number (among those allocated to HBE) will be linked randomly to a preset known prism height. This additional randomization procedure involving prisms according to their mean height, is planned due to the impossibility to guarantee that prism height will be identical with a precision of ±1 mm, keeping in mind that products will be cut with chainsaw and will be planed as part of an industrial process.