Ricerc@Sapienza

This study aims to investigate how the naturalness of movement is perceived in a sample of healthy participants. Specifically, 256 people (34.2 ± 10.8 years; M = 89; F = 167) were asked by means of an online questionnaire to give an evaluation of the naturalness of a video showing a girl walking along a walkway. We presented four videos of which only one had been recorded in „normal” forward walking and at a comfortable speed and which presented a gait ratio coinciding with the golden proportion.

Walking is a repeatable and cyclic locomotor act, presenting standardized biomechanical patterns within the gait cycle in healthy humans. Specifically, both stance and swing durations exhibit high reliability at comfortable speed, maintaining the same proportion between the twos with respect to different contextual features in forward walking. Recently, it was found that this proportion is close to the "golden ratio" (a well-known irrational number equal to 1.618…).

The scope of this mini review is to show as neuromotor control often applies mathematical principles and properties improving efficiency of movements. We reported four examples: harmony of human walking is based on the fractal property of self-similarity because based on the golden ratio, anatomy of human hand follows Fibonacci’s sequence for optimizing grasping, the 2/3 power-law at which curvilinear movements obey, and the possibility of brain to predict the movement of falling objects applying an implicit knowledge of the Newton’s gravitational law