
Propulsion in hexapod locomotion: How do desert ants traverse slopes?
Author(s) -
Toni Wöhrl,
Lars Reinhardt,
Reinhard Blickhan
Publication year - 2017
Publication title -
journal of experimental biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.367
H-Index - 185
eISSN - 1477-9145
pISSN - 0022-0949
DOI - 10.1242/jeb.137505
Subject(s) - traverse , geology , ground reaction force , propulsion , hexapod , terrain , brake , kinematics , geodesy , physics , computer science , ecology , biology , engineering , aerospace engineering , robot , automotive engineering , classical mechanics , artificial intelligence
The employment of an alternating tripod gait to traverse uneven terrains is a common characteristic shared among many hexapoda. Since this could be one specific cause for their ecological success, we examined the alternating tripod gait of the desert ant Cataglyphis fortis together with their ground reaction forces and weight-specific leg impulses for level locomotion and on moderate (±30°) and steep (±60°) slopes in order to understand mechanical functions of individual legs during inclined locomotion. Based on the experimental data, it was proposed that 1) the hind legs acted as the main brake (negative weight-specific impulse in the direction of progression) on both the moderate and steep downslopes while the front legs became the main motor (positive weight-specific impulse in the direction of progression) on the steep upslope. In both cases the primary motor or brake was found to be above the centre of mass. 2) Normalised double support durations were prolonged on steep slopes, which could enhance the effect of lateral shear loading between left and right legs with the presence of direction-dependent attachment structures. 3) The notable directional change in the lateral ground reaction forces between the moderate and steep slopes implied the utilisation of different coordination programs in the extensor-flexor system.