The Effects of Load on Timing and Joint-Angle Changes of the Walking Pattern of the American Cockroach
Insects are capable of climbing up walls and navigating irregular terrain such as wreckages because they are able to adapt their walking pattern depending on the specific environment. Variations in the walking pattern have been attributed mostly to sensory information coming from the legs. In an attempt to investigate the role of weight changes on the gait of an insect, load was attached to the back or leg of a cockroach. The purpose of attaching load to the back was to determine if the change in body weight alone can affect the gait of the insect. The purpose of attaching the load on the leg was to determine if changing the sensory information about load coming from just a single leg can affect gait. To conduct this experiment, digital video clips of the American cockroach (Periplaneta americana) walking at different velocities, were taken. These video clips were digitized and analyzed using Peak Motus, a computer software program. The results show that when load is attached to the back of the insect the normal leg movements and gait are maintained, presumably because the same sensory information or stress is transmitted from all the legs not just one. However, with weight on a leg, joint angles and the distance traveled by the loaded leg are affected while the timing between all legs is close to normal. Hence, when load is attached to a leg, a normal gait is maintained but movements of the loaded leg are changed. This effect is presumably due to the stress placed on the receptors in the leg.
School:
University of Illinois at Urbana-Champaign
Department:
Molecular and Cellular Biology
Research Advisor:
Fred Delcomyn
Department of Research Advisor:
Molecular and Integrative Physiology
Year of Publication:
2003