Abstract

Blickhan, R., Full, R.J. and Ting, L.H. 1993. Exoskeletal strain: evidence for a trot-gallop transition in rapid running ghost crabs. J. exp Bio. 179, 301-321.

This study provides evidence that a general model of terrestrial locomotion may indeed exist despite the diversity present. Equivalent gaits may be present in pedestrians that vary greatly in leg number, leg design and skeletal type. One obvious gait change is the trot to gallop transition in quadrupedal mammals. Associated with this gait change is a distinct alteration in bone strain. To test the hypothesis that ghost crabs change from a trot to a gallop, we measured in vivo strains of the meropodite of the second trailing leg with miniature strain gages. Exoskeletal strains changed significantly (increased by 5-fold) during treadmill locomotion at the proposed trot-gallop transition. Maximum strains attained during galloping were similar to the values measured for galloping mammals, even though this gait change reduces skeletal strain in mammals. Equivalent gaits may result from similarities in the operation of pedestrian locomotory systems.