Meeting Abstract

S5.3-1  Sunday, Jan. 5 13:30  Integrating experimental and computer simulation methods to reconstruct the evolution of avian bipedalism RANKIN, J.W.*; PAXTON, H; HUTCHINSON, J.R.; The Royal Veterinary College, London, United Kingdom; The Royal Veterinary College, London, United Kingdom; The Royal Veterinary College, London, United Kingdom jrankin@rvc.ac.uk

Advances in computer technology have enabled biomechanists to use increasingly complex computer models and simulation methods to complement traditional experimental methods. For example, models and simulations provide additional data that are difficult to obtain empirically (e.g., muscle mechanical work, tendon energy flow), which allow researchers to directly address questions essential to understanding muscle coordination, performance limits and form-function relationships. To illustrate how integrating these techniques can be used in comparative studies of terrestrial locomotor biomechanics, we discuss a case study that investigates how morphology influences locomotor capacity in two bird species on opposite extremes of the spectrum: the ostrich (Struthio camelus), which is extremely fast (>13ms^-1)and economical, and the broiler chicken (Gallus gallus), which has difficulty walking (<1ms^-1). To perform this comparison, a detailed musculoskeletal model of an ostrich and a broiler chicken were developed from dissections of representative individuals. Experimental walking kinematic data were collected from the two species either by using motion capture (ostriches) or combining high speed video with XROMM (chickens). Kinetic data were obtained using force plates. Representative trial data were then combined with the musculoskeletal models to generate two forward dynamics simulations of walking (one for each species), which we use to highlight how differences in morphology may influence locomotor function. In addition, we discuss how any understanding of terrestrial locomotor function in extant birds can help illuminate the evolution of the unusual bipedal gaits of birds and where our case study contributes to this area.