Meeting Abstract
Many aspects of animal and human gait and posture cannot be predicted from purely mechanical work minimization or entirely based on optimizing muscle efficiency. This poster introduces the Muscle–Mechanical Compromise Framework as a conceptual paradigm for considering the interactions and compromises between these two objectives. Consider: a bicycle allows vastly more economical locomotion than walking or running – cycling allows a mass or weight to be transported a given distance for far lower metabolic work. This can be attributed to two factors: the rolling wheel produces a low demand for mechanical work; and the pedals and adjustable gearing allow the mechanical work and power demands to be met by muscles operating in an economical manner – with a high duty cycle (approximately 0.5) and at favorable stresses, strains and strain rates. Walking, running and flapping gaits cannot meet both of these demands for economical locomotion simultaneously; the two aspects – mechanical and muscle-physiological – have conflicting requirements. The conceptual Framework allows these conflicts, especially distinguishing between the muscle activation demands for mechanical work and power over a contraction, to be considered. Applications of the Framework to the scaling of posture, terrestrial gaits (hopping, walking, running) and flying gaits (flapping, bounding and flap-gliding) are reviewed.
