Mr Yegian and his team predicted a “mechanical tradeoff” exists between the elbow and shoulder joints which “would… It may feel strange, look bizarre, and attract puzzled glances, but running with your arms straight may be as efficient as bending them at the elbow. He subjected the question to scientific testing after his interest was aroused when he saw a straight-armed jogger pacing through the campus. “If straight arms are better for walking, why aren’t they better for running, and vice versa?”, asked Andrew Yegian, a PhD candidate at Harvard University. The surprising findings emerged after an academic researcher questioned the unthinking, near-universal habits of both walkers and runners. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.