We present a new model of running which includes muscle activation and damping, and use a recently developed mathematical measure to study how the damping term affect how easily falls can be avoided. We designed a simulation experiment inspired by the famous tissue-paper experiments of Daley and Biewener, and found that the damping term in our model increases robustness of task-level stability; however, only a small amount of damping provides most of the benefit, and further increasing the damping term only has marginal benefits. These results suggest that the small amount of damping found in muscles may have a functional role, and is not simply an unavoidable source of losses to be minimized. We look forward to discussing these results with people who can follow up with more quantitative results (and anyone who is interested in general). By the time you read this, these results should have appeared in Royal Society Biology Letters. All Python code needed to reproduce our results is available at github.com/sheim/vibly.