“…No muscle contraction can violate these limits, and they are consequently thought to pose universal constraints on animal performance. A limiting work or power density have, in some form or another, been invoked to account for a remarkable diversity of non-trivial observations across the broad field of comparative animal biomechanics, including the maximum running speed (e. g. Hill, 1950b;Irschick et al, 2003;Meyer-Vernet and Rospars, 2015;Usherwood and Gladman, 2020), flight speed (Alexander, 2005;Pennycuick, 1968), swimming speed (e. g. Clemente and Federle, 2012;O'dor and Webber, 1991;Richards and Clemente, 2013;Richards and Sawicki, 2012;Wakeling and Johnston, 1998), and jump height (e. g. Bennet-Clark, 1977;Gabriel, 1984;Lutz and Rome, 1994;Marsh, 1994;Sutton et al, 2016;Wilson and James, 2000); size-specific variations in animal posture (Usherwood, 2013); the prevalence of latched "power-amplifiers" in small animals (Alexander, 1988;Bennet-Clark, 1975;Gronenberg, 1996;Ilton et al, 2018;Longo et al, 2019;Patek, 2023); the mechanical benefits of in-series elasticity in explosive muscle contractions (e. g. Aerts, 1997;Alexander, 1995;Galantis and Woledge, 2003;Hill, 1950a;James et al, 2007;Lichtwark and Wilson, 2005;Mendoza and Azizi, 2021;Peplowski and Marsh, 1997;Roberts, 2016;Roberts and Marsh, 2003;Rosario et ...…”