1. The relationship between net horizontal impulse and limb protraction duration to retraction duration ratio during steady-state locomotion.
The relationship between net horizontal impulse and limb protraction duration to retraction duration ratio during steady-state locomotion. (A) Lemurs (N=150 steps in the forelimb; N=110 steps in the hindlimb); (B) New World monkeys (N=126 steps in the forelimb; N=107 steps in the hindlimb); (C) Old World monkeys (N=35 steps in the forelimb; N=38 steps in the hindlimb); and (D) felines (N=107 steps in the forelimb; N=95 steps in the hindlimb). All horizontal impulse (HI) measures are presented as a percentage of body mass s–1 (%BM s–1). Negative impulse values represent a limb that is net braking, whereas positive impulse values represent a limb that is net propulsive. Limb protraction duration to retraction duration ratios greater than one indicate a limb that spends the majority of time in a protracted position, whereas a limb protraction duration to retraction duration ratio of less than one indicates a limb that spends the majority of time in a retracted position. In the primates, there was no significant association between the relative amount of protraction duration and retraction duration and whether the limb (forelimb or hindlimb) was net braking or propulsive. In the felines, there was no significant association observed in the hindlimb, but there was a significant (P=0.02) negative association (y=−0.85×−0.237; R2=0.05) between the relative amount of time spent with the limb in protraction or retraction and the net horizontal impulse in the forelimb.
Michael C. Granatosky et al. J Exp Biol 2018;221:jeb162917
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