Does phylogeny affect how body size influences musculoskeletal design?
The similarities observed between the phylogenetically constrained sample of primates and the diverse sample of mammals suggest that locomotor variables in both samples respond to the same functional signals. That is, larger animals tend to adopt more extended limb postures and have lower angular excursions than smaller animals. Larger animals also have lower joint moments and correspondingly greater effective mechanical advantages for their elbow and knee extensor muscles than smaller animals. These similarities demonstrate that the pattern of how body size influences knee and elbow kinematics is generally not influenced by the phylogenetic composition of the study sample. One important and illustrative exception to this similarity between closely related and diverse groups is observed at the ankle, where the EMA did not increase with increasing body mass for the primate sample, but did increase with mass in the non-primate sample. This difference in slopes probably reflects the diver
