Fig. 1. Rationale for the effects of body proportion on limb posture. Animals with longer limbs will have longer moment arms (R) and will experience increased joint moments compared with shorter-limbed animals [assuming that force magnitude, ground reaction force (GRF), and body posture are constant]. As a consequence, animals with longer limb segments below a joint are expected to adopt more extended joint postures to moderate the joint moments that they experience; that is, the product of GRF and R is smaller for the limb on the left (with R₁) than for the limb on the right (with R₂).