Limb work, due to forces along and deflections of the entire limb from ground contact to centre of mass, is minimized with purely vertical forces. Joint work, the summed positive work performed at each of the joints, is minimized with force vectors oriented through the proximal (hip or shoulder) joint. Both parasagittal quadrupeds and bipeds use ground reaction forces generally oriented between the proximal joint and vertical. This suggests a compromise between limb work and joint work minimization due to some degree of between-joint power transfer facilitated by multi-joint linkages. Here, we describe how leg form and kinematics influence joint work demands. The elbows-back, knees-forward design reduces the joint work demand of a low limb-work, skewed, vertical force profile typical of walking quadrupeds. This geometry allows periods of high force (late stance in forelimb; early in hind) to be supported when the distal segment is near vertical, imposing low moments about the elbow or knee, while the shoulder or hip avoids high joint power despite high moments because the proximal segment barely rotates – translation over this period is due to rotation of the distal segment. To explore 3-element limbs, we apply empirical measurements of a hopping wallaby, using centre of mass motions and anatomical segment lengths to determine the manifold of potential configurations through stance; and search for the trajectory across this manifold that minimizes the joint work due to the measured forces and modeled moment arms and joint angular velocities. Joint work minimization predicts the knee forward, ankle backward Z-leg, and broadly agrees with empirical joint powers and kinematics. Further, the modeled Z-leg results in lower joint work than any feasible 2-link leg.