Figure 1.

Experimental set-up, hypotheses and results. (a) Treatments to produce asynchronous landings. Throughout figure, right forelimb data are depicted in red, left in blue. (b) Graphical depiction of hypotheses. Red and blue solid lines represent elbow angle over time (increases = extension; decreases = flexion). Red and blue boxes designate the hypothetical onset and duration of pre-landing EMG activity in m. anconeus (anc.) of each limb. Vertical dashed lines designate limb touchdown times. (c,d) Results: images of toads in slope-left and roll-left landings with right and left arms designated by colour. EMG activity and elbow angle, θ, are shown for each limb. In roll-left treatment (c), note the asymmetries in EMG onset timing and elbow extension kinematics, with the left limb preparing for impact earlier than the right limb. (d) In slope treatments, EMG timing and elbow kinematics parallel one another between forelimbs despite the earlier left forelimb touchdown. This pair of results is only consistent with the vestibular control of landing hypothesis (shaded blue box). AO, m. anconeus onset; TD, forelimb touchdown time.