Fig. 4.

Bilateral spatiotemporal spinal motor outputs computed from ensemble-averaged electromyograms (EMGs) during walking at different speeds and slopes. Motor output (reported in % of maximal activation) is plotted as a function of gait cycle, the vertical white dotted line corresponding to half (50%) of gait cycle. Note that the intensities of both the lumbar and the sacral segments increase monotonically with speed, but that these intensities change differently on positive and on negative slopes.