Figure 4. Net (A), anterograde (B) and retrograde (C) femoral blood flow from the passively moved limb.

The increase in net blood flow results from an immediate increase in anterograde blood flow. Subsequently, net blood flow returns to baseline due to the combination of a decrease in antegrade blood flow and a more gradual increase in retrograde blood flow that eventually offsets anterograde blood flow. Note that both anterograde and retrograde blood flow remain elevated throughout the duration of passive exercise. s.d. bars were omitted to maintain clarity.