Hi folks, I was doing a search on this topic and came across this thread. Setting my animation speed to a negative number worked for me-
*I had an animation run to the last frame and loop was set to "no", speed set to 10
*When I wanted animation to reverse i set speed to -10, and "start animation from current frame" (in this case, my last animation frame).
This worked great for getting some acting out of characters that "start" and "stop" (in this case talking, looking up, or down etc.), but I don't know if it would be ideal for looping animations.