How to decide if something can or should be taught in a back chain.

Sounding out long words backwards may make sense. Reading sentences from the end doesn’t, because there is a logical sequence, and the meaning of one part predicts the rest.

Where speed and power are involved it’s hard to teach from the end, since you have to have the beginning skills to get going. For example kite surfing would be hard to teach backwards since you need to get in the water and launch the kite first before you can learn to do the rest.