There are several reasons why dogs like to run and jump back and forth:
1. Entertainment and exercise: Dogs are naturally lively and active, and running and jumping back and forth can provide them with entertainment and exercise.
2. Vent emotions: Some dogs will run and jump back and forth when they are excited, anxious, restless or bored, which can help them release their emotions.
3. Exploring the environment: Dogs will pay attention to the surrounding environment and smell when running and jumping, which can help them better explore the world around them.
4. Attract attention: Some dogs will run and jump back and forth to attract the owner's attention, hoping to get more Attention and play time.
In short, for most dogs, running and jumping back and forth is a normal behavior. As long as it does not cause harm to people and objects around them, you can safely let them play.