What causes a dog's back to twitch when lying down uncomfortably?

Hi there and thank you for using pet coach to address your concern. What you are describing could be due to back discomfort or discomfort associated with the skin. If Kobe is a high-energy dog and runs around and jumped on things it is possible that he may have injured his back. This may be a soft tissue injury such as a pulled back muscle or something to do with one of his spinal discs. As long as he is walking okay and not dragging his legs or in excruciating pain I would monitor for now as many times this is a soft tissue injury that will resolve with adequate rest and decreased activity. So I would start by either putting Kobe in a small area where he cannot run or jump or confine him to a crate for most of the day for the next seven to 10 days. If he is not improving or if he is worsening I would have his veterinarian examined him to ensure everything is okay. If he is not better I would also consider having x-rays taken of his back. The vet can also prescribe something for the discomfort if needed. I hope this helps! Please let me know if you have any other questions or concerns. I am also available via consultation if needed.