Yes, I have some recommendations. I see that he's only 5, so he needs proper back support that you can get at https://befit24.eu/en/back-support-belts-back-warmer-belts-and-hernia-belts/back-support-belts.html in order to help him. Believe me, when he'll be older he will thank you a lot for this. His back will be in great shape for a long time.