My son has worn compression shirts in the past and uses a weighted blanket when sleeping or upset. The scientific information to back it is in the Occupational Therapy world. It’s a replacement for a poor proprioceptive input sense. An OT could offer great insights on this for you. Also, google “joint compressions” — it’s another strategy for this. Poor proprioceptive input is common in hyperactive kids.
Also, you can read about Temple Grandin’s squeeze machine she built herself to help with her autism — it lead to the great additions she’s made to the treatment of cattle in that industry actually. Very fascinating stuff!
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism