Body Weight Support Harness System in Spinal Muscular Atrophy

The goal of this pilot interventional study is to learn about the use of an in-home harness system in children who have been treated for spinal muscular atrophy. The main questions it aims to answer are: 1. Is the in-home body weight support harness system a feasible option for families to use? 2. Is the in-home body weight support harness system a useful tool for children treated for spinal muscular atrophy? 3. Is the in-home body weight support harness system a safe tool for children treated for spinal muscular atrophy? Participants will be given an in-home body weight support harness system and taught how to use it. Families will document how often and for how long they use the system over 6 months. Children will be given tests of motor function at the beginning, 3-months, and 6-months. At the end of the study, families will be asked to fill out a questionnaire about thier experience using the system.