All participants will be entered into treatment arm and receive an in-home body weight support harness system

A portable, adjustable body weight support harness system that occupies roughly 9 feet x 9 feet space in the home. The system allows 360 degrees of mobility anywhere within the footprint of the frame. The amount of body weight support is adjustable.

A five question likert-style survey asking families to rate their experience during the study. The scales asks the family to rate (1) the perceived impact of BWSS on motor and (2) non-motor skills, (3) the child's perceived enjoyment using the system, (4) the ease of equipment use, and (5) if the family believed that use of the BWSS was beneficial on a 5-point Likert scale; scores of 4 or 5 were considered favorable, scores of 3 were considered neutral, and scores of 1 or 2 were considered unfavorable. Higher scores indicate greater perceived benefit of participation.

A 50-item performance-based outcome developed to quantify motor function across the span of age and abilities in individuals with neuromuscular disorders including spinal muscular atrophy (SMA). Scores range from 0 - 100 points; higher scores reflect a greater level of function. An increase in score indicates a better outcome.

A disease-specific and performance-based outcomes originally developed to measure motor skill in untreated individuals with SMA. Scores range from 0 - 66 points; higher scores reflect a greater level of function. An increase in score indicates a better outcome.

A disease-specific and performance-based outcomes originally developed to measure motor skill in untreated individuals with SMA, revised following Rasch analysis of HFMSE. Scores range from 0 - 69 points; higher scores reflect a greater level of function. An increase in score indicates a better outcome.

A log to document frequency (each use) and duration (how long it was used at one time) of harness system use.