Figure 4. Three-dimensional hand trajectory is projected to spherical coordinates and a spherical surface is fitted to obtain the reachable workspace envelope in 3D space.

The surface area is divided and analyzed for each of the four quadrants. Different projections are presented for each subject. The figure shows results in a healthy subject (A), the patients with the following diagnoses: (B) Becker Muscular Dystrophy (BMD), (C) Duchene Muscular Dystrophy (DMD), (D) mild and (E) severe of Facioscapulohumeral muscular dystrophy (FSHD), and (F) advanced Pompe Disease.