Table 1 Definition of patient/parent self-evaluated clinical severity stages

I

Early ambulatory with mild impairment: Gowers’ maneuver, waddling gait, walking on toes, problems with climbing stairs.

II

Late ambulatory with high impairment: Walking becomes increasingly difficult, more problems climbing stairs and getting up from the floor, part-time wheelchair use.

III

Early non-ambulatory: Loss of ambulation, active manual wheelchair use possible, independent standing and sitting still possible for some time.

IV

Late non-ambulatory: Independent electric wheelchair use but decline of upper limb function and ability to sit independently.

V

Non-ambulatory with confinement to bed: Loss of independent mobility, hand function preserved on a low level.