Background: In boys with Duchenne muscular dystrophy (DMD), loss of upper limb function becomes more evident after the onset of wheelchair-dependency, because of the inability to lift the arms against gravity. With an increasing population of older wheelchair-dependent boys with DMD it is worthwhile to know whether training can delay the loss of upper limb functions. Dynamic arm supports may enable boys with impaired arm function to train their muscles without becoming exhausted by providing external mechanical compensation for muscle weakness.
Objective: This study investigated the effect of gravity-compensated 3D-training for the arms on the functional abilities in boys with DMD.
Methods: An explorative RCT was conducted among boys with DMD with impaired arm function (n = 16). Boys in the intervention group (n = 7) trained their arms by playing virtual reality games while using dynamic arm support during 20 weeks. The primary endpoint was the difference in change in Performance of the Upper Limb (PUL) score between the intervention and control group (n = 9) after 20 weeks. Secondary outcome measures were at the different ICF-CY levels.
Results: No significant group differences were found for the PUL. Elbow range of motion (p = 0.018) and extension strength (p = 0.038) improved in the intervention group and worsened in the control group.
Conclusions: Although this study did not show a significant effect of training on the primary outcome measure, there are indications that training may decline the loss of range of motion and strength. This may prolong the functional abilities on long-term.
Trial registration: Netherlands Trial Register 3857.
Keywords: Duchenne muscular dystrophy; dynamic arm support; exercise; neuromuscular diseases; training; upper limb.