Dual-task performance as a clinical marker of upper limb decline in Duchenne muscular dystrophy

ObjectiveTo compare upper extremity performance of ambulant children with Duchenne muscular dystrophy and typically developing peers under single- and dual-task conditions, and to examine its associations with mobility and balance.DesignCross-sectional observational study.SettingData were collected at the Pediatric Neurology Department and the Pediatric Rehabilitation Unit of the Faculty of Physical Therapy and Rehabilitation.ParticipantsTwenty ambulant boys with Duchenne muscular dystrophy (6-12 years) and 19 age-matched typically developing peers.InterventionNot applicable.Main measuresUpper extremity performance was assessed using the Nine-Hole Peg Test under single-task, motor dual-task, and cognitive dual-task conditions. Functional mobility and balance, as well as clinical scales, were also evaluated.ResultsChildren with Duchenne muscular dystrophy performed significantly slower than typically developing peers under cognitive dual-task conditions (p < 0.001) and under motor dual-task conditions for the left hand (p = 0.032). Slower dual-task performance was moderately associated with poorer balance and trunk control. Cognitive dual-task performance showed high diagnostic accuracy for identifying Duchenne muscular dystrophy (area under curve = 0.91-0.96).ConclusionsDual-task paradigms may reveal functional vulnerability in upper-limb performance in ambulant children with Duchenne muscular dystrophy that is not evident during single-task testing. Increased cognitive-motor demands appear to exacerbate functional difficulties beyond muscle weakness. These findings suggest that dual-task assessment may complement conventional clinical evaluations and provide additional insight for rehabilitation planning.