Interference of functional dual-tasks on gait in untrained people with Parkinson’s disease and healthy controls: a cross-sectional study

BACKGROUND: In Parkinson’s disease (PD) population, performing secondary tasks while walking further deteriorates gait and restrict mobility in functional contexts of daily life. This study (1) analyzed the interference of functional cognitive and motor secondary task on untrained people with PD and (2) compared their walking with healthy subjects. METHODS: Forty people with PD (aged 66.72 [7.5] years, Hoehn and Yahr stage I-II-III, on-medication) composed the PD group (PDG) and 43 participants (aged 66.60 [8.75] years) formed the group of healthy counterparts (HG). Gait was evaluated through spatiotemporal, kinematic and kinetic outcomes in five conditions: single task (ST) and visual, verbal, auditory and motor dual-task (DT). RESULTS: The velocity, stride length, and braking force performance of both groups was statistically higher in the ST condition than in verbal, auditory and motor DT (p < .05), and inferior in double support time and midstance force (p < .05). The same pattern was observed when compared the ST and visual DT condition, where participants showed a significantly higher stride length, double support time and braking force in the ST (p < .05). In addition, the PDG exhibited a significant shorter double support time and midstance force, and showed a higher braking force in the visual DT than in the verbal DT (p < .05). Similarly, the PDG showed a wider stride in the visual DT than in the motor DT condition (p < .05). PDG participants had a significantly lower performance than the HG in all the variables analyzed except for the maximum hip extension in the stance phase (p > .05). Conclusions: In untrained participants with PD, verbal and motor secondary tasks affect gait significantly, while auditory and visual tasks interfere to a lesser extent. Untrained people with PD have a poorer gait performance than their healthy counterparts, but in different grades according to the analyzed variables. TRIAL REGISTRATION: The data in this paper are part of a single-blind, randomized, controlled trial and correspond to the evaluations performed before a physical rehabilitation program, retrospectively registered with the number at clinicaltrial.govNCT04038866.