Does dual task walking affect gait symmetry in individuals with Parkinson's disease?

Purpose: To investigate if dual task walking (DTW) alters spatiotemporal and angular symmetry of lower limbs of individuals with Parkinson's disease. Material and methods: Kinematic gait data of 22 volunteers (aged 40-75 years) with moderate Parkinson's disease (Modified Hoehn and Yahr scale 2-3) were collected. Participants were evaluated while walking at a maximum speed, without a secondary task (usual walking - UW) and performing a cognitive task often referred to as DTW. Spatiotemporal index for gait asymmetry and angular gait variables of hip, knee and ankle were assessed in both limbs. Results: Spatiotemporal index showed asymmetry in both conditions, with no difference in the degree of asymmetry between the two conditions (p = .136). Angular variables showed no significant interaction TASKxMEMBER, indicating that angular differences between right and left legs do not exist, in UW and in DTW. Conclusion: Spatiotemporal asymmetry in DTW seems to be similar to the UW and no greater angular asymmetry seems to occur during this type of dual task. These results suggest that both assessments and gait treatments could be done in DTW condition, without significantly compromising the gait symmetry of individuals with moderate Parkinson's disease.