Is foot clearance influenced by different types of dual task in once-only faller community-dwelling older adults?

BACKGROUND: Tripping is one of the main causes of falls in older adults and has an important association with minimum toe clearance (MTC). MTC variability while performing alternating (ADT) or concurrent (CDT) dual-task activities may be a useful gait parameter to differentiate once-only fallers from non-faller older adults. RESEARCH QUESTION: Is the MTC variability influenced by ADT and CDT in once-only faller community-dwelling older adults? METHODS: Twenty-two community-dwelling older adults with a self-report of up to one fall in the last 12 months were allocated to the fallers group and 38 to the non-fallers group. Gait data were collected by two foot-worn inertial sensors (Physilog® 5, GaitUp, Lausanne, Switzerland). MTC mean magnitude and variability, as well as the stride-to-stride variability, stride time and length, lower limb peak angular velocity, and foot forward linear speed at the MTC instant, were calculated across approximately 50 gait cycles for each participant and condition using the GaitUp Analyzer software (GaitUp, Lausanne, Switzerland). The statistical analyzes were performed in the Statistical Package for the Social Sciences (SPSS), v.22.0, using generalized mixed linear models, adopting an alpha of 5%. RESULTS AND SIGNIFICANCE: No interaction effect was observed; however, faller participants reduced the MTC variability (standard deviation) [(mean difference, MD = -0.099 cm; confidence interval, 95%CI = -0.183 to -0.015)], regardless of the condition. CDT compared to a single task (only gait) reduced the mean magnitude of the foot forward linear speed (MD=-0.264 m/s; 95%CI=-0.462 to -0.067), peak angular velocity (MD = -25.205 degrees/s; 95%CI = -45.507 to -4.904), and gait speed (MD = -0.104 m/s; 95%CI = -0.179 to -0.029), regardless of the group. These results suggest that MTC variability, regardless of condition, may be a promising gait parameter to differentiate once-only faller community-dwelling older adults from non-fallers.

Effects of two different dual-task training protocols on gait, balance, and cognitive function in community-dwelling older adults: a 24-week randomized controlled trial.

Background: Although alternating dual-task (ADT) training is functionally easier for older adults, a large part of the motor and cognitive tasks is simultaneously performed, especially during activities of daily living that require maintaining body balance. Objective: To evaluate the effects of mixed dual-task training on mobility, cognitive function, and balance in community-dwelling older adults. Methods: Sixty participants were randomly allocated at a 1:1 ratio into the experimental group-single motor task (SMT) and simultaneous dual task (SDT) interchangeably in stage 1 (for 12 weeks) and after strictly with SDT in stage 2 (the last 12 weeks)-or into the control group-only SMT and SDT interchangeably in stages 1 and 2. Gait parameters were acquired by two inertial sensors. Physical and cognitive performance were acquired by specific questionnaires. Generalized linear mixed models were used for analyzing interaction and main effects. Results: No between-group difference was observed for gait performance. Both protocols improved mobility (mean change ((MC) = 0.74)), dual-task effect (MC = -13.50), lower limb function (MC = 4.44), static (MC = -0.61), and dynamic balance (MC = -0.23), body sway (MC = 4.80), and cognitive function (MC = 41.69). Conclusion: Both dual-task training protocols improved these outcomes.