The effect of the motor dual-task on static and dynamic postural control and classification of the motor task difficulty - Systematic Review

Many daily activities require performing multiple tasks and involve the integration of cognitive and motor skills, on which the outcome depends. Many studies approach the influence of cognitive tasks on gait and postural control, but few studies analyze the effect of another motor task during gait or postural control. This review aims to analyze the motor tasks used in motor dual-tasks studies and classify motor tasks as to their difficulty level. The literature review was conducted according to PRISMA guidelines in the databases: Medline, Web on Science, and Scopus during December 2019, using the key-words: motor dual-task, secondary motor task, gait, and postural control. It included observational studies based on the effects of motor dual-tasking in static and dynamic postural control, published in the last ten years. N = 215 studies were found within the databases, and this review included sixteen studies. One study analyzed gait with secondary motor task of different levels of complexity. Three studies analyzed the primary motor task (gait) at different difficulty levels or conditions. They all found that more complex tasks lead to poorer gait performance.In conclusion, a classification of the motor tasks is suggested according to their complexity level and suggests the need for more studies with motor tasks of different levels of difficulty. The static and dynamic postural control parameters analyzed in this review were negatively affected compared to the simple motor task, regardless of age or clinical condition.