INFLUENCE OF CONCURRENT TASKS ON GAIT - A DUAL-TASK APPROACH

We studied the effect of concurrent tasks on motor control of gait wit h dual-task methodology. Ten healthy subjects were instructed to perfo rm different cognitive and motor tasks during gait on a conductive wal kway. Footswitch signals were recorded and stride lime and double-supp ort time were calculated. It was assumed that the former reflects gait -patterning mechanisms and the latter relates to balance control. Stat istical analysis showed an increase in double-support time when a memo ry-retention task (digit-span) and a fine motor task (buttoning) were executed simultaneously during gait. During gait performance of the co gnitive task declined compared to baseline conditions. Attentional dem and of concurrent cognitive and motor tasks appeared to force subjects to modulate their gait strategy to ensure control of balance. Stride time was consistent across task conditions except when subjects perfor med fast finger-tapping during gait. Then all but one subject showed a decrease in stride time and an increase in stride-frequency that was repeatable on retest. Since different rhythmic movements are likely to share common neurobiological networks, we assumed that the modulation of stride-frequency was due to structural interference.