Effect Of Dual Task Walking Activities Involving Smartphone Tasks On Walking Performance In Healthy Individuals

PURPOSE: To study the effects of dual-tasking activities (DTA) that involve performing smartphone tasks (SPT) while walking on spatiotemporal parameters of gait. METHODS: 40 subjects aged 18-45 years old (18 M, 22F, 24.9 + 3.78) performed 3 DTAs while in the capture volume of the Theia3D Motion Capture System. Each DTA involved performing a smartphone task (SPT) while continuously walking on a 8-meter path. In one, the SPT involved typing a sentence on the notepad app (DTA-T). In another, the SPT involved verbalizing object names while scrolling through a set of images (DTA-S). In the third, the SPT involved reading aloud a passage provided on the screen (DTA-R). All DTAs were performed for 1 minute as fast and accurately as possible. Each DTA was performed 3 times with a different attentional prioritization (AP). During equal-AP, subjects performed gait and SPT with equal attention. During gait-AP, subjects prioritized gait. During SPT-AP, subjects prioritized the SPT. The sequence of DTAs and their AP trials were randomized between subjects. DTA gait speeds were calculated. Software R was used to extract step distance and step time data from Theia3D video data for 15 subjects for each trial. A step was defined as the distance between successive points of feet contact in xyz plane. Repeated measures ANOVA was used to compare the effect of different DTAs on gait speeds, step distance and step time under similar APs. Variability in step distance and time were also calculated using Coefficient of Variance (CFVAR) and compared similarly using ANOVA. RESULTS: When comparing within similar APs, mean gait speeds for DTA-T were always lower than DTA-S or DTA-R. With SPT-AP, gait speed during DTA-T (0.995 + 0.18) was significantly lower (p = 0.008) than DTA-S (1.051 + 0.17), but not lower than DTA-R (1.017 + 0.18). With equal-AP, gait speed during DTA-T (1.070 + 0.17) was again lower (p = 0.027) than DTA-S (1.104 + 0.15), but not lower than DTA-R (1.090 + 0.16). Step distance for DTA-T was significantly lower than DTA-S with all APs (p < 0.026). Step time for DTA-T was significantly lower than DTA-S only with SPT-AP. CONCLUSION: Walking performance during texting might be more severely affected than during scrolling or reading phone tasks. Motor control systems might be the least efficient in allocating attentional resources to walking while texting.