The Effect Of Using Mobile Phone On Gait While Walking

Objective: Using mobile phone while walking has attracted people's attention.The purpose of this study is to study the gait characteristics of two kinds of mobile phone walking(looking at mobile phone and listening to mobile phone)to explore the effect of dual task with visual and cognitive occupation on walking characteristics of human walking,and compare the effects of walking tasks with reduced walking speed on walking characteristics of human walking.Methods: Eighteen healthy volunteers took part in the experiment and completed the four walking tasks.Which included "watching cell phone while walking","listening cell phone while walking","normal walk" and "speed limit walk".The cognitive task is to subtract 7 on the mobile phone continuously.The kinematics data are collected synchronously by 8 high speed motion capture system and three dimensional forceplatform.The margin of stability(MoS)was used to evaluate the stability changes of four walking tasks,and the continuous relative phase(CRP)was used to evaluate the change of lower extremity coordination under the four walking tasks.The results were statistically analyzed by paired t-test.Results:(1)The correct rate of answering questions is not affected by the four walking tasks,but the speed of answering questions when "watching mobile phone" is lower than that when "listening to mobile phone".And both of them are lower than the pre-test.(2)Compare with normal walking,when watching mobile phone while walking the speed has drcreased,the ankle flexion angle and knee flexion angle has increased.The center of gravity in vertical direction become higher when watching mobile phone while walking but he MoSx has decreased.The coordination of lower extremities also found significant difference is that the MARP and DP become higher when watching mobile phone while walking.(3)Compare with the listening mobile phone while waling,when watching mobile phone while walking the speed and the ankle flexion angle and the MoSx has decreased,the knee flexion angle and MARP of hip-hip has increased.(4)Compare with the speed limit walking,when watching mobile phone while walking the swing phase has decreased,the MARP of knee has increased.Conclusion: Watching mobile phone while walking does not decrease the stability of walking,which means that the dangerous behavior caused by the use of mobile phone during walking is not due to the change of stability.The possible reason is that pedestrians choose a "careful " walking strategy.Due to the lack of adequate visual feedback,when people look at mobile phones,the variability of coordination is greater than other walking tasks.Which proves that the lower extremity is walking in a more complicated way when watching mobile phone.Pedestrians can maintain this adaptive gait by constantly adjusting the relative relationship between each segment of lower extremity.