Narrow Results

Background: With cell phone use and ownership on the rise, daily circumstances often require individuals to divide attentional resources between walking and a cell phone-related task. This division of attention has been found to detrimentally effect task performance, making pedestrian cell phone usage an increasing safety concern. However, most studies have investigated the impact of dual-tasks on situational awareness and few have focused on tasks other than texting. Therefore, this study aimed to investigate the effect of various cell phone-related tasks on lower limb kinematics during walking.

Methods: Fourteen healthy, college-aged subjects completed gait analysis trials in five walking conditions, one single-task walking condition and four dual task conditions: Walk+Converse, Walk+Read (Simple), Walk+Read (Difficult), and Walk+Text. Subjects’ movements were recorded with a motion capture system and peak sagittal plane lower extremity joint angles, gait velocity, and stride length were calculated.

Results: Of the eight kinematic outcome measures analyzed, all but one revealed some significant (p < 0.05) differences between dual-task walking conditions. Gait velocity and stride length both decreased due to the addition of the dual tasking, with the magnitude of the reduction becoming more apparent with the increased difficulty of the cell phone-based task.

Conclusion: This study supports a fundamental change to gait kinematics in response to cell phone use while walking, with the magnitude of impact being directly related to the complexity of the secondary task. The significant changes to gait kinematics in complex dual-task situations could present a threat to balance.

During walking, attuning the heel contact to the external cueing is attentional and physical demanding. Based on this point of view, this is a preliminary study conducted for identifying the temporal accuracy of subjects for rhythmic auditory cueing, and to identify the balancing ability of the elderly based on this information. A measurement system was constructed to measure the motion delay time for the given rhythm and a pilot gait experiment was conducted for young adults while performing a cognitive dual task. The system consisted of a metronome and an accelerometer sensor measurement unit and is implemented as a program using LabVIEW. This pilot gait experiment measured individual delay times in 15 healthy adults in their 20s under two conditions: metronome walking (MET) and metronome walking with backward counting (MET+BC). Consequently, the delay time of MET and MET+BC conditions was $128.8\pm 29.0$msec and $200.2\pm 37.0$msec, respectively ($p<0.05$). Further experiments with the elderly will be needed to confirm whether such delay time can be used as an indicator for balancing ability.

Falling is one of the leading causes of accidental injury and death among elderly adults and construction workers, with costs exceeding US$31 billion each year. Having good balance reduces the likelihood of falling — therefore it is important to determine which possible factors might influence balance. The purpose of this study was to determine if consuming three different types of breakfast altered blood glucose levels in such a way that young healthy individual’s balance control was compromised. Balance was then measured while the subjects completed single- and dual-task standing trials with eyes open and closed. Although changing blood glucose did alter quiet standing balance — as measured by the separation distance between the COG and COP, the velocity of the COM, and the total distance traveled by the COG and COP along the anterior–posterior (AP) and medial–lateral (ML) axes — the results were contradictory to what was hypothesized. Subjects with lower blood glucose swayed less than those with higher blood glucose. This could potentially be due to the habitual skipping of breakfast in young adults. Though the changing of blood glucose did influence quiet standing balance of young healthy adults, it was not in a way which increased the risk of falling.