Texting during stair negotiation and implications for fall risk

Watch your step: A pilot study of smartphone use effect on young females' gait performance while walking up and down stairs and escalators

The increasingly ubiquitous use of smartphones has made distracted walking common, not only on flat ground, but also on stairs. Available information regarding changes in gait performance while walking and using a smartphone in different environments is still lacking. We aimed to investigate the differences in gait behavior and subjective walking confidence while walking up and down stairs and escalators, with and without smartphone use. A field experiment involving 32 female adults was conducted at a subway station. Gait parameters collected included step frequency, acceleration root mean square, step variability, step regularity, and step symmetry. The results showed that walking task, walking environment, and walking direction significantly affected gait performance and walking confidence. Overall, playing games or texting while walking down escalators resulted in the lowest walking confidence and the largest gait performance decrement: slower step frequency; reduced root mean square; decreased step regularity and step symmetry; and increased step variability. Step frequency, step variability, and step regularity significantly correlated with walking confidence. Smartphone use while walking on stairs and escalators significantly affects gait behavior and might increase the risk of falls. Interventions and prevention are needed to increase safety education and hazard warnings for the general population.

Risky behavior during stair descent for young adults: Differences in men versus women

Injuries commonly occur on stairs, with high injury rates in young adults, especially young women. High injury rates could result from physiological and/or behavioral differences; this study focuses on behaviors. The purposes of this observational study were (1) to quantify young adult behaviors during stair descent and (2) to identify differences in stair descent behavior for young adult men versus women. Young adult pedestrians (N = 2,400, 1,470 men and 930 women) were videotaped during descent of two indoor campus staircases, a short staircase (2 steps) and a long staircase (17 steps). Behaviors during stair descent were coded by experimenters. Risky behaviors observed on the short staircase included: No one used the handrail, 16.1% used an electronic device, and 16.4% had in-person conversations. On the long staircase: 64.8% of pedestrians did not use the handrail, 11.9% used an electronic device, and 14.5% had in-person conversations. Risky behaviors observed more in women included: less likely to use the handrail (long staircase), more likely to carry an item in their hands (both staircases), more likely to engage in conversation (both staircases), and more likely to wear sandals or heels (both staircases) (p≤0.05). Protective behaviors observed more in women included: less likely to skip steps (both staircases), and more likely to look at treads during transition steps (long staircase) (p≤0.05). The number of co-occurring risky behaviors was higher in women: 1.9 vs 2.3, for men vs women, respectively (p<0.001). Five pedestrians lost balance but did not fall; four of these pedestrians lost balance on the top step and all five had their gaze diverted from the steps at the time balance was lost. The observed behaviors may be related to the high injury rate of stair-related falls in young adults, and young women specifically.

Test-retest reliability of kinematic and kinetic parameters during dual-task stair walking in the elderly

Objective: This study aims to evaluate the test-retest reliability of kinematics and kinetics during single and dual-task stair walking in the elderly. Methods: Fifteen healthy elderly adults were recruited. Kinematic and kinetic parameters were measured using an infrared motion analysis system (Vicon, Oxford Metrics Ltd., Oxford, United Kingdom) and force platforms (Switzerland, Kistler 9287BA and 9281CA). Participants were tested under single-task and dual-task (serial 3 subtractions or carrying a cup of water) conditions. Each participant completed two sessions on two separate days with a 1-week interval. Intraclass correlation coefficients (ICC), Pearson correlation coefficient (r), and Bland-Altman plot were used to assess the reliability of stair walking. Results: When ascending stairs, the ICC of kinematics and kinetics ranged from fair to excellent (ICC = 0.500-0.979) in the single and dual tasks, except for step length (ICC = 0.394) in the single task. The r value of kinematics and kinetics ranged from 0.704 to 0.999. When descending stairs, the ICC of kinematics and kinetics ranged from good to excellent (ICC = 0.661-0.963), except for min hip moment (ICC = 0.133) and min ankle moment (ICC = 0.057) in the manual task. The r value of kinematics and kinetics ranged from 0.773 to 0.960 in the single and dual tasks. In the Bland-Altman plots, all the zero values and most of the dots fell in the 95% confidence interval, and the mean difference was found to be close to zero for all the parameters during stair walking. Conclusion: These results obtained from this study show the good test-retest reliability of step cadence, step speed, and step width during single- and dual-task stair walking in the elderly, and the poor reliability of step length during ascending stairs. All the kinetic parameters, including min hip moment, max knee moment, and min ankle moment, had good test-retest reliability during single- and dual-task stair walking, but min hip moment and min ankle moment had poor reliability during manual-task descending stair. These results may help researchers in the assessment of biomechanics of dual-task stair walking in the elderly and to interpret the effect of interventions in this population.

Risk perception and distraction engagement with smart devices in different types of walking environments

OBJECTIVE

The present study aims to: 1) determine whether the risks associated with distracted walking are influenced by walking environment by estimating the incidence and severity of phone-related distracted walking injuries; and 2) investigate individuals' perceptions of distracted walking risk within different walking environments to understand whether individuals are aware of the potential risks and the manner in which they understand those risks.

BACKGROUND

Distracted walking has been increasingly considered a public safety issue over the past few years. Research has focused on understanding the many factors that may influence pedestrians' engagement with smart-devices in order to address this issue. Risk perception may be one factor that guides engagement decisions but has not been widely studied in the context of distracted walking. Risk perception and the consequences of distracted walking are likely to be impacted by the walking environment, however, current research has typically focused on a subset of locations- streets and intersections.

METHOD

This study used the National Electronic Injury Surveillance System (NEISS), a national database of injuries due to consumer products, to understand the number and severity of distracted walking injuries and locations where it occurred. Phone related injury cases from 2011 to 2019 were extracted and categorized by two independent raters in terms of cause of injury and location of injury. An online questionnaire, N = 207, was used to understand how individuals' perception of risk in five different walking environments (intersections, stairwells, hallways, pedestrian plazas, and parking lots) were related to distraction engagement. Risk perception was measured through three different framings: risk of distracted walking (i.e., overall risk of engaging with the behavior), risk of collision and risk of falls (e.g., risks associated with the consequences of engaging with the behavior).

RESULTS

The NEISS analysis showed an upward trend of distracted walking injuries from 2011 (2184 incidents) to 2019 (4711 incidents) and that the number of injuries differed across the different walking environments. The survey results showed that individuals varied their risk perception levels (risk of distracted walking, collision, and falls) based on the walking environment and distraction status (distraction and no distraction). The relationship between overall risk of distracted walking and the risks of the different consequences (falls & collision) differed by walking environment. Finally, significant negative correlations were found between risk perception and actual distraction engagement for each location.

Effects of dual tasks on kinematic and kinetic performances during stair descent: Respective effects of manual and cognitive tasks

BACKGROUND

Stair descent is one of the most common and challenging daily activities for several populations, particularly under dual-task conditions. This study investigated the effects of cognitive or manual task on kinematics and kinetics during stair descent.

METHODS

A total of 37 participants performed stair descent under three conditions: stair descending only, stair descending while performing a cognitive task and stair descending while performing a manual task. Kinematic and kinetic data were collected. Multivariate analysis of variance with repeated measures was conducted to test the significant differences among the three conditions.

RESULTS

The gait performance, loading rate, lower limb joint moments and powers were significantly lower under the two dual-task conditions compared with stair descending only. The participants had lower knee flexion/extension range of motion, loading rate, peak hip flexion moment, first peak knee extensor moment, second peak ankle plantar flexion moment, first knee power absorption and less stride width under the manual task compared with the cognitive task.

CONCLUSIONS

Dual tasks during stair descent had a significant impact on the kinematics and kinetics of motion, and the effect was more significant while performing a concurrent manual task in healthy young adults. Further studies could focus on the complexity level of dual tasks on the biomechanical parameters during stair walking.

The effect of text-based math task on dynamic stability control during stair descent

Stair descent imposes a significant challenge for dynamic stability among young adults. The effect of a concurrent text-based math task on dynamic stability control remains unclear during stair descent when considering the influence of gait velocity. Twenty-six participants performed three successful stair descent trials under TEXTING or NO-TEXTING conditions at their preferred speed. Synchronous kinematics and kinetics were collected by an eight-camera Vicon infrared motion capture system and two force platforms. Repeated measures analysis of covariance and Wilcoxon signed rank test were used to analyze the differences between the two different task conditions with gait velocity as a covariate. The outcomes indicated that under TEXTING condition, sagittal margin of stability increased at right-foot-landing; step cadence, double-support percentage, sagittal and frontal joint moment decreased; and sagittal and frontal joint angles were also modified. It is concluded that concurrent TEXTING impaired sagittal and frontal stability control during stair descent despite slowing down the step cadence. Knee and ankle joint adjustment strategies were mainly adopted in response to stability control in the sagittal plane with the interference of TEXTING, whereas the hip joint adjustment strategy was adopted in the frontal plane. In conclusion, texting behaviors on mobile phones should be minimized during stair descent.

Effects of the use of mobile phone on postural and locomotor tasks: a scoping review

BACKGROUND

Using a mobile phone while performing a postural and locomotor tasks is a common, daily situation. Conversing or sending messages (SMS) while walking account for a significant share of accidental injuries. Therefore, understanding the consequences of using a mobile phone on balance and walking is important, all the more so when these postural and locomotor tasks are aggravated by a disease.

RESEARCH QUESTION

Our objective was to conduct a scoping review on the influence of a dual-task situation - generated by the use of mobile phone - on users' postural and/or locomotor tasks.

METHODS

The literature search was conducted in English on PubMed/Medline and CINHAL databases, using keywords associated with postural and locomotor tasks and with the use of mobile phone. Study location, population, number of subjects, experimental design, types of phone use, evaluated postural-locomotor tasks and expected effects were then analyzed.

RESULTS AND SIGNIFICANCE

46 studies were included in this work, 24 of which came from North America. All studies compared postural and locomotor tasks with and without the use of a smartphone. Ten studies also compared at least 2 groups with different characteristics. Only 4 studies included pathological subjects. Various modalities were tested, and most studies focused on walking. Results show that the use of smartphones slows down movement and induces a systematic imbalance, except when listening to music. The dual task of "using the smartphone during a postural or locomotor tasks" induces systematic disturbances of balance and movement, which must be taken into account in the rehabilitation approach. Future studies will have to extend the knowledge regarding pathological situations.

Effects of a Dual-Task Paradigm and Gait Velocity on Dynamic Gait Stability during Stair Descent

Falls during stair negotiation have become one of the leading causes of accidental death. The effects of a concurrent cognitive or manual dual-task paradigm on dynamic gait stability remain uncertain. How much dynamic gait stability is influenced by gait velocity is also not clear. A total of 16 healthy young females descended a staircase under three different walking conditions: descend stairs only (single task), descend stairs while performing subtraction (cognitive dual-task), and descend stairs while carrying a glass of water (manual dual-task). An eight-camera Vicon motion analysis system and a Kistler force plate embedded into the third step of the staircase were used synchronously to collect kinematic and kinetic data. Gait velocity decreased and dynamic gait stability increased with both cognitive and manual dual-task conditions. The center of mass–center of pressure inclination angle increased with gait velocity but decreased with the manual dual-task condition compared to the single-task condition. Changes in gait velocity caused by the dual-task paradigm can partially explain the effects of dual-task dynamic gait stability. The influence of gait velocity should be considered in the assessment of dual-task effects.

Effects of tai chi on postural control during dual-task stair negotiation in knee osteoarthritis: a randomised controlled trial protocol

INTRODUCTION

Stair ascent and descent require complex integration between sensory and motor systems; individuals with knee osteoarthritis (KOA) have an elevated risk for falls and fall injuries, which may be in part due to poor dynamic postural control during locomotion. Tai chi exercise has been shown to reduce fall risks in the ageing population and is recommended as one of the non-pharmocological therapies for people with KOA. However, neuromuscular mechanisms underlying the benefits of tai chi for persons with KOA are not clearly understood. Postural control deficits in performing a primary motor task may be more pronounced when required to simultaneously attend to a cognitive task. This single-blind, parallel design randomised controlled trial (RCT) aims to evaluate the effects of a 12-week tai chi programme versus balance and postural control training on neuromechanical characteristics during dual-task stair negotiation.

METHODS AND ANALYSIS

Sixty-six participants with KOA will be randomised into either tai chi or balance and postural control training, each at 60 min per session, twice weekly for 12 weeks. Assessed at baseline and 12 weeks (ie, postintervention), the primary outcomes are attention cost and dynamic postural stability during dual-task stair negotiation. Secondary outcomes include balance and proprioception, foot clearances, self-reported symptoms and function. A telephone follow-up to assess symptoms and function will be conducted at 20 weeks. The findings will help determine whether tai chi is beneficial on dynamic stability and in reducing fall risks in older adults with KOA patients in community.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of the Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine (#2018KY-006-1). Study findings will be disseminated through presentations at scientific conferences or publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR1800018028.

Dynamic Stability of Older Adults Under Dual Task Paradigm During Stair Descent

Daily stair activities have become increasingly challenging for older adults with deterioration in physical and cognitive capabilities. However, the dynamic stability of older adults during stair descent under a concurrent dual-task condition remains undetermined. The gait and dynamic stability variables of 40 healthy older adults were measured under single- and dual-task conditions during stair descent. The step length, step width, and single support time did not significantly increase (p > .05) under the dual-task condition during stair descent. The medial–lateral center of mass velocity significantly increased (p < .003), whereas the medial–lateral margin of dynamic stability value significantly decreased (p < .006) at the landing and initial single support under the dual-task condition during stair descent. The self-regulatory ability of healthy older adults under the dual-task condition during stair descent was underestimated. Dual tasking displayed a positive impact on the anterior–posterior dynamic stability of healthy older adults.

Training or Battling a Monster of a Location-Based Augmented-Reality Game While Descending Stairs: An Observational Study of Inattentional Blindness and Deafness and Risk-Taking Inclinations

Several emerging smartphone location-based augmented-reality (AR) games require three primary tasks: training or battling a monster, capturing a monster, and searching for a monster, which involve different levels of perceptual load. Using the AR game originated from Japan as a single case study, this study examined inattentional blindness and deafness and risk-taking inclinations among participants concurrently descending stairs and engaging in these three tasks. Participants descending stairs in Taipei Medical University were observed through recordings obtained from Wi-Fi cameras to determine whether they engaged in risk-taking behaviors such as hopping, not using the handrail, and stopping suddenly. After the participants descended the stairs, they were interviewed to obtain additional information regarding demographics, game tasks (training or battling a monster, capturing a monster, or searching for a monster), data plan, and screen size. Inattentional blindness and deafness were investigated by determining whether participants saw something unusual, a police ascending the stairs, and heard the national anthem played by the police, respectively. In total, 1036 participants descended the stairs and underwent the interview between August 2016 and July 2018. Logistic regression models revealed that training or battling a monster was most associated with inattentional blindness, deafness, not using the handrail, and stopping suddenly, whereas hopping behavior was the commonest among those capturing a monster. Other contributory factors include a large smartphone screen (≥5 in), unlimited mobile data, being an undergraduate student, and an increase in the daily gaming hours. Development of smartphone apps toward detection of stair locomotion may be beneficial for curbing phone use in general and AR game playing in particular.

Concurrent phone texting alters crossing behavior and induces gait imbalance during obstacle crossing

Texting during walking has become a very common daily activity and could alter gait performance, especially during locomotion when additional visual attention is demanded, such as obstacle crossing. The purpose of this study was to examine biomechanical changes in obstructed gait characteristics while engaging in a phone texting activity. Gait analyses were performed on ten young healthy adults under the following two tasks: 1) walking and crossing an obstacle set at a 10% of the subject's height and 2) walking and crossing an obstacle while responding to a text message. Whole body motion data were collected with a 10-camera motion capture system. Our data demonstrated that a conservative gait pattern was adopted while performing texting when approaching and crossing over the obstacle, which was indicated by slower walking speeds and greater toe-obstacle clearances. This gait pattern was, however, accompanied by a greater body sway in the frontal plane during crossing, which could be an indication of perturbed gait balance control. Increased visual-attentional demand from a concurrent phone texting could negatively impact young pedestrians' safety during obstacle crossing.