Performance of an attention-demanding task during treadmill walking shifts the noise qualities of step-to-step variation in step width.

BACKGROUND: The fractal scaling evident in the step-to-step fluctuations of stepping-related time series reflects, to some degree, neuromotor noise. RESEARCH QUESTION: The primary purpose of this study was to determine the extent to which the fractal scaling of step width, step width and step width variability are affected by performance of an attention-demanding task. We hypothesized that the attention-demanding task would shift the structure of the step width time series toward white, uncorrelated noise. METHODS: Subjects performed two 10-min treadmill walking trials, a control trial of undisturbed walking and a trial during which they performed a mental arithmetic/texting task. Motion capture data was converted to step width time series, the fractal scaling of which were determined from their power spectra. RESULTS: Fractal scaling decreased by 22% during the texting condition (p < 0.001) supporting the hypothesized shift toward white uncorrelated noise. Step width and step width variability increased 19% and five percent, respectively (p < 0.001). However, a stepwise discriminant analysis to which all three variables were input revealed that the control and dual task conditions were discriminated only by step width fractal scaling. SIGNIFICANCE: The change of the fractal scaling of step width is consistent with increased cognitive demand and suggests a transition in the characteristics of the signal noise. This may reflect an important advance toward the understanding of the manner in which neuromotor noise contributes to some types of falls. However, further investigation of the repeatability of the results, the sensitivity of the results to progressive increases in cognitive load imposed by attention-demanding tasks, and the extent to which the results can be generalized to the gait of older adults seems warranted.

Social media interruption affects the acquisition of visually, not aurally, acquired information during a pathophysiology lecture.

Poor academic performance from extensive social media usage appears to be due to students' inability to multitask between distractions and academic work. However, the degree to which visually distracted students can acquire lecture information presented aurally is unknown. This study examined the ability of students visually distracted by social media to acquire information presented during a voice-over PowerPoint lecture, and to compare performance on examination questions derived from information presented aurally vs. that presented visually. Students ( n = 20) listened to a 42-min cardiovascular pathophysiology lecture containing embedded cartoons while taking notes. The experimental group ( n = 10) was visually, but not aurally, distracted by social media during times when cartoon information was presented, ~40% of total lecture time. Overall performance among distracted students on a follow-up, open-note quiz was 30% poorer than that for controls ( P < 0.001). When the modality of presentation (visual vs. aural) was compared, performance decreased on examination questions from information presented visually. However, performance on questions from information presented aurally was similar to that of controls. Our findings suggest the ability to acquire information during lecture may vary, depending on the degree of competition between the modalities of the distraction and the lecture presentation. Within the context of current literature, our findings also suggest that timing of the distraction relative to delivery of material examined affects performance more than total distraction time. Therefore, when delivering lectures, instructors should incorporate organizational cues and active learning strategies that assist students in maintaining focus and acquiring relevant information.

Learning style versus time spent studying and career choice: Which is associated with success in a combined undergraduate anatomy and physiology course?

The VARK learning style is a pedagogical focus in health care education. This study examines relationships of course performance vs. VARK learning preference, study time, and career plan among students enrolled in an undergraduate anatomy and physiology course at a large urban university. Students (n = 492) from the fall semester course completed a survey consisting of the VARK questionnaire, gender, academic year, career plans, and estimated hours spent per week in combined classroom and study time. Seventy-eight percent of students reported spending 15 or fewer hours per week studying. Study time and overall course score correlated significantly for the class as a whole (r = 0.111, P = 0.013), which was mainly due to lecture (r = 0.118, P = 0.009) performance. No significant differences were found among students grouped by learning styles. When corrected for academic year, overall course scores (mean ± SEM) for students planning to enter dentistry, medicine, optometry or pharmacy (79.89 ± 0.88%) were significantly higher than those of students planning to enter physical or occupational therapies (74.53 ± 1.15%; P = 0.033), as well as nurse/physician assistant programs (73.60 ± 1.3%; P = 0.040). Time spent studying was not significantly associated with either learning style or career choice. Our findings suggest that specific career goals and study time, not learning preferences, are associated with better performance among a diverse group of students in an undergraduate anatomy and physiology course. However, the extent to which prior academic preparation, cultural norms, and socioeconomic factors influenced these results requires further investigation.

Frontal plane margin of stability is increased during texting while walking.

Injurious falls associated with cell phone use during ambulation are increasingly common. Studies examining texting while walking suggest this task alters the attentional component of walking to the extent that safety may be compromised. Here, we quantified the extent to which frontal plane dynamic stability while walking was affected by the cognitive and physical demands of texting. Twenty experienced texters performed four, 10-min treadmill walking tasks at a self-selected velocity in random order: (1) normal walk (control), (2) walking while verbally performing mathematical calculations (cognitive demand), (3) walking while bimanually holding and looking directly at a phone (physical demand), and (4) walking while texting continuous mathematical calculations (cognitive and physical). We quantified the frontal plane minimum margin of stability (MOSmin), a measure that considers the position and normalized velocity of the center of mass with respect to the lateral border of the base of support was calculated over each 10-min walking period. Compared to the normal walking condition, the texting and phone holding conditions resulted in a small but significant (6%) increase in MOSmin (p=0.005 and 0.026, respectively). Compared to normal walking, the effect of performing mathematical calculations on MOSmin was not significant (p=0.80). These results suggest that frontal plane stability of experienced texters during controlled treadmill walking conditions can be affected by the physical, but not the cognitive demand of texting. This may represent a compensatory mechanism by the CNS to ensure stability in the event of an unexpected disturbance.

Clay modeling versus written modules as effective interventions in understanding human anatomy.

The effectiveness of clay modeling to written modules is examined to determine the degree of improvement in learning and retention of anatomical 3D relationships among students with different learning preferences. Thirty-nine undergraduate students enrolled in a cadaver dissection course completed a pre-assessment examination and the VARK questionnaire, classifying learning preference as visual, auditory, read/write, or kinesthetic. Students were divided into clay, module, and control groups with preference for learning style distributed among groups. The clay and module groups participated in weekly one-hour classes using either clay models or answering written questions (modules) about anatomical relationships, respectively. The control group received no intervention. Post-assessment and retention examinations were administered at the end of the semester, and three months later, respectively. Two variables (Δ1, Δ2) represented examination score differences between pre- and post-assessment and between post-assessment and retention examinations, respectively. The Δ1 for clay and module groups were each significantly higher than controls (21.46 ± 8.2 vs. 15.70 ± 7.5, P ≤ 0.05; and 21.31 ± 6.9 vs. 15.70 ± 7.5, P ≤0.05, respectively). The Δ2 for clay and module groups approached but did not achieve significance over controls (-6.09 ± 5.07 vs. -8.80 ± 4.60, P = 0.16 and -5.73 ± 4.47 vs. -8.80 ± 4.60, P = 0.12, respectively). No significant differences were seen between interventions or learning preferences in any group. However, students of some learning styles tended to perform better when engaging in certain modalities. Multiple teaching modalities may accommodate learning preferences and improve understanding of anatomy.

Fear of falling does not alter the kinematics of recovery from an induced trip: a preliminary study.

OBJECTIVE: To provide preliminary information about the relationships between self-reported fear of falling (FOF) in healthy community-dwelling women, number of falls, and recovery kinematics in response to a laboratory-induced trip. DESIGN: Cohort study. SETTING: Clinical research laboratory. PARTICIPANTS: A subset of community-dwelling older women (N=33) recruited from studies of laboratory-induced trips and fall prevention. INTERVENTION: A laboratory-induced trip. MAIN OUTCOME MEASURES: Number of fallers in the FOF group versus the control group. Recovery kinematics of FOF group falls versus control group falls, and FOF group recoveries versus control group recoveries were compared. Degree of FOF was assessed by using the Activities-Specific Balance Confidence (ABC) Scale. RESULTS: Falls occurred in 6 of 14 (43%) FOF and 4 of 16 (25%) control subjects (P=.26). The kinematics of FOF group falls were similar to those of control group falls. At completion of the initial recovery step, the FOF group showed significantly greater trunk extension velocity than controls (-82.1°/s ± -66.1°/s vs -25.0°/s ± -53.0°/s, respectively; P=.05). All other variables were not significantly different. ABC Scale scores of FOF subjects did not differ significantly between fallers and those who recovered (mean, 75.2 ± 5.6, 71.1 ± 11.8, respectively; P=.84). CONCLUSION: Healthy community-dwelling older adults would benefit from fall prevention regardless of the presence of self-reported FOF.

Modifiable performance domain risk-factors associated with slip-related falls.

Falls are a major source of injury in older adults. Many falls occur after slipping. This study determined performance-related factors that both contribute to slip-related falls and that may be effectively and efficiently modified through targeted intervention. Thirty-five young adults and 21 healthy older adults (age: 70.9+/-5.1 years) were slipped in a laboratory using a slippery surface. The biomechanics of the 18 older adults who fell and the 30 younger adults who recovered following slips were analyzed. A set of potentially modifiable variables, initially based on significant between-groups differences, was further analyzed using stepwise discriminant analysis and logistic regression. The discriminant analysis correctly categorized 93.8% of the falls and recoveries based on two variables; the velocity of the slipping foot relative to the velocity of the whole body center of mass (COM), and the lateral placement of the recovery foot relative to the COM. The logistic regression determined the expected change in the odds of a recovery following a slip given a hypothesized intervention-induced improvement of these variables. Decreased velocity of the slipping foot relative to the COM, or decreased lateral placement of the recovery foot relative to the COM to zero, increased the odds of recovery by 17% and 27%, respectively. This suggests that intervention targeted at improving these specific lower extremity control variables following the onset of a slip has the potential to significantly decrease slip-related fall risk.

Trunk kinematics and fall risk of older adults: translating biomechanical results to the clinic.

This paper reviews some of our experiences over nearly 15 years of trying to determine modifiable factors that contribute to the high incidence of fall by older adults. As part of our approach, we have subjected healthy young and older adults to very large postural disturbances during locomotion, in the form of trips and slips, to which rapid compensatory responses have been necessary to avoid falling. For both trips and slips, the ability to limit trunk motion has consistently discriminated older adults who fall from both younger adults and older adults who have been able to avoid falling. We have shown that the ability to limit trunk motion can be rapidly acquired, or learned, by older adults as a result of task-specific training. The learned motor skill has demonstrated short-term retention and has been shown to effectively decrease fall-risk due to trips. Collectively, we believe the works strongly suggests that the traditional exercise-based fall-prevention and whole-body, task-specific training can synergize to reduce falls and fall-related injury in older adults.