Normal Speed Research Articles

Effects of step changes in railway noise exposure and earthquakes on sleep disturbance

In the areas spanning around 5 km north from Kumamoto Station (the northern area) and around 12 km south from the station (the southern area), Kyushu Shinkansen and conventional railway lines are closely parallel. After Kyushu Shinkansen Line was operated in 2011, the adjacent conventional railway line was elevated in the northern area, a new station was operated in the southern area, and large earthquakes struck Kumamoto area from March to April, 2016. Through socio-acoustic surveys from 2011 to 2017, sleep disturbances were compared between before and after the earthquakes per train type (Shinkansen and conventional train), area (north and south) and house type (detached and apartment). Sleep disturbance caused by Shinkansen railway for detached house in the northern area was significantly higher before than after the earthquakes. Sleep disturbance caused by Shinkansen railway for apartment house in the southern area was significantly higher after than before the earthquakes. The former may be caused by more frequently closing bed room windows of detached houses in the northern area. The latter was probably because Shinkansen trains slowed down just after the earthquakes and returned to the normal speed during the survey. There was no significant difference in the other six cases.

An observational pilot evaluation of the Walk with Ease program for reducing fall risk among older adults

BackgroundPhysical activity is an effective method of reducing fall risk among older adults. Previous evaluations of the six-week Walk with Ease (WWE) program have documented benefits to functional outcomes, but the potential effects on reducing fall risk have not been evaluated. This pilot study evaluates outcomes of a community delivered WWE program for potential suitability as a fall risk reduction program.MethodsA total of 59 older adults (age > 60) enrolled in a group version of WWE delivered by trained community-based leaders. Complete data (pre- and post-program) from functional fitness tests and behavioral instruments were obtained from 41 participants (aged 74.4 ± 6.6 years, 70% female). Functional outcomes included the 10-foot timed up and go (TUG), 30-second chair stand (CST) and 4-stage balance test (BT) included as part of STEADI, as well as a two-minute step test (ST) and normal gait speed test (GST). Survey assessments included STEADI fall risk screening, self-reported physical activity, and fear of falling measures. Analyses focused on reporting pre-post effect sizes, but paired t-tests were used to test statistical significance of differences.ResultsImprovements in functional performance approached significance for both CST (d = 0.31, p = 0.06) and ST (d = 0.26, p = 0.12), but all other tests were nonsignificant. Survey results demonstrated significant increases in self-reported walking (d = 0.54, p = 0.02) and moderate-to-vigorous physical activity (MVPA; d = 0.56, p = 0.004), but perceived fear of falling and overall fall risk scores had smaller, non-significant, effects (d ranging from 0.01 to 0.31). Stratified analysis suggested that participants screened at an elevated risk for falls at baseline consistently had larger effects on all functional and survey assessments, though the analysis was underpowered to test significance.ConclusionsWalk with Ease participation significantly increased self-reported physical activity but did not significantly improve physical function or reduce fall risk. However, consistently larger effect sizes among participants screened as at-risk for falls suggest that the program may be beneficial for those with elevated risk for falls or functional limitations. Further research is needed to document the consistency of these effects among participants with elevated fall risk status.

IMPACT OF TROPICAL CYCLONE SEROJA ON RAINFALL AND WIND SPEED IN EAST NUSA TENGGARA PROVINCE

Tropical cyclone phenomenon can give impacts such as heavy rain, strong winds, and high waves around its growth area. One of the tropical cyclones that has occurred is Seroja Tropical Cyclone which formed in the Sawu Sea on April 3, 2021. Therefore, this study aims to determine the effect of Seroja Tropical Cyclone on rainfall and surface wind speed in East Nusa Tenggara Province and the percentage comparison of rainfall and wind speed during the Seroja tropical cyclone event with the normal value of rainfall and surface wind speed over a 10-year period. The data used are daily rainfall and surface wind speed data during the Seroja tropical cyclone event, namely April 3 to 12, 2021 and daily average rainfall and wind speed data in April for 10 years in several affected districts in East Nusa Tenggara Province. Data processing is done by calculating the percentage comparison of rainfall and wind speed during the Seroja Tropical Cyclone event with normal rainfall and wind speed in several regions in East Nusa Tenggara. Based on the analysis, heavy to extreme rainfall and strong winds were found in several districts at a radius of about 400 km from the center of the cyclone. Although the category of this tropical cyclone is low, it is able to give impacts in the form of heavy to extreme rainfall and strong winds in the surrounding area. So it can be concluded that the tropical cyclone category does not directly affect rainfall and wind speed in an area, but the distance between the area and the center of the tropical cyclone is more influential in increasing rainfall and wind speed in an area. This is also proven by Sumaja's research in the case of tropical cyclones LUA and Narelle.

Multidisciplinary approach to the treatment of a patient with juxtarenal, abdominal aortic aneurysm and renal cell cancer

Currently, strategies for the management of tumor diseases of the urinary tract in combination with cardiovascular pathologies are controversial. In domestic literature, only isolated reports are found concerning the treatment of combined oncological and cardiovascular pathologies, and the global experience is limited to individual clinical observations and small retrospective series, primarily describing the experience of individual centers. The current challenge for specialists is to establish the ideal treatment sequence with regard to the optimal timing of each surgical procedure and the initial priority of treatment, or the possibility of performing them simultaneously. The article presents a case of successful simultaneous surgical intervention for juxtarenal abdominal aortic aneurysm (AAA) and renal cell carcinoma (RCC) of the left kidney. The patient underwent resection of an abdominal aortic aneurysm with the replacement of the left renal artery, resection of the left kidney under pharmaco-cold ischemia, with thrombectomy from the renal vein. The postoperative period proceeded satisfactorily. After 6 months, on the control computed tomography of the abdominal organs with contrast enhancement (CT) of the abdominal cavity with CU, the prosthesis of the abdominal aorta and the left renal artery are functioning. According to color duplex scanning (CDS) of the renal vessels, the blood flow in the left kidney is preserved to the periphery with normal speed indicators. No data on the recurrence of the oncological process were received.

Using Sound Location to Monitor Farrowing in Sows.

Precision Livestock Farming systems can help pig farmers prevent health and welfare issues around farrowing. Five sows were monitored in two field studies. A Sorama L642V sound camera, visualising sound sources as coloured spots using a 64-microphone array, and a Bascom XD10-4 security camera with a built-in microphone were used in a farrowing unit. Firstly, sound spots were compared with audible sounds, using the Observer XT (Noldus Information Technology), analysing video data at normal speed. This gave many false positives, including visible sound spots without audible sounds. In total, 23 of 50 piglet births were visible, but none were audible. The sow's behaviour changed when farrowing started. One piglet was silently crushed. Secondly, data were analysed at a 10-fold slower speed when comparing sound spots with audible sounds and sow behaviour. This improved results, but accuracy and specificity were still low. When combining audible sound with visible sow behaviour and comparing sound spots with combined sound and behaviour, the accuracy was 91.2%, the error was 8.8%, the sensitivity was 99.6%, and the specificity was 69.7%. We conclude that sound cameras are promising tools, detecting sound more accurately than the human ear. There is potential to use sound cameras to detect the onset of farrowing, but more research is needed to detect piglet births or crushing.

Relationship between quadriceps muscle computed tomography measurement and motor function, muscle mass, and sarcopenia diagnosis.

The quadriceps muscle is one of the human body's largest and most clinically important muscles and is evaluated using mid-thigh computed tomography (CT); however, its relationship with motor function and sarcopenia remains unclear. Herein, we investigated the relationship between the cross-sectional area (CSA) of the quadriceps muscle, CT attenuation value (CTV), dual-energy X-ray absorptiometry muscle mass measurements, and muscle strength and motor function to evaluate the relationship between muscle mass loss and motor function decline, determine the diagnostic ability for sarcopenia, and confirm the usefulness of quadriceps muscle CT evaluation. A total of 472 middle-aged and older community dwellers (254 men and 218 women) aged ≥40 years (mean age: 62.3 years) were included in this study. The quantity and quality of the quadriceps muscle were assessed using CSA and CTV (CSA×CTV) as a composite index multiplied by quality and quantity. Age-adjusted partial correlations by sex with eight motor functions (knee extension muscle strength, power, normal walking speed, fast walking speed, grip strength, sit-up ability, balance ability, and reaction time) were evaluated, including correction methods for height, weight, and body mass index (BMI). Further, the accuracy of sarcopenia diagnosis was evaluated using appendicular muscle mass with dual-energy X-ray absorptiometry measurements, grip strength, and walking speed as the gold standard, and receiver operating characteristic curves were plotted to evaluate diagnostic performance. In men, CSA and CSA×CTV were significantly associated with seven of the eight motor functions (p<0.05), excluding only balance ability. BMI-corrected CSA was significantly correlated with all eight motor functions in men and women (p<0.05). In the diagnosis of sarcopenia based on skeletal muscle index, CSA (area under the curve (AUC) 0.935) and CSA×CTV (AUC 0.936) and their correction by height (CSA/height (AUC 0.917) and CSA×CTV/height (AUC 0.920)) were highly accurate and useful for diagnosis in men but moderately accurate in women (CSA (AUC 0.809), CSA×CTV (AUC 0.824), CSA/height (AUC 0.799), CSA×CTV/height (AUC 0.814)). The present results showed that a single CT image of the quadriceps muscle at the mid-thigh is useful for diagnosing sarcopenic changes, such as loss of muscle mass, muscle weakness, and muscle function.

Abstract 12170: The Impact of Frailty on Urea Metabolism in Tanushimaru Cohort Study

Introduction: Urea metabolism activation, that is urea production, is thought to be very important as a body response for water retention in the process of human evolution. However, it is not clear how that body response is changing as aging. Previous metabolomics studies suggested that various metabolites were influenced by frailty. Thus, we investigated the association between frailty and urea metabolism (urea cycle and TCA cycle) in this study. Methods: We recruited 976 participants who had a health check-up in 2009 and were followed in 2018 in the prospective Tanushimaru cohort study. We defined people with cognitive decline ((≧28 score of Mini-Mental State Examination (MMSE) in 2009 and 24-27 score in 2018), slow gait speed (&lt;1m/s), weaker grip strength (&lt;28kg in men or &lt;18kg in women) in 2018 and weight loss (difference in weight ≧ 4.5kg or 5% of weight in 2009) as “frail-like group”, while those with normal cognitive function in 2009 and 2018 and normal gait speed, grip and no weight loss in 2018 as “control group”. Among them, we extracted 10 age, sex-matched samples randomly from each group and performed targeted metabolomics by the LC/MS/MS Method Package for Primary Metabolites Ver.2 in all 20 serum samples in 2009 and 2018. We compared the activity of the metabolites between the groups and years using t-test and two-way ANOVA. Results: Mean age of 20 samples was 70.2±5.5 years old. According to metabolomics, we found that urea increased significantly in frail-like group than in control group, while other metabolites in urea cycle were not changed. In TCA cycle, Aspartate, Aconitate and Succinate decreased in frail-like group compared to control group (Fig 1). Each metabolite activity was not significantly changed over time. Conclusions: Increased urea was observed in elderly with frailty. Frailty was associated with not urea cycle itself but urea-associated cycle. That may indicate a possibility of the connection of frailty with urea metabolism change.

Agreement of Two Physical Behaviour Monitors for Characterising Posture and Stepping in Children Aged 6-12 Years.

All new physical behaviour measurement devices should be assessed for compatibility with previous devices. Agreement was assessed between the activPAL4TM and activPAL3TM physical behavior monitors within a laboratory and a multi-day free-living context. Healthy children aged 6-12 years performed standardised (sitting, standing, stepping) (12 min) and non-standardised (6 min) activities in a laboratory and a multi-day (median 3 days) free-living assessment whilst wearing both monitors. Agreement was assessed using Bland-Altman plots, sensitivity, and the positive predictive value (PPV). There were 15 children (7M/8F, 8.4 ± 1.8 years old) recruited. For the laboratory-based standardised activities, sitting time, stepping time, and fast walking/jogging step count were all within ±5% agreement. However, the activPAL4TM standing time was lower (-6.4%) and normal speed walking step count higher (+7.8%) than those of the activPAL3TM. For non-standardised activities, a higher step count was recorded by the activPAL4TM (+4.9%). The standardised activity sensitivity and PPV were all >90%, but the non-standardised activity values were lower. For free-living agreement, the standing time was lower (-7.6%) and step count higher (all steps + 2.2%, steps with cadence >100 step/min + 6.6%) for the activPAL4TM than the activPAL3TM. This study highlights differences in outcomes as determined by the activPAL4TM and activPAL3TM, which should be considered when comparing outcomes between studies.

Discount or Speed?: An Analysis of Reward Offer in Exchange for No-Rush Shipping

This research investigates how a no-rush shipping reward program, which offers a discount or a reward to a customer who chooses no-rush shipping for her online purchased items, can be utilized by an online seller to reduce shipping and expediting costs. In particular, we consider a setting in which an online seller has to ship two items to a customer. Each item can be shipped either on time or late, depending on its uncertain lead time. If an item is delivered late, the seller will incur a loss in customer goodwill unless the customer opts in to a no-rush shipping reward program and agrees to take a reward in exchange for potentially receiving an item late. To avoid shipping an item late, the seller also has an option to expedite an item at an extra cost. The seller’s optimal decisions regarding whether to offer a no-rush shipping reward program on any items and whether to ship each item separately or together at a normal or expedited speed are characterized. Our findings reveal that the number of items that the seller should offer the no-rush shipping reward program decreases as the required reward to entice customer participation increases. If the no-rush shipping reward program is offered on both items, then consolidating them into a single shipment always emerges as the optimal strategy. However, in cases where the program applies to none or only one item, it would be optimal for the seller to consolidate the shipment if and only if the shipping cost is sufficiently large. Through numerical demonstration, we underscore the noteworthy cost savings attainable via the no-rush shipping reward program, especially when the expected wait time to receive an item is long, the expediting cost is large, but the normal shipping cost is small. This study suggests that implementing a no-rush shipping reward program empowers online sellers with enhanced shipping management flexibility, which in turn effectively reduces operating and shipping costs as well as the environmental impact, while also meeting customers’ expectation.

Optimizing video feedback for snatch technical error correction in young weightlifters: Comparing the effectiveness of different video playback speeds

Researchers are actively recommending optimal modes of usage for techno-pedagogical tools to ensure that athletes reap the benefits of technology in their training. In this study, we investigated the most effective video feedback viewing speed among normal-speed (NS), half-speed (HS), and quarter-speed (QS), for technical error correction in young weightlifters during the snatch movement. A total of 37 weightlifters (25 boys and 12 girls), aged 11–12 years, were randomly divided into three groups, namely the normal-speed (control group), the half-speed, and the quarter-speed group. Participants completed a pretest (T0), a seven-week snatch learning unit, and a posttest (T1), as well as a retention test one week later (T2). Video-mediated technical analysis of the snatch movement was conducted using the Kinovea motion analysis software. The main results showed that weightlifters who viewed their feedback videos at a quarter of the normal speed (QS) achieved significantly greater improvements in the displacement of the bar in the first pull Dx2 (T1 vs. T0: 27.41 ± 26.10%, Hedges’ g = 0.87, p &lt; 0.05; T2 vs. T0: 24.34 ± 27.11%, Hedges’ g = 1.07, p &lt; 0.05) and the vertical displacement VTR (T1 vs. T0: 22.89 ± 14.16%, Hedges’ g = 1.16, p &lt; 0.05) compared to those who viewed the videos at NS or HS. These findings suggest that slowing down video feedback playback to a quarter of the normal speed can be an effective strategy for enhancing technical error correction in young weightlifters.

A portable AFO solution for pneumatic actuator with cable tendon mechanism to assist ankle dorsiflexion

The limited portability of pneumatic pumps presents a challenge for ankle-foot orthosis actuated by pneumatic actuators. The high-pressure requirements and time delay responses of pneumatic actuators necessitate a powerful and large pump, which renders the entire device heavy and inconvenient to carry. In this paper, we propose and validate a concept that enhances portability by employing a slack cable tendon mechanism. By managing slack tension properly, the time delay response problem of pneumatic actuators is eliminated through early triggering, and the system can be effectively controlled to generate the desired force for dorsiflexion assistance. The current portable integration of the system weighs approximately 1.6 kg, with distribution of 0.5 kg actuation part on the shank and 1.1 kg power system on the waist, excluding the battery. A mathematical model is developed to determine the proper triggering time and volumetric flow rate requirements for pump selection. To evaluate the performance of this actuation system and mathematical model, the artificial muscle’s response time and real volumetric flow rate were preliminarily tested with different portable pumps on a healthy participant during treadmill walking at various speeds ranging from 0.5 m/s to 1.75 m/s. Two small pumps, specifically VN-C1 (5.36 L/min, 300 g) and VN-C4 (9.71L/min, 550 g), meet our design criteria, and then tested on three healthy subjects walking at normal speeds of 1 m/s and 1.5 m/s. The kinematic and electromyographic results demonstrate that the device can facilitate ankle dorsiflexion with a portable pump (300–500 g), generating sufficient force to lift up the foot segment, and reducing muscle activity responsible for ankle dorsiflexion during the swing phase by 8% and 10% at normal speeds of 1 m/s and 1.5 m/s respectively. This portable ankle robot, equipped with a compact pump weighing approximately 1.6 kg, holds significant potential for assisting individuals with lower limb weakness in walking, both within their homes and in clinical settings.

Condition assessment of cycle path texture and evenness using a bicycle measurement trailer

ABSTRACT Cyclists’ riding comfort, related to pavement texture and unevenness, has not been thourougly investigated, partly due to the lack of condition assessment methods specifically adapted to the speed and space limits on cycle paths. Metrics that better describe the perceived comfort of cyclists, rather than that of car users, are needed. In this paper a novel method, the Bicycle Measurement Trailer (BMT), is proposed to bridge this gap. Eight different cycle path surface types have been assessed with regards to pavement texture and for four of these surfaces the longitudinal evenness was assessed. The accuracy and repeatability of the BMT were evaluated. Finally, five different metrics (Dynamic Comfort Index, Evenness Coefficient, 0.5 m Straight Edge, International Roughness Index and Root Mean Square), were calculated from the collected data and assessed. The main findings suggest that the BMT has a high accuracy at normal and high cycling speeds and a high level of repeatability at normal cycling speed. The surfaces could be ranked according to texture, and the evenness was successfully analysed. In conclusion, the BMT could be a valuable tool to assess the cycle path surface condition in relation to bicycle riding comfort.

Manifestations of the weak shear rigidity of marine sediments in amplitudes and travel times of acoustic normal modes and lateral waves

Compressional-to-shear wave conversion at interfaces within unconsolidated marine sediments and interference of shear waves within thin sediment layers have been found to make significant contributions to sound attenuation [O. A. Godin, J. Acoust. Soc. Am. 149, 3586–3598 (2021)] and produce unexpectedly strong perturbations in the normal mode group speed even when the shear speed is small compared to the compressional wave speed. This paper extends the previous analysis to the lateral waves and their applications to characterize the compressional wave speed and attenuation in the seabed. Shear wave-induced contributions to horizontal refraction of normal modes over horizontally inhomogeneous seabed are modeled to characterize the bearing and travel time errors that arise in the fluid-bottom approximation. The acoustic travel time and amplitude effects of the shear waves are found to accumulate at different rates with the propagation range depending on the stability of the shear wave interference within the seabed. The ways to distinguish between the manifestations in acoustic observables of the weak shear rigidity in the seabed and the other environmental uncertainties are discussed for range-independent, range-dependent, and horizontally inhomogeneous shallow-water waveguides. [Work supported by ONR.]

Spatiotemporal Gait Parameters and Gait Asymmetry in Patients With Lumbar Disc Herniation, Treated With Microdiscectomy: A Prospective, Observational Study.

The aim of this study was to emphasize on the interaction of spatial and temporal gait parameters and analyse the gait asymmetry in the patients with lumbar disc herniation (LDH) before and after microdiscectomy. This was a prospective, observational study conducted on 59 cases of LDH planned for lumbar microdiscectomy, and healthy control group with 54 participants for analysis was performed prior to surgery and 15 days after surgery. The spatiotemporal gait parameters were measured using a "Win-Track" gait analysis platform system. All the participants walked barefoot for 10 times with their normal walking speed in the same day. The 3 flawless walking data were recorded and the arithmetic means were computed. The gait symmetry index was used to calculate the walking asymmetry. The pain intensity of the patients was recorded shortly before performing the analysis by a visual analogue scale. In the postoperative assessment LDH patients had significantly shorter temporal parameters, longer spatial parameters, faster walking speed, and more cadence than the preoperative assessment (p < 0.05). There were improvements in the asymmetry values of the postoperative gait parameters compared to the preoperative values, but these differences were not significant (p > 0.05). In addition, there was a significant difference in all parameters in terms of gait asymmetry between the postoperative assessment and the healthy controls (p < 0.05). These results can guide the patient-specific evaluating and implementation of gait rehabilitation programs, and design protocols before or after surgery in the LDH patients.

Corticospinal excitability during observation of basketball free-throw movement: Effects of video playback speed and stimulus timing.

Transcranial magnetic stimulation studies have indicated that action observation (AO) modulates corticospinal excitability. Although a few previous studies have shown that the AO of simple motor movements at a slow playback speed facilitates corticospinal excitability more than that at normal playback speed, it is unclear if this effect occurs during the AO of sport-related complex movements. Therefore, we investigated the changes in the motor evoked potential (MEP) amplitudes of the flexor carpi radialis (FCR) and abductor digiti minimi (ADM) muscles during the AO of a basketball free-throw movement at three different playback speeds (100%, 75%, and 50% speeds). Additionally, we evaluated the effects of stimulus timing (holding the ball vs. releasing the ball for shooting) and motor expertise (expert basketball players vs. novices) on the MEP amplitude during the AO. Our results demonstrated that regardless of motor expertise, the MEP amplitude of the FCR muscle was significantly smaller in the 50% speed condition than in the 100% condition. In the ADM muscle, the MEP amplitude was significantly larger when the ball was held after dribbling than when the ball was released. Therefore, it is suggested that corticospinal excitability in specific muscles during the observation of complex whole-body movements is influenced by video playback speed and stimulus timing.

ANALYSIS OF THE INFLUENCE OF RAIL LINE ON RAILWAY WHEEL FLENS WEAR

Ministerial Regulation number 175 of 2015 about Technical Specification Normal Speed Trains with Self-Propelling, the hardness rate of the train wheels must be lower than the hardness of the rail road. Trains operating at speeds of are considered as normal speed trains. Based on field observations, generally the flange is wear faster. In cases where flanges are wear out, the wheel’s flange must be to restored to its proper condition as long as the wheel diameter is still possible. This research was carried out by processing data using the Trend Linear and using the excel to get the results of a comparison of which wheels are faster to wear out on flange for each wheel in one train arrangement and which route causes wear out faster. Based on the data obtained, the Yogyakarta – Kutoarjo route traversed by An Electric-Diesel Locomotive Prambanan Express (Prameks) causes wear on flange than the Yogyakarta – Yogyakarta International Airport (YIA) route traversed by An Electric-Diesel Locomotive YIA and on the Solo – Wonogiri route traversed by An Electric-Diesel Locomotive Batara Kresna due to the total length of the mileage. and the longest total arc length of the two compared Lines. Meanwhile, the Solo – Wonogiri route traversed by An Electric-Diesel Locomotive Batara Kresna is ranked second in the cause of flange due to the smallest bend radius of the two compared lines. As well as the ranking of the last traffic that causes flange is the Yogyakarta - YIA.

Which trunk muscle parameter is the best predictor for physical function in older adults?

BackgroundDespite preliminary evidence demonstrating the relevance of trunk muscle strength for physical function in older adults, it is not clear which muscle-related trunk parameter is the best predictor for physical functions. Therefore, this study aimed to compare trunk muscle morphology or strength parameters regarding their predictive ability for physical functions. MethodsSeventy-four older adults (38 men, 36 women, mean age 76.85 years) were tested for maximum absolute and relative isokinetic trunk flexion and extension strength, trunk lean mass, and trunk muscle quality. Functional assessment included normal and fast walking speed, repeated sit-to-stand transfer, timed up and go, and postural sway during a closed-feet and a semi-tandem stance adjusted for body height. Pearson's correlations were used to compare relationship between trunk strength adjusted and unadjusted for body weight to physical functions. Linear regression analysis including sex and age as co-variables was performed between trunk muscle and functional test parameters. ResultsRelative back extension strength was the most consistent significant predictor for all physical function tests (p = 0.004–0.04) except for postural sway. Relative trunk flexion strength was related to normal walking speed (p = 0.024). Trunk lean mass was related to timed up and go performance (p = 0.024). ConclusionRelative back extension strength is associated with better performance in nearly all standard tests for physical function in older adults, while trunk flexion strength and lean mass seem to play a minor role. Our findings emphasize the importance of trunk muscle strength, especially the back extensor muscles, for physical function in older adults.

Continuous peripersonal tracking accuracy is limited by the speed and phase of locomotion

Recent evidence suggests that perceptual and cognitive functions are codetermined by rhythmic bodily states. Prior investigations have focused on the cardiac and respiratory rhythms, both of which are also known to synchronise with locomotion—arguably our most common and natural of voluntary behaviours. Compared to the cardiorespiratory rhythms, walking is easier to voluntarily control, enabling a test of how natural and voluntary rhythmic action may affect sensory function. Here we show that the speed and phase of human locomotion constrains sensorimotor performance. We used a continuous visuo-motor tracking task in a wireless, body-tracking virtual environment, and found that the accuracy and reaction time of continuous reaching movements were decreased at slower walking speeds, and rhythmically modulated according to the phases of the step-cycle. Decreased accuracy when walking at slow speeds suggests an advantage for interlimb coordination at normal walking speeds, in contrast to previous research on dual-task walking and reach-to-grasp movements. Phasic modulations of reach precision within the step-cycle also suggest that the upper limbs are affected by the ballistic demands of motor-preparation during natural locomotion. Together these results show that the natural phases of human locomotion impose constraints on sensorimotor function and demonstrate the value of examining dynamic and natural behaviour in contrast to the traditional and static methods of psychological science.

Speeding lectures to make time for retrieval practice: Can we improve the efficiency of interpolated testing?

Testing is increasingly recognized as an important tool in learning. One form of testing often used in lectures, particularly recorded lectures, is interpolated testing wherein tests are interspersed throughout the lecture. Like testing in general, interpolated testing appears to benefit performance on content tests among other outcome variables (e.g., mind wandering). While beneficial, adding testing also increases instructional time. In the present investigation, we examine one strategy to mitigate the costs of this increase in instructional time in the context of recorded lectures. Specifically, we examine the interaction between increasing the playback speed of a recorded lecture and adding interpolated tests. Results demonstrate that the conjoint effects of these two interventions are largely additive. That is, the benefit of testing was as robust in a normal speed lecture and a lecture that was sped up 1.5×. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Head impact kinematics and injury risks during E-scooter collisions against a curb

E-scooters as a mode of transportation is rapidly growing in popularity. This study evaluates head impact conditions and injury risk associated with E-scooter crashes. A multibody model of E-scooter falls induced by wheel-curb collision was built and compared with an experimental E-scooter crash test. A total of 162 crash scenarios were simulated to assess the effect of fall conditions (E-scooter initial speed and inclination, obstacle orientation, and user size) on the head impact kinematics. The forehead hit the ground first in 44% of simulations. The average tangential and normal impact speeds were 3.5 m/s and 4.8 m/s respectively. Nearly 100% of simulations identified a risk of concussion (linear acceleration peak >82 g and rotational acceleration peak >6383 rad/s2) and 90% of simulations suggested a risk of severe head injuries (HIC>700). This work provides preliminary data useful for the assessment and design of protective gears.