Normal Walking Research Articles

GMSN: An efficient multi-scale feature extraction network for gait recognition

In current gait recognition methods, researchers predominantly focus on gait information at specific spatial scales, with a tendency to overlook information variances across different scales. Additionally, from observation, we found variations in the spatiotemporal information offered by different human body parts. To address these issues, we present a Multi-scale Network for Gait Recognition (GMSN), which aims to highlight key body parts in a more discriminative gait representation. GMSN consists of two key modules: the Multi-scale Feature Extractor (MSFE) and the Part-based Horizontal Mapping (PHM). MSFE employs multi-scale parallel convolutional networks to comprehensively learn features across different scales, capturing both local details and global information for an enriched representation of gait. Meanwhile, PHM focuses on enhancing the learning of crucial body parts that provide clear contours and movement patterns. Experiments on three public datasets demonstrate that our approach attains state-of-the-art recognition accuracy. On the CASIA-B dataset, our model achieves rank-1 accuracies of 98.2 %, 96.0 %, and 87.0 % under normal walking, bag-carrying, and coat-wearing conditions, respectively. On the OU-MVLP and GREW datasets, it achieves a rank-1 accuracy of 90.4 % and 50.6 %, respectively. Also, it can achieve relatively stable results when adding square occlusions to the test samples.

Clinical effects of walking exercise program for older adults applied with an exercise assist robot (Bot Fit): A randomized controlled trial

BackgroundInterval walking exercise (IWE) consists of repeated walking for 3 min with high intensity, followed by 3 min of walking with low intensity. A wearable robot is an exoskeleton system that is worn on the body and helps the body move. Research questionThe purpose of this study is to verify the effects of performing IWE using Bot Fit (Samsung Electronics, Korea) on older adults. MethodsThe experimental group (EG; n = 10) performed the IWE program with Bot Fit, and the control group (CG; n = 12) performed the IWE program without Bot Fit, three times a week for six weeks. Both groups were evaluated for spatio-temporal parameters, pelvic movement, function, muscle power, and waist-to-hip ratio (WHR) at before, after three weeks and after six weeks of exercise. ResultsThere was a significant difference between the two groups in the pelvic tilt range after six weeks of exercise (P < 0.05). The pelvic rotation range showed a significant difference after six weeks of exercise in the EG (P < 0.01). During the stance phase, rectus abdominis (RA) muscle power and its contraction ratio significantly increased after six weeks of exercise in the EG (P < 0.05). The WHR was significantly lower after six weeks of exercise in EG than in the CG (P < 0.05). SignificanceBot Fit maximizes the normal walking effect, promotes correct posture and physical activity to prevent falls, improves quality of life (QOL). It has shown clinical effects and has been used for successful aging of older adults.

Effect of Elevated Acetabular Cup on Contact and Failure Analysis in Hip Implants for Different Microseparations and Cup Inclinations Under Routine Gait Activities Using In Silico Approach.

The acetabular cup design plays a critical role in reducing contact stress between femur head acetabular cup. Many studies used ellipsoidal and spheroidal geometry in acetabular cup design to effectively reduce contact stress. The present study focuses on elevated acetabular cup rim with round corner design to reduce contact stress with round corner geometry. The cobalt chromium femur head and cup are considered for finite element (FE) model of hip resurfacing. The gait loads of routine activities of humans like normal walking, stair ascending and descending and sitting down and getting up gait activities are applied to the developed 3D FE model. Five microseparations of 0.5, 1, 1.5, 2 and 2.5mm are considered in the present study. The acetabular cup inclination angle considered for this study are 35°, 45°, 55°, 65° and 75°. The contact stress and von Mises stress plot for each gait activities under these microseparations are analyzed for betterment of longevity of implants. Overall elevated cup rim design helped in reducing contact stress to a greater extent than conventional cup with different geometries. Also, the predicted von Mises stress for all the parameters considered in the current study are well within the yield strength of CoCr material. Therefore, elevated cup rim could be used as a better alternative to spline and, ellipsoidal and circular geometries of cup.

Vertical locomotion improves horizontal locomotion: effects of climbing on gait and other mobility aspects in Parkinson’s disease. A secondary analysis from a randomized controlled trial

BackgroundIn the Climb Up! Head Up! trial, we showed that sport climbing reduces bradykinesia, tremor, and rigidity in mildly to moderately affected participants with Parkinson’s disease. This secondary analysis aimed to evaluate the effects of sport climbing on gait and functional mobility in this cohort.MethodsClimb Up! Head Up! was a 1:1 randomized controlled trial. Forty-eight PD participants (Hoehn and Yahr stage 2–3) either participated in a 12-week, 90-min-per-week sport climbing course (intervention group) or were engaged in regular unsupervised physical activity (control group). Relevant outcome measures for this analysis were extracted from six inertial measurement units placed on the extremities, chest, and lower back, that were worn during supervised gait and functional mobility assessments before and after the intervention. Assessments included normal and fast walking, dual-tasking walking, Timed Up and Go test, Instrumented Stand and Walk test, and Five Times Sit to Stand test.ResultsCompared to baseline, climbing improved gait speed during normal walking by 0.09 m/s (p = 0.005) and during fast walking by 0.1 m/s. Climbing also reduced the time spent in the stance phase during fast walking by 0.03 s. Climbing improved the walking speed in the 7-m- Timed Up and Go test by 0.1 m/s (p < 0.001) and the turning speed by 0.39 s (p = 0.052), the speed in the Instrumented Stand and Walk test by 0.1 m/s (p < 0.001), and the speed in the Five Times Sit to Stand test by 2.5 s (p = 0.014). There was no effect of sport climbing on gait speed or gait variables during dual-task walking.ConclusionsSport climbing improves gait speed during normal and fast walking, as well as functional mobility in people with Parkinson’s disease.Trial registration This study was registered within the U.S. National Library of Medicine (No: NCT04569981, date of registration September 30th, 2020)

Porcine computational modeling to investigate developmental dysplasia of the hip.

While it is well-established that early detection and initiation of treatment of developmental dysplasia of the hip (DDH) is crucial to successful clinical outcomes, research on the mechanics of the hip joint during healthy and pathological hip development in infants is limited. Quantification of mechanical behavior in both the healthy and dysplastic developing joints may provide insight into the causes of DDHand facilitate innovation in treatment options. In this study, subject-specific three-dimensional finite element models of two pigs were developed: one healthy pig and one pig with induced dysplasia in the right hindlimb. The objectives of this study were: (1) to characterize mechanical behavior in the acetabular articular cartilage during a normal walking cycle by analyzing six metrics: contact pressure, contact area, strain energy density, von Mises stress, principal stress, and principal strain; and (2) to quantify the effect on joint mechanics of three anatomic abnormalities previously identified as related to DDH: variation in acetabular coverage, morphological changes in the femoral head, and changes in the articular cartilage. All metrics, except the contact area, were elevated in the dysplastic joint. Morphological changes in the femoral head were determined to be the most significant factors in elevating contact pressure in the articular cartilage, while the effects of acetabular coverage and changes in the articular cartilage were less significant. The quantification of the pathomechanics of DDH in this study can help identify key mechanical factors that restore normal hip development and can lead to mechanics-driven treatment options.

Intersegmental coordination in human slip perturbation responses

Intersegmental coordination (ISC) of lower limbs and planar covariation law (PCL) are important phenomena observed in biomechanics of human walking and other activities. Gait perturbations tend to cause deviation from the expected ISC pattern thus violating PCL. We used a data set of seven subjects, who experienced unexpected slips, to investigate and characterize the evolution of ISC during slip recoveries and falls. We have analyzed and presented the development of ISC patterns, encompassing the step preceding the slip initiation and duration of slip until it stops. The results show that the ISC patterns during slip recovery deviate considerably from the normal walking patterns. A newly proposed Euclidian distance-based metric (EDM) was used to quantify the deviation from the normal walking ISC pattern during four slip recoveries and three falls evaluated at gait events such as slip start, foot strike, and peak height of the swing foot. The timing of gait events after slip, pattern of EDM, placement of the feet after slip and temporal patterns of each limb angle have been presented. This initial investigation provides insight into the ISC during slip recovery which highlights the human natural recovery trajectories during such perturbations. The observed patterns of the ISC trajectories during slip can be used for the design of human-inspired controllers for exoskeleton devices that can provide external assistance to human subjects during balance recovery.

Influence of obesity on load-transfer mechanism, contact mechanics, and longevity of cemented acetabular cup

ObjectiveThis investigation aimed to assess the impact of obesity on the load-transfer mechanism, longevity, and contact mechanics of cemented acetabular cups. MethodsThree obesity scenarios were considered: obese case-I (100–110 kg), obese case-II (120–130 kg), and obese case-III (140–150 kg). Utilising six finite element models, the effects of different bodyweights on load transfer, contact mechanics, and cup longevity during normal walking conditions were assessed. Muscle forces and hip joint reaction forces were adjusted and linearly calibrated based on obesity cases. ResultsElevated stresses in cortical and cancellous bones, as well as the cement mantle, were observed in obese cases, suggesting a heightened risk of loosening and failure of the cemented fixation of the acetabular cup. Additionally, increased contact pressure and micromotion between articulating surfaces were noted in obese individuals, with a gradual escalation from obese case-I to obese case-III. ConclusionsThese findings highlight the significant negative impact of obesity on the performance of cemented acetabular cups, emphasizing the importance of considering bodyweight variations in the design and assessment of orthopaedic implants for optimal functionality and durability.

Continuous‐dilated temporal and inter‐frame motion excitation feature learning for gait recognition

AbstractThe authors present global‐interval and local‐continuous feature extraction networks for gait recognition. Unlike conventional gait recognition methods focussing on the full gait cycle, the authors introduce a novel global‐ continuous‐dilated temporal feature extraction (TFE) to extract continuous and interval motion features from the silhouette frames globally. Simultaneously, an inter‐frame motion excitation (IME) module is proposed to enhance the unique motion expression of an individual, which remains unchanged regardless of clothing variations. The spatio‐temporal features extracted from the TFE and IME modules are then weighted and concatenated by an adaptive aggregator network for recognition. Through the experiments over CASIA‐B and mini‐OUMVLP datasets, the proposed method has shown the comparable performance (as 98%, 95%, and 84.9% in the normal walking, carrying a bag or packbag, and wearing coats or jackets categories in CASIA‐B, and 89% in mini‐OUMVLP) to the other state‐of‐the‐art approaches. Extensive experiments conducted on the CASIA‐B and mini‐OUMVLP datasets have demonstrated the comparable performance of our proposed method compared to other state‐of‐the‐art approaches.

The impact of pediatric obesity on biomechanical differences across the gait cycle at three walking speeds

BackgroundObesity impacts a child's ability to walk with resulting biomechanical adaptations; however, existing research has not comprehensively compared differences across the gait cycle. We examined differences in lower extremity biomechanics across the gait cycle between children with and without obesity at three walking speeds. MethodsFull gait cycles of age-matched children with obesity (N = 10; BMI: 25.7 ± 4.2 kg/m2) and without obesity (N = 10; BMI: 17.0 ± 1.9 kg/m2) were analyzed at slow, normal, and fast walking speeds. Main and interaction effects of group and speed across hip, knee, and ankle joint angles and moments in sagittal, frontal, and transverse planes were analyzed using one-dimensional statistical parametric mapping. FindingsCompared to children without obesity, children with obesity had greater hip adduction during mid-stance, while also producing greater hip extensor moments during early stance phase, abductor moments throughout most of stance, and hip external rotator moments during late stance. Children with obesity recorded greater knee flexor, knee extensor and knee internal rotator moments during early stance, and knee external rotator moments in late stance than children without obesity; children with obesity also demonstrated greater ankle plantarflexor moments throughout mid and late stance. Interaction effects existed within joint kinetics data; children with obesity produced greater hip extensor moments at initial contact and toe-off when walking at fast compared to normal walking speed. InterpretationWhile few kinematic differences existed between the two groups, children with obesity exhibited greater moments at the hip, knee, and ankle during critical periods of controlling and stabilizing mass.

In-vivo 3-dimensional spine and lower body gait symmetry analysis in healthy individuals

BackgroundNumerous research studies have delved into the biomechanics of walking, focusing on the spine and lower extremities. However, understanding the symmetry of walking in individuals without health issues poses a challenge, as those with normal mobility may exhibit uneven movement patterns due to inherent functional differences between their left and right limbs. The goal of this study is to examine the three-dimensional kinematics of gait symmetry in the spine and lower body during both typical and brisk overground walking in healthy individuals. The analysis will utilize statistical methods and symmetry index approaches. Furthermore, the research aims to investigate whether factors such as gender and walking speed influence gait symmetry. MethodsSixty young adults in good health, comprising 30 males and 30 females, underwent motion capture recordings while engaging in both normal and fast overground walking. The analysis focused on interlimb comparisons and corresponding assessments of side-specific spine and pelvis motions. ResultsStatistical Parametric Mapping (SPM) predominantly revealed gait symmetries between corresponding left and right motions in the spine, pelvis, hip, knee, and ankle during both normal and fast overground walking. Notably, both genders exhibited asymmetric pelvis left-right obliquity, with women and men showing an average degree of asymmetry between sides of 0.9 ± 0.1° and 1.5 ± 0.1°, respectively. Furthermore, the analysis suggested that neither sex nor walking speed appeared to exert influence on the 3D kinematic symmetry of the spine, pelvis, and lower body in healthy individuals during gait. While the maximum normalized symmetry index (SInorm) values for the lower thorax, upper lumbar, lower lumbar, pelvis, hip, knee, and ankle displayed significant differences between sexes and walking speeds for specific motions, no interaction between sex and walking speed was observed. SignificanceThe findings underscore the potential disparities in data interpretations between the two approaches. While SPM discerns temporal variations in movement, these results offer valuable insights that may enhance our comprehension of gait symmetry in healthy individuals, surpassing the limitations of straightforward discrete parameters like the maximum SInorm. The information gleaned from this study could serve as reference indicators for diagnosing and evaluating abnormal gait function.

ARE THERE OBJECTIVE BIOMECHANICAL SYMPTOMS OF KNEE INSTABILITY AFTER ANTERIOR CRUCIATE LIGAMENT INJURY OR IT’S RECONSTRUCTION?

Background: Instability of the knee joint after rupture of the anterior cruciate ligament and even after its reconstruction remains a pressing problem. The use of a special functional test with fast walking can be considered as a potential tool for verifying instability.&#x0D; Aims: to find out whether there are biomechanical differences in joint function with and without instability, both in the period before and after anterior cruciate ligament reconstruction.&#x0D; Methods: A biomechanical study of the function of walking at fast speeds, including an electromyographic study, was used. 40 patients were examined, 22 underwent reconstruction of the anterior cruciate ligament. The patients were divided into two groups - with symptoms of instability - 33 people, and without them - 7 people and a control group (healthy) 20 people.&#x0D; Results: The time characteristics of the step cycle did not reveal significant differences between the groups and the control group. For the amplitudes of movements in the joints, there are also completely no significant differences between the parameters of one group from the other and the affected side from the intact side. Only for the intact side in the group with instability there is a significant increase in both amplitudes in the knee joint compared to the control. Electromyographic study also did not reveal significant differences.&#x0D; Conclusions: The use of a functional test with fast walking does not allow differentiating the state of instability. Thus, the instability of the knee joint during normal walking, even at high speed, does not manifest itself in any way. To detect it, it is necessary to develop special provocative tests.

Predicting Knee Joint Contact Forces During Normal Walking Using Kinematic Inputs With a Long-Short Term Neural Network.

Knee joint contact forces are commonly estimated via surrogate measures (i.e., external knee adduction moments or musculoskeletal modeling). Despite its capabilities, modeling is not optimal for clinicians or persons with limited experience. The purpose of this study was to design a novel prediction method for knee joint contact forces that is simplistic in terms of required inputs. This study included marker trajectories and instrumented knee forces during normal walking from the "Grand Challenge" (n = 6) and "CAMS" (n = 2) datasets. Inverse kinematics were used to derive stance phase hip (sagittal, frontal, transverse), knee (sagittal, frontal), ankle (sagittal), and trunk (frontal) kinematics. A long-short term memory network (LSTM) was created using matlab to predict medial and lateral knee force waveforms using combinations of the kinematics. The Grand Challenge and CAMS datasets trained and tested the network, respectively. Musculoskeletal modeling forces were derived using static optimization and joint reaction tools in OpenSim. Waveform accuracy was determined as the proportion of variance and root-mean-square error between network predictions and in vivo data. The LSTM network was highly accurate for medial forces (R2 = 0.77, RMSE = 0.27 BW) and required only frontal hip and knee and sagittal hip and ankle kinematics. Modeled medial force predictions were excellent (R2 = 0.77, RMSE = 0.33 BW). Lateral force predictions were poor for both methods (LSTM R2 = 0.18, RMSE = 0.08 BW; modeling R2 = 0.21, RMSE = 0.54 BW). The designed LSTM network outperformed most reports of musculoskeletal modeling, including those reached in this study, revealing knee joint forces can accurately be predicted by using only kinematic input variables.

Understanding the role of head size and neck length in micromotion generation at the taper junction in total hip arthroplasty

Modular hip implants allow intra-operative adjustments for patient-specific customization and targeted replacement of damaged elements without full implant extraction. However, challenges arise from relative micromotions between components, potentially leading to implant failure due to cytotoxic metal debris. In this study magnitude and directions of micromotions at the taper junction were estimated, aiming to understand the effect of variations in head size and neck length. Starting from a reference configuration adhering to the 12/14 taper standard, six additional implant configurations were generated by varying the head size and/or neck length. A musculoskeletal multibody model of a prothesized lower limb was developed to estimate hip contact force and location during a normal walking task. Following the implant assembly, the multibody-derived loads were imposed as boundary conditions in a finite element analysis to compute the taper junction micromotions as the relative slip between the contacting surfaces. Results highlighted the L-size head as the most critical configuration, indicating a 2.81 μm relative slip at the mid-stance phase. The proposed approach enables the investigation of geometric variations in implants under accurate load conditions, providing valuable insights for designing less risky prostheses and informing clinical decision-making processes.

Assessing the performance of pedestrian stoop evacuation under height constraints with different motivations

In some specific pedestrian evacuation circumstances such as where the presence of fire smoke, pedestrians are forced to take abnormal walking postures like stooping or crawling to avoid exposure to harmful smoke. Many previous studies have focused on the characteristics of pedestrians' upright walking or crawling. However, the performance of pedestrians’ stoop evacuation has not been comprehensively studied. In the present paper, a series of experiments were carried out to understand the performance of pedestrian stoop movement by considering three height constraints (H = 1.0, 1.5, and 2.0 m) and two motivation levels (normal walking and running movement). To quantificationally analyze the speed features, the trajectories of pedestrians were first extracted from video recordings. With these data, the distribution of pedestrian walking speed and the speed reduction characteristics during long-distance stoop motions were discussed. In addition, physiological indicators like blood pressure and heart rate (HR) were compared before and after the experiment. Finally, according to the collected HR data and questionnaire data, HR-based evaluation and self-reported evaluation of stoop movement intensity were discussed. The findings in this paper provide fundamental data for pedestrian stoop movement with height constraints which could be beneficial to the evacuation models and the building safety design.

Effect of elastic deformation on lubrication characteristics in different clearances and head size of metallic artificial hip joint

The issue of lubrication in metallic artificial hip joints is discussed to prevent the two bearing surfaces from contacting each other. This study aims to analyse the characteristics of elastohydrodynamic lubrication (EHL) and investigate the effect of radial clearance and head size on the tribological performance of metallic artificial hip joints under steady-state conditions using the Fluid-Structure-Interaction (FSI) method. The average load in the z-direction and flexion-extension motion around the y-axis were used to represent normal walking. This study demonstrates that the film thickness profile from the validation study aligns with the findings of the previous study. The contour of the fluid pressure in the central contact zone changes with different time steps – the direction of fluid movement corresponds to the solid-fluid reaction. Additionally, the deformation of the cup surfaces contributes to the continuous fluid film that separates the contact surfaces. Furthermore, design parameters also influence EHL performance. It has been discovered that less radial clearance and a larger head size led to an increase in fluid film thickness.

Association between sarcopenia-related markers and cholelithiasis: A prospective and Mendelian randomization study.

Cholelithiasis is a common digestive disease that drives a myriad of adverse complications. The correlation between sarcopenia and various digestive disorders has been extensively researched, whereas its association with cholelithiasis remains unreported. We aimed to investigate the association through prospective and Mendelian randomization (MR) analyses and establish a quantitative score reflecting the impact of sarcopenia-related markers on cholelithiasis. The prospective study involved 448 627 participants from the UK Biobank. Cox proportional hazard models were employed to investigate the correlation between sarcopenia-related markers and cholelithiasis. To quantitatively assess cholelithiasis risk, the SARCHO score was derived from a multivariable Cox model. Bidirectional two-sample MR analysis was conducted to validate the causal association. A total of 16 738 individuals developed cholelithiasis during a median follow-up of 12 years. Hazard ratios (HRs) of cholelithiasis decreased stepwise over skeletal muscle index tertiles (highest tertile: reference; middle tertile: 1.23, p < .001; lowest tertile: 1.33, p < .001). The tertiles of grip strength showed a similar pattern. Individuals with slow walking pace had a higher risk of cholelithiasis compared to those with normal walking pace (HR 1.23; p < .001). Our SARCHO score better quantifies the risk of cholelithiasis. MR analysis showed a causal relationship between muscle mass and cholelithiasis (OR 0.81; p < .001). No causal effect of cholelithiasis on lean mass was observed. Prospective and MR analyses have consistently demonstrated an increased risk of cholelithiasis in individuals with decreased muscle mass. Additionally, SARCHO score further quantified the cholelithiasis occurrence risk. These findings provide compelling evidence for muscle strengthening in preventing cholelithiasis.

Effect of geometrical, operational and material parameters in the lubrication regime of hard-on-hard hip implants

The lubrication regime of a hip implant is influenced by various parameters, including material, geometry, roughness, relative angular movement, and loading circumstances. These factors impact friction and wear performance, ultimately limiting the implant's longevity. In this study, a ball-on-plane model is considered to predict the lubrication regime across the entire gait cycle for the metal-on-metal and ceramic-on-ceramic hip implants. According to ISO 14242-1, a normal walking gait cycle is considered for the loads and rotations in the hip implant for this study. A comprehensive analysis is done to estimate the lubrication regime by considering different material combinations, body weights, femoral head sizes, clearances, and roughness across the entire gait cycle. The correlation coefficients show that the geometrical parameters are dominant in affecting the lubrication film thickness compared to the operational and material parameters. The femoral head size and body weight are found to be the most dominant and least dominant parameter respectively. Among the hard-on-hard tribo-pairs, ceramics operate predominantly in the full-film lubrication regime compared to metals due to its fine surface finish. The present research suggests that in order to maximise the longevity of a hip implant, an orthopaedic surgeon should choose one with a larger femoral head diameter, less clearance, and an ultra-fine surface finish, regardless of any material tribo-pair.

Lower leg muscle activation during the ebbets foot drills

Lateral ankle sprains (LAS) often lead to chronic ankle instability (CAI). The Ebbets foot drills were created to strengthen the lower leg muscles and reduce the risk of LAS. The current study aimed to explore the activation of the lower leg muscles during the Ebbets foot drills. Twenty-two (22) college students without LAS participated in the study. Surface electromyography (sEMG) of the tibialis anterior (TA), tibialis posterior (TP), and peroneus longus (PL) was collected during each of the Ebbets foot drills and a normal walking trial. The sEMG mean root mean square (RMS) was calculated for each walking and Ebbets foot drill trial duration. The mean RMS was higher during the Ebbets foot drills compared to normal walking for all muscles. The TA sEMG mean RMS was greater (4.0–68.3%, P = 0.001–0.023) during all the Ebbets foot drills than during the walking trial. The TP had greater mean RMS during the toe-in (50.4%, P < 0.001), toe-out (55.0%, P < 0.001), and backward walking (47.3%, P < 0.001) drills, than during the walking trial. The PL had greater mean RMS during all Ebbets foot drills (19.4–53.7%, P < 0.001) except for the heel walking and inversion drills. Ebbets foot drills higher muscle activity than regular walking, suggesting that the Ebbets foot drills could aid in the strengthening of the TA, TP, and PL muscles. These results build evidence on Ebbets’ theory and indicate that these drills may be used to rehabilitate LAS and CAI.

Does Texting While Walking Affect Gait's Plantar Pressure Parameters?

This study aims to examine the possible effects of mobile phone use on plantar pressure and spatiotemporal parameters during walking. Thirty volunteers (18 males and 12 females) participated in the study. A 10-m walking path was prepared, and a messaging connection was established. They were asked to write three posts without word or character mistakes and participants walked on the path walk as much as they wanted on the trail to make sure they were walking at their own pace. The gait's spatiotemporal parameters and plantar pressure parameters were recorded while walking. A paired samples t-test was used to determine whether there was a difference between normal walking and walking while texting. While walking and writing a message, cadence, speed, and step length decreased significantly (P < 0.05). In the plantar pressure parameters, the fore- and midfoot load and pressure were significantly increased (P < 0.05). Compared to normal walking, the forces on the forefoot and midfoot and the pressure per unit area increased in walking while texting. It is thought that the pace of walking slows down, and focus and attention shift to the front of the body.

Criterion-Related Validity of Consumer-Wearable Activity Trackers for Estimating Steps in Primary Schoolchildren under Controlled Conditions: Fit-Person Study.

The purposes were to examine the criterion-related validity of the steps estimated by consumer-wearable activity trackers (wrist-worn activity trackers: Fitbit Ace 2, Garmin Vivofit Jr, and Xiomi Mi Band 5; smartphone applications: Pedometer, Pedometer Pacer Health, and Google Fit/Apple Health) and their comparability in primary schoolchildren under controlled conditions. An initial sample of 66 primary schoolchildren (final sample = 56; 46.4% females), aged 9-12 years old (mean = 10.4 ± 1.0 years), wore three wrist-worn activity trackers (Fitbit Ace 2, Garmin Vivofit Jr 2, and Xiaomi Mi Band 5) on their non-dominant wrist and had three applications in two smartphones (Pedometer, Pedometer Pacer Health, and Google Fit/Apple Health for Android/iOS installed in Samsung Galaxy S20+/iPhone 11 Pro Max) in simulated front trouser pockets. Primary schoolchildren's steps estimated by the consumer-wearable activity trackers and the video-based counting independently by two researchers (gold standard) were recorded while they performed a 200-meter course in slow, normal and brisk pace walking, and running conditions. Results showed that the criterion-related validity of the step scores estimated by the three Samsung applications and the Garmin Vivofit Jr 2 were good-excellent in the four walking/running conditions (e.g., MAPE = 0.6-2.3%; lower 95% CI of the ICC = 0.81-0.99), as well as being comparable. However, the Apple applications, Fitbit Ace 2, and Xiaomi Mi Band 5 showed poor criterion-related validity and comparability on some walking/running conditions (e.g., lower 95% CI of the ICC < 0.70). Although, as in real life primary schoolchildren also place their smartphones in other parts (e.g., schoolbags, hands or even somewhere away from the body), the criterion-related validity of the Garmin Vivofit Jr 2 potentially would be considerably higher than that of the Samsung applications. The findings of the present study highlight the potential of the Garmin Vivofit Jr 2 for monitoring primary schoolchildren's steps under controlled conditions.