Comparison of Predictions Between an EMG-Assisted Approach and Two Optimization-Driven Approaches for Lumbar Spine Loading During Walking With Backpack Loads.

OBJECTIVE: The efficacy of two optimization-driven biomechanical modeling approaches has been compared with an electromyography-assisted optimization (EMGAO) approach to predict lumbar spine loading while walking with backpack loads. BACKGROUND: The EMGAO approach adopts more variables in the optimization process and is complex in data collection and processing, whereas optimization-driven approaches are simple and include the fewest possible variables. However, few studies have been conducted on the efficacy of using the optimization-driven approach to predict lumbar spine loading while walking with backpack loads. METHOD: Anthropometric information of 10 healthy male adults as well as their kinematic, kinetic, and electromyographic data acquired while they walked with various backpack loads (no-load, 5%, 10%, 15%, and 20% of body weight) served as inputs into the model for predicting lumbosacral joint compression forces. The efficacy of two optimization-driven models, namely double linear optimization with constraints on muscle intensity and single linear optimization without any constraints, was investigated by comparing the resulting force profile with that provided by a current EMGAO approach. RESULTS: The double and single linear optimization approaches predicted mean deviations in peak force of -5.1%, and -19.2% as well as root-mean-square differences in force profile of 16.2%, and 25.4%, respectively. CONCLUSION: The double linear optimization approach was a relatively comparable estimator to the EMGAO approach in terms of its consistency, slight bias, and efficiency for predicting peak lumbosacral joint compression forces. APPLICATION: The double linear optimization approach is a useful biomechanical model for estimating peak lumbar compression forces while walking with backpack loads.

A Video-Based Classification System for Assessing Locomotor Skills in Children.

The Test of Gross Motor Development 2 (TGMD-2) is currently the standard approach for assessing fundamental movement skills (FMS), including locomotor and object control skills. However, its extensive application is restricted by its low efficiency and requirement of expert training for large-scale evaluations. This study evaluated the accuracy of a newly-developed video-based classification system (VCS) with a marker-less sensor to assess children's locomotor skills. A total of 203 typically-developing children aged three to eight years executed six locomotor skills, following the TGMD-2 guidelines. A Kinect v2 sensor was used to capture their activities, and videos were recorded for further evaluation by a trained rater. A series of computational-kinematic-based algorithms was developed for instant performance rating. The VCS exhibited moderate-to-very good levels of agreement with the rater, ranging from 66.1% to 87.5%, for each skill, and 72.4% for descriptive ratings. Paired t-test revealed that there were no significant differences, but significant positive correlation, between the standard scores determined by the two approaches. Tukey mean difference plot suggested there was no bias, with a mean difference (SD) of -0.16 (1.8) and respective 95% confidence interval of 3.5. The kappa agreement for the descriptive ratings between the two approaches was found to be moderate (k = 0.54, p < 0.01). Overall, the results suggest the VCS could potentially be an alternative to the conventional TGMD-2 assessment approach for assessing children's locomotor skills without the necessity of the presence of an experienced rater for the administration.

Acute Effect of Brief Mindfulness-Based Intervention Coupled with Fluid Intake on Athletes' Cognitive Function.

During the half time of intermittent team sports, substantial physiological changes relating to acid-base balance and glycemic response affect the second-half performance. Refuel and rehydrate strategy is therefore necessary to be investigated. This field experiment assessed the acute effect of a brief mindfulness-based intervention (MBI) coupled with fluid intake on players' cognitive function in a simulated soccer game. In a single-blinded, randomized, cross-over experiment, 14 male players received three treatments [Control: noncarbohydrate solution + traveling introduction audio; CHO: Carbohydrate (CHO)-electrolyte solution + traveling introduction audio; and CHO-M: CHO-electrolyte solution + MBI] during a simulated half-time break of a soccer game. Participants' mindfulness level, blood glucose and lactate, rating of perceived exertion, and cognitive function performance assessed by the Stroop effect task (ST), Corsi block-tapping test (CBT), and rapid visual information processing task (RVIPT) were immediately measured before, during, and after the trial. Repeated measure ANOVA was used for statistical analysis. The results revealed that: (1) in ST, the CHO_M group performed better than the Control group and marginally better than the CHO group; (2) in CBT, both the Control group and CHO-M group responded faster in the posttest than in the pretest; however, the performance of the CHO group remained the same; (3) the CHO group spent less time on missing numbers in post RVIPT compared with the other two groups. In conclusion, findings of this study provided a preliminary evidence of the positive effect of MBI coupled with CHO intake on athletes' cognitive function, with both positive and negative effect of CHO ingestion.

Effects of backpack and double pack loads on postural stability.

Measurement of postural stability is crucial for identifying predictors of performance, determining the efficacy of physical training and rehabilitation techniques and evaluating and preventing injuries, particularly for heavy load carriage in hikers, mountain search and rescue personnel and soldiers. This study investigated the effect of load distribution on postural stability in an upright stance using backpack and double pack loads under conflicting or impaired somatosensory, visual and vestibular conditions. The sensory organisation tests were conducted on 20 young adults before and after a 10-min level walking exercise. Young adults' ability to use inputs from somatosensory and visual systems to maintain postural stability was significantly reduced following a 10-min walking exercise with a heavy backpack (30% of body weight), whereas no significant changes were observed for double pack carriage. Thus, the distribution of heavy loads to the front and back provides superior balance control compared with back-only loading. Practitioner summary: This study investigated the effects of heavy (30% of body weight) load distribution on postural stability after a 10-min walking exercise. Backpack carriage significantly reduced postural stability, whereas there was no significant effect under double pack loads. Distribution of heavy loads on the front-and-back is desirable for superior balance control.

Gender Differences in Energy Expenditure During Walking With Backpack and Double-Pack Loads.

OBJECTIVE: To investigate gender differences in energy expenditure during walking with backpack and double-pack loads. BACKGROUND: Studies have reported that energy expenditure during walking with double-pack loads is lower compared with backpack carriage. However, the effect of gender on energy expenditure while walking with these two load distribution systems has not been investigated. METHOD: Thirty healthy young adults (15 female and 15 male participants) walked on a treadmill with backpack and double-pack loads weighing 30% of their body weight at a speed of 0.89 m/s for 10 min. The energy expenditure in terms of oxygen consumption (VO2) and respiratory exchange ratio (RER) were continuously monitored using a portable gas analyzer throughout each walking exercise. A mixed-design analysis of variance model was adopted to test the effects of gender, pack, and time on VO2 and RER. RESULTS: No time effect was observed on VO2. However, significant gender, pack, and interaction effects were observed. The lowest VO2 was found in female participants under double-pack carriage. No significant gender or pack differences existed in RER. However, RER significantly and incrementally increased in time from the 4th through 6th, 8th, and 10th min. CONCLUSION: This study revealed that heavy double-pack load carriage for healthy young female participants had significantly lower energy expenditure (normalized by the entire system weight, i.e., the participant's weight plus the weight of the pack) than that of the male participants in a 10-min walking exercise. APPLICATION: The findings of this study indicated that healthy young female participants carried a heavy double-pack with less energy cost (normalized by the entire system weight, i.e., the participant's weight plus the weight of the pack) compared with their male counterparts during a 10-min walking exercise.

Effects of backpack load on critical changes of trunk muscle activation and lumbar spine loading during walking.

This study investigated the effects of carrying a backpack while walking. Critical changes featuring the disproportionality of increases in trunk muscle activation and lumbar joint loading between light and heavy backpack carriage weight may reveal the load-bearing strategy (LBS) of the lumbar spine. This was investigated using an integrated system equipped with a motion analysis, a force platform and a wireless surface electromyography (EMG) system to measure the trunk muscle EMG amplitudes and lumbar joint component forces. A predictive goal programming model was developed to determine the most critical changes in trunk muscle activation and lumbar joint loading. Results suggested that lightweight backpack carriage at approximately 3% of body weight (BW) might reduce the peak lumbosacral compression force by 3% during walking compared with no load condition. The most critical changes in both trunk muscle activation and lumbosacral joint loading were found at a backpack load of 10% of BW. Practitioner Summary: This study investigated the effects of backpack load on the LBS of lumbar spine while walking. A backpack load of 3% of BW might reduce the peak lumbosacral compression force by 3 and 10% of BW induced the most critical changes in LBS of lumbar spine.

Multi-objective analysis for assessing simultaneous changes in regional spinal curvatures under backpack carriage in young adults.

Change in sagittal spinal curvature from the neutral upright stance is an important measure of the heaviness and correctness of backpack use. As current recommendations, with respect to spinal profile, of backpack load thresholds were based on the significant curvature change in individual spinal region only, this study investigated the most critical backpack load by assessing simultaneously the spinal curvature changes along the whole spine. A motion analysis system was used to measure the curvature changes in cervical, upper thoracic, lower thoracic and lumbar regions with backpack load at 0, 5, 10, 15 and 20% of body weight. A multi-objective goal programming model was adopted to determine the global critical load of maximum curvature change of the whole spine in accordance with the maximum curvature changes of the four spinal regions. Results suggested that the most critical backpack load was 13% of body weight for healthy male college students. Practitioner Summary: As current recommendations of backpack load thresholds were based on the significant curvature change in individual spinal region only, this study investigated the backpack load by considering simultaneously the spinal curvature changes along the whole spine. The recommendation, in terms of the global critical load, was 13% of body weight for healthy male college students.

Exergaming and education: a relational model for games selection and evaluation.

Exergaming, or technology-driven physical exercise, has gained popularity in recent years. Its applications include physical education, health promotion, and rehabilitation. Although studies have obtained promising results regarding the positive effects of exergaming, the outcomes of exergaming for different populations remain undetermined. Inconsistencies in the literature on this topic have multiple potential explanations, including the content and demand of the exergames and the capability of the exergamer. A model with a sound theoretical framework is required to facilitate matching between games and gamers. This article proposes a relational model based on a matrix of Bloom's taxonomy of learning domains and the performance components of exergames. Appropriate matching of the physical demands of an exergame and the ability of the exergamer would enhance the effective usage of exergaming for individuals with various needs. This theory-based exergame model is developed to promote the general development, physical status, and psychosocial well-being of students, older adults, and individuals with rehabilitation needs. This model may provide a resource for future research on the application, effectiveness, and design of exergaming.

Tracking Bilateral Lower Limb Kinematics of Distance Runners on Treadmill Using a Single Inertial Measurement Unit.

Distance running related injuries are common, and many ailments have been associated with faulty posture. Conventional measurement of running kinematics requires sophisticated motion capture system in laboratory. In this study, we developed a wearable solution to accurately predict lower limb running kinematics using a single inertial measurement unit placed on the left lower leg. The running data collected from participants was used to train a model using long short-term memory (LSTM) neural networks with an inter-subject approach that predicted lower limb kinematics with an average accuracy of 80.2%, 85.8%, and 69.4% for sagittal hip, knee and ankle joint angles respectively for the ipsilateral limb. A comparable accuracy range was observed for the contralateral limb. The average RMSE (root mean squared error) of sagittal hip, knee and ankle were 8.76°, 13.13°, and 9.67° respectively for the ipsilateral limb. Analysis of contralateral limb kinematics was performed. The model established in this study can be used as a monitoring device to track essential running kinematics in natural running environments. Besides, the wearable solution can be an integral part of a real-time gait retraining biofeedback system for injury prevention and rehabilitation.

The "Trade-Off" of Student Well-Being and Academic Achievement: A Perspective of Multidimensional Student Well-Being.

Student well-being and its relationships with academic achievement in China have not been well-investigated. This study aimed at investigating student well-being and the trade-off of the well-being and academic achievement with a sample of 1,353 Chinese high-school students from four cities in China during coronavirus disease 2019 (COVID-19) pandemic period. The six dimensions of well-being (academic, psychological, self, physical, social, and spiritual) were utilised to test the relationships with three subjects including Mathematics, English, and Chinese using a quantitative analysis. In this study, the relationships between six dimensions of well-being and three academic subject achievements were tested in one statistical model. Results showed that spiritual well-being was ranked the highest, followed by psychological, physical, self, and social well-being. Students gave the lowest ranking to academic well-being. The two significant paths identified were between spiritual well-being and two subjects, namely, Chinese and Mathematics. It is interesting to note that the other five dimensions of well-being were significantly associated with any subjects and English was not significantly related to any dimensions of well-being in this study. Our findings suggested that policymakers and other stakeholders should avoid an "all or nothing" mindset on practice when considering well-being as a multidimensional construct.

The clinical effects of mobilization with passive ankle dorsiflexion using a passive ankle dorsiflexion apparatus on older patients with knee osteoarthritis: A randomized trial.

BACKGROUND: Active exercise is the only proven effective intervention for knee osteoarthritis (OA). The addition of manual therapy has shown to improve outcome of exercises. Passive mobilization with submaximal bilateral passive ankle dorsiflexion was examined in a double-blinded randomized controlled clinical trial. A passive ankle dorsiflexion apparatus was used to standardize the frequency, range of motion, and duration parameters. OBJECTIVES: The purpose of the study was to determine whether a simple standardised mobilization technique could be incorporated as a safe and unsupervised conservative treatment for knee OA. METHODS: In total, 73 participants were randomly assigned to the experimental (n= 37) or control group (n= 36). All participants performed active exercises and received six sessions of 10-minute dorsiflexion intervention, either real or sham, for two weeks. Pre- and post-experimental assessments for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS) for pain, and range of motion of the knee were conducted. RESULTS: Results were analyzed using two-way repeated measures analysis of variance and Independent-Samples Mann-Whitney U Test. The mean score of WOMAC for the experimental and control groups changed from 31.84 to 18.19 and 34.74 to 21.06, respectively, after the intervention. The VAS also showed significant improvements. Significant improvements were observed in WOMAC in both groups after the intervention; however, differences between the groups were not statistically significant. CONCLUSIONS: Exercise with either 30∘ or 5∘ of passive dorsiflexion yielded favorable clinical effects. Although submaximal bilateral ankle dorsiflexion was proven to be safe for elderly participants with osteoarthritis of the knee, whether it provided extra benefits to exercises alone was unclear. Further research is required to determine the effectiveness of dorsiflexion and optimal range of mobilization.

Effectiveness of maternity support belts in reducing low back pain during pregnancy: a review.

AIMS: This article aims to review the literature published to date on the types, current use, the biomechanical effects and adverse effects of maternity support belts for low back pain during pregnancy, to identify future research directions. BACKGROUND: Lumbar/pelvic support belts are frequently recommended for the prevention and treatment of low back pain during pregnancy. DESIGN: Systematic review. METHODS: MEDLINE, CINAHL, the Cochrane Library and patents databases were electronically searched. RESULTS: Maternity support belts belong to one of the four main types of maternity support garments, which are widely commercially-available. Current research showed limited evidence in support of the commercial maternity products regarding the effectiveness in the prevention and/or treatment of low back pain during pregnancy, other than that from the manufacturers. However, potential stabilisation effect of maternity support belt was demonstrated in some studies. Adverse effects reported include increased pain, fetal heart rate changes, skin irritation and discomfort. CONCLUSIONS: There is insufficient scientific evidence to conclude that wearing maternity support belts reduces pregnancy-related low back pain and/or pelvic girdle pain. Future research directions in the area of biomechanics and physiology are recommended. RELEVANCE TO CLINICAL PRACTICE: This review provides comprehensive understanding of the effectiveness of maternity support belts for the relief of low back pain during pregnancy which will facilitate healthcare professionals in providing evidence-based advice to their patients.

Garment needs of pregnant women based on content analysis of in-depth interviews.

AIMS: This study aims to identify the needs, concerns and problems of pregnant women when using maternity support garments. BACKGROUND: Maternity support belt is regarded as helpful in reducing low back pain during pregnancy. However, several garment-related problems exist which might lead to poor adherence behaviour undermining the benefit of garment therapy. DESIGN: A qualitative exploratory study. METHODS. Semi-structured interviews were conducted with 10 pregnant Chinese women who experienced low back pain during pregnancy. All the interviews followed an interview guide and different maternity support garments were shown to the participants as a method of tangible objects to stimulate responses. Content analysis was used to analyse the data. RESULTS: The results showed that 60% of pregnant women discontinued using maternity support garments due to excessive heat, perceived ineffectiveness, itchiness, excessive pressure around the abdomen and inconvenience of adjustment. The content analysis generated five main themes of needs including effective function, safety, skin comfort, ease to put on and take off and aesthetics of maternity support garments. DISCUSSION: The findings of the five main themes of needs were largely consistent with previous studies examining medical garments for overall satisfaction and compliance. The results revealed that women's physiological and psychological changes during pregnancy influenced their clothing preferences on both functional and aesthetical values. CONCLUSIONS: Maternity support garments are convenient and easily-accessible therapy to manage LBP during pregnancy and are frequently recommended and worn by pregnant women. However, inappropriate choice of garment therapy not only led to ineffectiveness but also undesirable effects. The key findings of the five main themes of garment needs in pregnant women will facilitate healthcare professionals in providing evidence-based advice to assist patients in the selection of an appropriate and optimal maternity support garment. RELEVANCE TO CLINICAL PRACTICE: These recommendations in the clinical practice will assist patients in making well informed treatment decisions and ultimately improve the quality of care.

An improved stiffness matrix model of the functional spinal unit for application to an improved understanding of pathological changes.

The stiffness matrix is a useful way to describe the mechanical behaviour of the functional spinal unit, which is defined as the superior and inferior vertebrae, capsules and ligaments. This usefulness is extended by means of the concept of the "balance point". The balance point is the load application point where the coupling coefficients of the stiffness matrix are minimized. Theoretical considerations are used to demonstrate that the stiffness matrix varies with load point location and thus a single stiffness matrix does not fully characterize the motion segment as well as to derive the stiffness matrix at any one specified point from the stiffness matrix at some other specified point. Special characteristics of the stiffness matrix obtained by loading through the "balance point" were shown. Some possible advantages derived from mechanical testing using the "balance point" concept are discussed. This study validates an improved stiffness matrix model that enhances the understanding of pathological changes by setting the gold standard of the behaviour of a normal functional spinal unit.

Reliability of the fluctuations within the stride time series measured in runners during treadmill running to exhaustion.

BACKGROUND: The fluctuations within stride time series (i.e., stride time variability and complexity) during running exhibit long-range correlation. Detecting the breakdown of the long-range correlation was proposed for monitoring the occurrence of running-related injuries during running. However, the stride time fluctuations were only measured from the unilateral side. In addition, the reliability of the stride time fluctuations of within-subject repeated measures remains largely unknown, particularly during exhaustive running. PURPOSES: This study investigated between-side and between-day reliabilities of the stride time variability and complexity of right and left sides during an exhaustive running. METHODS: The stride time variability and complexity of bilateral sides were obtained while 24 healthy participants performed a 31-minute treadmill running at their individual anaerobic threshold speed. Seven of the 24 participants performed the treadmill running test twice at two different days 5-7 days apart. Limits of agreement (LoA) and intraclass correlation coefficient (ICC) were respectively used to assess the absolute and relative between-side and between-day reliabilities. RESULTS: The stride time variability and complexity of right and left sides were highly symmetrical (LoA: (-0.500%, 0.459%) and (-0.052, 0.051), respectively; ICC: 0.94 (0.87, 0.97) and 0.98 (0.95, 0.99), respectively). The overall stride time variability and complexity revealed good between-day reliability (LoA: (-1.044%, 0.724%) and (-0.067, 0.115), respectively; ICC: 0.78 (0.45, 0.92) and 0.81 (0.48, 0.93), respectively). However, the segmented stride time complexity showed poor between-day reliability (ICCs<0.40). CONCLUSION: The findings demonstrated that the stride time series showed equivalent fluctuations between right and left sides and good between-day reliability in fluctuations during exhaustive running. Given the poor between-day reliability in the segmented stride time series, stride time series during exhaustive running could be collected from either right or left side and should be processed as an overall in the future.

EMG-based lumbosacral joint compression force prediction using a support vector machine.

Electromyography-assisted optimization (EMGAO) approach is widely used to predict lumbar joint loads under various dynamic and static conditions. However, such approach uses numerous anthropometric, kinematic, kinetic, and electromyographic data in the computation process, and thus makes data collection and processing complicated. This study developed an electromyography-based support vector machine (EMGB_SVM) approach for predicting lumbar spine load during walking with backpack loads. The EMGB_SVM is simple and uses merely the electromyographic data. Anthropometric information of 10 healthy male adults as well as their kinematic, kinetic, and electromyographic data acquired during walking exercises with no-load and with various backpack loads (5%, 10%, 15%, and 20% of their body weight) were used as the inputs of a biomechanical model, which was then used for predicting the lumbosacral joint compression force. The efficacy of the EMGB_SVM was investigated by comparing the force profiles obtained using this model with those obtained using the current EMGAO approach. On average, the EMGB_SVM obtained deviations in the peak and minimum forces of -3.3% and 5.1%, respectively, and a root mean square difference in the force profile of 7.5%. The EMGB_SVM is a comparable estimator in terms of its slight bias, favourable consistency, and efficiency at predicting the lumbosacral joint compression force.

Changes of lumbosacral joint compression force profile when walking caused by backpack loads.

Walking with backpack loads induces additional mechanical stress on the spine and has been identified as a risk factor of lower-back pain. This study evaluated the effects of walking with backpack loads on the lumbosacral joint compression force profile in both the magnitude and time domains. Ten male adults geared with anatomical markers and trunk surface electromyographic sensors walked along a walkway embedded with three force plates with no load and various backpack loads (5%, 10%, 15%, and 20% body weight). Lower-body movements, ground reaction forces, and trunk muscle activations were measured using a synchronized motion analysis, force plate, and surface electromyography system. The force profiles of identified gait cycles were predicted using an integrated inverse dynamic and electromyography-assisted optimization model and evaluated statistically. The results showed that as backpack load increased, the 10th, 50th, and 90th percentiles of force profiles escalated disproportionately. However, no significant changes were observed in the timing of the two peak force incidences. Such changes in the compression force might be an indication of the combined effects of the increase in both gravitational and mass moment of inertia of the system (body plus pack loads) when walking with a backpack. Pearson correlation coefficients of the force profiles between the five loading conditions were greater than 0.94. Strong associations between the force profiles at different backpack loads were confirmed.

Early physiotherapy intervention in an Accident and Emergency Department reduces pain and improves satisfaction for patients with acute low back pain: a randomised trial.

QUESTION: What is the effect of early physiotherapy intervention on pain and patient satisfaction in acute low back pain? DESIGN: Randomised trial with concealed allocation, assessor blinding, and intention-to-treat analysis. PARTICIPANTS: 110 patients attending the Accident and Emergency Department of a local acute hospital. INTERVENTION: The experimental group received early physiotherapy intervention which consisted of education, reassurance, pain management, mobility training, interferential therapy, walking training, and walking aids as indicated. The control group received only walking training and walking aids as indicated. All participants received conventional medical intervention and outpatient physiotherapy intervention. OUTCOME MEASURES: Pain was measured using the Numeric Pain Rating Scale and satisfaction was measured using the Numeric Global Rating of Change Scale at baseline, discharge from the Accident and Emergency Department, admission to the Physiotherapy Outpatient Department, 1 month, 3 months, and 6 months. RESULTS: Participants in the experimental group had 1.6 out of 10 points (97.5% CI 0.8 to 2.3) less pain than the control group on discharge from the Accident and Emergency Department and still had 0.9 points (97.5% CI 0.1 to 1.6) less pain on admission to the Physiotherapy Outpatient Department. Participants in the experimental group were 2.1 out of 20 points (97.5% CI 1.2 to 2.9) more satisfied than the control group on discharge from the Accident and Emergency Department. CONCLUSION: Early physiotherapy intervention was effective in reducing pain and increasing satisfaction for patients with acute low back pain in an Accident and Emergency Department but the effect tailed off.

Impaired dynamic balance control in adolescents with idiopathic scoliosis and abnormal somatosensory evoked potentials.

BACKGROUND: Both balance control dysfunction and dysfunction of the central nervous system have been proposed as being causative factors in adolescent idiopathic scoliosis (AIS), yet the relationship between these factors has not been investigated in detail. An intergroup comparative study was conducted to investigate the effect of abnormal somatosensory function on the dynamic balance parameters of girls with AIS. METHODS: The relationship between dynamic balance control and abnormal somatosensory function seen in AIS patients was examined by studying the dynamic balance parameters in normal controls, in AIS patients with normal posterior tibial nerve somatosensory cortical evoked potentials (PTN-SCEPs), and in AIS patients with abnormal PTN-SCEPs. Gait parameters were recorded in 18 AIS girls (8 showing abnormal PTN-SCEPs and 10 showing normal PTN-SCEPs). Eight healthy age-matched volunteers served as a control group. RESULTS: No significant left-right asymmetry of gait parameters was found for the controls or the AIS patients with normal PTN-SCEPs, whereas significantly higher gait parameters were found on the side of the curvature in the AIS patients with abnormal PTN-SCEPs. CONCLUSIONS: Somatosensory dysfunction in AIS patients shows to have an impact on dynamic balance control. Further studies to examine the association between somatosensory dysfunction and balance control and how they may be related to the etiology of AIS are recommended. LEVEL OF EVIDENCE: Diagnostic study, level IV (case-control study).

Accuracy of three methods in gait event detection during overground running.

Inertial measurement units (IMUs) have been extensively used to detect gait events. Various methods have been proposed for detecting initial contact (IC) and toe-off (TO) using IMUs affixed at various anatomical locations. However, the accuracy of such methods has yet to be compared. This study evaluated the accuracy of three common methods used for detecting gait events during jogging and running: (1) S-method, in which IC is identified as the instant of peak foot-resultant acceleration and TO is identified when the acceleration exceeds a threshold of 2g in the region of interest; (2) M-method, in which IC and TO are defined as the minimum before the positive peak shank vertical acceleration and the minimum in the region of interest, respectively; and (3) L-method, in which IC is indicated by the instant of peak pelvis anteroposterior acceleration and TO is identified by the maximum in the region of interest. The performance of the IMU-based methods in detecting IC and TO and estimating stance time (ST) were tested on 11 participants at jogging and running speeds against a reference provided by a force-platform method. The S-method was the most accurate for IC detection (overall mean absolute difference (MAD): 4.7±4.1ms). The M-method was the most accurate for TO detection (overall MAD: 7.0±3.5ms). A combination of M- and S-methods, called the MS-method, was the most accurate for ST estimation (overall MAD: 9.0±3.9ms). Thus, the MS-method is recommended for ST estimation; however, this method requires four IMUs for bilateral estimation.