Integrating OpenPose and SVM for Quantitative Postural Analysis in Young Adults: A Temporal-Spatial Approach.

Noninvasive tracking devices are widely used to monitor real-time posture. Yet significant potential exists to enhance postural control quantification through walking videos. This study advances computational science by integrating OpenPose with a Support Vector Machine (SVM) to perform highly accurate and robust postural analysis, marking a substantial improvement over traditional methods which often rely on invasive sensors. Utilizing OpenPose-based deep learning, we generated Dynamic Joint Nodes Plots (DJNP) and iso-block postural identity images for 35 young adults in controlled walking experiments. Through Temporal and Spatial Regression (TSR) models, key features were extracted for SVM classification, enabling the distinction between various walking behaviors. This approach resulted in an overall accuracy of 0.990 and a Kappa index of 0.985. Cutting points for the ratio of top angles (TAR) and the ratio of bottom angles (BAR) effectively differentiated between left and right skews with AUC values of 0.772 and 0.775, respectively. These results demonstrate the efficacy of integrating OpenPose with SVM, providing more precise, real-time analysis without invasive sensors. Future work will focus on expanding this method to a broader demographic, including individuals with gait abnormalities, to validate its effectiveness across diverse clinical conditions. Furthermore, we plan to explore the integration of alternative machine learning models, such as deep neural networks, enhancing the system's robustness and adaptability for complex dynamic environments. This research opens new avenues for clinical applications, particularly in rehabilitation and sports science, promising to revolutionize noninvasive postural analysis.

Identifying the Posture of Young Adults in Walking Videos by Using a Fusion Artificial Intelligent Method.

Many neurological and musculoskeletal disorders are associated with problems related to postural movement. Noninvasive tracking devices are used to record, analyze, measure, and detect the postural control of the body, which may indicate health problems in real time. A total of 35 young adults without any health problems were recruited for this study to participate in a walking experiment. An iso-block postural identity method was used to quantitatively analyze posture control and walking behavior. The participants who exhibited straightforward walking and skewed walking were defined as the control and experimental groups, respectively. Fusion deep learning was applied to generate dynamic joint node plots by using OpenPose-based methods, and skewness was qualitatively analyzed using convolutional neural networks. The maximum specificity and sensitivity achieved using a combination of ResNet101 and the naïve Bayes classifier were 0.84 and 0.87, respectively. The proposed approach successfully combines cell phone camera recordings, cloud storage, and fusion deep learning for posture estimation and classification.

Practice Effects, Test-Retest Reliability, and Minimal Detectable Change of the Ruff 2 and 7 Selective Attention Test in Patients with Schizophrenia.

BACKGROUND: The Ruff 2 and 7 Selective Attention Test (RSAT) is designed to measure selective attention. It tests automatic detection speed (ADS), automatic detection errors (ADE), automatic detection accuracy (ADA), controlled search speed (CSS), controlled search errors (CSE), and controlled search accuracy (CSA). The purpose of this study was to examine the test-retest reliability, practice effect, and minimum detectable change (MDC) of the RSAT in patients with schizophrenia. METHODS: A total of 101 patients with schizophrenia completed the RSAT twice at a 4-week interval. The intra-class correlation coefficient (ICC), paired t test, and effect size were used to examine the test-retest reliability and practice effect. The standard error of measurement (SEM) and MDC were calculated. RESULTS: The difference scores between the two assessments were significant in all the indexes. The absolute effect sizes were 0.14 to 0.30. The ICCs of the RSAT ranged from 0.69 to 0.91. The MDC% in the indexes of ADS, ADA, and CSA of the RSAT were <30%. CONCLUSIONS: The RSAT is reliable for assessing selective attention in patients with schizophrenia. The RSAT has good to excellent test-retest reliability, a trivial to small practice effect, and indexes of ADS, ADA, and CSA, representing acceptable random measurement error.

Characterizing the Validity of the Inverted Pendulum Model for Quiet Standing.

By assuming that the human body rotates primarily around the ankle joint in the sagittal plane, the human body has been modelled as a single inverted pendulum (IP) to simulate the human quiet stance. Despite its popularity, the validity of the IP model has been challenged in many studies. Rather than testing the validity of the IP model as a true or false question, this work proposes a feature to quantify the degree of validity of the IP model. The development of the proposed feature is based on the fact that the IP model predicts that the horizontal acceleration of COM is proportional to the COP error which is defined as the difference between the center of pressure (COP) and the vertical projection of the center of mass (COM). Since the horizontal components of the acceleration of COM and the ground reaction force (GRF) are always proportional, the proposed feature is the correlation coefficient between the anterior-posterior (AP) components of GRF and the COP error. The efficacy of the proposed feature is demonstrated by comparing its differences for individuals in two age groups (18-24 and 65-73 years) in quiet standing. The experimental results show that the IP model is more suited for predicting the motion of the older group than the younger group. Our results also show that the proposed feature is more sensitive to aging effects than one of the most reliable and accurate COP-based postural stability features.

Detection of Postural Control in Young and Elderly Adults Using Deep and Machine Learning Methods with Joint-Node Plots.

Postural control decreases with aging. Thus, an efficient and accurate method of detecting postural control is needed. We enrolled 35 elderly adults (aged 82.06 ± 8.74 years) and 20 healthy young adults (aged 21.60 ± 0.60 years) who performed standing tasks for 40 s, performed six times. The coordinates of 15 joint nodes were captured using a Kinect device (30 Hz). We plotted joint positions into a single 2D figure (named a joint-node plot, JNP) once per second for up to 40 s. A total of 15 methods combining deep and machine learning for postural control classification were investigated. The accuracy, sensitivity, specificity, positive predicted value (PPV), negative predicted value (NPV), and kappa values of the selected methods were assessed. The highest PPV, NPV, accuracy, sensitivity, specificity, and kappa values were higher than 0.9 in validation testing. The presented method using JNPs demonstrated strong performance in detecting the postural control ability of young and elderly adults.

Relationship between intraindividual auditory and visual attention in children with ADHD.

BACKGROUND AND AIM: Most previous attention-deficit/hyperactivity disorder (ADHD) studies have used only a single sensory modality (usually vision) to investigate attentional problems, although patients with ADHD might display deficits of auditory attention similar to their visual attention. This study explored intraindividual auditory and visual attention in children with and without ADHD to examine the relationship between these two dimensions of attention. METHODS: Attentional performances of 140 children (70 children with ADHD and 70 typically developing peers) were measured through the Test of Variables of Attention (TOVA) in the present study. RESULTS: For both groups, most attentional indices showed significant differences between the two modalities (d ranging from 0.32 to 0.72). The correlation coefficients of most of the attentional variables in children with ADHD were lower than their typically developing peers. All attentional indices of children with ADHD (ranging from 12.8%-55.7%) were much higher than those of their typically developing peers (ranging from 1.4%-8.6%). CONCLUSION: These results not only indicate that typically developing children display more consistent attentional performance, but also support the view that children with ADHD may show attention deficiency in one modality but not necessarily in the other.

Backward Walking Induces Significantly Larger Upper-Mu-Rhythm Suppression Effects Than Forward Walking Does.

Studies have compared the differences and similarities between backward walking and forward walking, and demonstrated the potential of backward walking for gait rehabilitation. However, current evidence supporting the benefits of backward walking over forward walking remains inconclusive. Considering the proven association between gait and the cerebral cortex, we used electroencephalograms (EEG) to differentiate the effects of backward walking and forward walking on cortical activities, by comparing the sensorimotor rhythm (8-12 Hz, also called mu rhythm) of EEG signals. A systematic signal procedure was used to eliminate the motion artifacts induced by walking to safeguard EEG signal fidelity. Statistical test results of our experimental data demonstrated that walking motions significantly suppressed mu rhythm. Moreover, backward walking exhibited significantly larger upper mu rhythm (10-12 Hz) suppression effects than forward walking did. This finding implies that backward walking induces more sensorimotor cortex activity than forward walking does, and provides a basis to support the potential benefits of backward walking over forward walking. By monitoring the upper mu rhythm throughout the rehabilitation process, medical experts can adaptively adjust the intensity and duration of each walking training session to improve the efficacy of a walking ability recovery program.

Qigong for the treatment of depressive symptoms: Preliminary evidence of neurobiological mechanisms.

OBJECTIVES: Qigong has been shown to effectively reduce depressive symptoms in older adults with chronic physical illness. Here, we sought to evaluate the effects of qigong on serotonin, cortisol, and Brain-derived Neurotropic Factors (BDNF) levels and test their roles as potential mediators of the effects of qigong on depressive symptoms. METHODS: Thirty older adults with chronic physical illness participated in a randomized clinical trial. They were randomly assigned to a qigong group (n = 14) or a control group for cognitive training of executive function and memory (n = 16). The participants provided blood and saliva samples at baseline and post-intervention. Levels of cortisol were measured from the salvia samples, and serotonin and BDNF were measured from the blood samples. RESULTS: Consistent with the study findings presented in the primary outcome paper, a significant Group × Time interaction effect emerged on depressive symptoms, explained by greater reductions in the qigong group than the control group. Qigong participants had significantly larger increases in serotonin and BDNF, and decreases in cortisol levels, compared with control group participants. Moreover, treatment-related changes in cortisol levels (but not serotonin or BDNF) fully mediated the beneficial effects of qigong on depressive symptoms. CONCLUSION: The findings provide preliminary evidence that treatment-related changes in cortisol may mediate the benefits of qigong on depressive symptoms. Given the limitation of small sample size of the present study, future studies with larger sample sizes and more extended follow-up assessment are warranted to determine the reliability of these findings.

Study of Postural Stability Features by Using Kinect Depth Sensors to Assess Body Joint Coordination Patterns.

A stable posture requires the coordination of multiple joints of the body. This coordination of the multiple joints of the human body to maintain a stable posture is a subject of research. The number of degrees of freedom (DOFs) of the human motor system is considerably larger than the DOFs required for posture balance. The manner of managing this redundancy by the central nervous system remains unclear. To understand this phenomenon, in this study, three local inter-joint coordination pattern (IJCP) features were introduced to characterize the strength, changing velocity, and complexity of the inter-joint couplings by computing the correlation coefficients between joint velocity signal pairs. In addition, for quantifying the complexity of IJCPs from a global perspective, another set of IJCP features was introduced by performing principal component analysis on all joint velocity signals. A Microsoft Kinect depth sensor was used to acquire the motion of 15 joints of the body. The efficacy of the proposed features was tested using the captured motions of two age groups (18-24 and 65-73 years) when standing still. With regard to the redundant DOFs of the joints of the body, the experimental results suggested that an inter-joint coordination strategy intermediate to that of the two extreme coordination modes of total joint dependence and independence is used by the body. In addition, comparative statistical results of the proposed features proved that aging increases the coupling strength, decreases the changing velocity, and reduces the complexity of the IJCPs. These results also suggested that with aging, the balance strategy tends to be more joint dependent. Because of the simplicity of the proposed features and the affordability of the easy-to-use Kinect depth sensor, such an assembly can be used to collect large amounts of data to explore the potential of the proposed features in assessing the performance of the human balance control system.

Psychometric Properties and Efficiency of the Computerized Adaptive Testing System for Measuring Self-Care Performance in Taiwanese Children With Developmental Disabilities.

OBJECTIVE: To investigate the psychometric properties and efficiency of the computerized adaptive testing system for measuring self-care performance (CAT-SC). The psychometric properties included intrarater and interrater reliabilities, concurrent validity, minimal detectable change, minimal important difference, and responsiveness. DESIGN: Criterion standard study. SETTING: A teaching hospital. PARTICIPANTS: A convenience sample of 60 caregivers of children with developmental disabilities was recruited at the initial assessment, and 95% of the children (N=57) were followed-up at 3 and 6 months. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The CAT-SC and the Pediatric Evaluation of Disability Inventory Chinese version were used at the initial assessment. We assessed the CAT-SC and asked caregivers to rate children's changes in self-care performance with a separate question rated on a 15-point Likert-type scale at the 3- and 6-month follow-ups. RESULTS: The CAT-SC had excellent intrarater and interrater reliabilities (intraclass coefficient=0.99 and 0.92, respectively), high concurrent validity with the Pediatric Evaluation of Disability Inventory (r=0.91-0.92), and trivial to small responsiveness at 3- and 6-month follow-ups (effect size=0.02 and 0.12, standardized response mean=0.08 and 0.33). The minimal detectable change of intrarater reliabilities and the minimal important difference at the first follow-up were 0.22 and 0.17 logits, respectively. The administration time of the CAT-SC was about 5 minutes. CONCLUSIONS: The results of our study validated the sound psychometric properties and good efficiency of the CAT-SC. Moreover, the values of the minimal detectable change and minimal smallest change can be used as a reference for clinicians and caregivers to interpret children's progress.

Test-Retest Reliability and Minimal Detectable Change of the D2 Test of Attention in Patients with Schizophrenia.

OBJECTIVE: The d2 Test of Attention (D2) is a commonly used measure of selective attention for patients with schizophrenia. However, its test-retest reliability and minimal detectable change (MDC) are unknown in patients with schizophrenia, limiting its utility in both clinical and research settings. The aim of the present study was to examine the test-retest reliability and MDC of the D2 in patients with schizophrenia. METHOD: A rater administered the D2 on 108 patients with schizophrenia twice at a 1-month interval. Test-retest reliability was determined through the calculation of the intra-class correlation coefficient (ICC). We also carried out Bland-Altman analysis, which included a scatter plot of the differences between test and retest against their mean. Systematic biases were evaluated by use of a paired t-test. RESULTS: The ICCs for the D2 ranged from 0.78 to 0.94. The MDCs (MDC%) of the seven subscores were 102.3 (29.7), 19.4 (85.0), 7.2 (94.6), 21.0 (69.0), 104.0 (33.1), 105.0 (35.8), and 7.8 (47.8), which represented limited-to-acceptable random measurement error. Trends in the Bland-Altman plots of the omissions (E1), commissions (E2), and errors (E) were noted, presenting that the data had heteroscedasticity. CONCLUSIONS: According to the results, the D2 had good test-retest reliability, especially in the scores of TN, TN-E, and CP. For the further research, finding a way to improve the administration procedure to reduce random measurement error would be important for the E1, E2, E, and FR subscores.

Auditory and Visual Attention Performance in Children With ADHD: The Attentional Deficiency of ADHD Is Modality Specific.

OBJECTIVE: This study explored auditory and visual attention in children with ADHD. METHOD: In a randomized, two-period crossover design, 50 children with ADHD and 50 age- and sex-matched typically developing peers were measured with the Test of Various Attention (TOVA). RESULTS: The deficiency of visual attention is more serious than that of auditory attention in children with ADHD. On the auditory modality, only the deficit of attentional inconsistency is sufficient to explain most cases of ADHD; however, most of the children with ADHD suffered from deficits of sustained attention, response inhibition, and attentional inconsistency on the visual modality. Our results also showed that the deficit of attentional inconsistency is the most important indicator in diagnosing and intervening in ADHD when both auditory and visual modalities are considered. CONCLUSION: The findings provide strong evidence that the deficits of auditory attention are different from those of visual attention in children with ADHD.

Relative and Absolute Reliabilities of the Conners' Continuous Performance Test II in Schizophrenia.

OBJECTIVE: The Conners' Continuous Performance Test II (CCPT-II) is one of the most commonly used tests of sustained attention in schizophrenia. To manage and monitor sustained attention deficits in schizophrenia, clinicians have to reliably assess the degree of attention impairment. The purpose of our study was to determine the relative and absolute reliability of the CCPT-II in schizophrenia. METHOD: The final sample was a total of 108 patients with schizophrenia. The primary measures in this study were the CCPT-II and the Clinical Global Impression-Severity (CGI-S). The CCPT-II was administered twice, 1 month apart, by a specially trained occupational therapist. We assessed two types of reliability: relative and absolute reliability. Relative reliability was determined with the intra-class correlation coefficient (ICC). Absolute reliability was quantified with standard error of measurement (SEM), minimal detectable change (MDC), and Bland-Altman's 95% limits of agreement (LOA). RESULTS: The ICCs for the five CCPT-II indexes (Omissions, Commissions, Hit RT, Hit RT Std Error, and Variability) ranged from 0.66 to 0.79. The MDCs (MDC%) of the five indices were 13.53 (156.78), 10.67 (47.85), 122.10 (34.16), 8.15 (106.82), and 25.81 (162.63), respectively. CONCLUSIONS: According to the results, the CCPT-II has limited reliability in monitoring the sustained attention function of patients with schizophrenia. Our results can be used as a reference for the measurement error of CCPT-II to help clinicians and researchers determine the true change between successive assessments of patients with schizophrenia.

Effects of weighted vests on attention, impulse control, and on-task behavior in children with attention deficit hyperactivity disorder.

OBJECTIVE. In this study, we examined the effectiveness of using weighted vests for improving attention, impulse control, and on-task behavior in children with attention deficit hyperactivity disorder (ADHD). METHOD. In a randomized, two-period crossover design, 110 children with ADHD were measured using the Conners' Continuous Performance Test-II (CPT-II) task. RESULTS. In the weighted vest condition, the participants did show significant improvement in all three attentional variables of the CPT-II task, including inattention; speed of processing and responding; consistency of executive management; and three of four on-task behaviors, including off task, out of seat, and fidgets. No significant improvements in impulse control and automatic vocalizations were found. CONCLUSION. Although wearing a weighted vest is not a cure-all strategy, our findings support the use of the weighted vest to remedy attentional and on-task behavioral problems of children with ADHD.

The test-retest reliability and the minimal detectable change of the Purdue pegboard test in schizophrenia.

BACKGROUND/PURPOSE: The Purdue pegboard test is widely used in measuring the hand dexterity of patients with schizophrenia. In patients with schizophrenia, the test-retest reliability and minimal detectable change (MDC) of this test remain largely unknown, limiting the interpretability of this popular measure. The purpose of this study was to estimate the test-retest reliability and the MDC of the Purdue pegboard test for patients with schizophrenia. METHODS: A total of 147 patients with schizophrenia participated in this study. The participants were administrated the five subtests of the Purdue pegboard test, three trials in a row at both of the two sessions 1 week apart. The intraclass correlation coefficient (ICC) was used to examine the test-retest reliability and the MDC was calculated on the basis of standard error of measurement. RESULTS: The test-retest reliabilities of the five subtests were moderate to good (ICC = 0.73-0.88). The MDC (MDC%) was 3.0 (22.9%) for the dominant hand subtest, 3.1 (26.1%) for the nondominant hand subtest, 3.0 (31.7%) for the both hands subtest, 6.1 (17.7%) for the dominant + nondominant + both hands subtest, and 8.5 (35.3%) for the assembly subtest. CONCLUSION: Our results reveal that the Purdue pegboard test has moderate-to-good test-retest reliability but substantial random measurement error. These findings should enable clinicians and researchers to monitor and interpret the changes in the hand dexterity of patients with schizophrenia more accurately and confidently.

Test-retest reliability of two attention tests in schizophrenia.

The Symbol Digit Modalities Test (SDMT) and Digit Vigilance Test (DVT), both well-recommended attention tests for schizophrenia, are measures of switching and sustained attention, respectively. The purpose of this study was to investigate the test-retest reliability of the two attention tests in schizophrenia. A rater administered both tests on 147 participants with schizophrenia twice at a 1-week interval. Test-retest reliability was determined through the calculation of the intra-class correlation (ICC) coefficient. We also carried out the Bland-Altman analysis, which include a scatter plot of the differences between test and retest against their mean. System biases were evaluated by use of a paired t-test. The ICC for the SDMT was 0.87 and that for the DVT was 0.83. The limits of agreement (LOAs) of the SDMT and DVT were 11.5 to -9.9 correct responses and 156.3 to -249.2 s, respectively. The mean difference scores of the SDMT and DVT were 1.5 (4.7% of the first session mean; p= .002) and -46.4 (7.6% of the first session mean; p< .001). The ICCs show that the SDMT and DVT are stable measures across assessment in different sessions in schizophrenia. However, the paired t-test indicates a practice effect, and the LOAs show large variations. Thus, the SDMT and DVT are reliable for a group of subjects but limited for individual subjects with schizophrenia in 1-week interval clinical trials.