Effects of Task Interference on Kinematics and Dual-Task Cost of Running in Early Childhood.

Children aged 3-8 are in a critical period for motor development and postural control. Running is a basic motor skill that children need to master in early childhood. While running, children are prone to dangerous events such as falls. This study investigates the kinematic characteristics of running by children associated with different interference tasks, i.e., normalized running, cognitive dual-tasks, and obstacle crossing tasks, and provides a theoretical foundation for the interference mechanism of children's dynamic postural control and for screening of motor disorders. Two hundred children aged 3-8 were recruited. The BTS Bioengineering infrared motion capture system was used to collect spatiotemporal and kinematic running data under three tasks. Repeated measures of variance analysis were used to compare the effects of different interference tasks and ages on children's running signs. The main and interaction effect tests were compared by the Bonferroni method. The results and conclusions are as follows: (1) Running characteristics of early childhood are influenced by interference tasks and age. With interference tasks, the overall characteristics of running by children aged 3-8 showed an increasing trend in running cycle time and a decreasing trend in stride length, step length, cadence, and speed. (2) Both cognitive and obstacle crossing tasks had costs, and cognitive task costs were greater than obstacle crossing costs. Children adopted a "task first" running strategy with different interference tasks. When facing cognitive tasks, their overall joint motion decreased, and they reduced joint motions to promote task completion. When facing obstacle crossing tasks, because of the characteristics of the task itself, children increased joint motions to cope with interference. (3) In terms of age, the running characteristics showed a nonlinear development trend in various indicators, with a degree of recurrence and high variability in adjacent age groups. (4) The dual-task interference paradigm of "postural-cognition" can be used as a motor intervention tool to promote the development of basic motor skills in early childhood.

Exploratory and confirmatory factor analyses identify three structural dimensions for measuring physical function in community-dwelling older adults.

Background: Physical function is a strong indicator of biological age and quality of life among older adults. However, the results from studies exploring the structural dimensions of physical function are inconsistent, and the measures assessed vary greatly, leading to a lack of comparability among them. This study aimed to construct a model to identify structural dimensions that are suitable and best assess physical function among community-dwelling adults 60-74 years of age in China. Method: This study was conducted in 11 communities in Shanghai, China, from May to July 2021. A total of 381 adults 60-74 years of age were included in the study. Measured physical function data were used in factor analyses. Data collected from individuals were randomly assigned to either exploratory factor analysis (EFA) (n = 190) or confirmatory factor analysis (CFA) (n = 191). The statistical software used in the study was SPSS for EFA and AMOS for CFA. To test the properties of the structural dimension model of physical function, various fit indices, convergent validity, and discriminant validity were calculated. Results: The EFA results derived seven indicators in three factors, with 58.548% of the total variance explained. The three factors were mobility function (three indicators), which explained 26.380% of the variance, handgrip strength and pulmonary function (two indicators), which explained 19.117% of the variance, and muscle strength (two indicators) which explained 13.050% of the variance. The CFA indicated that this model had an acceptable fit (χ2/df ratio, 2.102; GFI, 0.967; IFI, 0.960; CFI, 0.959; and RMSEA, 0.076), and the criteria for convergent validity and discriminability were also met by the model. Conclusion: The constructed structural dimension model of physical function appeared to be a suitable and reliable tool to measure physical function in community-dwelling adults aged 60-74 years in China. The structural dimension indicators identified by this model may help sports medicine experts and healthcare providers offer more targeted interventions for older adults to reverse or slow the decline of physical function and to offer actionable targets for healthy aging in this population.

Effects of Whole-Body Vibration Training on Lower Limb Muscle Strength and Physical Performance Among Older Adults: A Systematic Review and Meta-analysis.

OBJECTIVE: To evaluate the effects of whole-body vibration training (WBVT) on lower limb muscle strength and physical performance in older adults. DATA SOURCES: Web of Science, PubMed, Cochrane Library, and MEDLINE databases were searched for papers published in English, from January 1, 2000, to May 30, 2022. STUDY SELECTION: Randomized controlled trials of WBVT in older adults (mean age, 65 years or older) published in English. The Physiotherapy Evidence Database Scale was used to assess the quality of the selected studies. DATA EXTRACTION: Two investigators independently assessed articles according to the evaluation criteria. Differences between investigator assessments were resolved by consulting a third investigator before reassessment. DATA SYNTHESIS: Systematic review of 18 randomized controlled studies found that WBVT produced significant improvements in lower limb muscle strength and physical performance among older adults. We used the Cochrane Collaboration method to assess risk of bias and RevMan version 5.4a to extract means and calculate SDs. WBVT significantly improved knee strength (standard mean difference [SMD]=0.72, 95% confidence interval [CI] [0.38, 1.07], P<.0001, I2=58%) and explosive power (SMD=0.47, 95% CI [0.10, 0.83], P=.01, I2=0%) among older adults. Significant improvements in each physical performance were observed in the sit-to-stand test (SMD=0.57, 95% CI [0.30, 0.84], P<.0001, I2=35%), the subgroup of studies that evaluated balance with timed Up and Go test, SMD was 0.53 (95% CI [0.19, 0.88], P=.002, I2=56%) and the Tinetti total score, SMD was 0.72 (95% CI [0.04, 1.41], P=.04, I2=81%), walking speed (SMD=0.46, 95% CI [0.14, 0.77], P=.005, I2=49%), and walking endurance (SMD=0.43, 95% CI [0.02, 0.85], P=.04, I2=24%). CONCLUSIONS: WBVT may be an effective intervention to improve lower limb muscle strength and physical performance in older adults. Tinetti total score remains controversial and warrants assessment in future high-quality randomized controlled trials.

Intraoperative Hypertension Is Associated with Postoperative Acute Kidney Injury after Laparoscopic Surgery.

BACKGROUND: It is well demonstrated that intraoperative blood pressure is associated with postoperative acute kidney injury (AKI); however, the association between severity and duration of abnormal intraoperative blood pressure (BP) with AKI in patients undergoing laparoscopic surgery remains unknown. METHODS: This retrospective cohort study included 12,414 patients aged ≥ 18 years who underwent a single elective laparoscopic abdominal surgery during hospitalization between October 2011 and April 2017. Multivariate stepwise logistic regressions were applied to determine the correlation between the severity and duration of intraoperative mean arterial pressure (MAP, (systolic BP + 2 × diastolic BP)/3), acute intraoperative hypertension (IOTH) and postoperative AKI, in different periods of surgery. RESULTS: A total of 482 hospitalized patients (3.9%) developed surgery-related AKI. Compared with those without IOTH or with preoperative mean MAP (80-85 mmHg), acute elevated IOTH (odds ratio, OR, 1.4, 95% CI, 1.1 to 1.7), mean MAP 95-100 mmHg (OR, 1.8; 95% CI, 1.3 to 2.7), MAP 100-105 mmHg (OR, 2.4; 95% CI, 1.6 to 3.8), and more than 105 mmHg (OR, 1.9; 95% CI, 1.1 to 3.3) were independent of other risk factors in a diverse cohort undergoing laparoscopic surgery. In addition, the risk of postoperative AKI appeared to result from long exposure (≥20 min) to IOTH (OR, 1.9; 95% CI, 1.5 to 2.5) and MAP ≥ 115 mmHg (OR, 2.2; 95% CI, 1.6 to 3.0). Intraoperative hypotension was not found to be associated with AKI in laparoscopic surgery patients. CONCLUSIONS: Postoperative AKI correlates positively with intraoperative hypertension in patients undergoing laparoscopic surgery. These findings provide an intraoperative evaluation criterion to predict the occurrence of postoperative AKI.

Improved response inhibition induced by attentional capture is associated with physical activity.

The ability to stop a response promptly when a stop signal is presented is named response inhibition. It is generally accepted that the process of response inhibition requires a subject to pay attention to the stop instruction and then cancel the action. A wealth of converging evidence suggests that physical activity (PA) can promote response inhibition, but the potential contributions of attentional capture to the relationship between PA and response inhibition are currently unknown. In this study, the standard stop-signal task (SST) and two novel versions of the SST were used to solve this gap. A total of 58 college students were divided into a higher PA group and a lower PA group, respectively. In Experiment 1, the classical SST determined that the participants in the higher PA group displayed a significantly faster stop-signal reaction time (SSRT) than those in the lower PA group. Experiment 2 separated the attentional capture in the SST and revealed that the participants in the higher PA group could detect the signal faster than those in the lower PA group. Experiment 3 further added a stop signal to Experiment 2 and demonstrated that the participants in the higher PA group could more effectively deploy attentional resources to complete the task. Overall, these findings indicate that PA is positively associated with response inhibition and that the positive relationship is associated with effective allocation of attentional resources for faster attentional capture.

Effects of resistance training combined with balance training on physical function among older adults: a protocol for a randomised controlled trial.

INTRODUCTION: The world's population is ageing. Age-related declines in physical function negatively affect the quality of life but may be ameliorated by certain types of exercise. The purpose of this study is to investigate the effects of combining resistance training (RT) with balance training on physical function in older community-dwelling adults to provide a reference for this type of exercise compared with other exercises and to provide a theoretical basis for optimising exercise plans to improve physical function among older adults. METHODS: This single-blind randomised controlled trial will recruit 66 community dwelling adults 60-89 years of age with normal cognition. Participants will be randomly assigned to one of three groups: RT, RT combined with balance training or a control group with usual daily activities. Exercise interventions will be conducted in three 45 min sessions per week for 24 weeks. Primary physical function outcomes will be assessed using the timed up and go test, usual walking speed, maximal walking speed, 30 s chair stand and 30 s arm curl. Secondary assessments will be conducted using the 2 min step test, back scratch test and chair sit-and-reach test. All physical function assessments will be performed at baseline and after 12 and 24 weeks of exercise interventions. Exercise intensity will be monitored to maintain moderate intensity by heart rate, ratings of perceived exertion and OMNI-Resistance Exercise Scale. Data that conform to a normal distribution will be expressed as means±SD, otherwise as medians and interquartile intervals. Pretest, mid-test and post-test outcomes will be analysed for within-group and between-group comparisons using two-way repeated measures analyses of variance. ETHICS AND DISSEMINATION: This proposal was reviewed and approved by the Shanghai University of Sport Research Ethics Committee (102772021RT067). The results will be disseminated to the trial participants and as a peer-reviewed publication. TRIAL REGISTRATION NUMBER: ChiCTR2200056090.

Slower maximal walking speed is associated with poorer global cognitive function among older adults residing in China.

Background: Maintaining both walking speed and cognitive function is essential for active, healthy aging. This study investigated age-related differences in walking speed and global cognitive function with aging and the association between them among older adults residing in the developing country of China. Methods: This cross-sectional study measured usual (UWS) and maximal walking speed (MWS) of participants for six meters. The Chinese version of the Montreal Cognitive Assessment was used to evaluate global cognition through in-person interviews. Analyses of variance were used to compare the differences in UWS, MWS, and global cognition between genders and age groups. Multiple linear regression models were used to determine the association between walking speed and global cognitive function. Results: In total, 791 Chinese adults (252 men and 539 women) aged 60-89 years were included in this study. Markedly slowed UWS and worse global cognitive function scores were observed for both genders among adults ≥80 years of age. MWS slowed considerably in men ≥85 years of age and in women ≥80 years of age. There was a significant gender difference in MWS-with men walking faster than women-but not in UWS. Linear regression analysis adjusted for the confounding factors of gender, height, weight, years of education, and chronic disease indicated that MWS, but not UWS, was significantly associated with global cognitive function (ß = 0.086, [0.177, 1.657], P = 0.015) such that slower maximal walking speed was associated with poorer cognitive performance. This association was statistically significant only for adults aged 75-79 years (ß = 0.261 [0.647, 4.592], P = 0.010). Conclusion: Walking speed was slower in the older age groups. Global cognitive function deteriorated markedly after 80 years of age. After controlling for confounding variables, slower MWS, but not UWS, was associated with poorer global cognitive function. MWS may serve as a potential indicator for earlier identification of poor cognition and motoric cognitive risk syndrome in an older Chinese population.

Biomechanical Characteristics of Vertical Jumping of Preschool Children in China Based on Motion Capture and Simulation Modeling.

Vertical jumping is one of the basic motor skills, and it is an essential part of many sports. The main purpose of this paper is to investigate characteristics of vertical jumping of children. This paper uses a motion capture system, three-dimensional platforms, and a simulation modeling system to analyze the kinematics and dynamics performance of children's vertical jumping. The compression time increases from 3 to 4 years old, and flight height and time increases with age and stage gradually. In the compression phase and pushing phase, the hip and knee joint play a major role; in the landing phase, the knee and ankle joint play a major role. Muscle forces are mainly affected by age, and the three types of muscle force had two different trends. The muscle force of the shank and thigh increased with age, and the pelvic girdle muscles showed an "low-high-low" trend. The regression model suggests that the force of GMiP and the hip angular velocity have a great influence on jumping ability. Therefore, if we want to improve the jumping ability of preschool children, we should pay more attention to hip exercises. We should integrate the hip exercises into interesting games, which are more in line with their physical and mental health.

Strength Training Characteristics of Different Loads Based on Acceleration Sensor and Finite Element Simulation.

Deep squat, bench press and hard pull are important ways for people to improve their strength. The use of sensors to measure force is rare. Measuring strength with sensors is extremely valuable for people to master the intensity of exercise to scientifically effective exercise. To this end, in this paper, we used a real-time wireless motion capture and mechanical evaluation system of the wearable sensor to measure the dynamic characteristics of 30 young men performing deep squat, bench press and hard pull maneuvers. The data of tibia were simulated with AnyBody 5.2 and ANSYS 19.2 to verify the authenticity. The result demonstrated that the appropriate force of the deep squat elbow joint, the hip joint and the knee joint is 40% 1RM, the appropriate force of the bench press is 40% 1RM and the appropriate force of the hard pull is 80% 1RM. The external force is the main factor of bone change. The mechanical characteristics of knee joint can be simulated after the Finite Element Analysis and the simulation of AnyBody model are verified.

Effects and molecular mechanism of pachymic acid on ferroptosis in renal ischemia reperfusion injury.

Acute kidney injury (AKI) is a common clinical disease. Ferropotosis, a new type of regulatory cell death, serves an important regulatory role in AKI. Pachymic acid (PA), a lanostane­type triterpenoid from Poria cocos, has been reported to be protective against AKI. However, the protective mechanism of PA in AKI is not yet fully understood. The present study aimed to investigate the effect and molecular mechanism of PA on ferroptosis in renal ischemia reperfusion injury in vivo. A total of 30 mice were intraperitoneally injected with 5, 10 and 20 mg/kg PA for 3 days. A bilateral renal pedicle clip was used for 40 min to induce renal ischemia­reperfusion injury and establish the model. The results demonstrated that treatment with PA decreased serum creatinine and blood urea nitrogen, and ameliorated renal pathological damage. Transmission electron microscopy revealed no characteristic changes in ferroptosis in the mitochondria of the renal tissue in the high­dose PA group, and only mild edema. Furthermore, treatment with PA increased glutathione expression, and decreased the expression levels of malondialdehyde and cyclooxygenase 2. Treatment with PA enhanced the protein and mRNA expression levels of the ferroptosis related proteins, glutathione peroxidase 4 (GPX4), solute carrier family 7 (cationic amino acid transporter, y+ system) member 11 (SLC7A11) and heme oxygenase 1 (HO­1) in the kidney, and increased the expression levels of nuclear factor erythroid derived 2 like 2 (NRF2) signaling pathway members. Taken together, the results of the present study suggest that PA has a protective effect on ischemia­reperfusion induced acute kidney injury in mice, which may be associated with the inhibition of ferroptosis in the kidneys through direct or indirect activation of NRF2, and upregulation of the expression of the downstream ferroptosis related proteins, GPX4, SLC7A11 and HO­1.

Impact of situational sport games on gross movements and social development among children aged 4-5 years old / 中国学校卫生

Objective@#To explore the impact of situational sport games on gross movement and social development among children aged 4-5 years, and to provide references for promoting the healthy development of preschool children.@*Methods@#Seventy one children aged 4-5 were randomly selected from one public kindergarten in Beijing during Apr. to Jul. of 2019 and were randomly divided into experimental group ( n =36, 8 week situational sports game intervention) and control group ( n =35, regular learning and playing). The Test of Gross Motor Development (TGMD-3) and social development scale for children aged 3-9 were used to assess gross movement and social development, respectively, which were then compared and analyzed.@*Results@#Before intervention, the total score of gross motor development[intervention group (42.63±7.62), control group (43.00±9.16)] and social development[intervention group (211.88±6.68), control group (212.71±9.80)] showed no significant differences between the two groups( t =-0.18，-0.37， P >0.05). After intervention, increases in gross motor development[intervention group (67.80±9.80), control group (45.68±9.47)] and social development level[intervention group (228.30±6.37), control group (214.71±8.65)] were observed in both groups( t =25.82，3.22；15.90，2.13， P <0.05), with gross movement and social development scores higher in intervention group than that of the control group( t =9.66，7.54， P <0.05).@*Conclusion@#8 week situational sports games can promote gross movement and social development of 4-5 year old children. It is suggested that interventions to promote early childhood development should be aware of multiple dimensions of development.

Effect of Novel Rhythmic Physical Activities on Fundamental Movement Skills in 3- to 5-Year-Old Children.

Based on traditional rhythmic physical activities (TRPA), we created novel rhythmic physical activities (NRPA). The purpose of this study was to verify the effectiveness of NRPA in improving children's fundamental movement skills (FMS). 289 children (135 boys, 154 girls) from 3 to 5 years old were randomly divided into an experimental group and a control group. Tools of Test of Gross Motor Development-2, Tekscan instrument, and balance beam were to assess children's FMS. Two-way repeated measures ANOVA was used to analyze and compare the changes in the related parameters of locomotor, manipulative, and balance movement skills before and after intervention (groups × time). NRPA performed significantly better than TRPA from pre- to posttest for FMS. Furthermore, NRPA had significantly higher posttest scores than TRPA. Therefore, NRPA could effectively promote the development of children's FMS due to the concept of the sensitive period of motor development, the variability of movement parameters, and the incomplete repeatability of practice methods.

Augmenter of Liver Regeneration Alleviates Renal Hypoxia-Reoxygenation Injury by Regulating Mitochondrial Dynamics in Renal Tubular Epithelial Cells.

Mitochondria are highly dynamic organelles that constantly undergo fission and fusion processes that closely related to their function. Disruption of mitochondrial dynamics has been demonstrated in acute kidney injury (AKI), which could eventually result in cell injury and death. Previously, we reported that augmenter of liver regeneration (ALR) alleviates renal tubular epithelial cell injury. Here, we gained further insights into whether the renoprotective roles of ALR are associated with mitochondrial dynamics. Changes in mitochondrial dynamics were examined in experimental models of renal ischemia-reperfusion (IR). In a model of hypoxia-reoxygenation (HR) injury in vitro , dynamin-related protein 1 (Drp1) and mitochondrial fission process protein 1 (MTFP1), two key proteins of mitochondrial fission, were downregulated in the Lv-ALR + HR group. ALR overexpression additionally had an impact on phosphorylation of Drp1 Ser637 during AKI. The inner membrane fusion protein, Optic Atrophy 1 (OPA1), was significantly increased whereas levels of outer membrane fusion proteins Mitofusin-1 and -2 (Mfn1, Mfn2) were not affected in the Lv-ALR + HR group, compared with the control group. Furthermore, the mTOR/4E-BP1 signaling pathway was highly activated in the Lv-ALR + HR group. ALR overexpression led to suppression of HR-induced apoptosis. Our collective findings indicate that ALR gene transfection alleviates mitochondrial injury, possibly through inhibiting fission and promoting fusion of the mitochondrial inner membrane, both of which contribute to reduction of HK-2 cell apoptosis. Additionally, fission processes are potentially mediated by promoting tubular cell survival through activating the mTOR/4E-BP1 signaling pathway.

Biomechanical study on side slip and forward slip promotion among children aged 3-5 years / 中国学校卫生

Objective@#To explore the forces of lower limbs during side slip and forward slip through biomechanical study, and to provide a theoretical basis for the development of lower limb movements.@*Methods@#BTS SMART DX motion capture analysis system, 8 infrared high-speed cameras, Kistler three-dimensional dynamometer, BTS FREEEMG 1000 portable wireless surface electromyography system were used to collect real-time data of side slip and forward slip. SPSS 20.0 univariate analysis of variance (ANOVA) was used to compare the differences of indicators between different groups.@*Results@#In the side sliding movement, there were significant differences in hip motion (P<0.01) between 3-year-old group and 5-year-old group, hip motion(P<0.01) between 4-year-old group and 5-year-old group, knee motion(P<0.05) and ankle motion(P<0.05) between 3-year-old group and 5-year-old group. There was a significant difference in hip motion(P<0.05) between 3-year-old group and 5-year-old group. The Fx force(P<0.01) and vertical Fy force(P<0.01) in the left and right directions of the 3-year-old group and the 5-year-old group were significantly different in the side-slip movement, while the Fx force(P<0.01) in the right and left directions of the 3-year-old group and the 5-year-old group were significantly different in the forward-slip movement, and the vertical Fy force(P<0.05) was significantly different. There were significant differences in the long head of biceps femoris, gastrocnemius and anterior tibial muscle between 3-year-old group and 5-year-old group (P<0.05). There were significant differences in the middle gluteal muscle, gracilis muscle, adductor magnus, pubic muscle, medial femoral muscle and soleus muscle between 3-year-old group and 5-year-old group (P<0.05). There was significant difference in the anterior tibial muscle (P<0.05) between the 3-year-old group and the 5-year-old group in the supporting stage, and significant difference in the gastrocnemius muscle(P<0.05) during the swing stage. There was significant difference in the anterior tibial muscle(P<0.05) between the 3-year-old group and the 5-year-old group in the swing stage.@*Conclusion@#The development of side slip and forward slip in children aged 3 to 5 years old showed that the results suggest motor development increases significantly with age among preschoolers. Rhythmic movements of side slip and forward slip should be selected in the critical period of children’s movement development at different ages, laying the foundation for good physical and mental development.

Augmenter of liver regeneration promotes mitochondrial biogenesis in renal ischemia-reperfusion injury.

Mitochondria are the center of energy metabolism in the cell and the preferential target of various toxicants and ischemic injury. Renal ischemia-reperfusion (I/R) injury triggers proximal tubule injury and the mitochondria are believed to be the primary subcellular target of I/R injury. The promotion of mitochondrial biogenesis (MB) is critical for the prevention I/R injury. The results of our previous study showed that augmenter of liver regeneration (ALR) has anti-apoptotic and anti-oxidant functions. However, the modulatory mechanism of ALR remains unclear and warrants further investigation. To gain further insight into the role of ALR in MB, human kidney (HK)-2 cells were treated with lentiviruses carrying ALR short interfering RNA (siRNA) and a model of hypoxia reoxygenation (H/R) injury in vitro was created. We observed that knockdown of ALR promoted apoptosis of renal tubular cells and aggravated mitochondrial injury, as evidenced by the decrease in the mitochondrial respiratory proteins adenosine triphosphate (ATP) synthase subunit ß, cytochrome c oxidase subunit 1, and nicotinamide adenine dinucleotide dehydrogenase (ubiquinone) beta subcomplex 8. Meanwhile, the production of reactive oxygen species was increased and ATP levels were decreased significantly in HK-2 cells, as compared with the siRNA/control group (p < 0.05). In addition, the mitochondrial DNA copy number and membrane potential were markedly decreased. Furthermore, critical transcriptional regulators of MB (i.e., peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, mitochondrial transcription factor A, sirtuin-1, and nuclear respiratory factor-1) were depleted in the siRNA/ALR group. Taken together, these findings unveil essential roles of ALR in the inhibition of renal tubular cell apoptosis and attenuation of mitochondrial dysfunction by promoting MB in AKI.

Balance, Proprioception, and Gross Motor Development of Chinese Children Aged 3 to 6 Years.

The authors' aim was to find the features of balance, proprioception, and gross motor development of Chinese children 3-6 years old and their correlations, provide theoretical support for promoting children's motor development, and enrich the world theoretical system of motor development. This study used a Tekscan foot pressure measurement instrument (Tekscan, Inc., Boston, MA), walking on a balance beam, Xsens 3-dimensional positional measuring system (Xsens Technologies, Enschede, the Netherlands), and Test of Gross Motor Development-2 to assess static balance, dynamic balance, knee proprioception, and levels of gross motor development (GMD) of 3- to 6-year-old children (n = 60) in Beijing. The results are as follows: children had significant age differences in static balance, dynamic balance, proprioception, and levels of GMD; children had significant gender differences in static balance, proprioception, and levels of GMD; children's static balance, dynamic balance, and proprioception had a very significant positive correlation with GMD (p < .01), but no significant correlation with body mass index.

Correlation among proprioception, muscle strength, and balance.

[Purpose] To study the correlation among proprioception, muscle strength, and balance. [Subjects and Methods] A balance testing system (Biodex Balance System, BBS) and an isokinetic testing system (Biodex System 4, BS4) were used to test related indexes in 24 healthy young females. [Results] With the knee joint at 15 degree flexion, proprioception was significantly correlated with Limits of Stability-Time values, and was highly significantly correlated with Limits of Stability-Overall and Athlete Single Leg Medial/Lateral values. The sense of force was significantly correlated with Limits of Stability-Overall and Athlete Single Leg-Overall values. Quadriceps strength was significantly associated with Limits of Stability-Overall, Athlete Single Leg Medial/Lateral, and Athlete Double Leg-Overall values. The ratio of Quadriceps to Hamstring strength was significantly correlated with Athlete Single Leg Medial/Lateral, and Athlete Single Leg-Overall values. With the knee joint at 45°, proprioception was highly significantly correlated with dynamic balance, and was significantly correlated with double foot support under static balance; force sense had a high correlation with Limits of Stability-Overall, but no correlation with other indexes. Quadriceps strength had a significant correlation with dynamic and static balance; the ratio of Quadriceps/Hamstring had a highly significant correlation with Limits of Stability-Overall, Athlete Single Leg-Anterior/Posterior and Athlete Single Leg-Overall. [Conclusion] At different knee angles, the correlation differs among proprioception, force sense, quadriceps strength, the Quadriceps/Hamstring ratio, and balance.

Study of characteristic point identification and preprocessing method for pulse wave signals.

Characteristics in pulse wave signals (PWSs) include the information of physiology and pathology of human cardiovascular system. Therefore, identification of characteristic points in PWSs plays a significant role in analyzing human cardiovascular system. Particularly, the characteristic points show personal dependent features and are easy to be affected. Acquiring a signal with high signal-to-noise ratio (SNR) and integrity is fundamentally important to precisely identify the characteristic points. Based on the mathematical morphology theory, we design a combined filter, which can effectively suppress the baseline drift and remove the high-frequency noise simultaneously, to preprocess the PWSs. Furthermore, the characteristic points of the preprocessed signal are extracted according to its position relations with the zero-crossing points of wavelet coefficients of the signal. In addition, the differential method is adopted to calibrate the position offset of characteristic points caused by the wavelet transform. We investigated four typical PWSs reconstructed by three Gaussian functions with tunable parameters. The numerical results suggested that the proposed method could identify the characteristic points of PWSs accurately.

[Risks related to disability on children aged 0-4 in China: analysis on the supporting effects from family].

OBJECTIVE: This study aimed to explore the correlated effects of family environment on children aged 0-4 who were suffered from disabilities. Economic conditions of the families and socio-economic status of the parents were also analyzed. METHODS: Based on the database from the National Sample Survey on Disability in 2006, a new database was intercepted with the information of children aged 0-4 and their parents. The total sample size was 73 394. Descriptive analysis and binary logistic regression were used to explore the effects related to family environment. Software used in statistical analysis was SPSS 16.0. RESULTS: The risks of disability started before the age of 3, and increased along with age (the odds ratios on children at 0 to 4 years old were 0.47, 0.66, 0.90, 1.56 and 1.47), which described the "cumulative" nature of prevalence levels of disability. The risk of disability among male children was higher than female (OR = 0.82). The lower the per capita household income was, the higher the risks of disability of the children (OR(≤683) = 1.80; OR(684-944) = 1.79; OR(945-2948) = 1.23; OR(2949-7254) = 0.71; OR(≥7255) = 0.34) appeared. When living together with parents under the same roof, the risk of disability was significantly correlated with their parents' schooling: literate vs. illiteracy (with father P ≤ 0.001, OR = 2.18 and mother P = 0.02, OR = 1.82). Regarding the parents elementary school education, it appeared that only on father, the result was P = 0.05, OR = 1.56. Employment status of the father was not significantly correlated with children's incidence of disability, while the mother's employment status was significant (P = 0.02, OR = 1.19). Data from the descriptive analysis showed that factors as first marriage and remarriage of the mother were significantly correlated to their children's occurrence of disability while remarriage of the father was also a significant factor. However, in multivariate analysis, both father and mother's marriage status were not significantly important. CONCLUSION: Reducing the risk of disability was important on the health of children. Among younger children, the family environment appeared to have the direct impact on the occurrence of disability.

[Virtual colonoscopy navigation based on colon division].

OBJECTIVE: To develop a virtual navigation mode to enlarge the field of view and decrease the deformation of the visual area. METHOD: The method was implemented in 3 steps. The entire colon was first divided into consecutive sections, and each section was split into two halves by a plane. The virtual camera was finally assigned onto each half of the sections for navigation. RESULTS: Adequate subsections were achieved with this method, which also offer an enlarged field of view for the benefit of focal inspection. CONCLUSION: The division navigation mode is suitable for the development of a virtual colonoscopy navigation and diagnosis system.