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ObjectiveTo explore the correlation among knee hyperextension angle, lower limb joints kinematics parameters and the activation of main muscles of lower limb in stroke hemiplegic patients with knee hyperextension during walking. MethodsFrom August, 2020 to September, 2021, 24 stroke hemiplegic patients with knee hyperextension and 24 healthy subjects matched with sex, age, height and body mass with knee hyperextension were analyzed with three-dimensional gait analysis system and the wireless surface electromyography acquisition system, to record the range of motion of pelvis, hip, knee and ankle joints in sagittal plane, and the activation of bilateral gluteus maximus, biceps femoris, vastus medialis and gastrocnemius medialis. ResultsAs the maximum of knee hyperextension, range of motion of the joints in sagittal plane and the activation of the muscles were different between the patients and the healthy subjects during the single-support phase of walking (|t| > 3.080, P < 0.01), and the maximum of knee hyperextension correlated with the activation of gluteus maximus in the patients (r = -0.532, P < 0.01), and the range of motion of ankle plantar flexion in both the patients and the healthy subjects (r > 0.686, P < 0.001). ConclusionThe correction for knee hyperextension gait in stroke hemiplegic patients may not only need to pay attention to knee joint control, but also need further treatment of ankle control and hip muscle function.
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Background Essential and non-essential elements have an important impact on the development of the central nervous system during fetal development. Due to their less developed brain, preterm infants are more sensitive to element exposure, and are high-risk groups of neurodevelopmental abnormalities. However, it is not clear whether the effects of element exposure in utero on postpartum neurodevelopment are different between full-term infants and preterm infants. Objective To evaluate the effects of element exposure levels during pregnancy on neurodevelopment of children aged 6-24 months (of corrected age), and compare the effects between preterm and full-term children. Methods A prospective study design was adopted and this study was conducted based on the Maoming Birth Cohort Study (MBCS) in Maoming City, Guangdong Province. Twenty elements in cord blood of 197 preterm infants and 297 full-term infants were measured, including 11 essential trace elements [vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), strontium (Sr), tin (Sn), and iron (Fe)], and 9 non-essential trace elements [aluminum (Al), arsenic (As), thallium (Tl), lead (Pb), uranium (U), cerium (Ce), antimony (Sb), cadmium (Cd), and yttrium (Y)]. The neurodevelopment of the children at 6, 12, and 24 months were evaluated by the Ages and Stages Questionnaires-the Third Edition (ASQ-3). A generalized estimating equation (GEE) model was adopted to evaluate the associations between elements and neurodevelopment in full-term and preterm children separately. Results The positive rates of 10 elements (Mn, Cu, Zn, Se, Sr, Fe, Sb, Tl, Pb, and As) in cord blood were greater than 80%. Among the preterm birth children, the results of GEE analysis showed that after adjusting for the covariates, for each increase of interquartile range (IQR) in ln-transformed concentration, As was associated with problems/delay in the communication and problem-solving sub-scales, with the adjusted odds ratios (OR) and 95% confidence intervals (CI) of 1.36 (1.03-1.80) and 1.55 (1.10-2.20), respectively; the adjusted OR (95%CI) of problems/delay in the fine motor and problem-solving sub-scales were 1.44 (1.00-2.07) and 1.76 (1.09-2.84) for Sb, respectively; the adjusted OR (95%CI) of problems/delay in the communication sub-scale was 1.37 (1.09-1.74) for Se. No statistically significant associations between umbilical cord blood element concentrations and neurodevelopment indicators were observed among full-term children. The results of stratified analysis by sex showed that the associations between umbilical cord blood element concentrations and neurodevelopment problems/delay were only significant among female preterm children. Conclusion Exposures to As, Se, and Sb during pregnancy may increase the risk of neurodevelopment problems/delay in preterm children aged 6-24 months, and female seem to be more vulnerable.
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Objective@#To evaluate the association of long-term ambient fine particulate matters (PM2.5) exposure with elevated blood pressure in children.@*Methods@#From April 2012 to June 2013, we used cluster randomized sampling method to investigate 9 354 children aged 5-17 years old from 68 primary and middle schools in the seven Northeastern Cities (Shenyang, Dalian, Fushun, Anshan, Benxi, Liaoyang and Dandong) in Liaoning Province, and measured their blood pressure (BP). A spatial statistical model nested by aerosol optical depth (AOD) was used to inverse PM2.5 concentrations. Generalized additive model was used to quantify the association between PM2.5 exposure and blood pressure in children. To examine the associations, two-level regression model was used to evaluate individual characteristics′ modifying effect on the health influence of PM2.5.@*Results@#The prevalence of hypertension in children was 13.78% (1 289/9 354). The results showed that there was an associations between hypertension and pollutants, and the multivariable regression analysis indicated that the increase in mean systolic blood pressure (SBP), diastolic blood pressure (DBP), and the OR of hypertension associated with a 10 μg/m3 increase for PM2.5 were 3.12 (95%CI: 2.71-3.54) mmHg (1 mmHg=0.133 kPa), 1.45 (95%CI:1.12-1.78) mmHg, and 1.55 (95%CI: 1.10-2.19), respectively. Compared with non-breastfeeding children (OR=2.10, 95%CI: 1.39-3.17), children who were breastfeeding (OR=1.49, 95%CI: 1.00-2.20) exhibited consistently weaker effects, and the interaction effect of P value was 0.002.@*Conclusion@#Study findings indicate that long-term exposure to PM2.5 is associated with increased arterial BP and hypertension among the children. Breastfeeding may reduce this association.