Influence of different tasks on gait characteristics and task cost in early childhood / 中国康复理论与实践

ObjectiveTo investigate the influence of interference tasks and age on gait characteristics and task costs of children aged three to eight years. MethodsFrom April to August, 2021, 200 children from a kindergarten and primary school in Cangzhou, Hebei were enrolled to collect gait spatiotemporal parameters and kinematics data with infrared motion capture system; ground reaction force was collected with the Kistler force platform and simulated with Anybody 7.0, as walking naturally (standard gait), answering question (cognitive gait) and crossing obstacle (obstacle-crossing gait). ResultsA total of 182 children finished the test. The main effect of task was significant on spatiotemporal parameters (F > 5.167, P < 0.01), as well as age (F > 2.321, P < 0.05), except on stride width and speed; while the interaction effect of task and age was significant on double stance phase, single stance phase and step length (F > 3.040, P < 0.01). The main effect of task was significant on kinematics data (F > 83.019, P < 0.001), as well as age (F > 2.359, P < 0.05), except on range of motion of knee and maximum angular velocity of ankle; while the interaction effect of task and age was significant (F > 2.066, P < 0.05), except on range of motion of hip. The main effect of task and age was significant on kinetic parameters (F > 4.032, P < 0.05); while the interaction effect of task and age was significant (F > 2.189, P < 0.05), except on the strength of medial soleus, lateral gastrocnemius, medial gastrocnemius and tibialis anterior. The coefficient of variation was the most for cognitive gait, and then for the obstacle-crossing gait and standard gait. The main effect of task and age was significant on the cost of task for stride length and speed (F > 3.368, P < 0.01), while the interaction effect was not significant. ConclusionGait of early childhood is influenced by interference tasks and age. Under interference tasks, gait cycle increases, while single stance phase, stride length, frequency and speed decrease; and task costs increase, and overall gait stability decrease. Cognitive tasks impact on gait greater than obstacle crossing, which may be due to the higher costs of tasks. In terms of age, gait exhibits a non-linear age trend.

Biomechanical Characteristics of Lower Limbs for the Youth with Different Body Mass Index Performing Baduanjin Exercise Based on AnyBody Simulation / 医用生物力学

Objective To compare the biomechanical characteristics of lower limbs of young people with different body mass index (BMI) before and after the intervention of Baduanjin exercise, so as to provide references for scientific exercise and sport prescription for young Baduanjin practitioners with different BMIs. Methods Young volunteers with different BMI were divided into standard group, overweight group and obesity group. The BTS SMART 3D infrared motion capture system was used to capture the motion parameters and electromyography (EMG) parameters, the KISTLER dynamometer was used to collect the dynamic parameters, the AnyBody simulation software was used to calculate the kinematic parameters and dynamic parameters, and BTS SMART Analyzer was used to compare the different integral electromyography values. Results There was no significant difference in each parameter before the intervention of Baduanjin. After the intervention, the angle and angular velocity of the knee joint during extension and flexion in standard group, overweight group and obesity group, and the angular acceleration of the knee joint during extension and flexion in standard group significantly increased. Baduanjin significantly increased the knee flexion force and moment in standard group, overweight group and obesity group, and increased the hip flexion force and moment as well as ankle metatarsal flexion force and moment in standard group. Compared with obesity group, the knee flexion force and moment in standard group were significantly different. The knee joint force and moment were positively correlated with BMI. Baduanjin significantly increased muscle strength of iliopsoas, gluteus medius, piriformis, gluteus maximus, rectus femoris, sartorius, tibialis anterior, biceps femoris longhead, flexor digitorum longus, flexor pollicis longus, musculus peroneus longus and musculus peroneus brevis. Baduanjin significantly increased the integrated electromyogram (iEMG） of rectus femoris, tibialis anterior, biceps femoris. Conclusions Baduanjin can improve muscle strength and neuromuscular control ability of young people. The larger the BMI, the greater the flexion force and moment of the knee joint.

Characteristics of Different Tai Chi Step Types Based on AnyBody Simulation / 医用生物力学

太极拳； AnyBody仿真； 下肢； 动力学； 运动学

Biomechanical Characteristics of Lower Limbs of Yoga Posture Based on AnyBody Simulation / 医用生物力学

Objective The single leg support tree pose and Yan balace of yoga was selected to compare the biomechanical characteristics of lower limb joint angles, joint force and muscle strength for professional and non-professional yoga practitioners, so as to provide theoretical basis for scientific fitness of yoga beginners and exercise prescription determined by rehabilitation physicians. Methods BTS infrared motion capture system was used to collect kinematic data, Kistler forceplate was used to collect dynamic data, AnyBody 7.0 simulation software was used to calculate the joint force and muscle strength, and Biodex balance system was used to evaluate the stability of single support. Results In both tree pose and Yan balance, the muscle strength of lower limbs in professional group was greater than that in non-professional group. Support leg of tree pose: the muscle strength of the tibialis anterior, gluteus medius posterior, iliac medialis and sartorius in professional group was greater than that in non-professional group (P<0.05). Balance leg of tree pose: the muscle strength of the biceps femoris breve, sartorius, piriformis, gemellus inferior, iliac lateralis, iliac medialis, gluteus maximus inferior, obturator internus in professional group was greater than that in non-professional group (P<0.05). Support leg of Yan balance: the muscle strength of tibialis anterior, extensor digitorum longus, extensor hallucis longus, obturator internus, gluteus maximus superior in the professional group was greater than the non-professional group (P<0.05). Balance leg of Yan balance: The muscle strength of extensor hallucis longus in professional group was greater than that in non-professional group (P<0.05). The scores of front-rear, overall of PS-BI, overall, front-rear, left-right of athlete single leg (ASL) in professional group were significantly lower than those in non-professional group (P<0.05). Conclusions The joint angle will affect the degree of muscle exercise in lower limbs. During yoga practice, attention should be paid to the standard of postures and the exercise of corresponding muscles. In tree pose, the muscle strength of both legs in non-professional group was significantly different from that in professional group, and the difference in Yan balance was more obvious on the supporting leg. Yoga practice can improve the stability of single leg support in multiple directions.

Differential Analysis of Mutation of Fibroblast Cells Before and After Cadmium Treatment / 医学研究杂志

Objective Because in the environment there are many compounds to cause variation of cells, the study for high sensitivity’s method in which the variation of cells by environment can be tested is necessary. For example, the reports of detailed study for the application of cadmium on the human body cell’s lethal toxicity and the variation of cells are very few. This research is about a high sensitivity method of heavy metal cadmium’s variation active processed by cadmium in which the variation of cells can be tested by ultraviolet ray. Methods The study used cultured cells of human being and derivation. The assay of mutagenicity OuaR (Ouabain resistance) variation used picking law and Differential dot-blot of cancer gene K-ras variation the hybridization examination method. In order to test the induction’s frequency of cell variation, MTT (methyl thiazolyl tetrazoliun) and survival efficiency of formation were tested. The clarifing of mutagenicity mechanism used Western blot and the siRNA method to analysis the molecular of heat shock protein. Results Cadmium clarifiing mutagenicity variation detection had the same degree with the method of ultraviolet ray. The DNA was injury corresponding to the HSP27 protein cell’s change.The cell variation frequency also presented the high value. Conclusion Human fibroblasts in the role of the heavy metal cadmium showed that HSP27 protein expression in high-UVr-1 cells RSa has lowor-frequency variations than OuaR cells. K-ras dot blot method proved that RSa cells variation is higher than the cells UVr-1 mutation. In siHSP27 cells, we observed OuaR high variability of expression. Cadmium on DNA damage showns UVr-1 fibroblast cell is lower than RSa fibroblasts cell.