Relationship between lower limb muscle strength and walk speed in community dwelling older adults: the chain mediating role of flexibility and dynamic balance / 中国康复理论与实践

ObjectiveTo investigate the relationship between lower limb muscle strength and walking speed in older adults, and to analyze the mediating role of flexibility and dynamic balance. MethodsFrom November to December, 2021, a total of 155 older adults at the Shanghai Senior Sports and Health Home were included. Their basic health information was collected, and the lower limb muscle strength, flexibility, dynamic balance and walking speed were tested. A mediated effects analysis was conducted. ResultsThere was a pairwise correlation among lower limb muscle strength, flexibility, dynamic balance and walking speed in older adults (r > 0.210, P < 0.01). In the mediated effects model, after controlling for age and gender, lower limb muscle strength did not directly predict walking speed in older adults (β = 0.029, P = 0.699), however, lower limb muscle strength could influence walking speed through the partial mediation of dynamic balance (effect = 0.0130, 95% CI 0.0073~0.0197) and the chain mediation of lower flexibility and dynamic balance (effect = 0.0019, 95% CI 0.0003~0.0043). ConclusionLower limb muscle strength can indirectly affect walking speed in older adults through the mediators of flexibility and dynamic balance, or the dynamic balance alone.

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.

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 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.

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.

Effects of self-efficacy intervention on activities of daily living and outcomes in patients with acute ischemic stroke complicated with white matter lesions / 国际脑血管病杂志

Objective To investigate the effects of self-efficacy intervention on activities of daily living and outcomes in patients with acute ischemic stroke complicated with white matter lesions (WML).Methods From March 2016 to June 2017,patients with acute ischemic stroke complicated with WML admitted to the Departments of Neurology,the Second People's Hospital of Lianyungang were enrolled prospectively.They were randomly divided into intervention group and control group.The control group received routine treatment and nursing,and the intervention group implemented self-efficacy intervention on the basis of the control group.They were followed up until 90 d after onset.Stroke Self-Efficiency Questionnaire (SSEQ) was used to assess the stroke self-efficacy level.The Barthel Index (BI) was used to assess the activities of daily living (ADL) of the patients.The National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS) were used to assess the outcomes of the patients.Results The SSEQ scores in the intervention group were significantly higher than those at the time of admission and in the control group at 90 d (all P ＜0.01).The BI in the intervention group was significantly higher than that in the control group (66.51 ±22.35 vs.58.41 ±23.17;t =3.473,P =0.001),and the NIHSS score was significantly lower than the control group (5.51 ±2.98 vs.6.95 ±2.94;t =-2.094,P=0.040),and the proportion of patients with good outcomes (mRS score 0-2) was significantly higher than that of the control group (73.7％ vs.56.6％;x2 =4.896,P =0.027).Conclusion For patients with acute ischemic stroke complicated with WML,active self-efficacy intervention could improve the ADL and it was helpful to improve the outcomes of patients.

Protective effect of tanshinone ⅡA sodium sulfonate on skeletal muscle after exhaustive exercise in high temperature environment / 重庆医学

Objective To analyze the protective effect of tanshinone Ⅱ A sodium sulfonate on rat skeletal muscle after exhaustive exercise in high temperature environment.Methods Ninety rats were divided into the observation group,blank group and control group,30 cases in each group.The rats in the blank group received no intervention,while which in the observation group and control group received the exhaustive exercise intervention under high temperature environment.The rate in the control group was injected with 8 mg/kg normal saline by femoral vein at 5 h after exhaustive exercise under high temperature environment,while which in the observation group was injected with 40 mg/kg tanshinone Ⅱ A sodium sulfonate by femoral vein.The arterial blood in each group was collected by tail vein before killing the rat,and the right leg gastroc nemius muscle of each group was removed and frozen.The serum CK,LDH activity,TNF-alpha,IL-6,IL-1β,MDA,SOD and GSH-PX levels in skeletal muscles were examined.The rat skeletal muscle samples were conducted the HE staining for observing the morphological change.Results The levels of serum TNF-α,IL-6 and IL-1β and activity of CK and LDH in the observation group were significantly lower than those in the control group,while higher than those in the blank group,the difference was statistically significant (P＜0.05).The skeletal muscle MDA,SOD and GSH-PX levels had statistical difference between the observation group and other two groups (P＜0.05).The skeletal muscle structure was disordered,and the distribution of muscle nuclei was uneven.The structure of rat skeletal muscle in the blank group was normal,and the muscle nuclei were evenly distributed.The morphology and structure of skeletal muscle in the observation group were normal,but the distribution of muscle nuclei was slightly uneven.Conclusion Tanshinone Ⅱ A sodium sulfonate can effectively protect skeletalmuscle after exhaustive exercise inhigh temperature environment.

Prospective epidemiological study on the adults of lower respiratory tract infection with haemophilus influenzae in Chengdu area / 中华检验医学杂志

Objective To investigate the epidemic strains of biological type, drug resistance, and the basic clinical characteristics of haemophilus influenzae(Hi)isolated from hospitalized adults with lower respiratory tract infection in Chengdu area.Methods A prospective cross-sectional study was conducted to analyze the biological typing,capsular genes detected by PCR technique,and drug resistance tested by drug sensitive test of Hi epidemic strains isolated from the sputum of adults aged above 18 years who were hospitalized in two tertiary hospitals of west Sichuan in China.Results The positive rate of pathogenic bacteria in adults aged above 18 years who were hospitalized in the two hospitals was 46.71%(15 447/33 069)between November 2013 and October 2014.The positive rate of Hi isolated from the sputum of 100 adults with lower respiratory tract infection was 0.31%(101/33 069).The constituent ratio of Hi in lower respiratory tract infection pathogens was 0.65%(101/15 447).The Hi were all undifferentiated type detected by PCR,and the biological typing of Hi were typeⅠ(42.57%),Ⅳ(29.7%),Ⅱ(15.84%),Ⅲ(9.9%),Ⅶ(1.98%), and Ⅵ(0.9%).The diseases of Hi positive were acute phase of chronic obstructive pulmonary disease(59%), pneumonia(35%), and bronchitis(6%), in which community acquired infection was 55%.The rate of β-lactamase enzyme production was 38.61%.The frequencice of β-lactamase -nonproducing-ampicillin-resistant(BLNAR)strains was 2.97%,and of intermediary strains was 4.95%(5/101).The drug resistance rate of amoxicillin and clavulafiate was 2.97%.The drug resistance rate of cefuroxime was 12.87%, and intermediary rate was 12.87%.The drug resistance rate of cefaclor was 29.7%,and intermediary rate was 8.91%.The drug resistance rate of cefotaxime and ofloxacin was 6.93%and 1.99%.There were no obvious statistical differences between the drug resistance rates of the two hospitals.Conclusions The Hi epidemic strains isolated from the sputum of adults with lower respiratory tract infection were all undifferentiated type,and the common biological types were Ⅰ,Ⅳ,Ⅱ, andⅢ in west Sichuan in China.It should pay attention to the BLNAR strains and ofloxacin-resistant strains.

Study of characteristic point identification and preprocessing method for pulse wave signals / 生物医学工程学杂志

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.

Progress in visualization of MR diffusion tensor imaging / 生物医学工程学杂志

MR diffusion tensor imaging (DT-MRI) is a new technology which reflects the direction of molecule diffusion better than traditional diffusion weighted imaging (DWI) does. DT-MRI has great advantages of showing the distribution of white matter fiber path and its spatial structures because the water molecules in brain white matters have the obvious anisotropic diffusion. This paper introduces the basics of diffusion tensor imaging, and reviews the visualization methods used with DT-MRI.

A Novel Automatic Registration Method for Serial Brain Images / 中国医学物理学杂志

Registration of serial images plays an increasingly important role in medicine. A novel registration method used for serial images matching is proposed, which is based on the joint histogram. After thresholding the two images to be registered, the joint histogram is divided into four separate regions. Then the criterion function is defined as bin counting in a specific region of the joint histogram, which simplifies the computation of the criteria function greatly and speeds up the alignment process significantly. We choose the Powell optimization algorithm to calculate the registration parameters. The comparison of the results from both mutual information and our method shows that the new method based on segmentation and counting is a fast, simple, efficient and accurate registration method.

Registration and 3D rendering of serial tissue section images / 生物医学工程学杂志

It is an important morphological research method to reconstruct the 3D imaging from serial section tissue images. Registration of serial images is a key step to 3D reconstruction. Firstly, an introduction to the segmentation-counting registration algorithm is presented, which is based on the joint histogram. After thresholding of the two images to be registered, the criterion function is defined as counting in a specific region of the joint histogram, which greatly speeds up the alignment process. Then, the method is used to conduct the serial tissue image matching task, and lies a solid foundation for 3D rendering. Finally, preliminary surface rendering results are presented.

Digitalization of Ordinary Gastrointestinal Machine / 医疗卫生装备

Objective To upgrade ordinary gastrointestinal machine to a digital one which can be connected to PACS.Methods By adding extra camera lens,frame grabber and processing software,ordinary gastrointestinal machine was transformed.Results The updated machine could work in digital way with fully DICOM support.Conclusion By analyzing the X-ray imaging chain,a digitalization method of gastrointestinal machine is presented,which can server as a guideline to digital transformation of non-digital X-ray machines.

Application Research on High-Volt Generator of Mobile Photon Radiation Therapy System / 医疗卫生装备

Objective To design and develop a high-volt generator for mobile photon radiation therapy system's X-ray tube. Methods With a 12V storage battery as the power supply, high-frequency switch circuit and CW voltage doubling rectifying circuit were adopted to generate high voltage. Results Its main circuit was tested by using a simulation software, and it could meet the desired requirements. Conclusion The circuit is simple and reliable, and thus can be miniaturized.