Impaired motor control after sport-related concussion could increase risk for musculoskeletal injury: Implications for clinical management and rehabilitation

This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion(SRC)to increased risk for musculoskeletal injury.Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts.A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk.Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task.Motor control is inclusive of motor planning and motor learning.If sensory information is not accurately perceived or there is interference with sensory information processing and cognition,motor function will be altered,and an athlete may become vulnerable to injury during sport participation.Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria,including a normal neurological examination,resolution of symptoms,and return to baseline function on traditional concussion testing.In conjunction,altered motor function is demonstrated after SRC in muscle activation and force production,movement patterns,balance/postural stability,and motor task performance,especially performance of a motor task paired with a cognitive task(i.e.,dual-task condition).The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum.     

油田远程智能电机群控系统的研究

抽油机是石油开采中必须使用的设备,而电动机又是抽油机不可或缺的重要部分。根据电机在油田生产中的使用情况,采用无线电机群控系统方案,用于监测、保护和控制电机。本文对智能电机监控器的基本功能如电机参数的采集、电机保护、输出控制、数据传输等电路的设计原理和控制软件设计方法作了详细的阐述和认真的研究。     

Parents' views of the efficacy of conductive education in Sweden

Parents of children who have participated in a conductive education programme in Sweden were asked questions about their reasons for choosing the programme, the expectations they had of it and how they were fulfilled. The results showed that the parents were satisfied with the development of their child, and wanted to continue to take part in further courses with their child. They appreciated the intensive training and found it motivating and enjoyable for the child. They wanted an intensive training for their child because they believed that active training could help the child to develop. The parents learned more about cerebral palsy at the courses and now understood why and how they could train their child. Most of the parents continued the training at home with the child. They experienced financial difficulties in participating in further courses, and found it difficult to stay away from work and family for a long period of time.     

基于交-交变频技术实现异步电动机重载起动的研究

为解决异步电动机重载起动存在的不足,提出了一种以80C196KC DSP为控制技术的交-交变频系统的实现方法.该方法具有起动电流小、启动转矩大、启动平滑、运行稳定、控制效果好的特点,详细阐述系统主电路及控制部分的原理和实现方法.     

基于ARM的电机动态参数检测与处理系统设计

电机运行时会产生各种电磁和共模干扰,影响电机参数的准确获取。传统的电机参数检测方法不能充分滤除现场出现的各种干扰信号,从而增大测量误差,影响测量参数的准确性。为此,本文设计了一种实用的干扰抑制技术,大大提高了测量参数的准确性和精确性。最后通过GSM／GPRS无线网络数字传输技术,将下位机采集到的电机参数发送给上位机中心专家诊断端系统,进行在线实时故障诊断和排除。     

我国赛艇运动员专项知觉运动技能研究

通过问卷调查对全国13个省市476名赛艇运动员的专项知觉运动技能现状进行分析。结果发现:我国赛艇运动员的专项知觉运动技能总体水平较好,其中自身体能状态知觉运动技能水平最高,艇音知觉运动技能水平最低;男性运动员的艇平衡知觉运动技能和划桨动作状态、桨力状态知觉运动技能高于女性;大学及以上学历运动员、健将级运动员的专项知觉技能普遍优于其他学历水平和运动等级的运动员。     

基于虚拟仪器的计算机控制步进电机系统的设计

在扫描探针显微镜系统中,本文采用基于虚拟仪器的计算机控制步进电机,控制它的正转、反转及启动和停止,从而实现样品与探针的自动逼近。利用计算机通过I/O接口来直接产生各种方波信号,采用L abV IEW编程完成控制算法,以此来实现步进电机运动,提高了逼近系统的自动化性能和控制精度。     

Effectiveness of physical education to promote motor competence in primary school children

Background: Motor skill (MS) competence is an important contributing factor for healthy development.

Purpose: The goal was to test the effectiveness of primary school physical education (PE) on MS and physical fitness (PF) development.

Methods: Three classes (n?=?60, aged 9.0?±?0.9) were randomly assigned to three diverse conditions during a school year: two PE lessons/week (PE-2), three PE lessons/week (PE-3), and no PE lessons control group (CG). BMI, skinfolds, PF (9-min run/walk, sit-up, modified pull-ups), gymnastics, soccer, handball, basketball and track-and-field skills were evaluated. Effect sizes (d) were reported as magnitude of change.

Results: Skinfolds significantly increased only in CG (d?=?1.21). PF composite z-scores improved in PE-3 (d?=?0.61), but decreased in PE-2 (d?=?0.57), and had no changes in CG. Statistically significant improvement was verified in gymnastics and handball skills in both experimental groups (gymnastic: d?=?2.95 and d?=?2.61 for PE-3 and PE-2, respectively; handball: d?=?1.87 and d?=?0.57 for PE-3 and PE-2, respectively), and no changes were seen in CG. In soccer, there were improvements only in the PE-3 (d?=?0.55), and in basketball only in PE-2 (d?=?0.46). There were no changes in any group for track-and-field skills.

Conclusions: PE programs can effectively promote PF and MS development.     

基于V-M双闭环直流调速系统设计

本文采用转速—电流双闭环对一台直流电机进行调速控制,通过工程设计方法,将电流环设计为典型一阶系统,将转速环设计成典型二阶系统。通过测试,可以达到良好的启动性能,实现设定目标D=5,无静态误差;S≤5%,δn%≤10%,δi%≤5%。     

变频电机基于状态维护的研究与探讨

讨论了电机温度日常管理与维护,对电机温度进行了统计,绘制了趋势图,使用统计方法验证了环境温度变化对电机温度的影响关系,预测了维护时间,提出了维护策略,对于减少电机温度过高造成的事故风险有较大帮助。