The Relationship Between Balance Confidence and Cognitive Motor Interference in Individuals With Multiple Sclerosis

The authors examined and compared the development of oral and manual force control in preschool-aged children. In all, 50 typically developing children (aged 3-5 years) performed maximal strength tasks and submaximal visually guided tasks using tongue elevation, power, and precision grips. Dependent measures included strength, rate of force rise, initial force overshoot, force variability, and rate of force release. The authors performed age- and performance-related analyses. Results revealed similar changes for tongue, fingers, and hands across age- and performance-related measures for strength, initial force overshoot, and rate of force release. There were no significant changes in rate of force rise with increasing age. Force variability measures showed effector-specific changes with decreases across age- and performance-related measures for the hands and fingers but not for the tongue. Changes common across effector systems likely reflect biological development coupled with cognitive-strategic development. Effector-specific changes in force variability likely reflect experience gained through functional tasks influencing biological and cognitive-strategic development. Lack of change in force variability of the tongue suggests that fine control of the tongue is activity specific; thus, nonfunctional tasks are not likely to be sensitive to experience-related biological development.     

Grasp-Based Functional Coupling Between Reach- and Grasp-Related Components of Forelimb Muscle Activity

How are appropriate combinations of forelimb muscles selected during reach-to-grasp movements in the presence of neuromotor redundancy and important task-related constraints? The authors tested whether grasp type or target location preferentially influence the selection and synergistic coupling between forelimb muscles during reach-to-grasp movements. Factor analysis applied to 14–20 forelimb electromyograms recorded from monkeys performing reach-to-grasp tasks revealed 4–6 muscle components that showed transport/preshape- or grasp-related features. Weighting coefficients of transport/preshape-related components demonstrated strongest similarities for reaches that shared the same grasp type rather than the same target location. Scaling coefficients of transport/preshape- and grasp-related components showed invariant temporal coupling. Thus, grasp type influenced strongly both transport/preshape- and grasp-related muscle components, giving rise to grasp-based functional coupling between forelimb muscles.     

Motor Behavior Concepts in the Study of Balance: A Scoping Review

Abstract

Previous research suggests that using Fitts’ law; attentional focus or challenge point framework (CPF) is beneficial in balance control studies. A scoping review was conducted to examine studies that utilized these motor behavior concepts during balance control tasks. An extensive literature search was performed up to January 2018. Two independent reviewers conducted a study selection process followed by data extraction of the search results. Forty-six studies were identified, with 2 studies related to CPF, 12 studies related to Fitts’ law and 32 studies related to focus of attention. The CPF appears to be a useful method for designing a progressive therapeutic program. Fitts’ law can be used as a tool for controlling the difficulty of motor tasks. Focus of attention studies indicate that adopting an external focus of attention improves task performance. Overall, studies included in this review report benefit when using the selected motor behavior concepts. However, the majority (>80%) of studies included in the review involved healthy populations, with only three clinical trials. In order to ascertain the benefits of the selected motor behavior concepts in clinical settings, future research should focus on using these concepts for clinical trials to examine balance control among people with balance impairments.     

Head and Trunk Control While Walking in Older Adults with Diabetes: Effects of Balance Confidence

Investigations of gait in older adults with diabetes mellitus (DM) have been primarily focused on lower limb biomechanical parameters. Yet, the upper body accounts for two thirds of the body's mass, and head and trunk control are critical for balance. The authors examined head and trunk control during self-selected comfortable, fast, and dual-task walking and the relationship between balance confidence and potential head-trunk stiffening strategies in older adults with DM without diagnosed diabetic peripheral neuropathy (DPN). Twelve older adults with DM without diagnosed DPN (DM group) and 12 without DM (no-DM group) were recruited. Walking speed, peak-to-peak head and trunk roll displacement, head and trunk roll velocity, and head-trunk correlation were measured while walking at a self-selected comfortable or fastest possible speed with or without a secondary cognitive task. The Activities-specific Balance Confidence scale measured balance confidence. Subtle group differences in axial segmental control (lower trunk roll velocity; higher head-trunk correlation) were apparent in older adults with DM even in the absence of DPN. Balance confidence was 19% lower in the DM group than in the no-DM group, and partially explained (34%) the group difference in head-trunk stiffening. These results emphasize the need for proactive monitoring of postural control and balance confidence before the onset of DPN.     

Relationship Between Balance Recovery From a Forward Fall and Lower-Limb Rate of Torque Development

Abstract

The authors examined the relationship between the maximum recoverable lean angle via the tether-release method with early- or late-phase rate of torque development (RTD) and maximum torque of lower-limb muscle groups in 56 young healthy adults. Maximal isometric torque and RTD at the hip, knee, and ankle were recorded. The RTD at 50-ms intervals up to 250?ms from force onset was calculated. The results of a stepwise multiple regression analysis, early RTD for hip flexion, and knee flexion were chosen as predictive variables for the maximum recoverable lean angle. The present study suggests that some of the early RTD in the lower limb muscles, but not the maximum isometric torque, can predict the maximum recoverable lean angle.     

Balance Performance During Perturbed Standing Is Not Associated With Muscle Strength and Power in Young Adults

The authors investigate the ways in which varied postural responses to translating platform perturbations are associated with the variables of strength and power. Twenty-four physically active and 27 sedentary young adults were exposed to a set of postural perturbations at varied velocities (10 and 20 cm/s) and the respective accelerations (6.4 and 6.9 m/s²), constant distance (6 cm), and 4 directions of platform motion (forward, backward, left-lateral, and right-lateral). They also performed maximum voluntary isometric contraction (MVC) and chair rising/chair jumping tests. The analysis of variance revealed significant interaction effect for peak center of pressure displacement, direction by velocity: F_3,129 = 24.43, p = .002; and direction by acceleration: F_3,129 = 34.18, p = .001. There were no significant correlations between peak center of pressure displacements and peak force and peak rate of force development measured during MVC in either standing (r = .27–57) or sitting positions (r = .12–51) and peak power during chair jumping (r = .47–.59) in all participants. As such, only a small proportion of variance was explained (9–39%, 3–23%, and 23–41%, respectively). In conclusion, interaction effects indicate that the composition of stimuli strongly influences compensatory responses and this effect is more pronounced in sedentary than in physically active young adults. Nevertheless, the dynamic balance is not associated with muscle strength and power in either group.     

Y-Balance Test Performance and Leg Muscle Activations of Children with Developmental Coordination Disorder

This study compared Lower Quarter Y-Balance Test (YBT-LQ) performance and leg muscle kinetics between children with and without developmental coordination disorder (DCD), and investigated the association between YBT-LQ performance and muscle kinetics in children with DCD. Forty-eight children with DCD and 51 children without DCD participated in the study. Leg muscle kinetics were measured using surface electromyography when performing YBT-LQ. Children with DCD exhibited an overall lower YBT-LQ scores than controls. They had a lower peak gastrocnemius medialis activation for YBT-LQ posteromedial direction and shorter duration for the muscle to reach peak torque for YBT-LQ anterior direction. No relationship was found between YBT-LQ performance and leg muscle activations in children with DCD. Children with DCD exhibited a less competent YBT-LQ performance with atypical neuromuscular control.     

The Influence of Contraction Types on the Relationship Between the Intended Force and the Actual Force

Abstract

It has been demonstrated that the intended force (subjective estimation of force) does not always match to actual force without external feedback. The purpose of this study was to compare the influence of ballistic and tonic contractions on the relationship between the intended and actual force. Subjects produced isometric force at requested percentages of their MVC (20, 40, 60 and 80%) based on subjective estimation of force under two conditions (tonic and ballistic conditions). The tonic condition was to maintain force production, whereas the ballistic condition was to produce force as fast as possible. As a result, the actual force amplitude, the coefficient of variance and EMG amplitude were larger under the ballistic contraction compared with the tonic condition, even the same intended force levels. These results suggest that different motor unit activity and control systems in the ballistic and tonic contractions could alter the relationship between the intended force and the actual force.     

儿童社交问题解决与其社交地位关系的初步研究

本研究初步考察了小学儿童的社交问题解决与其社交地位的关系。采用访谈法研究了小学儿童在发动交往、维持交往和解决冲突三种情境中的社交问题解决。结果发现,不同社交地位的儿童对社交目标的选择并无显著差别;而在发动交往时,被拒绝儿童更倾向于借助他人帮助。被忽视和被拒绝儿童比正常儿童更少选择言语沟通和解释策略。被忽视儿童发动交往的有效性低于其他儿童,被拒绝儿童解决冲突的适当性低于受欢迎儿童和一般型儿童。     

Postural Balance Following Aerobic Fatigue Tests: A Longitudinal Study Among Young Athletes

General fatigue can cause aggravation of postural balance, with increased risk for injuries. The present longitudinal study aimed to evaluate the postural balance of young athletes following field aerobic tests throughout 1 year of training. Thirty children from a sports center in Nazareth, participating in a 3 times/week training program (specific to basketball, soccer, or athletic training), were assessed. Postural balance parameters were taken before, immediately after, and 10 min after a 20 m shuttle-run aerobic test, at 3 time points during 1 training year (Start/Y, Mid/Y, and End/Y). Fitness improved at the Mid/Y and End/Y compared to Start/Y. Postural balance significantly deteriorated immediately after the aerobic test and improved significantly in the 10-min testing in all 3 time points, with significant deterioration in the End/Y compared with the Start/Y. In conclusions, postural balance deteriorates immediately after aerobic exercises, and at the end of the year. To better practice drills related to postural balance and possibly to prevent injuries, it is best for young athletes to properly rest immediately following aerobic exercises and to practice postural balance mainly at the beginning and at the middle of the training year.     

医护人员工作倦怠与A型人格、控制点的关系研究

通过对320名医护人员的调查,探讨工作倦怠与A型人格,控制点之间的关系。结果表明：(1)情绪疲惫、去人性化与A型人格、控制点存在显著正相关,个人成就感与控制点存在显著负相关。(2)A型人格、控制点对情绪疲惫,去人性化具有正向预测作用,控制点对个人成就感具有负向预测作用。(3)与B型人格相比．A型人格者的去人性化程度更高;与内控者相比,外控者工作倦怠程度更高。     

The Connection Between Happiness and Service Businesses: A Preliminary Study

Happiness may be one of the most important goals that many people pursue in the world. This study adopts a qualitative approach to investigate the determinants of happiness for Taiwanese/Chinese people. Further, we investigate related service opportunities for happiness via a field survey of 808 respondents. This study identifies four happiness segments for people in Taiwan/China: Influential & Outgoing, Adequately Settled, Pleasure Seeking, and Young & Restless. These four happiness segments differ markedly in terms of characteristics and potential service opportunities. The findings of this study have implications for researchers who are seeking to understand happiness in an Asian country.     

人格坚韧性与健康关系的研究

坚韧性是一丛能够保护个体免于应激伤害的人格特质,包括承诺．控制和挑战三部分内容。KobaSa提出了两个不同的坚韧性与健康关系的理论模型,用以解释坚韧性与健康之间的关系。随后的许多研究证实了坚韧性对于健康的主效应,但是坚韧性的调节作用未能得到良好的支持。最后,文章对坚韧性研究的现状进行了简要评述,并指出了未来的研究方向。     

PDP启动型实验程序与Richardson-Klavehn模型的比较研究

2个实验对PDP的启动型实验程序与Richardson-Klavehn的修正模型进行了比较研究,通过对指示语的操纵,考察提取策略是否完全受意志控制,以及注意水平、刺激材料、测验类型、加工水平对被试作业的影响.结果发现刺激材料对有意识控制记忆的实验结果影响很大,对PDP的无意识自动加工参数无影响;启动型实验程序的结果与PDP理论相当一致;提取策略不一定是受意志精确控制的.     

A Preliminary Investigation of the Relationship Between Fluency and Application for Multiplication

Research suggests component skill performance has a strong positive relationship with composite skill performance. This study examined the association between accuracy and fluency for the component-composite relationship within multiplication. One hundred and fifty-seven fifth-graders did one-minute assessments for single-digit, and multi-digit multiplication problems. The results demonstrated the students achieved high levels of accuracy but low levels of fluency. Strong correlations between the component-composite skill fluency suggest that fluent component skills may have a significant role in composite skill performance. Moderate/low correlations between component and composite skill accuracy indicate that more than one skill component may contribute to composite skill acquisition.     

父母自主支持、父母心理控制和青少年网络成瘾的关系：一项交叉滞后研究

对1222名青少年进行六个月的追踪测查,以探讨父母自主支持、父母心理控制和青少年网络成瘾之间的相互预测关系。结果表明：（1）前、后测父母自主支持均与网络成瘾呈负相关。（2）前、后测父母心理控制均与网络成瘾呈正相关。（3）前测父母自主支持可以预测后测网络成瘾,前测网络成瘾也可以预测后测父母自主支持。（4）前测父母心理控制可以预测后测网络成瘾,但前测网络成瘾不能显著预测后测父母心理控制。本研究揭示了父母因素与青少年行为之间的相互作用,这对改善青少年网络成瘾有一定的实践意义。     

组织类型与员工建言行为的关系探索：基于权力的视角

研究目的是探索中国背景下国有企业、民营企业、外资企业、政府机关四类组织中员工建言行为的差异,及员工个人权力感和权力动机的中介作用。采用问卷法对员工和管理者进行配对取样调查,通过对回收的324份有效问卷进行数据分析。结果表明,员工建言行为在四种组织类型中存在显著性差异,而员工个人权力感和权力动机在其中起到中介作用。此外,研究还发现,权力距离倾向在组织类型和个人权力感之间起到调节作用。最后,研究梳理了组织类型与建言行为的关系模型,并对未来研究做了展望。     

Relationship Between Job Characteristics and Attitudes: A Study of Temporary Employees

We examine the relationship between job characteristics and employee attitudes in the context of temporary employees who are assigned to work at the client organizations but are formally employed by a temporary agency. Based on the rationale provided by social exchange and social identity theories, we hypothesized that job characteristics would be related to job satisfaction, organizational commitment, and turnover intention in regard to both the client organization and the temporary agency. Results based on data collected from a large temporary agency supported all hypothesized relationships in regard to the client organization, and most hypothesized relationships in regard to the temporary agency. We discuss implications of these findings for research and the practice of managing temporary employee attitudes.     

学习判断与学习时间分配的关系

学习判断与学习时间分配的关系是元认知领域的重要问题, 对学习判断的研究在于使个体了解自己的学习和记忆活动, 从而有效控制学习过程, 合理分配学习时间, 这是元记忆监测影响控制的典型例子。近来有研究者提出学习时间分配不仅表现控制功能, 而且还表现监测功能。于是围绕学习时间的双重功能, 他们提出了元记忆监测与控制至少存在两种关系模型—— MC(监测影响控制)模型和CM(控制影响监测)模型, 后来又提出了两模型相互协同作用的合并动态模型—— 连续波浪型模式和同时发生模型。未来的研究应在继续验证MC模型和完善CM模型的基础上, 尝试检验两模型的合并动态模型。     

负性生活事件与儿童反应性攻击性之间的关系:一个有多重中介变量的结构方程模型

以977名9~14岁学生为对象,探索负性生活事件与儿童反应性攻击性之间的关系。研究使用了反应性与主动性攻击性问卷、Rosenberg自尊量表、青少年生活事件量表、艾森克人格问卷(儿童版)–情绪稳定性维度问卷,建立了以自尊和情绪稳定性作为中介变量,描述负性生活事件与反应性攻击性之间关系的结构方程模型。结果发现,负性生活事件可直接影响儿童反应性攻击性的形成,同时还可以通过改变情绪稳定性来影响反应性攻击性,即当负性生活事件发生时,情绪状态会倾向于不稳定,进而提高反应性攻击性的水平。此外,负性生活事件也会通过降低自尊水平来提高情绪状态的不稳定性,从而提高反应性攻击性的水平。