Assessment of three-dimensional joint kinematics of the upper limb during simulated swimming using wearable inertial-magnetic measurement units

The analysis of the joint kinematics during swimming plays a fundamental role both in sports conditioning and in clinical contexts. Contrary to the traditional video analysis, wearable inertial-magnetic measurements units (IMMUs) allow to analyse both the underwater and aerial phases of the swimming stroke over the whole length of the swimming pool. Furthermore, the rapid calibration and short data processing required by IMMUs provide coaches and athletes with an immediate feedback on swimming kinematics during training. This study aimed to develop a protocol to assess the three-dimensional kinematics of the upper limbs during swimming using IMMUs. Kinematics were evaluated during simulated dry-land swimming trials performed in the laboratory by eight swimmers. A stereo-photogrammetric system was used as the gold standard. The results showed high coefficient of multiple correlation (CMC) values, with median (first–third quartile) of 0.97 (0.93–0.95) and 0.99 (0.97–0.99) for simulated front-crawl and breaststroke, respectively. Furthermore, the joint angles were estimated with an accuracy increasing from distal to proximal joints, with wrist indices showing median CMC values always higher than 0.90. The present findings represent an important step towards the practical use of technology based on IMMUs for the kinematic analysis of swimming in applied contexts.     

Accuracy of activPAL Self-Attachment Methods

This study examined the accuracy of self-attachment of the activPAL activity monitor. A convenience sample of 50 participants self-attached the monitor after being presented with written material only (WMO) and then written and video (WV) instructions; and completed a questionnaire regarding the acceptability of the instructional methods. Participants positioned the monitor lower than the instructed position on the thigh (WMO ?5.15 ± 2.75 cm, WV ?4.16 ± 2.15 cm; p = .008 difference) and approximately 2 cm laterally from the thigh midline (WMO 1.90 ± 0.92 cm; WV 2.08 ± 1.24 cm). The orientation of the device was positioned correctly along the midline (within < 1° of vertical). Acceptability was high for both instructional methods although preference was shown for the WV instruction. In conclusion, participants consistently self-attached the activPAL close to the intended placement with either instructional method. The addition of video instruction produced a slightly more accurate attachment and was preferred by the participants.     

肌肉形态特征与肌肉力量相关研究

肌肉力量是人体运动的基本素质 ,与肌肉形态有关 ,更有赖于肌肉的横断面积大小。测量人体肌肉的形态指标或肌肉的横断面积 ,推测肌肉力量 ,并对不同人群的肌肉力量进行比较 ,探索肌肉形态特征与肌肉力量的内在规律 ,这对运动员训练水平的评估、运动损伤的治疗与康复及科学选材等方面都具有十分重要的意义。     

台阶试验质疑

台阶试验是一项由BROHA建立的用以评价机体对强体力负荷的适应能力和身体机能的恢复能力的运动负荷试验,研究表明:台阶试验指数与运动耐力和最大耗氧量之间无高度相关,因此,不能对心血管系统功能作出准确评价;台阶试验指数只能够对受试者的状况作出好与不好的评价,而不能作出精确评价;台阶试验指数不能有效反映以最大耗氧量、最大心输出量为代表的心脏功能增龄性变化规律及其性别差异。鉴于以上原因,台阶试验作为心血管系统功能评价的运动负荷试验尚待进一步研究。     

高校学生体育伤害事故现状及预防对策研究

由于体育运动的激烈性、对抗性特征,高校学生体育伤害事故无可避免地存在着,成为高校体育运动开展及体育课教学的重要困扰因素。本文通过文献资料法、问卷调查法、专家访谈法对当前高校学生体育伤害事故现状进行剖析并提出相应改善对策。     

我国竞技篮球教练员岗位培训机制与对策研究

摘要：运用文献资料、专家访谈等方法对我国竞技篮球教练员岗位培训体制和机制等方面的内容进行探究,结果认为：我国竞技篮球教练员岗位培训体制不完善;培训目标认识欠缺;培训需求内驱力不足;培训师资以及课程设置不合理;培训经费成为制约“瓶颈”。并提出：加强教练员培训管理,进一步完善岗位培训制度;提高教练员人才素质,厘清“素质一知识一能力”发展关系;重视培训师资团队后备力量培养,加快教练员岗位培训课程建设;gI进社会资本参与教练员岗位培训,保证培训经费通道畅通4个方面的应对策略。     

交互方式与性别差异对旅游增强现实用户体验的影响研究

[目的 /意义]通过分析交互方式与性别差异对游客使用移动增强现实旅游产品的情绪体验和可用性影响,为旅游增强现实应用设计优化提供依据.[方法/过程]具体结合户外实验研究与质性访谈方法,邀请游客使用触摸交互、空中手势交互和基于设备交互三种增强现实常见的交互方式完成对象选择任务,考察男女参与者对不同交互方式的可用性评价和PA...     

网络舆情场中信息受众观点测度的机理及路径分析

[目的/意义]整合定性与定量的舆情研究视角,统一多模态研究对象,实现网络舆情信息受众的观点测度,可修复网络舆情分析与治理的理论与实践裂痕。[方法/过程]通过引入网络舆情场的概念,对网络舆情信息受众、受众观点测度的内涵进行诠释,就网络舆情场与信息受众观点测度的逻辑关系加以辩证讨论。[结果/结论]提出网络舆情场内舆情受众观点测度机理和具体测度路径,为后续网络舆情场中的网络舆情信息分析、多维度信息受众观点测度,受众认知规律发现,网络舆情监督和管控限制等层面的研究做相应铺垫。     

信息生态位宽度研究

本文借鉴现代生态学的基本原理详细分析信息生态位宽度的概念、基本原理,并对信息生态位宽度的测度进行研究,提出基于Levins物种生态位宽度测度公式的一维信息生态位宽度测度公式,以及多维信息生态位宽度测度公式.     

学科知识扩散过程探测研究——以社会网络领域为例

[目的/意义]在知识经济时代,学科知识的扩散与吸收极大地促进了学科的协同、交叉、融合、发展与创新。提出一种量化指标测度与知识语义信息挖掘相结合的学科知识扩散过程探测方法,以期丰富和完善学科知识扩散研究范式与方法,为学科知识管理及决策制定提供可资借鉴的参考。[方法/过程]在经典量化指标测度的基础上,利用形式概念分析方法,结合学科知识语义信息,对知识在学科中的传播扩散过程进行系统研究,挖掘学科知识扩散数量及主题特征;建立学科知识扩散Logistic模型,并对其演化趋势进行预测;最后,以社会网络领域为例,进行实证研究。[结果/结论]知识在各学科中的应用范畴不断拓展,其扩散过程符合幂率分布特征;不同学科吸纳和接受的领域知识主题存在一定的差异;当前社会网络知识在学科中的传播扩散进程正处于成熟期。