值得庆幸的是，作者感谢荷兰国家研究机构（NWO）提供的资金来源。此外，作者还感谢荷兰皇家足球协会（KNVB）通过提供研究设施来促进研究方案。最后，作者们要感谢蒂伊斯·威格斯对研究计划的贡献。

本节中描述的所有方法均已获得格罗宁根大学人类运动科学中心伦理委员会的批准（注册号：201800904）。
1. 现场测试和惯性测量单元准备
<ol><li>设置两个圆锥体彼此至少 1 米，以确定现场测试的开始。 注：圆锥体之间的 1 米距离使受试者能够轻松通过现场测试的起点。此距离可根据测试领导者的偏好进行调整。</li>
	<li>通过从测试起点滚动测量胶带，直到 30 米的线性距离，确定现场测试的终点。</li>
	<li>设置两个相互距离至少 1 米的圆锥体，以确定现场测试的终点。</li>
	<li>准备 IMUs 以正确连接到受试者的身体。 注：查看 IMU 尺寸和重量特征的 材料表 。<ol>
<li>将拉伸胶带切成 5 块，尺寸为 10 厘米 x 10 厘米。</li>
		<li>将双面胶带（例如托皮胶带）切成 5 块，相当于使用的 IMUs 的大小。</li>
		<li>将一块双面胶带连接到每个 IMU。</li>
		<li>标记每个 IMU，以便在数据分析期间单独识别它。</li>
	</ol>
</li>
</ol>2. 主题准备
<ol><li>获取有关受试者的性别、年龄、体重和身高的信息。要求受试者填写一份关于他们在团队运动中背景的调查问卷。获得符合包容标准的主体的书面知情同意。 注：问题的例子：（i）你踢足球多少年了？（二） 你在哪个级别踢足球？（三） 在过去的6个月里，你每周有多少小时的足球训练？（iv）你的比赛位置是什么？（v） 在过去 6 个月中，您是否经历过任何疼痛或下肢肌肉骨骼损伤？</li>
	<li>确定主体是否符合包含标准。 注：包括受试者在执行协议前的6个月内没有在下肢经历任何肌肉骨骼损伤或疼痛：科目应具有1年以上的业余组队运动经验。</li>
	<li>要求主题换上运动服（例如足球衫、足球短裤和足球鞋）。 注：因为传感器将被放置在头骨上，足球袜是不需要的。</li>
	<li>准备连接到主体主体的IMUs。<ol>
<li>对齐彼此旁边的所有5个IMUs。</li>
		<li>通过按下传感器顶部的按钮同时激活所有五个 IMUs。当绿灯闪烁时，传感器被激活。 注：从此时起，每个 IMU 以 500 Hz 的速度对数据进行采样，数据存储在 SD 卡内部。数据必须在测试完成后上传到笔记本电脑或计算机。</li>
		<li>通过同时在坚硬的表面上（例如在桌子上）敲击所有 IMUs 来确保生成机械峰值。 注：同步 IMU 信号需要机械峰值。IMU 信号的同步在数据处理过程中执行（第 5 节）。当使用市售传感器时，无需此部分。在这种情况下，使用相应的软件同步传感器。</li>
	</ol>
</li>
	<li>将IMUs连接到受试者的身体（图1）。<ol>
<li>在以下解剖位置剃掉受试者的身体毛发：在后部上部的 iliac 脊椎、右侧和左侧头骨的异常骨质部分以及左右大腿的侧面部分（即腹膜异常）之间的囊中。 注：传感器应放置的解剖位置可以通过触觉确定。</li>
		<li>在步骤 2.5.1 中描述的解剖位置喷洒胶粘剂喷雾。等待 5+10 s 以确保粘合剂喷雾干燥。 注意：将喷雾剂从皮肤上保持至少 10 厘米（4 英寸），然后用扫地运动喷洒所需的区域。</li>
		<li>从 IMUs 中去除双面胶带的保护层。</li>
		<li>将 IMU 放置在描述的解剖位置。用 IMU 的相应标签写下解剖位置（例如，右柄：IMU 1）。</li>
		<li>将拉伸胶带连接到每个 IMU 的顶部，以确保传感器被附加固定在皮肤上。</li>
	</ol>
</li>
</ol>3. IMU 传感器校准
<ol><li>指示受试者静止不动，双脚臀部宽度分开，双手侧身。将此位置保持至少 5 s。</li>
	<li>指示受试者在下垂平面中将左臀部和膝盖弯曲至 90° 角，然后将臀部扩展到第 3.1 步中描述的中性位置。 注：有关运动变量的定义，请参阅图 2。</li>
	<li>右臀部和膝盖重复步骤3.2。</li>
	<li>指示参与者将行李箱向地面弯曲，并返回到中立位置。</li>
	<li>等待至少5s的周期。</li>
	<li>重复步骤 3.1=3.5 一次。</li>
</ol>4. 执行 30 米线性冲刺测试
<ol><li>指示主题进行热身（例如，足球特定的国际足联11+热身计划20）。</li>
	<li>通知受试者有关测试协议的信息。<ol>
<li>明确指出，在测试期间受伤的风险并不高于正常训练期间，受试者可以随时中止测试，而无需给出任何理由。</li>
		<li>指示受试者站在正确的起跑位置，他们的首选脚站在起跑线上，肩膀站在场上的起跑线后面。</li>
		<li>指示主题，测试领导将从 3 倒数到 0，然后大喊"开始"。指示当"开始"被调用时，测试开始。</li>
		<li>通知受试者尽可能快地冲刺，直到达到30米终点。在达到30米终点后，主体必须尽快减速到静止状态。</li>
		<li>允许被试者提问。如有必要，允许受试者执行练习运行，以便将主题与协议熟悉。</li>
	</ol>
</li>
	<li>询问主题说明是否清楚。</li>
	<li>确保主题处于正确的起始位置。</li>
	<li>从"3"倒计时到"0"，并大喊"开始"以开始测试。在给出开始符号时启动定时器。</li>
	<li>鼓励主题以达到最大性能。</li>
	<li>当参与者达到静止状态时，停止超时器。</li>
	<li>重复步骤 4.4=4.6，直到执行了三个冲刺。 注意：让参与者在试验之间休息至少2分钟。包括数据分析的最快冲刺。</li>
	<li>指示受试者进行冷却。</li>
	<li>通过从受试者的身体中取出拉伸胶带和双面胶带，将 IMUs 从主体中分离。</li>
</ol>5. 数据处理
<ol><li>使用 USB 电缆将 IMU 与计算机连接起来。将原始 IMU 数据导出到计算机上的特定文件夹。</li>
	<li>打开 MATLAB（版本 r2018b）。导入原始 IMU 数据文件（即加速度计、陀螺仪和磁力计数据）。</li>
	<li>同步原始 IMU 数据文件。<ol>
<li>导入一个传感器的加速数据文件（例如骨盆传感器）。</li>
		<li>通过区分 X、Y 和 Z 加速度信号来计算挺举。总结X，Y和Z抽搐，以获得总挺举。</li>
		<li>通过在数据文件中查找总抽搐已达到最大值的索引值来获取机械峰值。索引值是测量的开始。</li>
		<li>在传感器的指数值之前删除加速数据、磁力计数据和陀螺仪数据的所有数据点。</li>
		<li>对于相应传感器的每个原始数据文件，重复步骤 5.3.1=5.3.3。</li>
		<li>通过获取每个数据文件的样本数据点数，确定哪个传感器包含的数据点数量最少。</li>
		<li>剪切与在最短时间内注册信号的传感器大小相等的所有其他数据文件。</li>
	</ol></li>
	<li>使用第二阶低通巴特沃斯滤镜过滤陀螺仪数据，截止频率为 12 Hz。 注：在以前的试点实验中，根据可视数据检查选择过滤器和特定的截止频率。</li>
	<li>通过使用马奇威克滤镜35计算传感器的方向四重奏，获得与全球地球框架的传感器方向。 注：马奇威克等人对全球地球框架传感器方向的计算进行了广泛的描述。</li>
	<li>将传感器坐标帧对齐到车身段。<ol>
<li>在校准过程中，当主体静止不动时，选择数据文件的索引数（步骤 3.1）。 注：假设传感器的纵向轴与重力向量相似。</li>
		<li>使用步骤 5.6.1 的索引数来计算静态校准期间每个传感器相对于全球参考帧的平均方向。然后旋转每个传感器的传感器框架，以便在静态校准期间与全球参考帧对齐。</li>
		<li>执行左腿校准运动时，选择数据文件的索引数（步骤 3.2）。</li>
		<li>旋转左腿传感器的方向，使校准运动仅是前轴的旋转。</li>
		<li>重复步骤 5.6.3 和 5.6.4 用于右腿和躯干的校准运动。</li>
	</ol></li>
	<li>通过在每个关节的近部段的坐标框架中表达断肢体段的方向来获得关节方向。</li>
	<li>通过将获得的关节方向分解为"XZY"欧拉角度来获得关节角度。 注：如何将获得的关节方向分解为"XZY"欧拉角度，在Diebel36的作品中进行了描述。</li>
	<li>获得表达其相应近部段坐标框架中每个断面段的陀螺仪信号的关节角速，减去近部段的角速。</li>
	<li>使用步测算法识别线性冲刺过程中的每一步。<ol>
<li>在 MATLAB 中导入过滤陀螺仪数据。</li>
		<li>使用峰值检测功能识别陀螺仪信号中的峰值。 注：峰值高度设置为 286.5 °s-1， 最小峰值距离设置为 100 个样本（=0.2 s）。</li>
	</ol></li>
	<li>对于每一步，计算臀部角度、膝盖角度、臀部角速和膝盖角速的最大值。</li>
	<li>对于每一步，计算臀部角度、膝盖角度、臀部角速和膝盖角速的最低值。</li>
	<li>对于每一步，通过从最大臀部角度减去最小臀部角度来计算臀部运动范围。</li>
	<li>对于每一步，通过从最大膝盖角度减去最小膝盖角度来计算膝盖的运动范围。</li>
	<li>将已处理的数据保存到计算机上的特定文件夹，以便将其用于进一步分析。</li>
</ol>6. 数据分析
<ol><li>在 MATLAB 中导入已处理的 IMU 数据。</li>
	<li>根据步数检测算法识别的步骤，将冲刺分为加速、最高速度和减速阶段。 注：本文中的冲刺阶段是任意选择的。加速阶段定义为步骤 3 到 837，而减速阶段定义为冲刺的最后八个步骤。最高速度数据源自这些阶段之间执行的步骤。</li>
	<li>选择角度速度数据进行数据分析。</li>
	<li>计算 30 米线性冲刺测试每个阶段所有步骤运动变量的平均值和标准偏差。</li>
	<li>重复步骤 6.3 和 6.4 的角度数据。</li>
</ol>

作者没有什么可透露的。

目前监测运动员在团队运动中的方法没有记录下肢运动学，这可能是识别受伤危险因素的有用措施。在冲刺过程中分析下肢运动学的黄金标准是光电子测量系统29、30、31、32。虽然光电子测量系统是金本位制，但由于测量面积有限，这些系统缺乏生态有效性。本文中提出的传感器设置克服了当前测量系统的局限性，而且相对便宜。通过传感器设置测量，在现场注册下肢运动学的可能性可能会改善运动员的监测实践。
先前的研究，检查冲刺运动学29，31，37，38，39报告臀部角度从210°延伸到90°弯曲。此外，这些研究还报告了膝盖角度从160°最小的弯曲和40°的最大弯曲。本研究中观察到的值在先前报告的范围之内。一项研究38报告臀部角速范围从 -590 °s-s -1到 700 °s-1和膝盖角速度范围从 -1，000 °s-s -1到 1，100 °s-1.虽然在这项研究中观察到的值较高，但随着时间的推移，它们也呈现出类似的趋势。该方法已得到验证，可用于运动员在现场监测40。
目前的研究有一些需要解决的局限性。首先，除了已使用的IMUs的特性外，用户必须知道，来自IMUS的信号受到几个错误源的影响，这些误差源限制了41个应用程序的可能范围。首先，骨骼周围软组织的振荡（即软组织人工制品42）会影响运动学的注册。因此，必须根据协议中描述的步骤，将IMUs仔细地附着在主体的身上。虽然采取了必要的步骤，但应当指出，目前的研究没有包括防止传感器错误移动的额外弹性表带。这可能改善结果，并可能被视为这项研究的局限性。其次，来自其他设备（主要是建筑物内部）的铁磁干扰改变了 IMU 磁力计测量磁场矢量的大小或方向，从而导致估计方向43的错误。因此，应尽可能避免铁凝干扰的来源。此外，必须指出，传感器设置不适用于滑动滑轮，因为传感器会因接触地面而脱离皮肤。因此，应指示参与者不要在小侧游戏期间执行滑动滑动。解决这个问题的一个可能的解决方案可能是将传感器设置集成到智能服装 （即智能传感器紧身衣）中。
传感器设置获得运动变量可用于分段模型，以监控现场的运动员。先前的研究发现，在足球比赛模拟44后，每半场的臀部弯曲和膝盖伸展角度（即理论腿筋长度）减少最大。在同一研究中，在每半结束期间观察到柄角速度的增加。较低的腿筋长度加上刀柄速度的加快可能表明疲劳后腿筋过度拉伤的风险增加。使用惯性测量单元 （IMU） 驱动的细分模型，可以在字段设置中检测到冲刺运动学中的这种变化。除了关节运动学的变化，对身体整体起作用的力量也可以估计。地面反应力 （GRF） 描述了整个肌肉骨骼系统经历的生物力学负荷，并且可以使用牛顿的第二运动定律（即 F = m = a） 进行估计。目前研究在运行中使用GRF估计优化冲刺性能45，46或评估潜在的伤害风险47，48，49，50。这些研究表明，装载率、垂直冲击力峰值和水平断裂力与肌肉骨骼过度使用损伤有关。虽然在高度动态的团队运动特定动作51、52中准确估计 GRF 是一项挑战，但在现场测量期间监控这些变量的可能性可能会提供新的信息来优化性能或防止受伤。
本文介绍的结果仅限于在线性冲刺期间监测下肢运动学，重点是腿筋拉伤机制。然而，应该指出的是，臀部和腹股沟受伤也经常发生在团队运动14，17，53，54，55。这些伤害可能是由踢和改变方向的重复参与造成的。因此，未来的研究不仅应限制他们在与腿筋拉伤机制的关系中冲刺的重点，而且应侧重于扩大有关改变方向任务的知识56和踢57，58，59与臀部和腹股沟受伤的关系。
总之，此传感器设置可以集成到智能服装中。智能服装可以在团队运动特定任务期间在运动场注册下肢运动学，从而改善未来对运动员的监测。这可以帮助日常运动环境中的专业人士评估他们的训练计划并优化他们，以降低受伤风险。

团队运动（如足球和曲棍球）的特点是交替的短暂爆炸性动作，如高强度跑步或短跑，较长的步行或慢跑等要求较低的活动时间较长，如步行或慢跑1，2，3，4，5，6。在过去的几十年里，游戏的身体需求随着高速和短跑、更快的球速和更多的传球7、8的距离而演变。
运动员不断刻苦训练，以保持和提高身体承受比赛身体要求的能力。正确应用训练刺激与足够的恢复相结合，诱导反应，导致人体适应，提高体能和性能9。相反，训练刺激和恢复之间的不平衡可能导致长期疲劳和不良的训练反应（不适应），这增加了职业和业余团队运动运动员10，11，12，13受伤的风险。
伴随高训练和比赛刺激的主要风险之一是肌肉拉伤。肌肉拉伤占团队运动中所有时间损失伤害的三分之一以上，导致超过四分之一的伤病缺席，其中腿筋是最常见的涉及14，15，16，17。此外，每年遭受腿筋拉伤的运动员人数每年增加18、19人，尽管已经引进了多个项目来预防腿筋拉伤12、13、20、21。因此，从运动22和财务23的角度来看，这具有负面影响，因此，对个别运动员的充分监测对于优化训练计划、尽量减少受伤风险和优化成绩至关重要。
目前运动员在团队运动中的监测实践主要基于由本地或全球定位系统24、25测量的位置数据。这些系统以 GPS 为基础的指标（如覆盖的距离、平均运行速度或基于加速度的指标，如 PlayerLoad26 、27、28）来监控活动。这些措施的缺点是，它们不包括下肢运动学。光电测量系统作为黄金标准，在直线冲刺29、30、31、32期间对下肢进行运动分析。这些系统的缺点是缺乏生态有效性，因为其测量区域有限，需要专家来操作该系统和耗时的数据分析。因此，这种方法不适合日常运动练习。
传感器技术的飞速发展可以克服目前监测运动员的方法的局限性。惯性测量单元 （IMU） 最近的可靠性、小型化和数据存储可能性使传感器技术能够在现场应用。IMUs包含一个加速度计、陀螺仪和磁力计，分别在33、34个正交轴中测量加速度、角度速度和磁场。通过将传感器安全地固定在车身段、传感器融合算法和生物力学模型中，可以估计联合运动学33。联合运动学的注册，结合不同身体部位加速的信息，可以改善运动员对团队运动的监测。
通过将 IMU 传感器设置与标准化现场测试耦合在一起，可以说明在野外线性冲刺期间，下肢运动学是如何注册的，这可能是识别伤害风险因素的有用措施。传感器设置可以为当前监控措施提供额外信息，专业人员可以使用这些信息来优化培训计划，以提高性能并最大限度地降低伤害风险。因此，本文的主要目的是演示一个惯性传感器设置，用于估算田径运动中团队运动运动员的臀部和膝盖关节运动学。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Computer software</td>
			<td>The MathWorks, Inc., Natick, MA, USA</td>
			<td></td>
			<td>Matlab Version 2018b</td>
		</tr>
		<tr>
			<td>Cones</td>
			<td>Nike</td>
			<td></td>
			<td>n = 4</td>
		</tr>
		<tr>
			<td>Double-sided adhesive tape</td>
			<td></td>
			<td></td>
			<td>For attaching IMUs on the skin</td>
		</tr>
		<tr>
			<td>Inertial Measurement Units</td>
			<td>MPU-9150, Invensense, San Jose, California, United States</td>
			<td></td>
			<td>n = 5; Dimensions: 3.5 x 2.5 x 1.0 cm; Weight: 0,011 kg; Sample frequency: 500Hz; Accelerometer: &#177; 16 G, Gyroscope: &#177; 2000 &#176;/s</td>
		</tr>
		<tr>
			<td>Measuring tape</td>
			<td></td>
			<td></td>
			<td>Minimal length: 30 meters</td>
		</tr>
		<tr>
			<td>Pre-tape spray</td>
			<td>Mueller Tuffner, Mueller Sports Medicine, Inc., Wisconsin, United States</td>
			<td></td>
			<td>Contents: 283 g</td>
		</tr>
		<tr>
			<td>Stretch Tape</td>
			<td>Fixomull, BSN Medical, Almere, The Netherlands</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

an inertial measurement unit based method to estimate hip and knee joint kinematics in team sport athletes on the field

目前团队运动中的运动员监测实践主要基于全球定位或本地定位系统测量的位置数据。这些测量系统的缺点是，它们没有记录下肢运动学，这可能是识别伤害危险因素的有用措施。传感器技术的快速发展可以克服当前测量系统的局限性。通过惯性测量单元（IMUs）安全地固定在车身段、传感器融合算法和生物力学模型中，可以估计联合运动学。本文的主要目的是演示一个传感器设置，用于估计田径场上团队运动运动员的臀部和膝盖关节运动学。5个男性科目（年龄22.5±2.1岁：体重77.0±3.8公斤：身高184.3±5.2厘米：训练经验15.3±4.8岁）进行了30米线性冲刺。臀部和膝盖关节角度和角度速度是由放在骨盆上的五个IMUs获得的，大腿和双柄。臀部角度范围从 195° （± 8°） 扩展到 100.5° （± 8°） 弯曲和膝盖角度范围从 168.6° （± 12°） 最小的弯曲和 62.8° （± 12°） 最大弯曲。此外，臀部角速范围介于 802.6 °s-1 （± 192 °s-1）和 -674.9 °s-1 （± 130 °s-1）之间。膝盖角度速度介于 1155.9 °s-s -1 （± 200 °s-1）和 -1208.2 °s-1 （± 264 °s-1）之间。传感器设置已得到验证，可以提供有关运动员在现场监测的其他信息。这可以帮助日常运动环境中的专业人士评估他们的训练计划，旨在减少伤害和优化性能。

五个科目（全部为男性;所有足球运动员;年龄22.5±2.1岁;体重77.0±3.8公斤;身高184.3±5.2厘米：训练经验15.3±4.8岁）进行了30米线性冲刺。臀部角度范围在 100.5° （± 8°） 最大弯曲和 183.1° （± 8°） 最大扩展之间， 104.1° （± 8°） 最大弯曲和 195° （± 8°） 最大扩展在最高速度，128.4° （± 11°） 最大弯曲和 171.9° （± 23°） 减速期间最小弯曲。臀部角度速度在加速期间介于 744.9 °s-s -1 （± 154 °s-1）和 –578 °s-1 （± 99°s-1）之间， 802.6 °s-1 （± 192 °s-1）和 -674.9 °s-s -1 （± 130 °s-1） 在最高速度， 减速期间为 447.7 °s-1 （± 255 °s-1）和 -430.3 °s-1 （± 189 °s-1）。
此外，膝盖角度范围在 73.5° （± 12°） 最大弯曲和 162.6° （± 7°） 之间，在加速度期间最小弯曲， 62.8° （± 12°） 最大弯曲和 164.8° （± 6°） 在最高速度下的最小弯曲，以及 81.1° （± 16°） 最大弯曲和 168.6° （± 12°） 减速期间的最小弯曲。膝盖角速在加速期间在 935.8 °s-s -1 （± 186 °s-1）和 -1137.8 °s-1 （± 214 °s_s+1） 之间变化， 最高时速为 1155.9 °s-1 （± 200 °s-1）和 -1208.2 °s-1 （± 264 °s-1）之间， 和 1000.1 °s-1 （± 282 °s-1）和 -1004.3 °s-1 （± 324 °s-1）。图 3显示了线性 30 米冲刺测试的一个试验的连续运动数据，而图 4和图 5则说明了一个试验的加速、最高速度和减速期间单步周期的运动数据。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/60857/60857fig1.jpg"> 图1：传感器放置的表示。 （A） 传感器放置在左右柄上。（B） 传感器放置在骨盆上，以及左右大腿上。 <a href="https://www.jove.com/files/ftp_upload/60857/60857fig1large.jpg" target="_blank">请点击这里查看此数字的较大版本。</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/60857/60857fig2.jpg"> 图2：臀部和膝盖关节角度和角度速度的定义。 （A） 代表下垂平面中的中性位置。中性位置的关节角度为 180°。（B） 表示臀部关节（θ臀部）、膝盖关节（θ膝盖）和运动范围（ROM）。 <a href="https://www.jove.com/files/ftp_upload/60857/60857fig2large.jpg" target="_blank">请点击这里查看此数字的较大版本。</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/60857/60857fig3.jpg"> 图3：在加速、最高速度和减速阶段，一个试验的冲刺运动学可视化。 星号表示已检测到步骤。（A） 左右臀部弯曲和延伸角度随着时间的推移。（B） 随着时间的推移，左右臀部角速度。（C） 随着时间的推移，左膝和右膝的角度。（D） 随着时间的推移，左膝和右膝角速度。 <a href="https://www.jove.com/files/ftp_upload/60857/60857fig3large.jpg" target="_blank">请点击这里查看此数字的较大版本。</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/60857/60857fig4.jpg"> 图4：极地图，其中臀部关节角度（°）和一步角速度（弯曲/延伸）在加速、最高速度和减速过程中被说明。<a href="https://www.jove.com/files/ftp_upload/60857/60857fig4large.jpg" target="_blank">请点击这里查看此数字的较大版本。</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/60857/60857fig5.jpg"> 图 5：在加速、最高速度和减速过程中显示膝盖关节角 （°） 和一步角速度（弯曲/延伸）的极地图。<a href="https://www.jove.com/files/ftp_upload/60857/60857fig5large.jpg" target="_blank">请点击这里查看此数字的较大版本。</a>

Watch this Scientific Journal Video about An Inertial Measurement Unit Based Method to Estimate Hip and Knee Joint Kinematics in Team Sport Athletes on the Field at JoVE.com

An Inertial Measurement Unit Based Method to Estimate Hip and Knee Joint Kinematics in Team Sport Athletes on the Field

监测运动员对于提高团队运动成绩和降低受伤风险至关重要。目前监测运动员的方法不包括下肢。将多个惯性测量单元连接到下肢可以改善对运动员的监测。

一种基于惯性测量单元的方法，以评估场上团队运动运动员的臀部和膝盖关节运动学

Current athlete monitoring practice in team sports is mainly based on positional data measured by global positioning or local positioning systems. The ...

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Behavior

Unit 1

Moment of Inertia

SCIENTISTS IN ACTION

7.7K 次观看.  University of Groningen. 监测运动员对于提高团队运动成绩和降低受伤风险至关重要。目前监测运动员的方法不包括下肢。将多个惯性测量单元连接到下肢可以改善对运动员的监测。

视频: An Inertial Measurement Unit Based Method to Estimate Hip and Knee Joint Kinematics in Team Sport Athletes on the Field

Electrophysiological Motor Unit Number Estimation (MUNE) Measuring Compound Muscle Action Potential (CMAP) in Mouse Hindlimb Muscles

Compound muscle action potential (CMAP) and motor unit number estimation (MUNE) are electrophysiological techniques that can be used to monitor the functional status of a motor unit pool in vivo. These measures can provide insight into the normal development and degeneration of the neuromuscular system. These measures have clear translational potential because they are routinely applied in diagnostic and clinical human studies. We present electrophysiological techniques similar to those employed in humans to allow recordings of mouse sciatic nerve function. The CMAP response represents the electrophysiological output from a muscle or group of muscles following supramaximal stimulation of a peripheral nerve. MUNE is an electrophysiological technique that is based on modifications of the CMAP response. MUNE is a calculated value that represents the estimated number of motor neurons or axons (motor control input) supplying the muscle or group of muscles being tested. We present methods for recording CMAP responses from the proximal leg muscles using surface recording electrodes following the stimulation of the sciatic nerve in mice. An incremental MUNE technique is described using submaximal stimuli to determine the average single motor unit potential (SMUP) size. MUNE is calculated by dividing the CMAP amplitude (peak-to-peak) by the SMUP amplitude (peak-to-peak). These electrophysiological techniques allow repeated measures in both neonatal and adult mice in such a manner that facilitates rapid analysis and data collection while reducing the number of animals required for experimental testing. Furthermore, these measures are similar to those recorded in human studies allowing more direct comparisons.

Electrophysiological Motor Unit Number Estimation MUNE Measuring Compound Muscle Action Potential CMAP in Mouse Hindlimb Muscles

We present refined protocols that allow in vivo monitoring of motor unit function in the mouse. Techniques to measure compound muscle action potential (CMAP) and motor unit number estimation (MUNE) in the mouse hind limb muscles innervated by the sciatic nerve are described.

电电机组数估计（MUNE）在小鼠后肢肌肉测量复合肌肉动作电位（CMAP）

Compound muscle action potential (CMAP) and motor unit number estimation (MUNE) are electrophysiological techniques that can be used to monitor the ...

科研

行为学

Force and Position Control in Humans - The Role of Augmented Feedback

During motor behaviour, humans interact with the environment by for example manipulating objects and this is only possible because sensory feedback is constantly integrated into the central nervous system and these sensory inputs need to be weighted in order meet the task specific goals. Additional feedback presented as augmented feedback was shown to have an impact on motor control and motor learning. A number of studies investigated whether force or position feedback has an influence on motor control and neural activation. However, as in the previous studies the presentation of the force and position feedback was always identical, a recent study assessed whether not only the content but also the interpretation of the feedback has an influence on the time to fatigue of a sustained submaximal contraction and the (inhibitory) activity of the primary motor cortex using subthreshold transcranial magnetic stimulation. This paper describes one possible way to investigate the influence of the interpretation of feedback on motor behaviour by investigating the time to fatigue of submaximal sustained contractions together with the neuromuscular adaptations that can be investigated using surface EMG. Furthermore, the current protocol also describes how motor cortical (inhibitory) activity can be investigated using subthreshold TMS, a method known to act solely on the cortical level. The results show that when participants interpret the feedback as position feedback, they display a significantly shorter time to fatigue of a submaximal sustained contraction. Furthermore, subjects also displayed an increased inhibitory activity of the primary cortex when they believed to receive position feedback compared when they believed to receive force feedback. Accordingly, the results show that interpretation of feedback results in differences on a behavioural level (time to fatigue) that is also reflected in interpretation-specific differences in the amount of inhibitory M1 activity.

Controlling an identical movement with position or force feedback results in different neural activation and motor behavior. This protocol describes how to investigate behavioral changes by looking at neuromuscular fatigue and how to evaluate motor cortical (inhibitory) activity using subthreshold TMS with respect to the interpretation of augmented feedback.

力和位置控制人类 - 增强反馈的作用

During motor behaviour, humans interact with the environment by for example manipulating objects and this is only possible because sensory feedback is ...

A Method for Evaluating the Reinforcing Properties of Ethanol in Rats without Water Deprivation, Saccharin Fading or Extended Access Training

Operant oral self-administration methods are commonly used to study the reinforcing properties of ethanol in animals. However, the standard methods require saccharin/sucrose fading, water deprivation and/or extended training to initiate operant responding in rats. This paper describes a novel and efficient method to quickly initiate operant responding for ethanol that is convenient for experimenters and does not require water deprivation or saccharin/sucrose fading, thus eliminating the potential confound of using sweeteners in ethanol operant self-administration studies. With this method, Wistar rats typically acquire and maintain self-administration of a 20% ethanol solution in less than two weeks of training. Furthermore, blood ethanol concentrations and rewards are positively correlated for a 30 min self-administration session. Moreover, naltrexone, an FDA-approved medication for alcohol dependence that has been shown to suppress ethanol self-administration in rodents, dose-dependently decreases alcohol intake and motivation to consume alcohol for rats self-administering 20% ethanol, thus validating the use of this new method to study the reinforcing properties of alcohol in rats.

This protocol describes a novel and efficient method to quickly initiate operant responding for ethanol in rats that, contrary to standard methods, does not require water deprivation or saccharin/sucrose fading to initiate responding.

一种用于评价大鼠乙醇的补强性能没有禁水，糖精衰落或扩展访问训练方法

Operant oral self-administration methods are commonly used to study the reinforcing properties of ethanol in animals. However, the standard methods ...

The Rodent Psychomotor Vigilance Test (rPVT): A Method for Assessing Neurobehavioral Performance in Rats and Mice

The human Psychomotor Vigilance Test (PVT) is a widely used procedure for measuring changes in fatigue and sustained attention. The present article describes a rodent version of the PVT&#8212;termed the &#34;rPVT&#34;&#8212;that measures similar aspects of attention (i.e., performance accuracy, motor speed, premature responding, and lapses in attention). Data are presented that demonstrate both the short- and long-term usefulness of the rPVT when employed with laboratory rats. Rats easily learn the rPVT, and learning to perform the basic procedure takes less than two weeks of training. Once acquired, rat performances in the rPVT show a high degree of similarity to these same performance measures in the human PVT, including similarities in, lapses in attention, reaction times, vigilance decrements across session time (i.e., the human &#34;time-on-task&#34; effects), and the response-stimulus interval (RSI) effect described for humans. Thus the rPVT can be an extremely valuable tool for assessing the effects of a wide range of variables on sustained attention quite similar to human PVT performances, and thus can be useful for developing novel treatments for neurobehavioral dysfunctions.

The Rodent Psychomotor Vigilance Test rPVT: A Method for Assessing Neurobehavioral Performance in Rats and Mice

A rat version of the human Psychomotor Vigilance Test (PVT) is described that measures aspects of attention similar to those measured with the human PVT, including aspects of human vigilance such as performance accuracy, motor speed, premature responding, and lapses in attention.

鼠类精神运动警觉测试（rPVT）：一个在大鼠和小鼠的神经行为评估性能的方法

The human Psychomotor Vigilance Test (PVT) is a widely used procedure for measuring changes in fatigue and sustained attention. The present article ...

Basic Methods for the Study of Reproductive Ecology of Fish in Aquaria

Captive-rearing observations are valuable for revealing aspects of fish behavior and ecology when continuous field investigations are impossible. Here, a series of basic techniques are described to enable observations of the reproductive behavior of a wild-caught gobiid fish, as a model, kept in an aquarium. The method focuses on three steps: collection, transport, and observations of reproductive ecology of a substrate spawner. Essential aspects of live fish collection and transport are (1) preventing injury to the fish, and (2) careful acclimation to the aquarium. Preventing harm through injuries such as scratches or a sudden change of water pressure is imperative when collecting live fish, as any physical damage is likely to negatively affect the survival and later behavior of the fish. Careful acclimation to aquaria decreases the incidence death and mitigates the shock of transport. Observations during captive rearing include (1) the identification of individual fish and (2) monitoring spawned eggs without negative effects to the fish or eggs, thereby enabling detailed investigation of the study species' reproductive ecology. The subcutaneous injection of a visible implant elastomer (VIE) tag is a precise method for the subsequent identification of individual fish, and it can be used with a wide size range of fish, with minimal influence on their survival and behavior. If the study species is a substrate spawner that deposits adhesive eggs, an artificial nest site constructed from polyvinyl chloride (PVC) pipe with the addition of a removable waterproof sheet will facilitate counting and monitoring the eggs, lessening the investigator's influence on the nest-holding and egg-guarding behavior of the fish. Although this basic method entails techniques that are seldom mentioned in detail in research articles, they are fundamental for undertaking experiments that require the captive rearing of a wild fish.

A series of basic methods to enable the study of the reproductive ecology of fish kept in aquaria are described. These are useful protocols for collecting fish using SCUBA, transporting live fish, and observing the reproductive behavior of wild-caught fish kept in aquaria.

鱼类生殖生态学研究的基本方法

Captive-rearing observations are valuable for revealing aspects of fish behavior and ecology when continuous field investigations are impossible. Here, a ...

An Automated Method to Determine the Performance of Drosophila in Response to Temperature Changes in Space and Time

Temperature is a ubiquitous environmental factor that affects how species distribute and behave. Different species of Drosophila fruit flies have specific responses to changing temperatures according to their physiological tolerance and adaptability. Drosophila flies also possess a temperature sensing system that has become fundamental to understanding the neural basis of temperature processing in ectotherms. We present here a temperature-controlled arena that permits fast and precise temperature changes with temporal and spatial control to explore the response of individual flies to changing temperatures. Individual flies are placed in the arena and exposed to pre-programmed temperature challenges, such as uniform gradual increases in temperature to determine reaction norms or spatially distributed temperatures at the same time to determine preferences. Individuals are automatically tracked, allowing the quantification of speed or location preference. This method can be used to rapidly quantify the response over a large range of temperatures to determine temperature performance curves in Drosophila or other insects of similar size. In addition, it can be used for genetic studies to quantify temperature preferences and reactions of mutants or wild-type flies. This method can help uncover the basis of thermal speciation and adaptation, as well as the neural mechanisms behind temperature processing.

An Automated Method to Determine the Performance of Drosophila in Response to Temperature Changes in Space and Time

Here we present a protocol to automatically determine the locomotor performance of Drosophila at changing temperatures using a programmable temperature-controlled arena that produces fast and accurate temperature changes in time and space.

一种自动测定果蝇在空间和时间温度变化中的性能的方法

Temperature is a ubiquitous environmental factor that affects how species distribute and behave. Different species of Drosophila fruit flies have specific ...

Integrating Visual Psychophysical Assays within a Y-Maze to Isolate the Role that Visual Features Play in Navigational Decisions

Collective animal behavior arises from individual motivations and social interactions that are critical for individual fitness. Fish have long inspired investigations into collective motion, specifically, their ability to integrate environmental and social information across ecological contexts. This demonstration illustrates techniques used for quantifying behavioral responses of fish, in this case, Golden Shiner (Notemigonus crysoleucas), to visual stimuli using computer visualization and digital image analysis. Recent advancements in computer visualization allow for empirical testing in the lab where visual features can be controlled and finely manipulated to isolate the mechanisms of social interactions. The purpose of this method is to isolate visual features that can influence the directional decisions of the individual, whether solitary or with groups. This protocol provides specifics on the physical Y-maze domain, recording equipment, settings and calibrations of the projector and animation, experimental steps and data analyses. These techniques demonstrate that computer animation can elicit biologically-meaningful responses. Moreover, the techniques are easily adaptable to test alternative hypotheses, domains, and species for a broad range of experimental applications. The use of virtual stimuli allows for the reduction and replacement of the number of live animals required, and consequently reduces laboratory overhead.
This demonstration tests the hypothesis that small relative differences in the movement speeds (2 body lengths per second) of virtual conspecifics will improve the speed and accuracy with which shiners follow the directional cues provided by the virtual silhouettes. Results show that shiners directional decisions are significantly affected by increases in the speed of the visual cues, even in the presence of background noise (67% image coherency). In the absence of any motion cues, subjects chose their directions at random. The relationship between decision speed and cue speed was variable and increases in cue speed had a modestly disproportionate influence on directional accuracy.

Here, we present a protocol to demonstrate a behavioral assay that quantifies how alternative visual features, such as motion cues, influence directional decisions in fish. Representative data are presented on the speed and accuracy where Golden Shiner (Notemigonus crysoleucas) follow virtual fish movements.

在 Y-Maze 中集成视觉心理物理分析,以隔离视觉特征在导航决策中扮演的角色

Collective animal behavior arises from individual motivations and social interactions that are critical for individual fitness. Fish have long inspired ...

An Instrumented Pull Test to Characterize Postural Responses

Impairment of postural reflexes, termed postural instability, is a common and disabling deficit in Parkinson's disease. To assess postural reflexes, clinicians typically employ the pull test to grade corrective responses to a backward perturbation at the shoulders. However, the pull test is prone to issues with reliability and scaling (score/4). Here, we present an instrumented version of the pull test to more precisely quantify postural responses. Akin to the clinical test, pulls are manually administered except pull force is also recorded. Displacements of the trunk and feet are captured by a semi-portable motion tracking system. Raw data represent distance traveled (in millimeter units), making subsequent interpretation and analysis intuitive. The instrumented pull test also detects variabilities influencing pull test administration, such as pull force, thereby identifying and quantifying potential confounds that can be accounted for by statistical techniques. The instrumented pull test could have application in studies seeking to capture early abnormalities in postural responses, track postural instability over time, and detect responses to therapy.

Impairment of postural reflexes, termed postural instability, is difficult to quantify. Clinical assessments such as the pull test suffer issues with reliability and scaling. Here, we present an instrumented version of the pull test to objectively characterize postural responses.

一种表征姿势反应的仪器拉力测试

Impairment of postural reflexes, termed postural instability, is a common and disabling deficit in Parkinson's disease. To assess postural reflexes, ...

Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training

An elevation in cardiac troponin T (cTnT), as a highly specific biomarker of cardiomyocyte damage, after moderate-intensity continuous exercise (MCE) has been described. The exercise-induced cTnT response distorts the diagnostic role of the cTnT assay. Although high-intensity interval exercise (HIE) is growing in popularity and concerns remain about its safety, available data related to cTnT release after HIE is limited, which hampers the use of HIE as a health intervention. Here, we present three representative HIE protocols [traditional HIE (repeated 4 min cycling at 90% V&#775;O2max interspersed with 3 min rest, 200 kJ/session); sprint interval exercise (SIE, repeated 1 min cycling at 120% V&#775;O2max interspersed with 1.5 min rest, 200 kJ/session); and repeated sprint exercise (RSE, 40 x 6 s all-out sprints interspersed with 9 s rest)] and one representative MCE protocol (continuous cycling exercise at an intensity of 60% V&#775;O2max, 200 kJ/session). Forty-seven sedentary, overweight young women were randomly assigned to one of four groups (HIE, SIE, RSE, and MCE). Six bouts of respective exercise were performed by every single group, with each being 48 h apart. Meanwhile, for four groups, the duration of the entire testing period was identical, being 10 days. Before and after the first and final exercise bouts, an assessment was conducted of cTnT. The current study provides a frame of reference giving a clear picture of how a specific exercise session affects the circulating cTnT concentration at the early stage of training. The information may assist with clinical interpretations of post-exercise cTnT elevation and guide the prescription of exercise, especially for HIE.

Here, we present protocols of high-intensity interval and moderate-intensity continuous exercise to observe the response of circulating cardiac troponin T (cTnT) concentration to acute exercise over 10 days. The information may assist with clinical interpretations of post-exercise cTnT elevation and guide the prescription of exercise.

高强度间歇锻炼和中强度连续运动对心脏肌钙蛋白T级在训练早期阶段的影响

An elevation in cardiac troponin T (cTnT), as a highly specific biomarker of cardiomyocyte damage, after moderate-intensity continuous exercise (MCE) has ...

Comparative Analysis of Lower Limb Kinematics between the Initial and Terminal  Phase  of 5km Treadmill Running

Running is beneficial for physical health, but it is also accompanied by many injuries. However, the main factors leading to running injury remain unexplained. This study investigated the effects of long running distance on lower-limb kinematic variables and the lower limb kinematic difference of between the initial (IR) and terminal phase (TR) of 5 km running was compared. Ten amateur runners ran on a treadmill at the speed of 10 km/h. Dynamic kinematic data was collected at the phase of IR (0.5 km) and TR (5 km), respectively. The peak angle, peak angular velocities, and range of motion were recorded in this experiment. The main results demonstrated the following: ankle eversion and knee abduction were increased at TR; ROMs of ankle and knee were increased in the frontal plane at TR than IR; a larger peak angular velocity of ankle dorsiflexion and hip interrotation were found in TR compared to IR. These changes during the long distance running may provide some specific details for exploring potential reasons of running injuries.

This study investigated the biomechanical characteristics of the lower extremity kinematic variables between the initial and terminal phase of 5 km treadmill running. The lower-limb kinematic data of 10 runners were collected using a three-dimensional motion capture system on a treadmill at the initial phase (0.5 km) and the terminal phase (5 km), respectively.