Park Jihong, Denning W Matt, Pitt Jordan D, Francom Devin, Hopkins J Ty, Seeley Matthew K
J Sport Rehabil. 2017 Jan;26(1):78-93. doi: 10.1123/jsr.2015-0119. Epub 2016 Aug 24.
Although knee pain is common, some facets of this pain are unclear. The independent effects (ie, independent from other knee injury or pathology) of knee pain on neural activation of lower-extremity muscles during landing and jumping have not been observed.
To investigate the independent effects of knee pain on lower-extremity muscle (gastrocnemius, vastus medialis, medial hamstrings, gluteus medius, and gluteus maximus) activation amplitude during landing and jumping, performed at 2 different intensities.
Laboratory-based, pretest, posttest, repeated-measures design, where all subjects performed both data-collection sessions.
Thirteen able-bodied subjects performed 2 different land and jump tasks (forward and lateral) under 2 different conditions (control and pain), at 2 different intensities (high and low). For the pain condition, experimental knee pain was induced via a hypertonic saline injection into the right infrapatellar fat pad. Functional linear models were used to evaluate the influence of experimental knee pain on muscle-activation amplitude throughout the 2 land and jump tasks.
Experimental knee pain independently altered activation for all of the observed muscles during various parts of the 2 different land and jump tasks. These activation alterations were not consistently influenced by task intensity.
Experimental knee pain alters activation amplitude of various lower-extremity muscles during landing and jumping. The nature of the alteration varies between muscles, intensities, and phases of the movement (ie, landing and jumping). Generally, experimental knee pain inhibits the gastrocnemius, medial hamstring, and gluteus medius during landing while independently increasing activation of the same muscles during jumping.
尽管膝关节疼痛很常见，但这种疼痛的一些方面尚不清楚。尚未观察到膝关节疼痛对着陆和跳跃过程中下肢肌肉神经激活的独立影响（即独立于其他膝关节损伤或病理状况）。
研究膝关节疼痛对在两种不同强度下进行着陆和跳跃时下肢肌肉（腓肠肌、股内侧肌、半腱肌内侧头、臀中肌和臀大肌）激活幅度的独立影响。
基于实验室的前测、后测、重复测量设计，所有受试者均进行了两次数据收集环节。
13名身体健康的受试者在两种不同条件（对照和疼痛）下，以两种不同强度（高和低）进行了两种不同的着陆和跳跃任务（向前和侧向）。对于疼痛条件，通过向右侧髌下脂肪垫注射高渗盐水诱发实验性膝关节疼痛。使用功能线性模型评估实验性膝关节疼痛对整个两种着陆和跳跃任务中肌肉激活幅度的影响。
在两种不同的着陆和跳跃任务的各个部分，实验性膝关节疼痛独立改变了所有观察到的肌肉的激活情况。这些激活变化并不一致地受任务强度影响。
实验性膝关节疼痛会改变着陆和跳跃过程中各种下肢肌肉的激活幅度。这种改变的性质因肌肉、强度和运动阶段（即着陆和跳跃）而异。一般来说，实验性膝关节疼痛在着陆时会抑制腓肠肌、半腱肌内侧头和臀中肌，而在跳跃时会独立增加相同肌肉的激活。
