Faculty of Sport Sciences, Motricité, Interactions, Performance Laboratory, University of Nantes, EA 4334, Nantes, France.
J Electromyogr Kinesiol. 2010 Oct;20(5):1000-6. doi: 10.1016/j.jelekin.2010.03.009.
The present study aimed to standardize isotonic (IT) and isokinetic (IK) eccentric exercises by equalizing the amount of work and the angular velocity at two intensity levels, to be able to compare specific effects of these exercise modes on the neuromuscular system. Fourteen subjects participated in three test sessions consisting of two IT and two IK sets on a customized isokinetic dynamometer. IT sets were comprised of 8 eccentric contractions of the knee extensors at 120% of the maximal repetition (1RM) in the first two sessions, and 100% in the third session. IK sets were performed at the same mean angular IT velocity and stopped when the amount of work performed corresponded to the IT set. External work, angular velocity and Root Mean Square (RMS) of electromyographic activity of three superficial muscles of the quadriceps femoris were calculated. Results showed concordance of work and angular velocity for each test session. Both modes involved the same number of repetitions at 120% and fewer repetitions in IK mode at 100% of 1RM. Work and RMS values remained steady in all sets. This study allowed the standardization of isotonic and isokinetic eccentric exercises, a first step before determining their specific effects on neuromuscular function.
本研究旨在通过在两个强度水平上使工作量和角速度相等，使等张（IT）和等速（IK）离心运动标准化，以便能够比较这些运动模式对神经肌肉系统的特定影响。14 名受试者参加了三个测试会议，包括在定制的等速测力计上进行两次 IT 和两次 IK 集。在头两个会议中，IT 集由 120%最大重复次数（1RM）的 8 个离心收缩膝关节伸肌组成，在第三个会议中为 100%。IK 集以相同的平均 IT 角速度进行，当完成的工作量与 IT 集相同时停止。计算了股四头肌三个浅表肌肉的外部工作、角速度和均方根（RMS）的肌电图活动。结果表明，每个测试会议的工作和角速度都具有一致性。两种模式在 120%时涉及相同数量的重复，而在 1RM 的 100%时 IK 模式的重复次数较少。在所有集合中，工作和 RMS 值均保持稳定。这项研究允许等张和等速离心运动的标准化，这是确定它们对神经肌肉功能的特定影响的第一步。
