Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
J Strength Cond Res. 2010 Feb;24(2):348-57. doi: 10.1519/JSC.0b013e3181cc23d5.
The main issue addressed here is the paradox of muscle contraction to optimize speed and strike force. When muscle contracts, it increases in both force and stiffness. Force creates faster movement, but the corresponding stiffness slows the change of muscle shape and joint velocity. The purpose of this study was to investigate how this speed strength is accomplished. Five elite mixed martial arts athletes were recruited given that they must create high strike force very quickly. Muscle activation using electromyography and 3-dimensional spine motion was measured. A variety of strikes were performed. Many of the strikes intend to create fast motion and finish with a very large striking force, demonstrating a "double peak" of muscle activity. An initial peak was timed with the initiation of motion presumably to enhance stiffness and stability through the body before motion. This appeared to create an inertial mass in the large "core" for limb muscles to "pry" against to initiate limb motion. Then, some muscles underwent a relaxation phase as speed of limb motion increased. A second peak was observed upon contact with the opponent (heavy bag). It was postulated that this would increase stiffness through the body linkage, resulting in a higher effective mass behind the strike and likely a higher strike force. Observation of the contract-relax-contract pulsing cycle during forceful and quick strikes suggests that it may be fruitful to consider pulse training that involves not only the rate of muscle contraction but also the rate of muscle relaxation.
这里主要讨论的问题是肌肉收缩以优化速度和打击力的悖论。当肌肉收缩时，它的力量和刚性都会增加。力量产生更快的运动，但相应的刚性会减缓肌肉形状和关节速度的变化。本研究旨在探讨如何实现这种速度力量。由于必须非常快速地产生高打击力，因此招募了五名精英混合武术运动员。使用肌电图和三维脊柱运动测量肌肉激活。进行了各种打击。许多打击旨在产生快速运动，并以非常大的打击力结束，表现出肌肉活动的“双峰”。初始峰值与运动的开始时间相对应，可能是在运动之前通过身体增强刚度和稳定性。这似乎在大“核心”中为肢体肌肉创造了一个惯性质量，以“撬动”肢体运动。然后，随着肢体运动速度的增加，一些肌肉经历了松弛阶段。当与对手（重袋）接触时，观察到第二个峰值。据推测，这将通过身体连接增加刚度，从而使打击后的有效质量更高，并且可能使打击力更高。在强力和快速打击过程中观察到的收缩-松弛-收缩脉冲循环表明，考虑涉及肌肉收缩速度和肌肉松弛速度的脉冲训练可能是有益的。
