IntroThe relaxation-tension-relaxation sequence of body control allows the body apply power quickly and smoothly to a technique. Relaxation helps disconnect the arm or leg from the body so it may move with greater quickness. In the execution of a technique, the entire body must relax initially so it may move quickly and powerfully. Then fire the arm or leg at the target. At the instant of impact, the entire body must tense (especially the abdomen) so it may transfer its energy to the opponent and absorb the reactive jolt of the impact that will ripple back through the body. An instant later, the entire body must relax so it may quickly recover to a defensive position.
Agonist/antagonist musclesThere are two kinds of muscles involved in every movement. Agonist muscles contract and make the movement happen and antagonist muscles that relax to allow the movement to happen. Both sets of muscles cannot tense at the same time. If the antagonists are tensed during a movement, they will slow the movement and may possibly be injured.
Power is a combination of strength and speed. Strength comes from tension and speed comes from relaxation. The body should be relaxed until the moment of impact. Even then, the tension only lasts for a split second. A most common mistake is to tense the wrong muscles at the wrong time.
Tensing muscles at the wrong times
- At the beginning of a movement. Typical symptoms of this mistake are grunts, gritted teeth, tensed neck, shoulders pulled up near the ears, and chin pulled down. The first motion of any movement must be sudden and explosive, no preliminary movements or useless motions.
- At the half-way point of a motion. For example, in the front snap kick. The foot comes off the floor and the knee comes up. Beginners tend to stop here for a moment and then continue the kick; the kick should be a continuous motion from start to finish. When they stop the movement, they tense the leg and the body, and the head bobs. People also tend to tense during the last part of a step, attack or block.
- Tensing body while kicking. During kicks, the upper body should be completely relaxed, with the hands ready to attack or defend. Although the entire body is involved in kicking, the muscles of the kicking leg, the hips, and the abdomen are the ones used primarily.
- Tensing too long at the point of contact. The tension at impact with the target should last only a split second. The duration of the tension depends upon what is intended. If muscle conditioning is being emphasized, then a longer, isometric contraction may be used. In a split-second snap back technique, power is derived from the motion of the body, rather than locking into the technique.
- Tensing unnecessarily while standing. Some muscles are needed to maintain proper posture, but many people tense too many muscles, and tense them much more than needed. As a result, they are rigid and immovable. They must relax to move, but by then it is usually too late. It like standing at attention in military formation. You are standing erect and straight, but if your joints are locked and you are not relaxed, you will faint after a short time. Whereas, if you are relaxed, you may be bored but you probably won’t faint.