Visualization is a useful tool in developing karate both on a physical as well as a mental level. The way visualization may be used is to picture in your mind the karate movements while in a stationary position. This can be used in both the practice and development of technique as well as kata.
There are two common ways in which to visualize the technique or kata. The visualization can either be first person or second person. With first person visualization, in your mind you are doing the technique yourself and seeing your body movements as if you were seeing yourself do the movement from your own perspective. You see your hand and foot movements as if you were actually doing the movement yourself. The second person visualization sees yourself doing the movement but from an observational viewpoint. In this case you are watching yourself make the movements as if you were a spectator watching yourself do the movements. This type of visualization is also very good in determining position on a training floor for you can also visualize yourself doing the movements from an any viewpoint including an overhead view. This is especially useful when visualizing kata in which your relative position on the floor (in your mind) is an important part of the movements.
Visualization allows you to practice a technique that you may have never physically done. Using only your mind you can work on how you want the movement to be performed. By repeating the sequence of movements in your mind, the technique becomes more and more familiar to you. When you finally perform the technique physically, you will find that the physical movements come much easier to you because in your mind you have already done them several times. This can be useful in the development of new techniques yet untried and tested. An experienced karateka in many cases can determine if a technique is practical by visualizing the movement before the movement is ever performed for the first time. Familiar techniques can be repeatedly practiced without actually doing the movements by using visualization.
Visualization in the practice of kata allows you to perform a kata in your mind where as you may be in a situation or place where you are not able to perform a kata. Perhaps you are a passenger in an airplane or are traveling and staying in a hotel room with no physical space to practice kata. Visualization allows you to practice when you are injured or incapacitated. This allows the karateka recovering from an injury to continue their training even though they may be bedridden. Practicing kata in the mind is also a powerful tool for developing mental strength by exercising the mind and mental focus. By exercising the mind a greater level of concentration and control can be achieved over one's thoughts. Consciousness is raised and the level of the unity of mind and body is increased. A stronger mind and a greater mind to body unity makes for a stronger karateka both mentally but physically as well. Visualization therefore should be used as a supplement to one's training as well as a substitute for actually doing the movements when space or time does not allow for conventional practice.