Physics and biomechanics is a suitable alternative paradigm for some of the physical concepts and meaning of Ki a provide an example analysis. Clearly though this is a non-trivial task given the complexity of modern physics when used for even simple interactions. To apply modern physics to a physical interaction, a thorough understanding of Newtonian mechanics, mathematics to calculus level and biomechanics is an essential requirement. This paper describes how this might be achieved and provides a simple but popular Ki test called unraisable body as an example. In this example a 'conversational' level of physics is presented as an alternative to the traditional Ki concept.

The Development of Science in the East and West

The development of the physical sciences in Japan as we know it today was in conjunction with its contact with the west (though this is perhaps an ethnocentric observation), however development of the internal mind and philosophies was widely prevalent and advanced in East well before this Western influence [4]. Prior to this contact the development of the physical sciences in the East focused primarily on observation [5], for example the observations of the early Chinese astronomers was highly regarded. Discovery of the relationship between cause and effect was seen as less important [5], hence a theory such as Ki could satisfy observable data without discovering causality. The effects of the Ki paradigm then would be well documented but an understanding of how it works would not. Hence a physical science approach is not required or sought after for describing the physical world when a more philosophical description fits the observable. This would explain the tendencies of historical eastern culture to favour these sorts of explanations when describing complex observed events as this was more easily understood. However for today's scientific mind, assimilation of information in this way is difficult to accept. As scientists we can then try to understand the techniques of aikido and other eastern martial arts using paradigms that we are more familiar with. This paper suggest physics as a suitable alternative paradigm for some of the physical concepts and meaning of Ki a provide an example analysis. Clearly though this is a non-trivial task given the complexity of modern physics when used for even simple interactions. To apply modern physics to a physical interaction, a thorough understanding of Newtonian mechanics, mathematics to calculus level and biomechanics is an essential requirement. This paper describes how this might be achieved and provides a simple but popular Ki test called unraisable body as an example. In this example a 'conversational' level of physics is presented as an alternative to the traditional Ki concept.

A Physical Look at the Techniques of Aikido

A conversational level of ability in physics allows us to describe physical interactions, though to pursue a more rigorous solution is considerably more demanding. Newtonian mechanics allows us to calculate the interaction of simple particles and shapes for elastic and non-elastic collisions [6]. Here the position of any point in arbitrary space can be described using only 3 numbers in orthogonal space (x,y,z). To describe this point's movement in space another 3 numbers for three velocity components are necessary. To model the interaction of 2 people we would need to describe their position and velocity in space over a period of time and so this becomes a considerably more complex task. In this case a mechanics equation is required to describe the motion of each independent part of the body for a given movement. For example to represent the motion of a person by describing only the major interconnecting bones, we are dealing with approximately 20 equations using one for each joint of the body. The approach itself is still simplistic in that we are ignoring the complexity of muscle action and reaction on each of the interconnecting bones. Each of these equations would then contain descriptions for position (3 variables), velocity (3 variables) and acceleration (3 variables) say. If we try to describe the interaction of them over even a short period of time, say a three second aikido technique, and we analyse the motion every 0.01s we end up dealing with about 2x20x9x300 = 100,000 unknown variables to compute. Clearly this becomes a considerable task even on today's computers, assuming the expertise was available to code this.

Static analysis of human joints is a complex but straightforward task. The analysis of how a variety of joint control and pinning techniques such as nikyo[7] and sankyo[8] as performed in aikido and other martial arts has been described previously. These works present the anatomical basis of these controls but do not describe the interaction of the attacker and defender prior to or during application of the control. Thus far this complex interaction has not been analysed technically in the available literature or adequately explained otherwise. This too would seem also to be beyond the scope of this paper. Instead this paper will examine a simpler interaction between attacker and defender that is often used to develop Ki power or extension in an aikido student. This analysis will use basic physics to explain the physical forces developed during this Ki test and how an aikidoka (practitioner of aikido) manipulates these to demonstrate Ki development. The analysis is then validated using experimental results.