The kata Sanchin Miyagi/San Po/Dai chi, Sanchin Higashionna/Dai ni and Tensho are of the Heishu teaching or the closed/clasped hand forms that are associated with control of tension and breath that lead in combination to the cultivation of the internal energies. All other kata are of the Kaishu teaching or the open hand.

This is in parallel with Five Ancestor Kung Fu in which school Sam Chien is just one of ten Chien or Tension forms that produces the internal energy (Chi Kung) and the external Iron Body (Ti Po Sha).

The non tension forms of Five Ancestors are referred to as Kun or Fist forms.

The roots of these two distinctions may lie in one of Buddha's lessons to his disciples. Picking up leaves in his hand he stated that those teachings he had imparted were equal to those he held, and that the clasped hand (Chuan shou), was that of the teacher. Whilst those individual teachings that could have been imparted were equal to what leaves remained on the trees and that he (Shakyamuni) had the open hand (Kai shou) of a Buddha.

From the Chuan Shou (clasped hand) came the Chuan Fa 'clasped fist teaching', or as it is commonly referred to the 'fist way'. Which when transported to Japan became the term Kempo.

The term closed or clasped hand teaching would indicate those teachings that are passed from master to student which are specific to that individual. In this instance we would say it is knowledge 'handed' on from one generation to another.

The open (empty) hand teaching would therefore be the general teachings and openly available knowledge but were not necessarily those which a student needed given his specific temperament and abilities.

This being the underlying concept of the Heishu and Kaishu kata then this would indicate that the closed hand forms contain the teachings that are specifically relevant to our journey to master and realize ourselves.

Whilst the open hand forms of general teachings are so vast and varied we cannot consider each one individually

We can conclude from this then that San Chin does indeed contain the core teachings and its study is absolutely necessary if we are to understand the essence of Karate. The other open hand forms then contain the myriad of teachings of techniques through which a single facet can be shown

Therefore the closed hand form and the open hand forms are both required equally so that the immutable energy (of Sanchin) and the adaptable application (of the other kata) can manifest and be realized.