Reasons for the difference and diversity of teachings, intention, and forms of aikido can be traced to the shift in training focus after the end of Ueshiba's seclusion in Iwama from 1942 to the mid-1950s, as he increasingly emphasized the spiritual and philosophical aspects of aikido. As a result, strikes to vital points by , entering () and initiation of techniques by , the distinction between (front side) and (back side) techniques, and the use of weapons, were all de-emphasized or eliminated from practice.
