The uneven bars apparatus originally consisted of men's parallel bars set to different heights. Consequently, the bars were very close together, and gymnasts could transition from one to the other with little difficulty. Routines of the early 1950s chiefly consisted of simple circles, kips, and static balance elements and holds. In the late 1950s the trend shifted toward fluid motion, and gymnasts began to perform routines composed of more difficult circles, kips, beats (bouncing the body off the low bar while hanging from the high bar), wraps (wrapping the body around the low bar while hanging from the high bar) and transitions. Release moves also began to come into play, although they were almost entirely limited to transitions between the low and high bars.