If you are uncertain about your balance, you had better grip the attached handrail or the drainpipe like the one in the upper right picture (commonly called grunt bar, however, it must be strong enough).
不安がある場合は備え付けの手すり、または右上写真のような配水管（俗称gruntbar、ただし十分な強度がある場合に限る）につかまるといい。