A rubber band was a round band made of rubber that was used on Earth to secure things together. Similes often referred to the way a stretched rubber band would quickly snap back.
Philippa Georgiou criticized Michael Burnham's plan to strand herself in the 32nd century using the red angel suit by comparing her to "some galactic rubber band with a martyr complex." (DIS: "Such Sweet Sorrow")
In his captain's log, James T. Kirk compared the USS Enterprise's accidental time travel to the year 1969 to snapping a rubber band. (TOS: "Tomorrow is Yesterday")
In 2365, when Grebnedlog asked for help, Geordi La Forge responded by saying, "Let me guess. Their rubber band broke, right?" (TNG: "Samaritan Snare")