Some fun things about the language in this caption:
According to Wikipedia, the line "Help! I've fallen and I can't get up!" is a "famous catch phrase of the late 1980s and early 1990s popular culture based on a line from a United States-based television commercial."
The commercial was advertising a medical pendant that elderly people could wear to sound an alarm if they fell and could not get up. But apparently it was so funny that the line took on a life of its own. It was parodied on T-shirts, in stand-up comedy routines and on TV shows. Take a look at a compilation of these videos on YouTube!
Other parts of the language to explore:
present perfect tense with have + past participle. How would the meaning change if it read "I fell and I can't get up?" "I fell" is clearly in the past tense, but it doesn't indicate how long ago the person fell. "I've fallen" indicates that the action was completed recently or "just now." The effects of the completed action are being felt in the present, and the speaker is asking for immediate reassurance that help is coming. The use of the present perfect tense also connects more fluidly with the present tense of the next verb phrase: "can't get up"
How does this phrase contrast with similar phrases such as, "I've fallen, but I can get up" or "I've fallen, but I should be ok. Why use "but" here instead of "and?" Perhaps because the present perfect here infers that the speaker is still on the ground and needs help. "But" provides contrast, while "and" is kinda what you would expect if someone says "I've fallen." Not so with "I fell." Then you would assume that the speaker is now standing.
Phrasal verb "get + up" - a classic and well-used phrasal verb! Note how this phrasal verb, like a lot of phrasal verbs, implies reflexivity. Reflexiveness is so simple in Spanish or French: verb + object pronoun, yes? Llevantarse in Spanish or se lever in French. The full meaning of "get up" is "get myself up." Myself, yourself, oneself though - these words are way to burdensome on the mouth to use often! So...we English speakers have learned to imply reflexivity through spatial references. Cool.