Approximately the same word, yes, but the stress is different, especially at the outset of shimmies. I mean, from the get-go you've gotta put a lot of muscle power behind the shoulders to get 'em rollin' in a proper (or improper) series of shimmies. That's why the stress is on shimmies right away, first syllable. Now "chemises"...that's altogether different stress-wise. A more relaxed, soft kind of word, chemises is not stressed till its end, like the cloth itself wearing out after one too many shimmies.