Then another barrister rose — a chicken-breasted little man, wearing gold pince-nez.    From Wordnik.com.  [The Years] Reference

A chicken-breasted chest is seen in Pott's disease of the spine, and to some extent in bad cases of enlargement of the tonsillar tissue; a "violin-shaped" chest in rickets; a bulging of one side in pleurisy with fluid; and a long, narrow chest, with a general flattening of the upper part, in older children predisposed to consumption.    From Wordnik.com.  [The Mother and Her Child] Reference

And by a pack of base boors, by a puny, cream-faced, chicken-breasted, outlandish starveling, have I been robbed of it.    From Wordnik.com.  [The Old Man of the Mountain, The Lovecharm and Pietro of Abano Tales from the German of Tieck] Reference

The other man was narrow and chicken-breasted, his long legs weak, his smile a smirk, his pronunciation so affected that we disgraced him because we blundered from pure lack of comprehension.    From Wordnik.com.  [At Plattsburg] Reference

(making a guttural sound as if of execration) 'he (viz. the said Scotsman) was so chicken-breasted.'.    From Wordnik.com.  [The Uncollected Writings of Thomas de Quincey—Vol. 1 With a Preface and Annotations by James Hogg] Reference

"I wisht I'd 'a' had him runnin 'the' Guzzuh 'instead of that little chicken-breasted chaffer they three-shelled on to me in Los Angeles.    From Wordnik.com.  [Overland Red A Romance of the Moonstone Cañon Trail] Reference

His breast-bone projects out, and the sides of his chest are flattened; hence he becomes what is called chicken-breasted or pigeon-breasted; his spine is usually twisted, so that he is quite awry, and, in a bad case, he is hump-backed; the ribs, from the twisted spine, on one side bulge out; he is round-shouldered; the long bones of his body, being soft, bend; he is bow-legged, knock-kneed, and weak-ankled.    From Wordnik.com.  [Advice to a Mother on the Management of Her Children] Reference