1704, of persons, "having slender shanks," 1813 of hawks; see sharp (adj.) + shin (n.).
Entries linking to sharp-shinned
sharp adj.
Old English scearp "having a cutting edge; pointed; intellectually acute, active, shrewd; keen (of senses); severe; biting, bitter (of tastes)," from Proto-Germanic *skarpaz, literally "cutting" (source also of Old Saxon scarp, Old Norse skarpr, Old Frisian skerp, Dutch scherp, German scharf "sharp"), from PIE root *sker- (1) "to cut" (source also of Lettish skarbs "sharp," Middle Irish cerb "cutting").
The figurative meaning "acute or penetrating in intellect or perception" was in Old English; hence "keenly alive to one's own interests, quick to take advantage" (1690s). Of words or talk, "cutting, sarcastic," from early 13c. Meaning "distinct in contour" is from 1670s. The musical meaning "half step above (a given tone)" is from 1570s. Meaning "stylish" is from 1944, hepster slang, from earlier general slang sense of "excellent" (1940). Phrase sharp as a tack first recorded 1912 (sharp as a needle has been around since Old English). Sharp-shinned attested from 1704 of persons, 1813 of hawks.
shin n.
Middle English shin, from Old English scinu "fore part of the leg below the knee; shinbone," from Proto-Germanic *skino "thin piece" (source also of Dutch scheen, Middle Low German schene, Old High German scina "shin," German Schienbein "shin, shinbones"), from PIE root *skei- "to cut, split." Shinbone, shin-bone is Old English scinban. Shin splints is attested by that name from 1930.