krook'-bakt (gibben; kurtos): A disqualification for the priesthood (Le 21:20); was probably an angular curvature of the spine, usually the result of tubercular caries of the vertebrae. It was by no means uncommon in ancient Egypt, where I have found a considerable number of spines affected with this disease. Some Talmudic authorities explain it as meaning "very dark colored," but this is unlikely.
The woman bound by the spirit of infirmity and unable to lift herself (Lu 13:11-17) was affected with senile kyphosis, a chronic bone disease often found among aged men (and more frequently women) whose lives have been spent in agricultural labor. In these the vertebrae become altered in shape so that it is impossible to straighten the back. Some rabbinical authorities believed all deformities to be due to Satan, and to this our Lord seems to have alluded in his rebuke to those who caviled at His healing on the Sabbath. I have found this condition in some Egyptian skeletons, and have seen it in a Palestinian fellah. A skeleton affected with a similar curvature was found buried under the threshold of a house at Gezer, where she had evidently been offered as a foundation sacrifice.