Popular consensus seems to be that ergonomic keyboards (with the middle split or curve) are better for your physical health than standard keyboards, and reduce the likelihood of carpel tunnel syndrome or other medical issues. If this is the case, I am surprised that there continue to be many more models of standard keyboards available for sale than ergonomic keyboards.

Is there definitive data on the health benefits (or lack thereof) associated with using an ergonomic keyboard versus a traditional keyboard?