If you're learning the handstand for calisthenics, you may have seen a lot of people doing the handstand with an arched back. I used to arch all the time, too. If the arching is not intentional, it ...

A healthy spine has a gentle arch or curve. Arching your back excessively can tighten the muscles and lead to discomfort. However, arching the spine for brief periods should not cause health problems.