Kinked Backs in Pond and Goldfish
Kinked backs in pond and goldfish are usually impacts from being carried with other fish in a net. Koi Socks seldom damage fish in this way.
Test for Stray voltage and make sure your nutrition for the fish is TOP NOTCH.
Testing for stray voltage means that you can detect MILLIAMPS because most stray voltage is 110-120 VOLTS but measured in milliamps.
Handling is the number one cause of kinked backs showing up about a week after being carried UNDER a bunch of other flopping fish in a net.