Some years ago I visited the site of Dachau concentration camp. The photograph below was on display. It shows prisoners being punished by pole hanging. Prisoners were handcuffed behind their backs and then they were hung from a hook for one or two hours. This would be what the American Government would call a stress position [but definitely not torture].
This was such a common punishment at Dachau that a room was devoted to it with hooks along walls and on support pillars.
Pole hanging appears to have been used in many Nazi concentration camps. This photograph shows poles at a camp near Berlin.
When I visited Dachau recently all references to pole hanging had disappeared. The photographs and exhibits in the camp museum appear to have been sanitised over the years.