[john scott]

Due to old age my shoulder mobility is not all it should be. I have started doing mobility exercises (posted on this site - thank you) but so far I am still not able to reach my valves. Hence I was planning to invert my twin tens to enable me to do shutdowns.
However, talking to the owner of a LDS who runs GUE courses I was told that inverted twins were not allowed for cavern and cave courses. Is this a rule for all organisations who operate cave training?