well I must confess while on facebook to being roped into a discussion about rollkur which I've never even looked into so only know that within American circles in particular it's a highly charged emotive topic....
Really not sure why!
Have seen some hideous you-tube clips of horses being abused with training gadgets, and yet other riders use the gadgets as they should be used and all is good, a valuable training aid in the right hands....
So WHY is rollkur so evil??? Hyperflexion is even used in the gyms by people but if done RIGHT it is a valuable tool for catching those muscles missed by other exercises...
Have seen the you-tube clip of Patrik whatshisface and the blue tongue on his horse (likely caused by the tongue getting caught between the 2 bits NOT by the rollkur itself) and agree, the rollkur caught in that video clip is NOT being used in a productive way (90 mins of anything non stop is not beneficial) and have seen some clips of Anky using it much less graphically for for short bursts, which would look to be that it is being used as a variation to get the horse to respond to something or in a particular way and then released when that is obtained...
Like I said, first time today I've actually looked at it, let alone into it, so feel free to educate me...
(emotive browbeating is not and never will be educating

)