>>76523147 (OP)
More nordic curls. Its actually really rare to see someone be able to do a single nordic curl where they start at the top go down to the bottom and come back up. Usually what happens is they go almost halfway down, drop to the ground, and push themselves back up. The linked article does have some good information, and I do like sliding/suspended leg curls.
As usual, its people can't actually do/hate training the exercise, rely on EMG studies, and only talk about training specific muscles in isolation which is not how your body uses them in real life.
Try finding videos of people doing nordic curls where they go all/most of the way down and come back up. Its actually pretty hard to find. For many people it will take two or three years of training nordic curls 3-4 times a week before they can do a single fullish nordic curl. Thats why you are not seeing people being able to do one. Just go look for the videos, there should be ton given the amount of people talking about the exercise. Theres almost none.