âJust wanted to expand on this a little.
First, this exercise is not new. Recently it's been called the Copenhagen Adduction exercise while ten years ago it was called the Bunkie exercise for the Medial Stabilizing Line. Prior to that, I'm sure it's had its fair share of names as well.
Many currently use it for adductor strengthening while others use it to isometrically load the MCL during early stages of rehab. Some use this exercise for torso control and others may even use it for the shoulder. In my opinion, it may be one of many valuable rudimentary exercises to include in a GPP circuit.
What's most important though, is to use it appropriately. While the goal would be to use the longest possible moment arm for the longest reasonably possible duration, many in early stages of rehab are unable to do so. There simply is no way to hide it.
So for very early stages of adductor or MCL strength loading, it's best to keep the moment arm as short as necessary and choose the appropriate starting point for duration. If starting with a ten second hold, each subsequent repetition would be one second less in duration. A countdown. 10, 9, 8, 7, 6....and so on.
As one progresses, each subsequent repetition can then be performed with a slightly longer moment arm, where the line of force moves distally. Again, 10, 9, 8, 7, 6...and so on.
From here we have several options. Once the individual is able to load for strength distally, it would be appropriate to load for endurance. Therefore, starting distally, if the athlete is able to load for five seconds (for example), then they may be able to perform 5 x 5 sec holds while shortening the moment arm with each subsequent repetition.
From here, it is possible to progress with a longer duration first repetition (i.e. 6, 5, 5, 5, 5) as well as a minimizing the amount of moment arm shortening so that the line of force stays as distal as appropriately possible.
The possibilities are endless. This is not to make things more complex, it is to make the exercise more appropriate. It's simple progressions and regressions with the goal of progressive adaptation.