If you utilize the S-mount in training, take a look at the video. The questions I ask is do you have the proper amount of hip rotation in each leg? Are you able to do opposite rotation at the same time? This exercise is based off a key movement/stretch in Ginastica Natural. If you don't know what Ginastica Natural is, then you should definitely go to their YouTube page. There is some great info for anyone who trains BJJ.
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