I had to google what those exercises are, I gave the superman planking exercise a go out of interest. It seems to have a similar effect to one of the things I do with the silly ball - puts some rotational force on the torso - the core is not just the abs. It also requires the body to balance - I am told that core reflexes help protect - not just strength.... I can do all the exercises prescribed, except the bird dog/superman which are still painful
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One of the massage therapists who has treated me insisted that some of the body builders with ripped abs did not have a good solid core.