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I would leave the smashing to an even softer ball at this point to get started and stay away from the joint of the hip and work along the crest of the pelvis instead. If you have never done any of this kind of stuff before it is important to start smaller than you think. Pair any banded hip work with some kind of goblet squat holding a kettlebell or dumbbell, light one. There are many resources available about goblet squats.