James Brown was famous for his rather over-the-top dance moves (see the photos here). The extract you posted means that Bruce Springsteen danced quite a lot during his performance but he wasn't quite as lithe as James Brown. He did the best he could given that he is now old enough to claim Social Security (he is of pension age). If he had wanted to emulate James Brown to a greater extent, he would have risked injuring his back!
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