Nigel Lythgoe has walked away from So You Think You Can Dance in the wake of Paula Abdul’s sexual assault lawsuit, but RadarOnline.comdiscovered the television mogul was already dropping his workload months before then, which included quietly resigning from a dance organization he co-founded. American Dance Movement — formerly known as Dizzy Feet — is an organization that Lythgoe started with his business partner Adam Shankman, known for his work on films like Hairspray and Step Up, in 2010. American Dance Movement funds dance education in underserved communities and grants to programs that ma…