 Sinzheimer was one of the first academics specialising in labour law; he published an introduction to this field ("Der korporative Arbeitsnormenvertrag") in 1907.He was one of the members of the Weimar National Assembly, which promulgated the Weimar Constitution.As a major influence on the drafting of the labour law section of the constitution, he is considered to be "the father of labour law" in Germany.