In the Baji system, there are 3 different power generation methods.Silk reeling (纏絲, chánsī) is specific feature of Taijiquan (especially Chen style).
There is definitely a spiraling motion and my opinion looking to Chen xin work on silk reeling is highly recommended or Chen xiaowang explaining it.
Hi Brendan not sure why you quoted me after a thread almost 2 months to add that tidbit.Chen Xin and Chen Xiaowang come from the Chen village style. Chen Zhonghua is from Hong Junsheng's 'Practical' Chen style. The approaches differ.