◎ 甩开膀子 shuǎikāi bǎngzi
[lay oneself out] 形容全力而为的样子
他甩开膀子,一气呵成

1.have a big go; go all out; set to; go (at sth.) with a free-hand [free-handed]; get into the swing of one's work; cast away all restraint and have one's full swing