The bodybuilders contracted their biceps in unison.

健美运员们一起收缩肱二头肌。

The article explains the morphology factor of chinning in combined grip. It points out that chinning movement can well-developed muscles such as pectoralis major, latissimus dorsi and biceps brachii.

文章阐述了正握引体上比反握引体上难做的因素,明确了做引体上作,主要用来发展胸大肌、背阔肌和肱二头肌的肌力,发达这些肌肉的肌肉块。