扩肩，挺胸。

Shoulders back, chest out.

他挺胸顶着波浪大步走进海里。

He strode into the ocean, breasting the waves.

双手合十呈祈祷姿势，双肩外展，挺胸收腹。

Place your palms together in a prayer position, roll your shoulders back and down and lift your chest.

单杠向后大回环脱手的原因主要是倒立后摆阶段抬头、挺胸、塌腰和悬垂前摆时翻腕等技术错误，以及思想和肌肉过度紧张等。

The reasons of hand leaving in horizontal bar giant swing backward such as technical error and muscle tension etc. Were analyzed.