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.
塌腰