On the inhale bend your left knee as you bring your arms forward and raise them overhead, fingers interlocked, palms facing up, and upper back arched slightly.
吸气时曲左膝，同时双臂向前高举过头，交叉十指，掌心向上，上背部微微拱起。
2
The biceps of the both upper arms bend the elbows, drawing the torso into the stretch.
大臂上的二头肌使手肘弯曲，拉向躯干的方向，辅助伸展动作。
3
The biceps brachii and branchialis (muscles down the front and inside of the upper arm) bend the elbows, drawing the feet upward and opening the pelvis region.