bend one's back as in fear or deference.
to obey submissively; to bend one's neck; to follow with docility; to be docile and obedient
[Informal] to bend one's back; to stoop
Walking on the ancient Jiuqu Bridge makes people relaxed and happy, because every bend on the bridge is carved with vivid flowers, I heard that if you walk through each flower heart, you will bring good luck.