pelvic floor

例句：

1. 1.The pelvic floor is a crucial part of the body's support system.
   骨盆底是身体支撑系统的重要组成部分。
2. 2. Pelvic floor exercises can help improve posture and prevent back pain.
   骨盆底锻炼可以帮助改善姿势，预防背痛。
3. 3. During childbirth, the pelvic floor muscles are stretched and strengthened.
   分娩过程中，骨盆底肌肉被拉伸并加强。