Sankaku Channel/knees on chest

A general term for body postures where the legs are retracted towards the torso with the knees either:

• very close to the chest
• tugged against the chest
• by the sides of the chest

 
Due to the inherent nature of the posture, the following tags are often relevant:

• lying / on_back
• legs_up / spread_legs / leg_lift
• leg_grab / leg_hold (when legs are held in position by hands)

 
For explicit posts, the posture is more often than not, achieved with the following positions:

• missionary
• standing and carrying
• top-down_bottom-up / upside_down