What is the difference between free floating head and unstable lie?

what is the difference between free floating head and unstable lie?

A condition where the presentation is constantly changed even beyond 36th week of pregnancy when it should have been stabilised. Page 459 DC Dutta Obstetrics 8th edition. Floating head : In many multiparous and some nulliparous, fetal head is freely moveable above the pelvic inlet at the onset of labour which is referred as floating head.

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