Udisha
Flat on the stomach
While this may be comfortable, sleeping flat on your stomach forces your neck into a weird angle which puts a strain on the cervical spine. Your torso also sinks, affecting the curve of your lower back.
Back sleeping without support
Sleeping flat on your back forces your lower spine into an uncomfortable arch. The natural curve of your lumbar also gets disrupted, leading to a pain in the lower back.
The fetal position
Curling up and sleeping tightly in the fetal position restricts the diaphragm, affecting breathing. Your back and joints also become tensed, causing stiffness.
The arm under the pillow method
A lot of us sleep with our arms under our heads or the pillow on a side. However, this restricts blood flow and your arm becomes numb, and you wake up with a stinging sensation.