There are different ways of holding a guitar to play in a seated position.
1. Classical position - Guitar body sits on the left leg with the same leg given elevation using a foot stool, head stock positioned at 45 degrees angle
2. Standard position - Guitar body sits on the right leg
Important pointers
1. Elbow of right hand should be on the guitar body
2. Shoulders down and not shrugged
4. Muscles of the hands should be relaxed
5. Back should be straight
It is advisable to immediately stop playing if any discomfort or pain persists.