Guitar question

tommyboy26

I have been learning to play the guitar the last few weeks and have had a few lessons but due to the bank holiday I have no lesson for 2 weeks so Said i would ask here.

When I am holding a chord lets say an "A" when I'm holding down the strings my hand is arched down so as not to catch bottom string off the Pam of my hand then with 3 fingers on strings and my thumb pushing on the back of the neck i strum the chord but when I lift my fingers to switch to a "E" chord my thumb pushes the neck forward and my fingers end up on the wrong strings.

I hope all that makes sense.

Now the question:
Am I doing something wrong with my hands?
Would a strap fix the problem?

I play sitting down if that Makes a difference

Any help would be greatly appreciated

refusetolose

try to take off the thumb pressure when you lift your other fingers to switch?