Are your knuckles buckling? That is, are your fingers nice and curved, or flattening out when you’re trying to play chords?
If they are flattening, one issue could be your fingernails. I know it’s a drag for some people, but your nails on your fretting hand (left hand for most) should be real short.
The tip of your finger should have an unimpeded direct contact with the strings. In most cases, the direction of force should be perpendicular to the fretboard.
If it’s not your fingernails, check your thumb placement. Depending on the size of your hand, it could be too far under or too much on top of the neck. Try playing with the thumb placement and see if you can get that perpendicular direction of force.
Questions? Problems? Let me know, we can solve’em!
Matt
