Help moving bones

I was trying to get this model
into this pose
so I moved its skeleton into this position
and the model looks like this
Is there a way I can change the way the bones interact with the mesh so that it looks the way I intended it to?

Can you post your images here in future! You are allowed three in each post.

It is impossible to tell you what went wrong without seeing the blend file, but it looks like you may have either unapplied rotations and scales on either your mesh or armature, or bad vertex assignment, or something else, I cannot tell from the pictures.

Unapplied rotations and scales are easily overcome - just select the mesh and armature in Object Mode and key CTRL+A then select “Rotation and Scale”. To avoid things like this happening, only scale or rotate objects in EDIT mode.

I, and others who might help you will need more info to get to the bottom of this.

Cheers, Clock.

PS. You can use for blend files if they are too big to post here.