Yes, knees out and lumbar control are the obvious problems. They are somewhat related, but coaching the finer points of this is a little tricky over the internet.
You need to be generating a lot more stiffness with your core.
These are relevant, despite being primarily about deadlifting.
http://www.youtube.com/watch?v=mjbvf0P0bas
http://www.youtube.com/watch?v=a-DJu0bEVPw
You need to learn how to hip hinge effectively, which means to move around your hips with your spine neutral and completely locked down. This involves lats, glute med., and core. You should feel like you're sitting onto your hamstrings and glutes, rather than folding over to make depth.
Could you show me a video of you doing RDLs as described in the OP? These are fairly awesome for exposing and correcting these faults. A guy I'm working with has used these a lot and now has pretty sexy technique when before I had to cover my eyes watching him
You need to be generating a lot more stiffness with your core.
These are relevant, despite being primarily about deadlifting.
http://www.youtube.com/watch?v=mjbvf0P0bas
http://www.youtube.com/watch?v=a-DJu0bEVPw
You need to learn how to hip hinge effectively, which means to move around your hips with your spine neutral and completely locked down. This involves lats, glute med., and core. You should feel like you're sitting onto your hamstrings and glutes, rather than folding over to make depth.
Could you show me a video of you doing RDLs as described in the OP? These are fairly awesome for exposing and correcting these faults. A guy I'm working with has used these a lot and now has pretty sexy technique when before I had to cover my eyes watching him