Need help with squat and deadlift form

[ellie210]

I'm starting to have problems squatting and deadlifting properly as I continue to lift more weight. Before I try to lift any more weight, I just want to make sure I'm doing the technique sufficiently well and correct any huge mistakes before moving on.

Squat: A month ago, I made a form critique topic and most people said I wasn't using any hip drive. Now I feel like I'm not using my legs enough. What do you guys think? Am I using my legs enough? Here's a video of me squatting last Friday (130 lbs):



Also, I have problems getting the bar lower on my back. I notice that the bar is pretty high on my back, but I can't seem to get it any lower. Here's a couple of photos I took, front and back, to show where the bar is when I squat:





Is there a way I can get that bar lower on my back? Should I just lean forward more when I'm about to squat?


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Deadlift

A huge problem is that I keep rounding my back when I'm going up. However, when I deadlifted on Monday and did my warm up sets, I seemed to have not rounded my back. It was only when I did my work set that I rounded it. Should I just lower the weight on my deadlift until I stop rounding my back? Or will the proper technique come with practice?

Here's a video of me deadlifting:

70x5
70x5
105x3
150x2
180x4
135x5



Anyways, I would just like some feedback because I wouldn't want to screw up my form as I add more weight. Better to know now what I'm doing wrong than later on. Appreciate any feedback from you guys!