I'm a beginner lifter (female) doing Starting Strength. I'm having a problem with my deadlift form that I think might be partly related to individual morphometry.
So, what happens is this: I set up as described in Rippetoe's SS with the bar at midfoot. I take my grip. I bend my knees until my shins touch the bar. Because I have (very) disproportionately long thighbones compared to the length of my torso and shin bones, this puts my hips quite low, my back at about a 45-degree angle to the floor, and my knees jutting pretty far out over the bar. It's a very awkward arrangement. When I start to pull, inevitably my knee angle "wants" to open first to the point that my back is horizontal before the bar actually leaves the ground (just like in Fig 4-35 in Rippetoe's SS). With this kind of form, I was deadlifting 1.28X my bodyweight. If I force myself to maintain the same back angle through the pull, I could probably deadlift more like 1X my bodyweight, if that. Even if I deload to just 65 lbs, it stills feels really awkward that my knees are in the way of the bar as I start to pull.
I noticed that Rippetoe does allow for substantial differences in deadlift back angle due to individual morphometry – e.g., in Fig 4-31, the leftmost stick figure's back is almost horizontal. However, like I said, when I set up according to his instructions, my back angle is actually more like 45 degrees.
So my questions are: what kind of form, especially back angle, is correct for someone with my morphometry (long thighbones)? An additional complication is that my squat is embarrassingly weak, so is it a problem of weak quads? And what should I do about it?
EDIT: Indeed, my hips are rising to near-horizontal before the bar leaves the ground.