I've been doing Crossfit full-time (5-6 days/week) for a year now, and I have a really, stubbornly weak squat. It's so weak that it's always my limiting factor on compound movements like thrusters, cleans & jerks (not my upper body). I have very long limbs in general and especially long femurs, but it would surprise me if that's the only problem.
My stats and 1RMs
Body weight: 135 lb
Sex: Female
Back squat: 103 lb
Front squat: 93 lb
Deadlift: 183 lb
Squat snatch: 68 lb (the limiting factor is the squat)
Power clean: 103 lb (better than my squat clean because no squat)
Strict press: 68 lb
Strict pullups: 5
Here are some hypotheses I have considered and ultimately dismissed (but correct me if I should reconsider):
Hypothesis #1: I should do Starting Strength.
Counter-evidence: I did SS assiduously(*) for 9 months before starting Crossfit. It worked moderately well for most of my lifts except my squat, which plateaued extremely fast. Now that I'm doing Crossfit, my other lifts are again improving, while my squat rarely budges.
Hypothesis #2: I should eat more.
Counter-evidence: I eat around 2400 calories/day with a lot of protein, and my squat is the only lift that's so stubborn, so I assume this isn't the problem.
Hypothesis #3: I have a mobility problem.
Counter-evidence: If anything, the coaches at my gym comment that my mobility is unusually good. I can sit in an ass-to-grass squat with my knees touching my chest and my butt touching the ground, for example.
Hypothesis #4: I have a squatting form problem.
Counter-evidence: I'm lucky that my Crossfit gym has a strong emphasis on lifting technique, and the coaches think my squat form is reasonable. Their main comment is that I have a hard time keeping my torso upright (especially in back squats, but also front squats). I've tried to work on this, but it seems partly like a necessarily evil given the extreme length of my femurs compared to my upper body.
So what should I do to suck less at squatting? Are there diagnostics I can use to figure out what the problem is?
(*) Pun intended. Not going to lie.