Adarq.org

I really dont agree with everyone who is telling you to do paused squats as a remedy. I've done paused squat reps in every warmup set (alternating reps) for the last 12 months.. i can nevertheless goodmorning those paused reps no problem lol. It's not going to stop you from doing that per se. But it may help with nailing the descent, ascent can still be goodmorninged though.

One thing you might want to explore is bodybuilding for assistance work to fix weak points. Don't be dismissive, russian and chinese olympic lifters use BB assistance work regularly. I found doing cable rows helped with keeping my chest position out of the bottom position of a squat, previously it would drop. Never thought doing something as simple as a cable row would help with my squat but it did. Which reinforces my thought that it doesn't necessarily have to be the quads or hams that are the culprit (they might still be weak though).

yeah that's the issue, i'd have to do any pause squats with a prettty light weight so that i could actually maintain back angle...i;m talking like...50kg atm. whether it would be beneficial over normal squats i dont know. They may help in teaching me to engage my quads earlier - i think part of the problem is i bounce off of my PC then as soon as i lose the bounce my quads don't kick in fast enough/sufficiently to keep that bar/upright torso moving up. i don't know, i'll try them out and video them and see how they look.

I think it's still a matter of quad strength.

I never ever goodmorninged any squat, and I'm quad dominant.

It can't be the hamstrings, because when you're goodmorninging a squat you are loading up the hamstrings more, and you wouldn't do that if they were weaker.

yeah i think ultimately it is down to quad strength, or PERHAPS even just activation. i've had tonnes of knee issues patella/quad tendonitis for years, so maybe my quads are just sleepy from years of this. the fact that my issue got worse after taking 6 weeks off of any quad work whilst continuing to pull when resting my knees also points to this.

i do a fair but of upper body type stuff, both stuff that's programmed in (rows) + i do an extra day or two just for aesthetics/balance. i;m considering throwing in some extra lower body stuff...one leg stuff to get my leg drive going etc. i just gotta be careful with the volume considering im doing oly lifts/squats 4x /week already

Here you go:

http://strengtheory.com/fixing-the-good-morning-squat/

Also:

1) If you’re prone to turn your squat into a good morning, these findings throw another potential culprit into the mix – your glutes.  Since they can contribute to knee extension via the rectus femoris, if you’re unable to produce enough knee extension torque to come up out of the bottom of a squat without your back angle relative to the ground decreasing (hips rising faster than the bar), they could potentially be to blame.

To quote:

1) The origins and insertions of the hamstrings and rectus femoris allow them to extend the hip and knee simultaneously, even though their actions oppose each other.

2) Two joint muscles allow force from single joint muscles to be transmitted to joints they wouldn’t otherwise be able to effect.  For example, the rectus femoris allows the glutes to help extend the knee.

3) You can put these principles to work for you by learning the best way to grind through your sticking point on a squat

4) Because two joint muscles transmit force throughout all of your hip and thigh musculature, squats aren’t truly knee or hip dominant, regardless of how they look or what the external torques at the joints are.

It's similar to this: