Squat and deadlift form checks

[Guan Cheng Lin]

Hello, coaches

1) 5th set of 5 squat
V 20201204 184550 vHDR Auto~2 - YouTube

2) Set of 5 deadlift. Unfortunately, I tweaked my back in the last rep
V 20201206 163037 vHDR Auto~3 - YouTube

Any suggestion will be helpful, thanks for your time.

[Mark Rippetoe]

Have you read the book? The sticky?

[Guan Cheng Lin]

Have you read the book? The sticky?

I have read the book and the sticky.
Should I provide more detail about my back pain?

[Guan Cheng Lin]

The pain is deep inside my left erector. It didn't bother when I squat, just a little weird feel at the spot.
I was fool enough to deadlift (back off 10%) two days after, I felt soreness in rep 4,
and it hurt so much when I was just about to look out rep 5.
I can walk after the injury, but whenever I have to posteriorly tilt my pelvis, it hurts.

[Mark Rippetoe]

Your technique is not what we teach, and the squats are above parallel. Your low back is in flexion when you start the pull. Read the book again.

[Guan Cheng Lin]

Get it. Sorry for bothering you