Hi! Why is the girl squatting making mistakes? Her squats look good to me! Your clarification would help. Thanks
Her hip hinge is awful and over exaggerated. Look at her lower back. How would she support any type of weight throwing her ass out like that? If she has any weight on the bar it would send her leaning forward immediately. A great deal of power is generated through the posterior chain in the squat and she disengages it immediately because her glutes will be shouldering none of the load like this. Her lower back needs to remain as straight as possible throughout the lift. Hip hinge is good to send the ass back, but it needs to be done with the lats and glutes engaged and tight to keep the lower back aligned properly. Take a look at this post (http://twotontwentyone.tumblr.com/post/134068332549/jsheeter-personal-best-back-squat-with) ironically the very next thing I posted to see my man @jsheeter executing a very heavy, very good looking squat to get an idea of what it should look like.
