by Jonathon Sullivan MD, PhD, SSC
Attempting to squat on a vertical shank is a common form error. Let's fix it.
People think the squat is complicated, but it's not. Sure, we can talk about the mechanics of the squat ad nauseum...in fact, we are about to do that now, so maybe you should pop your favorite anti-emetic before we continue.
But in essence the squat is very simple. Not easy, mind you, but simple. You stand up with the bar on your back, establish knee position and back angle, and then just lower your hips and raise your hips so as to make the bar go straight down (thataway) and then straight up (thisaway).
Study Figure 1. There you are in A, about to do your second heavy set, and asking yourself for the umpteenth time exactly why you thought this barbell training stuff was a good idea. But it's too late now, so in B you have put your ass back, establishing your back angle and hip position to the rear, and you have put your knees forward, just past your toes and out (external femoral rotation or knees-out). You are about a third of the way down.
Now, you just keep your back angle right there, and you keep your knees right there, and you just lower your hips. At the bottom (C), you reverse the direction of your ass and drive hips up, with back angle still right there and knee position still right there (D), until you get about 2/3 of the way up. Then you just stand up and your back to start.
Great. Just four more reps to go.
This figure is a mental model of performance, or as I call it, "The Thinkage of the Squattage." It overlooks a lot of anatomy and physics and finer points like grip and thoracic extension and gaze direction and are your leggings tight enough or too tight? Stuff that really shouldn't be taking up much of your mental bandwidth when you're under a heavy load, stuff that we study or master earlier or at a more appropriate time. The insertion of the external femoral rotators is very important to squatting, but if you're thinking about that under the bar, you're doing it wrong.
Something else you may do wrong, because a lot of people do it wrong, is illustrated in Figure 2. In A the situation is the same, except that here the lifter has initiated movement with his hips (mere flexion), but not his knees. In other words, he has not put his knees out over his toes, even though he has bent over (without really putting his ass back). The lifter really wants to squat with a vertical shank.
I have observed various permutations of this error, of which only one is illustrated here, in which the lifter is bent over, putting the bar way out beyond the middle of the foot. If he's paying attention and the load is not trivial, he's already got the feeling that Something Ain't Right. In other variations, the lifter lowers the bar on a vertical shank, but keeps it over the midfoot by not bending over, meaning he's trying to front squat a low bar back squat. In yet another variant, the lifter puts his ass back on a vertical shank, pulling the knees back toward the heel in an attempt to keep the bar over the midfoot.
No matter which variation of this error the lifter displays, there will come a point as he approaches the bottom where the squat goes from from an unfortunate initiation to a full-blown Goat Rodeo. If the lifter sticks with the "I'll front squat this back squat" variant, the bar will move behind the middle of the foot (C), and without correction the lifter will fall on his ass with a bar on his back. It's all very colorful and exciting and noisy and spectacular.
However, a tardy correction usually occurs, so this entertaining and potentially expensive scenario rarely actualizes in my experience. Because, you see, the lifter's cerebellum and motor cortex understand, even if he doesn't, that at some point he's going to need to (a) get that bar back over the middle of the foot; and (b) use his damn quads, if he has any hope of getting out of the hole, completing the lift, and passing on his mediocre genetic material to the next generation.
Neither (a) nor (b) requirements can be satisfied with a vertical shank.
So now, rather too late in the day, the lifter thrusts his knees forward in a frantic attempt to get into position, and in almost every case he overshoots. The sudden knee thrust forward pulls the hips and the rest of the barbell-lifter system along for the ride, and the lifter ends up with the bar out front, hip drive neutered, with a moment around the midfoot. He's on his toes, the bar is out of the slot, and the biomechanics of the situation are now somewhat dire. Injury is extremely unlikely (I've never seen it), but the lift will will be ugly and uncomfortable, and he'll be lucky not to dump the bar on the pins.
So here's the moral of the story: Don't do that.
Or, perhaps more helpfully, when you begin the squat, begin slowly, so you can focus on unfolding knees and hips at the same time, establishing your back angle and your knee position very early. In your mind, the squat is all about lowering and raising the hips. The lion's share of the movement consists of nothing more than that. Your job is to immediately get your hips, back angle, and knees into position, so you can focus on raising and lowering the hips such that the bar goes straight up and straight down.
If you learn (from coach or video) that you are squatting with a vertical shank, think about initiating with the knee until the situation is corrected. The TUBOW (or TUFR) can be used in this scenario, as a "target" for your knees to achieve early in the movement. TUBOW or no, you'll probably find that if you think about starting with the knee that your hips and knees actually unlock simultaneously. In a very short period of time, you and your brain will learn to appreciate the delightful benefits of this approach, and you will have incorporated the correct integration of hips and knees into your movement.
Then you can move on to the next problem.
Jonathon Sullivan MD, PhD, SSC, PBC is a retired emergency physician and research physiologist, and the owner and head coach of the Greysteel Strength and Conditioning Clinic in Farmington Hills, Michigan, which specializes in training adults over 50. He is the author of The Barbell Prescription: Strength Training for Life After Forty, with Coach Andy Baker.