 entire body and, as a result, burn more calories, so even for those more concerned with fat loss or aesthetics, squats are an unparalleled exercise.
Furthermore, squats do a fantastic job of offsetting many of the postural imbalances we see from those who spend much of their lives sitting in front of a computer perusing Facebook or playing Angry Birds on their iPhone.
Someone who can perform a proper squat demonstrates that they have the ample ankle dorsiflexion, hip flexion, hip abduction, t-spine extension, core stiffness, and glenohumeral ROM (among other talents) to do so. 
While I’m 100% in favor of people squatting with a full ROM (which for me is when the front surface of the thighs drop below knee level), sometimes it’s just not feasible, and borderline counterproductive.
As an example, encourage someone with chronic anterior knee pain or Femoral Acetabular Impingement (FAI) to squat “ass to grass” and you’re setting him or her up for something bad.
Likewise, having someone with a degenerative disc issue do squats could be bad news, as it could for someone who goes into lumbar flexion (butt wink) when going to a certain depth, or someone who has any number of postural imbalances.
Of course, context must always be considered. Every person has a unique injury history and training experience that may or may not dictate what kind of squat variation is indicated.
Too wishy-washy? 
It’s human nature to seek out absolutes, but there really aren’t any in the fitness world, or in the “real” world for that matter.
Listen, I’m not saying that I don’t do it – I certainly have my biases. I feel everyone should deadlift (in one form or another) at least once a week.
Also, if you have a history of shoulder issues – especially dislocations – you should never perform another dip. Like ever.
Those examples aside, I do a pretty bang up job of not leaning too far to the left or right on any given topic. With few exceptions, I feel there’s a time and place for everything – yes, even leg presses (as much as it pains me to admit it), and I’d encourage everyone reading to foster the same approach.
Still, the squat is one hell of an exercise, and I generally lean towards the camp that thinks (most) people should include it – to some capacity – in their programming.
Of course, much of the time it’s simply a matter of placing a premium on coaching someone to squat properly.
Groove a proper hip-hinge pattern (learn to sit back).
Coach a more vertical shin angle (especially for those with chronic knee pain), although we can’t forget that there’s going to be some forward translation of the tibia during any squat.
Teach clients to push their knees out. I can’t even begin to tell you how this simple cue works wonders in helping to clean up squat technique.
Learn to engage core stiffness (get tight). Each set should begin with taking a big breath and encouraging more apical expansion of the torso. This is something that I’ve recently started to realize that I’ve missed the mark on for many years.
Physical therapist Bill Hartman keyed me in on the notion that it’s unwise to only focus on pushing the belly out (which encourages more anterior pelvic tilt, and places far more stress on the facet joints of the lumbar spine). Along with pushing the belly out, we also need to be cognizant of attaining lateral and posterior (apical) expansion.
Learn to engage the lats, and as a result, the thoraco-lumbar fascia to provide more stability to the spine.

While there’s more to it than that, if everyone made it a point to hone in on those key objectives when squatting, we’d undoubtedly see less injuries and (probably) bigger numbers under the bar.
Nevertheless, it can’t be understated: it’s imperative to teach people to squat within a ROM that’s safe for them!
A safe and acceptable depth for one person could be harmful for the next. It’s still possible to reap all the benefits of a squat without necessarily going “ass to grass,” so it behooves everyone to take the time to find out exactly what their “acceptable” range is.
A quick aside: assessment is the foundation for any program that I write. It’s a way for me to delve into the bigger picture and construct a program that will allow for the quickest and safest results possible.
More to the point, it’s also a way for someone to prove to me that they move well enough that I’m confident they’re capable of performing the movements or exercises I deem appropriate for their skill level.
It’s important to reiterate that squatting deep is not dangerous or bad. Contrarily, and without getting derailed, squatting deep (whatever that means to you) can be argued to be safer than the alternative, as I noted in this article.
But how do we “assess” the appropriate squat depth for you?
“In order to find the optimal hip width (or amount of standing hip external rotation), have the athlete adopt a four point kneeling stance. From neutral, rock or drop the buttocks back to the heels.
Mark the angle at which spine flexion first occurs. Then repeat with varying amounts of space between the knees. Look for the optimal knee width that allows the buttocks to get closest to the ankles without any spine motion.
But even this is a somewhat convoluted or limited way to assess things, as squatting by its nature isn’t performed in a quadruped position (not to mention squatting is a bit more dynamic in nature, especially under load).
At Cressey Performance, part of our initial assessment with every new client is to take a look at their standing overhead squat and ascertain their squatting proficiency.

Assume a shoulder width-apart stance with your toes facing straight ahead and your arms fully extended overhead and then squat down as far as you can go.
If you’re one of the few who can squat all the way down without any major compensation(s) coming to the forefront (heels coming off the ground, knees caving in, excessive lumbar flexion, excessive forward lean, to name a few), congratulations, you get a gold star!
This is more of an evaluative squat assessment, and isn’t how I’d go about coaching someone to squat, but more on that shortly.
What this demonstrates is that you have ample hip internal rotation to go into deep hip flexion with very little (if any) ramifications. Granted, we could make a case for hypermobility/laxity, which has it’s own set of drawbacks, but the majority of people reading won’t have this luxury anyway.
More commonly people will have difficulty attaining proper depth performing this particular assessment, which is why I’ll tweak it further.
Widen your stance, allow for a little “out-toeing,” and perform the exact same drill.
Things tend to clean up significantly with this tweak, namely because you’re giving yourself a wider base of support and the out-toeing provides a bit more stability, which serves to open up the hips more to attain more depth.
This is how I prefer to coach someone to squat, and deem this more of a performance-based screen.
Plenty of coaches and trainers like to teach squatting with the toes pointing straight head – and more power to them, it’s not necessarily wrong – but I argue from a performance standpoint, squatting with a wider base and with some slight out-toeing allows for more weight to be lifted.
That said, if things still look a little dicey, we can move onto the next tweak.
Perform the exact same protocol as above, but this time, elevate your heels with a 10-pound plate underneath each foot. Most likely you were able to squat much deeper.
Much in the same way why Olympic lifters wear shoes with a high heel lift, it places the body at a mechanical advantage to squat deep(er).
In the likelihood that using a heel lift drastically improves your depth, it may dictate that you have the ankle mobility of the Tin Man and that you need to address it rather than rely on the heel lift as a crutch.
Sadly, for many, this is the route they end up taking, and it’s all because they don’t take the time to dig a little deeper.

Usually we see a profound improvement not only in squat technique, but also squat depth.

Without performing this last screen, many would automatically assume that the reason they can’t squat to depth is because of a mobility issue, when in fact, as Alwyn Cosgrove has noted on numerous occasions, it’s a stability issue.
Without this differentiation, we can see how many people would be barking up the wrong tree, and doing themselves a massive disservice on the training side of things.
Think what would happen if we omitted or neglected to perform the last squat screen – we’d assume that we have a mobility deficit somewhere and just focus on that one component, rather than address the realissue at hand, namely lack of stability.
Hopefully you understand that using the above screening process can help better determine what would be an appropriate depth for any individual.
And with that information at our disposal, we can also ascertain how to go about addressing some common squatting mishaps.
Some people picked the right parents, have awesome levers, and are