Some of these recommendations are per Mark Rippetoe’s amazing book, Starting Strength. I usually don't hand our credit easily, but his books are definitly the most applicable and best I've read in a long while.
As Mark Rippetoe says, the squat begins at the rack. The height of the bar should be at about the trainee’s mid-sternum level.
Foot placement will really depend on each trainee’s individual anthropometry, however, in general, a little wider than shoulder-width will suit most with feet angled slightly outward at about 30 degrees.
Before you place the bar on your back, it’d be wise to feel what the “bottom position” should be, where you are squatted down. At the bottom position, your feet should be flat on the floor and your knees should be pointed outward, since they are supposed to follow the direction your toes are pointed on the way down. Your knees should be slightly in front of your toes at the bottom.
It’s important to understand where your body needs to be in space in this bottom position, and also, why you are doing the things that you are. Your knees need to go in front of the toes so that you maintain balance. If your knees did NOT do this, in order to stay upright, it’d be required for your torso to lean overly forward, which in turn, will place an unwarranted level of strain and torque on your lumbar spine.
It’s also important to understand that you don’t want your knees too far forward either, which would require you to raise up on your toes.
You want to find that sweet spot where you get deep enough down that your hips are lower than your knees, yet, the weight is still planted on a flat foot.
The squat is an exercise that utilizes the entire lower body. You’ll hear many people explain the squat as a quad dominant exercise. However, done properly, the hamstrings and posterior chain will activate nicely as well. And this is why it’s important to get deep in the bottom position.
Many people only understand the squat as a knee flexion and extension exercise. In order to squat down, you need to flex at the knee joint and in order to stand back up, you need to extend at the knee joint. Only focusing on this will really screw up the exercise. What people miss is the idea of hip drive. When you are in the bottom position, you come out of it with the hips first. Not by extending your knees first. The knees will follow the hips. As Mark says, don’t worry about anything… “Just drive your hips up out of the bottom and the rest will take care of itself.”
Think of it like this. At the bottom position, your torso will be leaning slightly forward to balance you. To get out of the “hole,” lead with your hips. Think as if you were using your tailbone to push up something above it… if that makes any sense at all. Many coaches will teach this by placing a finger on either side of the trainee’s lower back and telling them to push their hips/low back up against the fingers.
If you understand this stuff, it’s time to actually go through the motions with the bar on your back. It’s best to start with no weight on the bar. This assures that you learn the movement properly with no undue stress from added weight first.
For the novice’s purpose, especially those on this site, it’s best to find a comfortable place on your shoulder/traps/back for this bar to rest. Ideally, this is going to be midway down your traps resting on your posterior deltoids.
I’d recommending taking as narrow a grip as shoulder-flexibility allows. This will tighten the shoulder muscles creating some cushion and stability for the bar to rest on. It will also help in keeping your chest high, which I will comment on here.
Ideally, you want to “lock into” your position before taking the load on your back. This means you set yourself up to take the weight. You don’t take the weight first, then set up. Setting up involves a few mental cues that will translate into physical positioning. First, you want to really puff out your chest. In other words, keep your chest high throughout the entire movement. This should be accompanied, simultaneously with scapula retraction, or squeezing your shoulder blades together. Again, pinch your shoulder blades together while lifting your chest. This will most likely feel a little strange at first, but it’s very important.
You also want to keep your lower back arched. Nothing excessive. Our lumbar spines are naturally arched. We simply don’t want any back rounding. Seems simple enough, however, once you start getting down into the squat exercise, especially towards the bottom of the movement, many tend to round their backs due to posterior chain flexibily in order to offset the force pushing them backwards…. essentially preventing them from tipping backwards.
I'd practice getting down into the bottom position again now, knowing how, both the lower and upper body are supposed to be throughout the movement.
If it feels strange.... keep practicing.
Here are a few quick tips I’ve stated elsewhere in for forum to keep in mind. I most likely won’t spend as much time discussing the other exercises. Quite frankly, the squat is my favorite exercise. I think it’s the most critical for the novice to learn. It also requires the most understanding and is the most technical.
With a bar on your shoulders, here are the cues:
1. Chest up (don't cave in)
2. Shoulder blades pulled back together, which reinforces number 1
3. Hands gripping the bar are not wide, but closer. Not so close that it becomes uncomfortable for your shoulders though.
4. Pull your elbows under the bar. Make them point to the floor. This will keep you more upright.
5. Initiate at the hips (think about sitting down) and stick your butt out.
6. Keep a nice, tight arch in your lower back.
7. Keep your abs tight.
8. Stance should be feet slightly wider than shoulder width. This will vary from person to person.
9. You should point your toes slightly outward, maybe 30 degrees.
10. As you start to flex at the knees, your knees should follow the path (line) of your toes.
11. If you leaning excessively forward, you are using too much weight or you have flexibility issues. This is not an exercise for the lower back, do not make it one.
12. Your heels should stay planted on the floor at all times. Many people have flexibility issues and the squat is the exercise that uncovers the issues. Many people, in order to get deep in the squat, feel the need to elevate their heels from the ground. In this case, at the bottom of the movement, their weight is on the balls of their feet. Instead, the entire movement, you should keep your feet flat on the floor and drive the weight pushing through your heels.
13. Remember the hips!
At the bottom of the movement, your hips should be deeper than your knees. This is a full squat.
Here are some links that are certainly worth checking out. Actually, I will be updating this list as time goes on. I am currently running short of that commodity right now. Some of these are video links. Some of the vids are rather long. I HIGHLY recommend checking out every one of these links.
Difference between high bar vs. low bar squat -- VIDEO Lower back rounding at bottom of movement -- VIDEO Leaning too far forward out of the bottom -- VIDEO Engaging the glutes and hamstrings -- VIDEO PART I Engaging the glutes and hamstrings -- VIDEO PART II Bar placement and squat depth -- VIDEO Mobility and Flexibility -- VIDEO Selected Exercises -- VIDEO PART I Selected Exercises -- VIDEO PART II Bands and Chains, not for beginners -- VIDEO Shoes for squatting -- VIDEO Squat set-up and breathing -- VIDEO Bodyweight Squats -- VIDEO Dumbell Squats -- VIDEO Barbell Squat -- VIDEO Barbell Squat 2 -- VIDEO Squat critique from another forum, this forum tends to be brutal in language and avatar pics, so age sensitive -- VIDEO AND COMMENTARY Body Recomposition Forums