A good squat isn't just moving up and down. You have to think about your setup. A common mistake? Not engaging your feet.

Grip the floor by squeezing the ground with your toes. This engages the muscles in your foot's arch, providing the base of support upon which the rest of your squat is built.

A strong arch limits or prevents an inward collapsing ankle. This is sometimes the result of a weak foot arch and sometimes from poor ankle dorsiflexion. Left unaddressed, a collapsing ankle will take the knee inward into valgus collapse.

A little knee valgus won't destroy your knees; it's a normal part of your ankle dorsiflexing around your tibia. But excessive, uncontrolled knee valgus can lead to increased risk of ACL or other knee injuries. It can also lead to poor patella tracking and knee pain.

Poor ankle mobility may be due to bone-on-bone restriction or tight calves. Stretching the Achilles tendon or foam rolling your calves before squatting may relax the neutral tension of the muscles and tendons enough to allow proper range of motion and movement.

You can also try out squat shoes with an elevated heel or use a wedge to allow less demand for ankle dorsiflexion while squatting to greater depth.

If you don't require squat shoes with heels, try squatting in a flat, firm-soled training shoe instead of cushioned running shoes. This gives you a better feel for the ground and feels more stable. Conversely, don't jog in your Chuck Taylors.

You've been told to keep your knees out. This cue can work for some, but it often fails to address the cause of the inward collapse.

Knees cave in during squats for a number of reasons: poor foot engagement, poor hip external rotation (covered next), or sometimes just not focusing on keeping the knees aligned with the feet and hips as you squat. Often, just focusing on the knee tracking path is enough to fix this issue.

Coaches argue over the validity of the "knees out" cue, as it can falter with below-parallel squats. A better approach? Create a secure foot foundation below and focus on controlling your knees as you squat while engaging your glutes to externally rotate the femurs and prevent collapse.

Let's also kill two myths about knees and squats:

1 It's safe to squat below a 90-degree knee angle.

Anyone telling you otherwise is selling you their BS program or justifying their ego lifting. Your knee joint connective tissue experiences the greatest stress at 90 degrees. Healthy knees can safely tolerate this stress, so there's no reason to artificially restrict your squat depth. If you have a history of knee injury, approach squat depth with more caution and work within your pain-free range of motion.

This logic is often used to allow people to ego-lift loads they otherwise can't control with deeper squats. Lose the ego and get your squats deeper, as long as you have the hip mobility to allow it. If you have knee injury concerns, work within a pain-free range of motion. Shallow squats with extra heavy weight aren't doing those painful knees any favors.

2 Your knees can go past your toes.

A normal squat will have your knees crossing forward past your toes. It won't implode your knees.

This nonsense sprung out of the misinterpretation of an old study that suggested the knee experienced more stress when it passed your toes. People just assumed this was automatically bad for your knees instead of understanding the knee's tolerance to handle stress. Appropriate stress on joint tissue combined with enough recovery means stronger joints.

Try box squats if you have chronic knee pain like patellofemoral pain aggravated by deep or knee-forward squats.

Healthy knees are strong enough to handle the added force on the joint as the knees cross forward. Ensure your weight is loaded into your heel and sit back into your hips, glutes, and hamstrings while maintaining a more vertical shin angle.

Your hips are mobile joints stacked between two comparatively stable structures: your knees and lower back. If your hips lack mobility, we often see pain and injury up or down the chain because the knees and lower back are forced to move in ways they weren't designed to tolerate under heavy load. Uncontrolled rounded back or knee collapse can increase injury risk.

Find the femur-to-torso angle where you have the greatest mobility at your hip. This can be found with a quick hip scour on the ground. It tests your hip's passive range of motion.

If you can get into a deep passive squat range but fail to achieve a similar range while actively standing and descending into a squat, you don't have bone-on-bone restriction – you have mobility and motor control problems. Work on controlling a flat lower back and stable knees as you work into a deeper squat range.

You increase injury potential when you force range of motion you can't control. If you can't control the bottom of a squat with bodyweight, then you load it heavily and bounce in the bottom, you're begging to get hurt. But you may see your form tighten up once a little load is applied.

We can also discard the garbage notion that if your bodyweight squat isn't flawless, you have no business adding load. Use your brain here.

Once you've stacked your feet and knees, use the glutes to externally rotate the femur to keep the hip aligned above the knee. This outward rotation helps keep your knee from collapsing from above. Engaged glutes allow a deeper squat range of motion.

If you have the passive range of motion to squat deeper but still experience hip restriction while squatting with a barbell, you can switch to adding support with a suspension strap squat. Often the added stability allows you to get much deeper while keeping a neutral spine.

Set up your feet and knees as described previously and lean back with straight arms holding suspension straps. Brace your core and externally rotate your hips with your glutes. Drop into the deepest squat you can reach with a neutral spine. Use this as a warm-up and practice to develop better motor control into a deeper squat.

The center of gravity of the load is often the issue. Move a barbell back squat to a front or goblet squat, and, almost as if by magic, you get a substantially deeper squat with a stable lower back.

For a goblet squat, cradle a dumbbell in both palms snug against your chest. If the anterior loading allows you to squat more freely and/or without discomfort, use it as a motor learning tool until you have better control of your back squat, or switch to front-loaded squats.

While lifting with a slightly rounded or extended lower back doesn't spell automatic doom, the more engaged the muscles encasing your spine, the safer you are. Maintaining a neutral spine throughout your squat optimizes safety.

Also worth noting, your lower back will always see some flexion and extension when squatting or deadlifting. It's meant to. When we say "neutral spine," we account for this and want minimal movement and braced control. Excessive and controlled lumbar flexion and extension patterns under load are where trouble arises.

Many lifters assume because a rounded back is bad, an aggressively arched back is the solution. This can lead to pain and discomfort. Starting with an aggressively arched lower back and anterior pelvic tilt will often cause an exaggerated "butt wink" at the bottom of the squat because the position of your pelvis tilts from anterior toward posterior at the bottom. An exaggerated change of position of the lower spine increases the chance you get hurt.

To keep your spine neutral through the bottom of a squat, start by figuring out how deep you can squat while staying in control of your spine.

Coaches argue over the need for ass-to-grass squatting. More range of motion in a squat is beneficial for muscle and strength development, but only if you aren't getting hurt doing it. Use the range of motion you can control for the best long-term results. Lost training time from injury is the single greatest obstacle to long-term results.

To increase hip mobility at the bottom of a squat, brace your core with a big breath. Whether inhaling at the top or during the initial descent, and whether exhaling on the path up or at the top, a strong breath adds intra-abdominal pressure to protect your lower back.

If your core is effectively engaged, your hips are free to move as designed. The hips will donate stability upward to compensate when your core isn't engaged, restricting hip range. When we force greater depth than our hips allow, we tend to find the added range by rounding our backs.

To keep your spine neutral, start by imagining a big Superman logo on your chest. Keep this logo open and facing the wall in front of you. Your torso will still pivot forward, but this cue keeps you from collapsing your chest. Then take your ribcage and sternum and lock them down to your pelvic bones. Not in a crunch, but in the distance between ribs and pelvis. Do this by engaging and bracing your abs.

To further help protect your lower back, keep your upper back tight. Engage lats, rhomboids, middle traps, and the entire upper back musculature to retract and set your shoulder blades. This keeps added tension off your lumbar spine and helps prevent rounding when you go heavy.

There's no universal correct head position. Staying close to neutral is ideal for most. Some may pack their necks a little more to aid in core bracing. That's fine as long as you don't restrict breathing. Others may extend their necks to keep their backs straight. If you avoid extremes in neck flexion or extension, you're safe.

If their squat has more torso lean, some lifters extend their necks as they squat. To keep your head in a stable position, imagine locking (not aggressively tucking) your chin to your collarbones and fixing your gaze on the floor 10-20 feet in front of you instead of eye level of the wall.

Hand width on a back squat is primarily a function of comfort, and comfort is usually a function of shoulder mobility and bar position.

Low-bar squats often aggravate elbow issues and can create pain from wrist to shoulder. Low-bar squats are sometimes best done after a little shoulder mobility work. They're best used as an occasional tool to train/retain the skill and as a powerlifting competition tactic to maximize load. Excessive low-bar position shifts training volume away from your quads and doesn't give the arm joints enough recovery.

Regardless of bar position, some lifters have the mobility to keep their hands narrow and near their shoulders. Others, especially lifters with heavily muscled upper backs and delts, place their hands ultra-wide on the bar. This works as long as you maintain upper back tightness.

Elbow position also varies by preference and shoulder mobility. To optimize vertical drive for maximal squat effort, aim to stack your elbows under your hands. Create full-body drive pushing upward, including pushing your arms upward through the bar. Stacked joints and aligned force vectors throughout your body helps to direct all your power into your lift.

Squats aren't the only road to big legs. They're hard to beat for pure system stress and overload, but they also create disproportionately greater fatigue of your entire system and accessory structures like your lower back.

Squat effectiveness can vary by individual anthropometry (a fancy word for body segment/limb lengths). A tall squatter with long femurs won't find squats as effective as a lifter with shorter femurs. Likewise, one person may be able to squat deep naturally while another person can't. That's due to differences in hip mobility.

Heavy squats may not be enough to fully fatigue quad muscle fibers before fatiguing your whole system and your lower back. Add sets of single-leg, quad-dominant exercises like supported Bulgarian squats. Add in lunges, leg presses, and leg extensions to fully train the quads and drive new muscle growth.

Round out your lower-body training with effective overloading exercises for hamstrings, glutes, and calves. While squats will train glutes and hamstrings to some degree, they're best built with Romanian deadlifts, hip thrusts, lunges, and other hip extension exercises. Calves also need targeted isolation work.

Focus on making your sets tough while progressively making your overall pattern of workouts, load, reps, sets, and intensity harder. Take deloads when needed and focus on good recovery, nutrition, and sleep.

• If your goal is strength, focus more on sets of lower reps: 1-5 with 3-5 minutes of rest between working sets.
• If your goal is building muscle, aim for 7-12 reps with 90 seconds to 3 minutes of rest.