The barbell squat or deep knee bend is among the best exercises. It is the only movement needed for complete lower body development. Despite this, performing an otherwise normal motion with a heavy barbell across your back can feel unnatural so you must learn good form.
The squat works the hip, thigh, and leg regions. The main joint motions are hip extension, knee extension, and plantarflexion. The core muscles, outer hips, and upper back contract to hold your position along with many other muscles.
This guide focuses on the raw barbell squat.
Equipment
You will need a barbell, weight plates, and uprights with saddles. You also need a way to remove the barbell from your back at the bottom. Use a bar with a rough knurling in the center. This keeps the bar fixed against the back. Make sure to use a shirt that has some friction. Too much sweat will prevent the bar from staying stable. Bring an extra shirt if necessary. Use chalk on the central knurling and where the barbell meets your back.
Spotting a squat can feel unsafe for everyone involved. Dumping the barbell off your back during a failed rep can cause injury. A power rack provides the best solution. A half rack or similar setup would work as well. These allow it to be done safely alone. Place the safety bars at a position slightly below the range of motion you choose. For most trainees, strive for the crease of the hip just below the top of the knee. Achieve at least a 90° bend at the knee. If you fail to complete a repetition, bend forward slightly by pushing your hips out at the bottom to rest the barbell upon the safety bars.
A safety squat bar or a barbell pad may allow a more comfortable position on the upper back. The safety bar allows a less restrictive hand position. Nonetheless, these options make it difficult to keep the bar firmly on the back. They also ruin the motion by forcing the bar to place too highly on the trapezius. A slightly cambered bar can serve as the only safe substitute for a barbell. You do not need a towel around the bar. The upper back will adapt over time.
Safety
Elevating the heel on a block increases the shear on the knees. This attempts to isolate the quadriceps. Never do this. Sitting down on a box can compress the spine, especially if the trainee relaxes. Both these additions come from powerlifting and bodybuilding.
Advice on the squat often comes from powerlifting. It serves as one of their three core lifts. Keep in mind that lifting more weight in competition does not always mean better or safe. They teach technique that makes sense only when applying special equipment and rules. This includes performing with an elastic suit, belt, and knee wraps that does not apply to raw squatting. A very low placement of the barbell improves leverage but may carry other disadvantages. Using elastic bands and chains change the resistance curve to match leverage but not where muscles function strongest. This may teach acceleration at best but has no use for the average trainee. The safest and most effective version balances stress on all the major muscle groups. A simple barbell along with proper form works best.
Variations present no advantages beyond the basic barbell placed on the upper back. The front squat places anterior stress on the knee. It slackens the hamstrings, preventing contribution. Other variations such as the hack and zercher options use awkward and dangerous positions. Isolation does not work effectively and can harm you. I also suggest against equipment for assistance, with the rare exception for elite lifters that may need to protect their joints, not lift more weight.
High-Bar Squat
The high-bar squat is easy to learn. The bar goes across the upper trapezius. This leads to a more upright posture. The bar lines up with the foot automatically to adjust for the center of gravity. Due to the lack of a stretch in the hamstrings, this version feels smooth. This may prevent the hamstrings from lengthening enough to contribute much though if placed too highly. Without the hamstrings contracting, anterior knee stress develops. This unbalance, with force affecting the front but not the back, can harm the knees.
It can feel difficult to get under the bar and stay balanced if the barbell places too highly. This causes a tendency to tip forward. Too high of a position does not allow the barbell to move linearly. It also loads the spine from an angle that maximizes compression. These issues occur due to a long moment arm. The moment arm is the distance between the barbell and low back. There also exists less muscular support. This position feels less comfortable for handling a heavy barbell, due to the upper trapezius alone handling the load. The body adapts though with time.
It strains the wrist, elbows, and shoulders less compared with the low-bar squat. Any barbell squat can irritate these joints though. It does not require as severe a hand position behind the head, which forces more external rotation at the shoulder and wrist extension. Olympic weightlifters use this version as an assistance exercise. It closely matches the receiving phase required for snatches and clean and jerks used in their sport.
Low-Bar Squat
The low-bar position places the barbell across the top of the rear deltoids. Seek the notch between the middle and rear deltoid heads. You will feel the weight in these two areas on the shoulders for the low bar squat as opposed to only one area on the upper back for the high bar squat. This leads to an inclined torso that stretches the hamstrings. The low-bar position feels technical and requires practice to learn. The bent-over position adds passive tension in the hamstrings, which can make the movement feel tight. Keeping the chest up prevents the tension from feeling excessive. It balances the forces on the knee better, due to more hamstrings involvement. This protects the knees.
Due to the greater leverage and muscle recruitment, it allows more weight relative to the high-bar position. The decreased distance between the barbell and the lower back reduces the strength required there. The bar moves more easily in a linear path. It feels easier to maintain the proper position. The spine loads more safely due to greater muscular support and the lesser moment arm. The rear deltoids hold heavier weights more comfortably than the trapezius.
Unfortunately, the low-bar position can hurt the wrists and shoulders. This occurs due to the extreme external rotation at the shoulder and the greater wrist extension. This can be offset with the proper chest and hand positions. It may involve the quadriceps at the knee less due to the reduced range of motion and short moment arm affecting the knee. More weight does not necessarily mean a better stimulus for the muscles. The lesser range of motion at the knee makes you less likely to reach the 90° minimum angle. This muscle length of the quadriceps is required for the best improvement. The bar can potentially slip down the back as fatigue develops. This develops partially because of the posture required that relies on maintaining the chest up position more diligently.
High Bar Vs. Low Bar
I suggest you use the low bar position if possible. Ultimately though, if you keep the chest up, the position difference matters very little. Do whatever allows you to reach the range of motion safely. You must pinch the shoulder blades tightly together for both versions. This will help you find a secure notch. This can feel hard as your muscles never adapted to support a barbell. Smaller trainees and women find this more difficult. Nonetheless, as long as you keep your shoulder blades pinched together, you should find an area to handle the barbell.
Starting Position
There is no slightest question about the effectiveness of squats; they are certainly one of the most result producing exercises in existence.
– Arthur Jones
Position the barbell at the chest. Keep it level with the sternum. Use a pronated (overhand) grip to grasp the barbell. You may use a standard power grip or a false grip with the thumbs unwrapped. The thumbs rest on top of the bar, alongside the fingers, when using the false option. This may allow the wrist to align better with the forearm. This can reduce wrist stress. The bar must rest on the upper back. The bar should not rely much on the wrist and hand to keep it positioned.
Drive the chest up and pull back the shoulder blades while keeping your elbows tucked in and pointed down. Do this for the entire movement. Keeping the chest up represents the most important tip, by far, for a proper squat. It allows your hips to stay under you. The range of motion needed will come more easily. Your lower back will stay in a safe, neutral position. It even ensures your calves stay in the movement. This also provides a solid platform for the barbell. Do not forget this tip: chest up and out.
The eyes should focus straight ahead or slightly down. Never look toward the ceiling. Once again, this will also make the range of motion much easier to achieve. The neck should feel in a comfortable position. Do not tuck the chin or rotate the head. Press your neck back into the barbell. Pick a point to keep your eyes focused on during the entire movement.
Using a mirror can harm coordination and lead to a lack of balance. Rely instead on feel and not sight when learning the squat. Do not squat with your face too close to a wall or other object. This can also harm coordination.
A closer grip allows the shoulder blades to pull further back. The creates a strong, stable shelf for the barbell and keep the body tight. A wider grip reduces this effect but eases the strain on the shoulders, elbows, and wrists. A wide grip also allows your elbows to point down at the floor, allowing you to squat with your chest up. You need to strike a personal balance. Find a close enough grip that allows you to rest the barbell securely in a groove on your back and without hurting your joints.
Liftoff
Tighten the upper back prior to removing the weight. Squeezing the bar intensely with your hands will help with this. Step underneath and unrack the barbell with a partial squat. You should not have to dip too low, with only a slight bend at the knees and hip. Make sure you stay under the barbell. Only take as many steps back as necessary away from the saddles. The knees should remain near full extension as you walk out. Always back out away from the saddles. Never step forward. This allows you to see your actions and remain in control.
The feet placed shoulder-width apart at the heels works well as a starting point. The toes should point outward between 10-30°. This angle increases with a wider stance. Toes pointed straight can harm hip extension strength and irritate the knees. Any closer than the width of the hips sacrifices stability, makes you likely to round the lower back, prevents the inner thigh muscles from contributing, and will pull the hip flexors out of alignment. Excessive width tightens the hips and prevents a smooth range of motion. While the base of support improves with a wider stance, you lose even stress across the muscles along with explosiveness. Choose a standard, medium stance.
Bracing of the core occurs naturally during a squat. Abdominal hollowing is an unnatural activity that increases the risk of injury. Do not suck in the stomach.
Action
Lowering (Negative) Phase:
Any inflexibility in the active muscles can lead to rounding of the lower back. Make sure these muscles feel loose enough through a proper warm-up and a stretching routine if necessary. Do not allow the heels to leave the floor. Tight calves can make it impossible to keep your heel on the floor.
Take in a deep breath before descending. Hold it until you begin the lifting phase. This protects the spine by providing support created by a column of held air. This benefit makes up for any blood pressure increases for nearly all trainees.
Imagine moving your body between your legs as you descend. Focus on directing the hips back foremost. Push them down and back while keeping the chest out. Relax the hip flexors located on the front hip near the upper thigh during the descent. Driving the hips too far back will cause a pelvic tilt. This prevents the hip muscles from activating properly. Prevent this by keeping the chest up. The knees will bend naturally, so do not focus on them.
Do not confuse hip extension with using your lower back. Pushing your hips back does not mean the back has rounded. A vertical torso does not represent the correct way to squat. A forward lean comes with a correct squat. Keep the weight moving in a straight line by not tipping forward. Prevent this by keeping the chest up. The knees should not travel much beyond the toes. Failure to properly use the hips and maintain tightness in the bottom position will allow this to happen. Stay tight by shoving the knees outward. Imagine spreading the floor with your feet. You should feel pressure on the outside of each foot. Spreading the floor also allows inner thigh activation. The knees should never twist inward.
Keep the elbows down and not too far behind you. The traditional advice to keep the elbows up is overemphasized. Overdoing this makes it impossible keep your hips under the bar and the chest out. Elbows not too high ensures that the hips remain engaged. It keeps you from tipping forward. A slight elevation may feel necessary to keep the barbell in place though.
Getting low can feel challenging. Most trainees undershoot. The top of the patella meeting the crease of the hip joint provides a good depth to achieve. You do not need to go far beyond this standard. As the hip and knee joints move further away from the line of action, the load will feel heavier and you will grow weaker. Too low maximizes harmful forces involved while working the muscles at a weak length. Some depth does allows you to activate a stretch reflex which helps propel you upward. Never a range of motion that prevents you from keeping a neutral spine.
Minimize time spent in the bottom position by using the rebound to quickly remove yourself from this position of weakness. Avoid excessive bouncing out of the bottom position. Make a fast but smooth transition.
Lifting (Positive) Phase:
Do not push forward with the hands during the repetition. The same mechanics apply as the lowering phase. The hips and shoulders should rise from the bottom position at the same pace. One you reach the bottom, do not waste time there. You are in a weak position that is meant to propel you due to the stretch reflex. Your hips should not push back, instead the back should rise. Attempt to keep the elbows under the bar to encourage hip extension without an excessive lean. Pulling the bar downward across the back helps some trainees with explosiveness. The load should feel distributed across the foot. The heel drive is simply a teaching method.
Finish
Dump the bar on the safety bars of the power rack when finished.
The Barbell Squat
Make all adjustments possible before not performing this exercise. It truly ranks as among the best, if not the single best exercise you can use. This lift tends to improve everything else, as it seems to have a huge indirect effect. Nonetheless, it may pose a risk to the shoulders of some trainees. This comes due to the external rotation required. A trap bar dead-lift may be an alternative in this case. Otherwise, you must squat.