The squat looks simple: bend the knees, lower the hips, stand back up. That apparent simplicity is why so many people get it wrong for years. A lift that begins as a natural movement for a toddler becomes, by adulthood, a tangle of compensation patterns, tight hips, and half-remembered gym advice. The mistakes below are the ones that show up again and again on gym floors and in physical therapy clinics, and each one has a fix that can be applied on the next set.
The Half Squat That Never Reaches Depth
Walk into any commercial gym and the most common sight is a person loading a bar with plates and then bending the knees maybe a quarter of the way down, hips barely breaking parallel, before driving back up. It looks like a squat. It photographs like a squat. It trains almost none of the range of motion the movement is meant to build.
The cause is usually a mix of ego and fear. Heavy weight feels more impressive, and a shallow range means more plates can go on the bar. But the deeper cause is often a lack of ankle mobility or hip flexion, which makes full depth genuinely uncomfortable. The body protects itself by stopping short.
The fix is a box squat to a height that forces true depth, with bodyweight or a light bar, and a deliberate pause at the bottom. A stack of bumper plates or a plyo box set just below parallel works. The cue: sit down onto the box, do not fall onto it, and stay there for a two count before standing. Depth has to be earned before it is loaded.
Knees Caving Inward Under Load
As the weight gets heavier, the knees drift toward each other. The technical term is knee valgus, and it shows up most often in lifters who are strong but not yet stable, or who were never taught to push the knees out over the toes.
This one carries real stakes. Repeated valgus collapse under load loads the inside of the knee joint in a way it is not built to handle, and the hip abductors and external rotators get no stimulation. The patella can start to complain. Eventually something gives.
A simple cue fixes most cases: think about spreading the floor apart with the feet, or pushing the knees out toward the little toes as the descent begins. A light resistance band looped just above the knees gives physical feedback, and the band pushes back against the caving. Two sets of bodyweight squats with the band, ten reps each, before working sets, trains the pattern. The cue should be repeated on every rep, not just the first.
Heels Lifting Off the Floor
When the heels rise, the whole movement shifts forward onto the toes. The squat becomes a quad-dominant hinge with a narrow base, and the ankle has effectively refused the job. This is one of the most common errors and one of the most fixable.
Stiff ankles are the usual culprit. Years of sitting, formal shoes with heel lifts, and a lack of dorsiflexion work leave the ankle joint unable to close the angle enough for the knees to travel forward over the toes. The body compensates by lifting the heel.
Two fixes work in tandem. First, elevate the heels with a small plate or a purpose-made wedge, which immediately restores a neutral foot and lets the knees track forward. Second, add ankle mobility work: a knee-to-wall stretch, done for a couple of minutes on each side, daily. The wedge is a bridge, not a permanent home. The goal is to squat flat-footed without it within a few months.
The Lower Back Rounding at the Bottom
Watch a lifter descend and the lower back goes from a slight arch to a rounded curve right as the hips pass parallel. This is the butt wink, and it is the single most-discussed squat fault in strength training circles.
The rounding comes from the pelvis tucking under as the hip joint runs out of flexion range. It can stem from tight hamstrings, a stiff hip capsule, or simply going deeper than the individual's current mobility allows. Under a heavy bar, a rounded lumbar spine is a real injury risk, particularly for the discs.
The immediate cue is to stop the descent at the depth where the back stays neutral. Film the set from the side; most people cannot feel the tuck happening. Then work on the underlying restriction: hamstring stretches, hip flexor work, and a slow tempo squat with a pause at the point just before the tuck. Depth that preserves a neutral spine beats depth that does not.
The Bar Drifting Forward of Midfoot
On a back squat, the bar should travel in a straight vertical line over the midfoot. When it drifts forward, the lifter is fighting a lever arm that grows longer the further the bar gets from the base. The result is a good-morning squat: hips shoot up, chest drops, and the bar ends up ahead of the toes.
The cause is usually a failure to keep the chest up and the upper back tight as the descent begins. The lifter relaxes at the bottom, the torso pitches forward, and the bar follows.
The cue is to think about pushing the upper back into the bar throughout the rep, and to imagine the chest staying tall as the hips drop. A front squat, done with a light weight, teaches this fast: the bar cannot drift forward without the lifter losing it entirely, so the pattern corrects itself under duress.
Gripping the Bar Too Narrow or Too Wide
Hand placement on the bar seems like a minor detail, and it is treated as one by most lifters. It is not. A grip that is too wide forces the elbows up and out and prevents the upper back from tightening. A grip that is too narrow jams the shoulders and wrists and pulls the torso out of position.
The right width is roughly where the hands land when the arms hang naturally and the palms face forward, plus a finger's width. The cue for the upper back is to think about bending the bar across the shoulders, which pulls the shoulder blades down and together and creates a shelf for the bar to rest on.
Wrist and shoulder discomfort during squats is often a grip-width problem masquerading as a mobility problem. Before spending months on shoulder stretches, check the hand position.
Rushing the Descent and Bouncing Out of the Hole
There is a time and a place for a fast, bouncy squat: competition powerlifting, where the stretch reflex at the bottom adds kilos to the total. For most people learning the movement, that bounce is a way of avoiding control.
A controlled descent builds the position. A bounce masks a lack of it. When the lifter drops fast and rebounds off the bottom, the tissues that should be stabilizing the joint are bypassed, and the spine takes the load in a less protected position.
The fix is a three-second tempo squat: three seconds down, no pause, stand up. It feels slow and humbling, and it exposes every positional fault. Once the descent is controlled and the bottom is stable, speed can return. Until then, tempo is the teacher.
Loading the Bar Before the Pattern Is Owned
New lifters add weight because the empty bar feels too easy. The empty bar is supposed to feel easy. It is a diagnostic tool, not a workout. Adding plates before the movement pattern is stable simply trains the faults under load, and the body learns the compensation more deeply with every rep.
A reasonable rule: two weeks of bodyweight and empty-bar work, filmed from the side, before any meaningful load goes on. The weight will come fast once the pattern is clean. It will stall and hurt if the pattern is not.
The Footwear That Quietly Undermines the Squat
Running shoes with thick, compressible foam are the default gym shoe, and they are the wrong shoe for squats. The foam squishes under load, the foot loses its stable base, and the ankle has to work harder to compensate. A soft heel that collapses under a heavy bar turns a stable platform into a wobble board.
The fix is a flat, firm shoe: a minimalist trainer, a purpose-made lifting shoe with a hard sole and a slight heel, or simply socks on a stable surface. The change is small and the improvement in stability is immediate.
The most useful tool in fixing all of these faults is a phone propped against a water bottle, recording every working set from the side. Most lifters have never actually seen their squat. The camera shows the heel lift, the knee cave, the butt wink, and the bar drift that the body has learned to feel as normal. Once the fault is visible, the cue has something to correct. The lift that felt fine for years can be rebuilt in a few weeks of honest, filmed, unglamorous reps.