WHY DO hack squats?
Too many lifters chase bigger quads by loading up the Barbell Squat without realizing their form is breaking down, their knees are screaming, and their progress has stalled.
You’re not weak. You’re just using the wrong tool for the job. This is where the Hack Squat comes in.
This movement was designed to take stress off your spine and put tension on your quads where it belongs.
Done right, the hack squat can help you grow bigger, stronger legs without crushing your joints in the process.
But, like most compound lower body exercises, most people screw it up.
They use too much weight, the wrong depth, or a foot placement that destroys their knees instead of sparing them.
Let’s break down exactly how to do the hack squat the right way along with how to program it for maximum gains without the pain.
hack squats: MUSCLES WORKED
The Hack Squat is often seen as a quad-dominant movement and for good reason.
It places constant tension on the front of your thighs, especially when performed with proper depth and foot placement.
But the benefits don’t stop there.
When executed correctly, the hack squat muscle activation includes your glutes, hamstrings, and core stability, making it a smart addition to any balanced leg day.
Here’s what’s really working during the movement.
VASTUS MEDIALIS
You want that teardrop shape on the inside of your thigh? Then you’d better start paying attention to the vastus medialis.
This muscle sits on the inner part of your thigh, just above your knee. It’s the most distinct-looking part of the quad group, which is why it has earned the nickname, the “teardrop muscle.”
Functionally, the vastus medialis helps with knee extension, helping you stand, walk, run, jump, and squat.
But here’s what most people miss: it’s also one of your body’s key knee stabilizers.
It works hard behind the scenes to track your kneecap correctly during every rep of your Hack Squats, Split Squats, and Barbell Squats.
When this muscle is underdeveloped or firing late (a common issue), you’re setting yourself up for knee pain, patellar tracking problems, and instability, especially under heavy loads or deep ranges of motion.
VASTUS INTERMEDIUS
You won’t see it in the mirror, but that doesn’t mean it’s not doing work.
The vastus intermedius is buried deep in the middle of your thigh, sitting right underneath the rectus femoris, sandwiched between the vastus lateralis (outer quad) and vastus medialis (inner quad).
You can’t flex it for the camera but it’s firing every time you extend your knee.
Its job? Knee extension, pure and simple.
Whether you’re sprinting, squatting, lunging, or hammering reps on the Hack Squat machine, this muscle is contracting hard to help you straighten your leg with force and control.
Because of its location, the vastus intermedius doesn’t get much attention, but it’s critical for strength and joint integrity.
It works in sync with the rest of your quads to keep your knees tracking properly and your movements smooth under load.
VASTUS LATERALIS
If you want legs that scream strength, the vastus lateralis is the muscle that gives your thighs that wide, athletic look.
Running down the outer side of your thigh, this is the largest and most powerful muscle in the quadriceps group. It’s the first one you see when your shorts ride up on leg day and if you’re training smart, it’s also the one doing serious work.
Like the rest of the quads, it handles knee extension, helping you stand, run, jump, and squat.
But here’s where it pulls ahead: the vastus lateralis is your go-to muscle for stabilizing the outside of the knee, especially when you’re going heavy.
Neglect this muscle and you’re not just missing out on leg size, you’re leaving yourself vulnerable to knee misalignment, patellar tracking issues, and poor lateral stability.
RECTUS FEMORIS
Front and center is where you’ll find the rectus femoris. It’s the most visible part of your quads and the only one that crosses both the hip and the knee. That makes it a unique weapon in your lower body arsenal.
Most quad muscles stop at the femur. The rectus femoris goes further, originating from the pelvis and running straight down the front of your thigh to the knee. Because of that setup, it’s got two key functions:
Knee extension (like every quad) as well as hip flexion. This makes it really important for lifting the thigh during sprinting, kicking, or driving out of the bottom of a Split Squat or Bodyweight Squat.
This dual-action role makes the rectus femoris a major player in athletic performance, especially in movements that demand speed, coordination, and power (think sprint starts, box jumps, or even stepping up into a Landmine Squat.)
Here’s the catch: when it’s tight or overworked (which happens often with poor mobility or bad training balance), it can limit your hip movement and pull on the pelvis, throwing off your posture and performance.
GLUTEUS MAXIMUS
When people talk about the glutes, they’re really talking about the gluteus maximus, which is the largest and most powerful muscle in the posterior chain.
And for good reason: this is the muscle that drives almost every explosive lower-body movement you care about.
Located on the back of your hips, the glute max runs from the top of your hip bones and lower spine down to the top of your thigh bone.
It’s the outermost glute muscle, responsible for the shape and size of your butt, but it’s not just there to look good in jeans.
Functionally, it’s necessary for hip extension. It’s what fires when you stand up from a squat, sprint, jump, climb, or drive through a heavy Reverse Hack Squat.
Without it, good luck getting out of a chair, let alone crushing your leg day.
But its role goes deeper than movement. The gluteus maximus also keeps your torso upright, stabilizes the pelvis, and supports spinal alignment during walking, running, and loaded lifts.
And here’s where most lifters go wrong: they sit on this muscle all day (literally), then try to train legs without ever activating it properly.
Weak glutes mean poor posture, limited hip drive, and compromised performance, not to mention a higher risk of injury.
BICEPS FEMORIS
When people talk about the hamstrings, they usually lump them together but the biceps femoris deserves its own spotlight.
This is the lateral (outermost) muscle of the hamstring group, and it plays a massive role in both performance and injury prevention.
There are two parts to this muscle: the long head and the short head.
The long head starts way up at your hip joint and runs all the way down the outside of your thigh, attaching just below the knee.
It’s part of the powerful posterior chain or the muscles responsible for hip extension, knee flexion, and explosive movement.
Any time you sprint, jump, or push through the top of a squat or deadlift, the biceps femoris is firing to extend your hip and bend your knee.
It also helps stabilize your pelvis and knee, especially during single-leg movements like the Split Squat.
Neglecting this outer hamstring muscle can throw your lower body mechanics out of balance. That means tight hips, weaker glutes, and a higher risk for hamstring strains.
SEMITENDINOSUS
The semitendinosus sits right in the middle of your hamstring, between the outer hamstring muscle (biceps femoris) and the inner thigh muscle (gracilis).
Most people think the hamstrings only kick in when you’re bending your leg, like during a Leg Curl.
And yes, knee flexion is one of their main jobs. But the semitendinosus also helps extend the hip, especially when you’re standing tall and powering through a Squat, Hip Thrust, or Deadlift.
It spans from the lower part of your pelvis to just below the inside of your knee, and it stabilizes your hips, pelvis, and knee during dynamic movement.
It even pitches in during rotation of the lower leg, especially in compound athletic motions like sprinting or cutting.
If you’re only training your hamstrings with isolation curls, you’re leaving the semitendinosus underdeveloped and that’s a fast track to weak hips, sluggish speed, and injury risk.
HACK SQUAT BENEFITS
Most people treat the Hack Squat like a second-rate squat variation. That’s a mistake.
The Hack Squat machine (or the Barbell Hack Squat with weight plates) can be one of the most effective tools for building strong, muscular legs, especially when your goal is hypertrophy without compromising your spine or your knees.
Let’s break down why this lift belongs in your program.
QUAD GROWTH WITHOUT THE BACK BREAK
If you’ve got a history of low back pain or just want to take pressure off your spine, the Hack Squat is your fix.
Unlike the Barbell Squat or Super Squat, the Hack Squat keeps your back supported and your torso upright, allowing you to target your quads without putting a bar on your spine.
This makes it an ideal choice for athletes recovering from injury, older lifters, or anyone chasing leg muscle mass growth without the risk of loading the spine the wrong way.
LASER-FOCUSED KNEE STABILITY
The Hack Squat forces your knees to track properly. If they don’t, you’ll feel it immediately.
That’s because it hits the vastus medialis and other stabilizing quads muscles harder than sloppy squats ever will.
While Bodyweight Squats and Goblet Squats have their place, they don’t provide the same constant tension or controlled tracking.
And if you’re struggling with knee cave during a Smith machine or Belt Squat, this machine can help retrain proper movement patterns under load.
EASY TO LEARN
Unlike the Barbell Hack Squat, Belt Squat, or Landmine Squat, which require extra setup and precision, Hack Squat machines offer a fixed range of motion that makes them simple to learn and safe to load.
You can focus on effort and form instead of balancing the weight. And if you start with the signature Hack Squat machine, this same form transfers over to the Barbell Hack Squat and Landmine Hack Squat.
BUILT FOR PROGRESSIVE OVERLOAD
You want to grow? You’ve got to apply progressive overload and the Hack Squat lets you do that safely.
Without worrying about stabilizers failing or bailing out of a heavy Barbell Squat, you can push your sets further with slow negatives, rest-pause, or drop sets.
It’s a perfect tool for volume-based hypertrophy training, especially when paired with lighter moves.
HIGHLY ADAPTABLE TO YOUR TRAINING GOALS
Want more quad focus? Place your feet low on the platform.
Want to bring in the glutes and hams? Try a Reverse Hack Squat or shift your feet higher.
You can even use different rep ranges depending on whether you’re chasing strength or size.
Combine it with a Landmine Hack Squat and you’ve got a well-rounded leg routine that hits every angle without hammering your joints.
HOW TO DO HACK SQUATS
You can’t just hop on strength training equipment, move some weight, and call it training.
If you’re not performing the hack squat with proper form, whether it’s on a machine or using a landmine setup, you’re not getting the full benefit, and worse, you could be putting unnecessary stress on your knees and lower back.
Let’s walk through both the Traditional Hack Squat Machine and the Landmine Hack Squat variation, so you can train with intent, target the right muscles, and stay injury-free.
HACK SQUATS (machine)
HOW TO DO THE HACK SQUAT (MACHINE):
- Adjust the machine so the shoulder pads and backrest line up with your height. You should feel secure but not compressed.
- Step onto the adjustable wide footplate and plant your feet about shoulder-width apart, with a slight outward turn of the toes. The lower you place your feet on the platform, the more quad dominant it becomes.
- Brace your core and unhook the safety handles.
- Lower slowly by bending at the knees and hips. Keep your back and head pressed into the pad. Avoid rounding and arching.
- Go deep, ideally until your thighs are at least parallel. Stop your knees from drifting way past your toes.
- Push through your heels to return to the top. Don’t lock out your knees. Keep tension on the quads.
- Maintain tight form and smooth control from start to finish.
WHAT MAKES IT EFFECTIVE: The angle of the Hack Squat machine allows for deep knee flexion and a more natural squatting motion, especially if the machine has an adjustable footplate. That means more quad activation and less stress on your lower back.
HACK SQUATS (landmine)
HOW TO DO THE HACK SQUAT (LANDMINE):
- Wedge one end of a barbell into a corner or landmine attachment.
- Load plates on the free end, then hoist the bar onto one shoulder (you can use a pad or towel to cushion it).
- Angle your torso to match the bar path, getting into a diagonal squat stance.
- Feet should be slightly forward to allow proper knee tracking and glute muscle engagement.
- From here, squat down in a controlled manner, maintaining tight form and depth.
- At the bottom, drive up through your heels and push your hips forward. You’ll feel this light up your glutes more than a Traditional Hack Squat.
- Repeat for reps, then switch the bar to the opposite shoulder for the next set.
WHAT MAKES IT EFFECTIVE: The angle of the landmine setup mimics the Hack Squat path while activating more glutes and hips, making this a great hybrid between a quad-dominant squat and a posterior chain builder. Think of it as a cross between a Reverse Hack Squat and a Hip Thrust, with some serious core demands.
HOW TO USE THEM IN YOUR WORKOUT
The Hack Squat is versatile. You can use it as a main lift or a key accessory, depending on your goals and how your body holds up to heavier lifts.
If you’re dealing with lower back issues or just want to reduce spinal loading, the Hack Squat can take the lead as your primary movement.
Otherwise, it works best after your main compound lifts, when you’re still fresh enough to push volume but want to stay in a safer, more controlled range of motion.
Programming for Size (Hypertrophy):
- 3–4 sets of 8–12 reps
- Focus on constant tension—no bouncing out of the bottom
- Use techniques like drop sets or rest-pause to push past fatigue and overload the quads
- Try pairing with isolation or volume-based moves like the Sissy Squat or Leg Extensions for a brutal finisher
Programming for Strength:
- 4–5 sets of 5–8 reps
- Use slow eccentrics (3–4 seconds down) and controlled lockouts to build strength without sacrificing form
- Ideal for lifters who can’t always tolerate heavy Smith Machine Squats, Belt Squat Machine work, or deep Goblet Squats due to joint limitations
Smart Pairings for a Complete Leg Day:
- Hack Squat + Walking Lunges for stability and unilateral strength
- Hack Squat + RDLs to balance anterior and posterior chain
- Hack Squat + Belt Squat Machine for volume without spinal fatigue
The Hack Squat gives you options. Use it to hit the quads hard, clean up your form, and push intensity without punishing your spine.
Just be smart about how you plug it into your routine and train with intent, not ego.
HACK SQUAT: COMMON MISTAKES
The Hack Squat is built for safety and control but that doesn’t mean you can’t mess it up.
Poor form not only kills your results, but it also opens the door for joint strain and long-term injury.
Here are the most common hack squat mistakes and how to fix them like an athlete.
KNEES CAVING IN (VALGUS COLLAPSE)
When your knees buckle inward under load, you’re placing extra strain on the ACL and taking tension off your quads.
This usually happens when the glutes and outer quads aren’t firing properly.
Focus on driving your knees outward as you descend and rise. Think about pushing out against imaginary resistance.
You can also train with Banded Squats or Goblet Squats to reinforce proper knee tracking.
RISING ONTO YOUR TOES
If your heels are popping up, you’re shifting the load away from the glutes and hamstrings, placing more stress on the knees and robbing yourself of posterior chain support.
Keep your heels flat and drive through your midfoot. If needed, adjust your foot position lower on the platform, or experiment with slight toe-out angles until you find a stable base.
CUTTING RANGE OF MOTION SHORT
Going halfway down doesn’t count. Partial reps might feel easier, but they limit quad activation and reduce time under tension.
Drop the ego and go deeper. Aim for at least thighs parallel to the platform, if not slightly below.
If mobility is a limiting factor, build it up with Bodyweight Squats, Sissy Squats, and controlled eccentrics.
ARCHING YOUR LOWER BACK OFF THE PAD
Losing contact with the back pad means you’re disengaging your core and putting your lower spine in a compromised position.
Brace your core like you’re about to take a punch.
Keep your entire back, from your hips to your head, pressed firmly into the pad throughout the lift.
If your hips are tucking or arching off the pad, reduce the weight and clean up your form.
HACK SQUAT VS. OTHER SQUAT VARIATIONS
Not all squats are created equal. Each variation hits your body differently and knowing when to use each one can make the difference between progress and plateaus.
Here’s how the Hack Squat stacks up against other popular squat variations:
BACK SQUAT
The classic. Great for building full-body strength, improving athletic power, and engaging both the anterior and posterior chain.
The trade-off? It loads your spine and demands solid mobility, core strength, and technique.
For some lifters, it’s a must-have. For others, it’s a one-way ticket to lower back pain.
HOW TO DO THE BARBELL BACK SQUAT:
- Get under the bar. Set the barbell across your traps, not your neck.
- Pull your shoulder blades together to create a solid shelf. Your feet should be shoulder-width apart, flat on the ground. No heels up. No toes rocking.
- Brace your core and lock in. Keep your chest up and your elbows tucked under the bar. Don’t let your torso collapse forward.
- Angle your toes slightly outward and keep your knees tracking in line with them. Push your knees out, not in, as you descend. If your knees collapse inward, slap a resistance band around them and fix the pattern.
- Lower with control. Sit your hips back and down while keeping your spine neutral and your upper back upright.
- Drive through the floor. Pause briefly at the bottom, then push through your midfoot and heels to return to the top.
- Keep the movement smooth and powerful. No bouncing. No knee cave.
WHAT MAKES IT EFFECTIVE: The Barbell Back Squat trains multiple major muscle groups: quads, glutes, hamstrings, core, and even upper back. It builds raw strength, explosive power, and full-body stability. When done correctly, it improves movement patterns, athletic performance, and long-term joint resilience.
FRONT SQUAT
More quad-focused than the back squat, and much easier on the lower back. But it’s harder to stabilize.
Your upper back and core have to do a lot of work to keep the weight in position.
Great for athletes and experienced lifters, but there’s a steeper learning curve.
HOW TO DO THE BARBELL FRONT SQUAT:
- Set the bar at chest height. Walk up and grab it with a clean grip: fingertips under the bar, elbows up and pointed straight ahead.
- Can’t get into that position? Use lifting straps looped around the bar as a workaround. The goal is to keep your elbows high, so the bar sits across your front delts, not in your hands.
- Unrack and step back. Feet shoulder-width apart, chest up, core tight, and spine neutral. Take a breath and brace like you’re about to get punched in the gut.
- Sit straight down between your heels, not back like a Back Squat. Keep your elbows high the entire time to prevent your torso from tipping forward.
- Drop until your thighs are parallel or lower, assuming your mobility allows for it. Knees should stay tracking over your toes.
- Press through your midfoot and heels, keeping your torso vertical and core braced.
WHAT MAKES IT EFFECTIVE: The Front Squat forces you into an upright torso position, which shifts more demand onto your quads and core while reducing compressive load on the spine. This is one of the best alternative exercises to the Back Squat if you want serious lower body strength without beating up your low back. It also exposes (and corrects) weak links in your mobility and posture.
LEG PRESS
Similar to a Hack Squat in that your back is supported and the movement is guided.
But leg presses can be deceiving. You can load them heavy and still use terrible form.
They’re less controlled, easier to cheat, and don’t force you to move through a natural squatting path.
HOW TO DO THE LEG PRESS:
- Step into the machine and lock in. Your back and head should be firmly against the pad. Adjust the seat so that your hips, knees, and feet are in a straight line. If your hips are off, your knees are going to feel it and not in a good way.
- Keep your feet flat and shoulder-width apart on the platform. For more quad emphasis, place your feet lower. This increases knee flexion, putting more direct tension on the quads. For more glutes and hamstrings, move your feet higher.
- Disengage the safety stops and lower with control. Bend your knees and bring the platform down slowly.
- Aim for a 90-degree bend in the knees or slightly deeper if your mobility allows. Don’t let your knees collapse inward or shoot forward past your toes.
- Push through the entire foot to return to the top. Extend your legs with control.
- Focus on keeping the quads, glutes, and hamstrings engaged. Don’t lock out at the top. Keep the muscles under tension and the joints safe.
WHAT MAKES IT EFFECTIVE: The Leg Press allows you to overload the lower body with less spinal stress compared to squats. Done right, it can rival isolation movements like the Leg Extension for targeted quad muscle growth without turning your spine into a crash zone.
HACK SQUAT
This is the most isolated and quad-dominant variation of the bunch.
Because your back is supported and the track controls your movement, you can focus purely on effort, depth, and constant tension.
It’s ideal for hypertrophy and for lifters who want to take the pressure off their lower back and hips.
WHICH ONE SHOULD YOU USE?
Short answer: All of them (if you’re able to).
The best training programs don’t pick sides. They use the right tool for the right job.
Rotate the Hack Squat with other variations like the Back Squat or Front Squat depending on your goals, joint health, and recovery.
Each one fills a gap the others leave behind.
The Hack Squat is more than just a machine. It’s a precision tool for building serious lower body strength without crushing your spine.
When you dial in the form, foot placement, and programming, it becomes one of the most effective ways to target your quads and reinforce proper squat mechanics.
Use it the right way, and you’ll train smarter, stay injury-free, and build legs that perform.
Check out our complete line of ATHLEAN-RX Supplements and find the best training program for you based on your fitness level and goals.
- The Hack Squat locks your body into a controlled path, allowing you to load the quads heavily with minimal spinal stress and maximum time under tension.
- Here’s how to do Hack Squats:
- Start by adjusting the machine so the shoulder pads and backrest match your height.
- Step onto the footplate and set your feet about shoulder-width apart with a slight toe flare. If you want more quad isolation, place your feet lower on the platform.
- Brace your core, lock your upper body against the pad, and release the safety handles.
- Begin the descent by bending at the hips and knees, keeping your back and head firmly against the pad the entire time.
- Lower until your thighs hit parallel or deeper if your mobility allows. Keep your knees in line with your toes and avoid letting them drift too far forward.
- On the way up, drive through your heels, stay tight, and don’t lock out your knees. The goal is to keep the quads working, not to rest at the top.
HACK SQUAT FAQ
The Traditional Hack Squat is a machine-based squat variation designed to target the quads with precision while minimizing strain on the lower back.
Unlike the Barbell Back Squat, which requires full-body stabilization, the Hack Squat locks you into a fixed path, allowing you to focus entirely on leg drive and form.
There are two other common variations.
First, the plate loaded Barbell Hack Squat is when the bar is placed behind your legs like a Reverse Deadlift.
Second, the Landmine Hack Squat uses a barbell in a corner-mounted landmine setup and mimics the same upright posture and quad-dominant focus as the machine version.
Hack Squats are great for quad hypertrophy, joint-friendly leg training, and cleaning up poor squat mechanics.
By locking your torso in place, the machine version lets you train hard without worrying about spinal compression or upper-body breakdown.
They’re ideal for lifters who need a break from heavy barbell work, athletes looking to improve knee tracking and hip control, or anyone chasing leg size without sacrificing form.
Use them as a primary lift if you have back issues, or as a finisher to completely burn out the quads after compound movements.
“Better” depends on your goal. If you want total body strength, athletic carryover, and performance gains, the barbell back squat wins.
But if you want to target your quads, train with joint control, and minimize spinal stress, the Hack Squat pulls ahead.
Where the Back Squat relies on perfect mobility, bracing, and bar control, the Hack Squat removes those variables so you can focus on depth, tension, and quad dominance.
Add in the Barbell Hack Squat or Landmine Hack Squat variation and you’ve got squat alternatives that allow similar benefits with fewer form breakdowns.
Bottom line: don’t replace squats. You should rotate them. The Hack Squat is a tool, not a replacement.
For most people, yes. The Hack Squat Machine keeps you in a more natural squat position and forces better control of knee and hip alignment.
The Leg Press, on the other hand, lets you pile on weight with less accountability, which means form often goes out the window.
The Hack Squat encourages proper knee tracking, full range of motion, and constant tension on the quads.
The Leg Press can still be valuable, especially for volume work, but it’s easier to cheat, easier to overload, and doesn’t carry over as well to free-weight squats or athletic movement.
Because it eliminates the shortcuts.
Unlike Free Squats, where you can shift tension to your hips or cheat with speed, the Hack Squat Machine keeps you in a strict path with constant tension on your legs from start to finish.
There’s no room to hide weak links. Your quads, glutes, and core have to work the entire time—no rest at the top, no bounce at the bottom.
Even the Barbell Hack Squat and Landmine Hack Squat require laser focus and total-body coordination to maintain posture, balance, and drive through your legs. That challenge is exactly what makes the Hack Squat so effective.
REFERENCES
Jeff Cavaliere M.S.P.T, CSCS
Jeff Cavaliere is a Physical Therapist, Strength Coach and creator of the ATHLEAN-X Training Programs and ATHLEAN-Rx Supplements. He has a Masters in Physical Therapy (MSPT) and has worked as Head Physical Therapist for the New York Mets, as well as training many elite professional athletes in Major League Baseball, NFL, MMA and professional wrestling. His programs produce “next level” achievements in muscle size, strength and performance for professional athletes and anyone looking to build a muscular athletic physique.
