Sissy Squat Ultimate Guide

Biomechanics, benefits, how-to video, and variations.

By: Jeremy Fox, CNC, CPTPublished: June 17, 2021

The sissy squat sounds like an exercise for wimps. And its strange appearance can make it hard to know what muscles it’s actually working.

But sissy squats definitely are not for the faint of heart. This movement can be challenging to master and humble even the strongest of lifters.

So I’m going to explain the biomechanics and benefits. As well as how to do a sissy squat for beginners all the way up to advanced fitness levels.

Sissy Squat

What Is A Sissy Squat?

A sissy squat is a bodyweight exercise that targets your thighs and core while strengthening your knees. Generally, it’s performed by squatting down without bending your hips, which emphasizes knee flexion and extension.

There are also alternative forms that involve machines or other pieces of equipment, which I’ll get into more below.

Body Mechanics Involved

You can think of your body as a series of levers and pivot points. Where the levers are your bones and the pivots are your joints. In most exercises, these mechanics create hinging movements around one or more joints.

During a sissy squat, your knee is the hinge and your leg bones are the levers. In this case, the weight of your body is trying to close the hinge. While the muscles of your legs counteract this force to pull the hinge open.

Sissy Squat Mechanics 1
Sissy Squat Mechanics 2

Figure 1. The levers and pivot points. Figure 2. Forces involved in knee flexion and extension during a sissy squat.

Sissy Squat Muscles Worked

The quadriceps is the muscle group responsible for knee extension. These are four muscles on the front of the upper leg. Including the vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris.

In addition, the leaned-back body position engages your rectus abdominis (also known as abs). While the large range of motion strengthens the tendons and ligaments of the knee joint. 

Sissy Squat Muscles Worked II

Figure 3. Muscles and joints worked.

Comparison to Leg Extension

If you zoom in on the lower body, the sissy squat movement looks like a leg extension. Both exercises indeed isolate the quads with a single hinge movement around the knee.

However, there are key distinctions between sissy squats and leg extensions. These differences have to do with the range of motion (ROM) and muscle loading.

First, the ROM on a leg extension is usually from 90-180o. In comparison, a sissy squat could theoretically go from 0-180o. So you get up to twice the ROM with sissy squats. And recent studies suggest squatting below 90o actually preserves joint health1.

Second, the quad loading on a leg extension is mostly in the contracted position. In contrast, the loading on sissy squats is highest in the stretched position. So it’s like strengthening the bottom of a squat rather than the lockout at the top.

Sissy Squat Benefits & Limitations

  • Straight upper body position isolates quads more than any other squat exercise
  • Builds bigger and more defined quads
  • Increases strength in other squat movements
  • Works quads through their entire range of motion
  • Activates hip stabilizer muscles and improves balance
  • Engages multiple areas of the abdominals
  • No equipment needed
  • Strengthens the knee joint with progressive load and range of motion
  • Could aggravate an existing knee injury if loaded too much or too quickly

You may hear people say that sissy squats are bad for your knees. But this simply isn’t true! Sissy squats are actually good for your knees as long as you start slow and gradually build up the load and range of motion.

One exception would be if you have an active knee injury or you’re in rehabilitation. In that case, talk to your doctor before attempting this exercise.

How To Do A Sissy Squat

  1. Start by standing with your feet about hip-width apart
  2. Next, bend your knees and let your upper body lean back slightly
  3. Lower your body until your upper leg and lower leg form a 90-degree angle
  4. Then extend your knees (flex your quads) to raise your body back to the starting point

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Proper Sissy Squat Form

In addition to the steps outlined above, here are some tips for proper sissy squat form.

  • Allow your knees to pass well over your toes on the way down
  • Keep your upper legs and torso as straight as possible
  • Try to get to where your upper and lower leg form an acute angle (<90o)
  • Use your arms as a counterbalance or hold on to a sturdy object
  • The key to balancing is to keep your center of gravity directly over the balls of your feet (see Figure 2)

Progression From Beginner To Advanced

The first time you try sissy squats, you might not be able to do them exactly as described or demonstrated in the video. And that’s perfectly fine. Here’s how you can go from beginner to advanced.


For your first attempt, hold on to something like a power rack or other piece of equipment. You could also use TRX bands or have a partner spot you.

Ease into it by using a partial range of motion. Don’t worry about getting to 90o on the first day. Just get a feel for the movement by going down a few inches and coming back up.

For added stability, place an object beneath your heels. This gives your feet and ankles a sturdier base so you don’t have to think as much about balance. Below I demonstrate with some small hex dumbbells.

Sissy Squat Heels Supported

Figure 4. Using heel supports gives you a more stable base.


Once you build up your strength, balance, and range of motion, you can add some variations to make the exercise more challenging.

For starters, you can go past 90o of knee flexion. Like the limbo, see how low you can go! Eventually, you might be able to touch your knees to the floor. Then you could even try deficit sissy squats by standing on an elevated platform.

Another way to make sissy squats a little more challenging is by putting your hands on your hips instead of out in front of you. This takes more skill because you don’t have the counterbalance to keep you stable.

Sissy Squat Hands On Hips

Figure 5. Placing your hands on your hips moves your center of gravity back and requires more balance.

And if that’s still not challenging enough, you can make it even harder by adding weight. Weighted sissy squats involve holding a dumbbell or plate near your chest as you perform the exercise to increase the resistance.

Finally, you can play around with foot placement. Wider feet and/or toes pointed out target more inner quad or teardrop. While narrower feet and/or toes pointed in target the outer sweep.

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Sissy Squat Alternatives

If your unable to do sissy squats, there are some alternative variations of this exercise. A lot of them involve using machines or equipment for added stability. This can have advantages, but it also changes the exercise.

In this section, I’ll explain how these alternatives compare to the original version in terms of mechanics and muscles worked.

Sissy Squat Machine

A sissy squat machine (or sissy squat bench) is a piece of equipment with pads that lock your legs below the knees. With this apparatus, you can perform a squat motion by bending only at the knees and hips. Your back stays straight.

One benefit of this variation is that it’s more stable, so you don’t have to worry about balancing. And it doesn’t require as much quad strength, so it’s a good starting point.

On the other hand, you will notice some significant differences in body position and loading.

First, the range of motion is often stopped at 90o due to the pad. This means you’re only loading the quads through a very limited ROM.

Second, bending at the hips shifts your center of gravity forward. So there is less distance between the load and the pivot point. And you actually get less resistance on the quads.

Sissy Squat Machine Mechanics

Figure 6. Balance of forces involved with a sissy squat machine. Notice the different mechanics compared to the free-standing version (see Figure 2).

For these reasons, the sissy squat machine doesn’t provide the same benefits as a free-standing sissy squat.

Another drawback is that sissy squat machines are not a standard piece of equipment in most gyms. So if you want to do assisted sissy squats without the machine, here are some other alternatives.

Smith Machine Sissy Squat

A Smith machines sissy squat uses the stationary bar to lock the lower legs in position during the movement. But it doesn’t have an ankle pad like a sissy squat machine. So you have to be really careful not to let your feet slip out.

Again, this movement does not provide the same loading or range of motion as a free-standing sissy squat. Although it is an acceptable way to ease into the sissy squat movement.

Banded Sissy Squat

A banded sissy squat involves anchoring one end of a resistance band to a sturdy object, then wrapping the other end around the back of your knees. In doing so, you lock your lower legs in place similarly to the previous two variations.

Of course, the bands have some give, so you’re really not locked in place. This variation does involve a little more balance, meaning you will get some stabilizer activation as well.

Hack Squat Variation

This final variation removes the locking of the lower legs. Instead, the hack squat machine involves a padded sled on your back and shoulders that keeps your back straight and upright relative to your legs.

The key to replicating a sissy squat on the hack squat machine is to place your feet low on the platform. By doing this, you reduce hip flexion and increase knee flexion. Therefore, you shift almost all of the load to the quads.

As you can see in the image below, this body position allows for a greater range of motion below 90o. It also gives you the benefit of stability since the sled moves on linear bearings. And it’s also easy to progress by adding more weight.

Hack Squat Sissy Squat

Figure 7. Forces involved with a hack squat variation. The mechanics are better than the so-called sissy squat machine.


The sissy squat is a lot more challenging than the name and appearance suggest. While it involves relatively low weight, it will humble even the biggest of bodybuilders.

By isolating the quads and increasing the range of motion, you gain benefits that traditional squats and leg extensions don’t provide. Such as greater quad activation, more coordination, and increased joint stability.

So if you’ve steered clear of this exercise in the past, now is as good a time as any to toughen up by doing sissy squats!

For more excellent leg exercises and workouts, be sure to check out my related articles below.

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By |June 17, 2021|Workouts|0 Comments
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