How to Do It, Benefits, and Muscles Worked

A deep squat is a squat in which your hips are below the height of your knees at the lowest depth of the movement pattern. In other words, the angle of your knee joint is greater than 100 degrees at the lowest point.

One study found the average angle of the knee in a deep squat was greater than 120 degrees (1).

In contrast, in a standard squat, you only bend down until your thighs are parallel with the ground, and your knees are bent at around a 90-degree angle.

In addition to greater knee flexion in the deep squat, your hips and ankles have to flex enough to keep your center of gravity over your feet. Also, your trunk has to stay straight and stable, especially if you’re using weight.

At those depths, the backs of your thighs come into contact with the backs of your calves. This contact has been shown to decrease the compressive load on your knee joint, which can help decrease the risk of injury to this area (2).

Deep squats can be performed as a bodyweight exercise, front squat with the resistance load (barbell, dumbbell, band, etc.) supported in front of your shoulders, or a back squat with the resistance load supported behind your shoulders.

Summary

Deep squats require your hips to descend lower than your knees.

In the past, anecdotal sources claimed that deep squatting contributed to joint degeneration (arthritis) or damage to the tendons and ligaments of the legs. This has come under scrutiny over the past few decades.

In fact, recent research found no correlation between deep squats and the incidence of tissue injury to bone, ligament, or cartilage. Now, some researchers believe compressive forces in the knee may be higher in a partial squat than in a deep squat (3).

Summary

Research has not found any correlation between deep squats and injury.

A proper deep squat begins with your support base — your feet, which are typically shoulder-width apart and flat on the floor. Meanwhile, your toes are either straight ahead or at a small, 7-degree toe-out position, your knees are straight, and your trunk is erect (4).

Begin by squatting down as if you’re sitting into a chair. Your ankles, knees, and hips will bend in unison while your spine stays straight. As you begin to lower, your knees will travel forward over your toes, and your hips will travel backward to keep your center of gravity over your feet.

Your feet should remain flat on the ground during the entire movement.

Your trunk and pelvis will stay neutral and aligned as you bend at your hips. At the lowest depth, your pelvis will be in relative alignment with your shins. Ideally, your pelvis will remain in a neutral position, without tucking under or tilting backward.

Your knees will stay in alignment with your feet when viewed from the front.

Finally, push through your feet with your weight centered just in front of your ankles and return to the starting position.

A note on form

The deep squat requires significant mobility in several joints — namely your hips, knees, ankles, and even your lumbar spine.

If your range of motion at any of these places is limited, you may notice one or more compensations, such as your tailbone tucking (commonly known as butt wink), your heels lifting, or your knees tracking incorrectly.

Before performing a weighted deep squat, it’s a good idea to work with a trainer, biomechanics coach, or physical therapist who can help you optimize your movement patterns to avoid injury.

The deep squat involves most of the muscles of your lower body to produce force. Other muscles, such as those in your trunk, work as stabilizers. Stabilizer muscles keep your joints aligned to decrease excessive or compressive forces that could cause injury.

Hips

Your buttock muscles (glutes) produce much of the force to perform this movement correctly. In addition, your hamstrings are involved to a lesser extent.

Both muscle groups work to control your hips during descent (hip flexion) and produce force to overcome gravity during ascent (hip extension).

Your hip joint is also surrounded by smaller muscles that control the rotation of your hip during the movement. They work to keep the joint stable.

In conjunction with the upper glutes (gluteus medius and minimus), they work to keep your knees in alignment with your feet during the movement. Thus, using these muscles prevents your knees from moving toward the midline of your body and reduces excessive torque.

Knees

Your quadriceps femoris muscles, commonly called your quads, on the front of your thighs control the bending of your knee joints as you lower yourself into a deep squat. Then they work to straighten your knee on the ascent.

Ankles

The muscles on the front of your shins called the anterior tibialis (also called tibialis anterior) help pull your shin bones forward and maintain your body over your feet while lowering and raising.

In one study, the strength of the shin muscles correlated with the ability to perform a deep squat among women (5).

Your calf muscles also work to maintain control during the descent portion of the squat. They also work in conjunction with your gluteal and quadricep muscles to produce force during the ascent phase of the movement.

Trunk

Muscles in your back called the erector spinae keep your spine straight and extended enough to decrease the risk of injury to the spine or intervertebral discs.

Summary

The glutes, hamstrings, quadriceps, and calf muscles work to produce force to control the descent of the movement and return to an upright position.

The benefits of the deep squat are slightly different than the benefits of a standard squat, mostly because of the increased range of motion they involve.

Increased strength

The deep squat has been shown to be more effective at building the glutes and inner thigh muscles than a standard squat (6).

Additionally, it develops strength throughout the entire range of motion in the joints.

Lower back and pelvic stability

Deep squats require more strength and stability in your lumbar spine to maintain proper alignment. Given that the joints of the spinal column are the most vulnerable in a squat, proper care should be taken to maintain a neutral lumbar spine at all times (4).

Functional movement training

Deep squatting is a functional movement involved in many everyday activities, including standing up from sitting on a low stool, picking up a heavy box from the floor, or preparing to kneel down to the ground.

The deep squat movement is also used in many sports, such as baseball, football, and hockey, and it’s very important to Olympic weightlifters due to the nature of how they propel weight from the ground to overhead.

Do more with less

Given the demand on your muscles to work through a full range of motion during the deep squat, research suggests that you’ll see greater increases in muscle strength and size than you would by performing shallow squats with heavier weight (7).

Increased mobility

Mobility is a function of both strength and flexibility. Deep squats will help you improve your range of motion in the involved joints, as well as strengthen the muscles throughout that range, therefore increasing your mobility.

Summary

Deep squats are beneficial for flexibility of the joints and strengthening the lower body muscles through a greater range of motion.

Maintaining proper form during squatting is important to decrease your risk of injury and experiencing pain.

Three common errors occur during the squat:

Heels lifting

One of the most important things to watch for is keeping your feet flat on the ground. This will improve your balance, stability, and force production.

Difficulty with this is usually related to poor ankle flexibility and letting your knees go beyond your forefoot or toes, which can be caused by stiffness in the calves.

If you’re having difficulty keeping your heels down, you can always place a lift, such as a board, under your heels until your flexibility improves.

However, it may be better to decrease any added weight and work on your range of motion in the beginning. As your range of motion improves, you can increase the weight again slowly.

Misalignment in knees

Another major challenge when performing the deep squat is poor gluteal and hip rotator strength. A lack of strength in these muscles may result in your knees bowing inward toward each other as you ascend or descend.

When your knees come out of alignment, there’s torque at your knee, which can lead to injury. Deep squatting is not recommended for people with knee pain. It may be better to alter your movement pattern or choose a different exercise.

Bending the spine

The final common issue with squat form is not keeping your spine straight and aligned with your pelvis. Your spine should remain relatively straight and parallel to your shins.

This helps keep your shoulders over your knees and your knees over your toes, as well as maintain balance and decrease the risk of strain and shear force in the spine.

If you lack the appropriate mobility at your hips, knees, or ankles to maintain proper alignment during a deep squat, it may be advantageous to perform a squat in which your hips do not go below your knees.

Summary

When performing the squat, be mindful to keep your feet flat, your knees aligned with your feet, your pelvis aligned with your trunk, and your spine straight.

Multiple variations of the deep squat can either make the exercise more accessible or more challenging.

Bodyweight only

Also called an air squat, this version of the deep squat is the easiest to perform. To add difficulty, raise your arms overhead and keep them in line with your torso. This is a variation of a functional test to assess trunk stability and lower body and shoulder mobility (8).

Holding onto something

If you’re looking to perfect your alignment when doing the deep squat, holding onto something like a railing, suspension trainer, or even an upright pole can help.

By holding on with your hands, you’ll have more stability when shifting your center of gravity, and you’ll be better able to correct for compensations in your form.

Placing a lift under your heels

If your heels are lifting when performing the deep squat, placing a small board or pad under them can help. Doing so will give your ankle joints a little bit more mobility, which will help the entire kinetic chain.

Wall squat

This squat is performed with your back against a wall or surface that doesn’t have excessive friction. Keep your back and buttocks against the wall and your feet 6–8 inches (15–20 cm) away from the wall. Slide down the wall until your hips are below your knees.

Keeping your feet flat and back and buttocks against the wall, push back up to a position in which your knees are extended. Repeat.

Front squat

This version can be performed using a barbell, kettlebell, or bands. Start standing up as mentioned above. Have the weight racked in your hands relatively level with or slightly below your collar bones. Perform the deep squat, maintaining proper form throughout the movement.

Keeping the weight in front of your center of gravity puts greater emphasis on your quads.

Back squat

The back squat is performed like the front squat, except that the weight is positioned on your upper back with your hands level with the tops of your shoulder blades.

Keeping your weight behind your center of gravity puts greater emphasis on your buttocks, or gluteal muscles.

Summary

Many variations of the deep squat can either make the exercise easier or more challenging to perform.

Deep squats are an excellent lower body workout. Research does not substantiate any increased risk of knee injury. Nevertheless, use good form as described above to ensure less risk of injury to your spine and lower body.

Adding deep squats to your workout will add challenge and help you improve your mobility and strength throughout your full range of motion.