Deep Squatting: Definition, Benefits, Biomechanics, and How to Perform

What is it called when you squat all the way down?

Squatting all the way down, where your hips descend below your knees, is commonly referred to as a deep squat, full squat, or sometimes colloquially as an "ass-to-grass" (ATG) squat. This full range of motion is a foundational movement in human locomotion and a cornerstone of effective strength training.

Defining the Deep Squat

The term "deep squat" signifies a squat where the crease of the hip drops below the top of the knee. This contrasts with a "parallel squat" (where the hip crease is roughly in line with the top of the knee) or a "half squat" (where the hips descend only partially). While "ass-to-grass" (ATG) is a more informal term, it vividly describes the maximum achievable depth, often with the glutes coming very close to or touching the heels, provided sufficient ankle and hip mobility.

Anatomy and Biomechanics of a Deep Squat

Executing a deep squat engages a comprehensive array of muscles and joints, demanding coordinated action and significant mobility.

• Primary Movers:
  • Quadriceps Femoris: (Rectus Femoris, Vastus Lateralis, Vastus Medialis, Vastus Intermedius) – Primarily responsible for knee extension during the ascent.
  • Gluteus Maximus: Crucial for hip extension, especially as you drive out of the bottom position.
  • Adductor Magnus: Plays a significant role in hip extension, particularly at deeper squat depths.
  • Hamstrings: (Biceps Femoris, Semitendinosus, Semimembranosus) – Act as synergists and stabilizers, especially at the hip.
• Stabilizer Muscles:
  • Core Musculature: (Transverse Abdominis, Obliques, Rectus Abdominis, Erector Spinae) – Essential for maintaining a neutral spine and transferring force efficiently.
  • Calves: (Gastrocnemius, Soleus) – Provide ankle stability and contribute to balance.
• Joint Actions:
  • Hip Flexion/Extension: Significant hip flexion occurs on the descent, followed by powerful extension on the ascent.
  • Knee Flexion/Extension: Deep knee flexion is characteristic of the movement, followed by extension.
  • Ankle Dorsiflexion: Critical for allowing the knees to track forward over the toes without losing balance or rounding the lower back. Limited ankle dorsiflexion is often a primary barrier to achieving a deep squat.

Benefits of Deep Squatting

When performed with proper form, deep squats offer a multitude of advantages for strength, mobility, and overall physical function.

• Enhanced Muscle Activation: Research consistently shows that deep squats lead to greater activation of the gluteus maximus and quadriceps compared to partial squats. This translates to superior muscle growth and strength development in these key lower body muscles.
• Improved Mobility and Flexibility: The repetitive movement through a full range of motion can significantly improve joint flexibility, particularly in the ankles and hips. This can translate to better performance in other movements and a reduced risk of injury.
• Increased Strength and Power: Training through a full range of motion builds strength at all points of the movement, including the often-challenging bottom position. This comprehensive strength contributes to greater power output and improved athletic performance.
• Better Functional Movement: Deep squatting closely mimics natural human movements like sitting down, standing up, or picking an object off the floor. Training this pattern improves your ability to perform daily activities with greater ease and safety.
• Joint Health and Resiliency: Contrary to outdated beliefs, deep squatting, when executed correctly, can actually strengthen the connective tissues around the knee joint. The forces are distributed over a larger surface area of the joint, potentially reducing peak stress compared to partial squats.

Dispelling Common Myths: Are Deep Squats Bad for Your Knees?

One of the most persistent myths in fitness is that deep squats are inherently dangerous for the knees. This belief largely stems from outdated research and a misunderstanding of biomechanics.

• The Truth: Modern scientific literature largely supports the safety and efficacy of deep squats for healthy individuals. When performed with proper technique, deep squats can actually strengthen the structures surrounding the knee, including ligaments and tendons, making the joint more resilient.
• Patellofemoral Joint Stress: While deeper squats do increase patellofemoral (kneecap) joint compression, this stress is distributed over a larger contact area as the knee flexes. This distribution can mitigate the risk compared to the concentrated stress often seen in partial squats.
• Ligamentous Integrity: Studies have shown that deep squatting, with appropriate loading, does not compromise the integrity of knee ligaments (e.g., ACL, PCL). In fact, the controlled movement can contribute to ligament health.

The key differentiator is proper form and progressive loading. Squatting deeply with poor form, excessive weight, or pre-existing knee issues without proper guidance can indeed be problematic.

Who Should Deep Squat (and Who Might Not)

Most healthy individuals can and should incorporate deep squats into their training regimen, benefiting from the full range of motion.

• Ideal Candidates:
  • Athletes: Especially those in sports requiring explosive lower body power (e.g., Olympic weightlifting, football, basketball).
  • Strength Enthusiasts: Individuals looking to maximize muscle growth and strength in their lower body.
  • General Population: For improved functional fitness, mobility, and overall health.
• Considerations and Modifications:
  • Significant Pre-existing Knee Injuries: Individuals with acute or severe knee injuries should consult a medical professional or physical therapist before attempting deep squats.
  • Limited Mobility: Those with significant ankle or hip mobility restrictions may need to work on these limitations before achieving full depth comfortably. Modifications like elevating heels or using a goblet squat can be temporary solutions.
  • Specific Goals: While generally beneficial, some athletes (e.g., powerlifters competing under specific rules) might prioritize parallel squats for maximal load if depth isn't strictly required by their sport.

How to Achieve a Safe and Effective Deep Squat

Achieving a comfortable and safe deep squat requires a combination of mobility, stability, and proper technique.

1. Assess Your Mobility:
   • Ankle Dorsiflexion: Can you maintain your heels on the ground while driving your knees far forward over your toes? Limited ankle mobility is a common barrier.
   • Hip Mobility: Can you comfortably move your hips through a full range of flexion and external rotation?
   • Thoracic Spine Mobility: Can you maintain a neutral spine and keep your chest up throughout the movement?
2. Start with Bodyweight: Master the movement pattern without external load. Focus on:
   • Foot Stance: Typically hip-to-shoulder width apart, with toes slightly pointed out (10-30 degrees) to allow for hip external rotation.
   • Initiate with Hips: Think about pushing your hips back and down simultaneously, rather than just bending your knees.
   • Knees Out: Actively push your knees outwards, tracking over your toes, to engage the glutes and protect the knees.
   • Maintain a Neutral Spine: Keep your chest up, shoulders back, and core braced throughout the entire movement. Avoid rounding your lower back ("butt wink").
   • Depth: Descend as far as your mobility allows while maintaining good form, aiming for your hip crease below your knees.
3. Incorporate Mobility Drills: If mobility is an issue, regularly perform drills such as:
   • Ankle Rocks: Kneeling or standing, drive your knee over your toes while keeping your heel down.
   • Goblet Squat Stretch: Hold a light weight at your chest, squat deep, and use your elbows to push your knees out.
   • Pigeon Stretch/90/90 Stretch: For hip external/internal rotation.
4. Progress Gradually: Once bodyweight deep squats are comfortable, gradually add resistance using dumbbells (goblet squat), kettlebells, or a barbell, always prioritizing form over weight.

Conclusion

Squatting all the way down, or deep squatting, is a fundamental and highly beneficial movement pattern. Far from being detrimental, when performed with proper technique and appropriate progression, deep squats are a powerful tool for building comprehensive lower body strength, enhancing mobility, and improving overall functional fitness. Embrace the full range of motion, prioritize good form, and unlock the full potential of this foundational exercise.