Deep Squats: Benefits, Risks, and How to Safely Squat Below Parallel

Should you go past 90 degrees when squatting?

For most individuals with adequate mobility and proper form, squatting past 90 degrees (below parallel) is not only safe but also offers significant biomechanical and physiological advantages for strength, muscle development, and joint health, provided it's executed without pain and with appropriate technique.

Understanding Squat Depth: What is "90 Degrees"?

When discussing squat depth, "90 degrees" typically refers to the point where your hip crease is roughly level with or slightly above the top of your knee, meaning your thighs are parallel to the floor. Squatting "past 90 degrees" or "below parallel" means descending further, so your hip crease drops below the top of your knees, often into what's known as a "deep" or "full" squat. This range of motion is crucial for understanding the biomechanical implications.

The Biomechanics of Squat Depth

The depth of your squat profoundly impacts the forces and muscle activation around your joints.

• Knee Joint:

  • Patellofemoral Joint: Research indicates that compressive forces on the patella (kneecap) and femur are highest around 90 degrees of knee flexion. As you descend past 90 degrees, these forces can actually decrease, shifting some load to the hip extensors.
  • Cruciate Ligaments (ACL/PCL): Stress on the Anterior Cruciate Ligament (ACL) is highest at shallower depths (0-60 degrees of knee flexion), while Posterior Cruciate Ligament (PCL) stress increases at deeper angles (past 90 degrees). However, for individuals with healthy ligaments, these stresses remain well within physiological limits during properly executed squats, even with significant loads. The notion that deep squats are inherently "bad" for the ACL is largely a misconception.
  • Menisci: The menisci, cartilage pads in the knee, experience compressive forces that increase with deeper flexion. However, these forces are part of normal joint loading and contribute to cartilage health, not necessarily damage, in healthy knees.

• Hip Joint:

  • Deeper squats require greater hip flexion, engaging the gluteal muscles and hamstrings more intensely as primary hip extensors.
  • Adequate hip mobility, particularly in flexion and often with some external rotation, is essential to achieve depth without compensatory movements.

• Ankle Joint:

  • Significant ankle dorsiflexion (the ability to bring your shin over your foot) is critical for maintaining an upright torso and preventing the heels from lifting or the lower back from rounding during a deep squat. Limited ankle mobility is a common barrier to achieving full depth.

• Spinal Alignment:

  • As you descend into a deep squat, there's a natural tendency for the pelvis to tuck under, causing the lower back to slightly round – often called "butt wink." While a slight, controlled butt wink at the very bottom of a deep squat can be normal for some, excessive or uncontrolled rounding under load can place undue stress on the lumbar spine. This is often a sign of limited hip or ankle mobility rather than an inherent flaw of deep squatting itself.

Benefits of Squatting Below Parallel

For those who can execute it safely, squatting past 90 degrees offers several advantages:

• Greater Muscle Activation: Deeper squats significantly increase the activation of the gluteal muscles (gluteus maximus) and adductors, in addition to the quadriceps, compared to partial squats. This leads to more comprehensive lower body development.
• Improved Mobility and Flexibility: Consistently squatting to full depth can improve range of motion in the hips and ankles over time, which translates to better movement quality in daily life and other athletic endeavors.
• Enhanced Strength and Power: Training through a full range of motion builds strength across that entire range, leading to more robust and functional strength. Athletes often benefit from training movements that mimic their sport's demands, many of which involve deep knee and hip flexion.
• Reduced Knee Stress (Paradoxical): While counterintuitive to some, the shift in forces at deeper depths can actually be beneficial. By engaging the powerful hip extensors more effectively, the load on the patellofemoral joint may be reduced compared to squats stopped at 90 degrees, where these forces peak.

Potential Risks and Considerations

While deep squats are generally safe, certain factors warrant caution:

• Pre-existing Conditions: Individuals with severe knee osteoarthritis, specific meniscal tears, hip impingement (Femoroacetabular Impingement - FAI), or significant spinal issues should consult with a healthcare professional before attempting deep squats.
• Limited Mobility: Insufficient ankle dorsiflexion or hip mobility can force compensatory movements, such as excessive "butt wink" or leaning too far forward, increasing the risk of injury, particularly to the lower back.
• Improper Form: Rushing depth without mastering foundational form can lead to issues. Key indicators of poor form include excessive spinal rounding, knees caving inward (valgus collapse), or inability to maintain balance.
• Load: While deep squats are safe with appropriate loads, attempting maximal loads with compromised form or limited mobility significantly increases risk.

Who Should Squat Deep?

• Individuals with good baseline mobility: Those who can comfortably achieve a deep squat without pain or significant compensatory movements.
• Athletes: Many sports require dynamic full-range-of-motion strength and power, making deep squats a highly functional exercise.
• Those seeking maximum muscle development: For comprehensive lower body hypertrophy, deep squats are superior due to greater muscle activation.
• Individuals aiming for improved joint health and mobility: When done correctly, deep squats can contribute to maintaining and improving range of motion.

Who Should Consider Limiting Depth?

• Individuals with specific, diagnosed joint pathologies: Especially if deep flexion exacerbates pain or symptoms.
• Those with significant, unaddressed mobility restrictions: Prioritize improving ankle and hip mobility before forcing depth.
• Beginners: It's often prudent to master squatting to parallel with excellent form before gradually increasing depth.
• Individuals recovering from certain injuries or surgeries: Follow the guidance of your physical therapist or medical professional.

How to Safely Achieve Deeper Squats

If you're aiming for deeper squats, focus on a progressive and methodical approach:

• Prioritize Mobility Drills:
  • Ankle Dorsiflexion: Calf stretches, ankle rocks, elevated heel squats.
  • Hip Mobility: 90/90 stretches, pigeon pose, hip internal/external rotation drills.
• Warm-up Effectively: Dynamic stretches that prepare your joints and muscles for the full range of motion.
• Focus on Form Over Depth: Always prioritize a neutral spine, knees tracking over toes, and controlled movement. Use a mirror or video to assess your technique.
• Gradual Progression: Don't force depth. Gradually increase your range of motion over weeks or months as your mobility and strength improve. Use lighter loads initially when exploring new depths.
• Appropriate Footwear: Flat, stable shoes (e.g., weightlifting shoes with an elevated heel, or minimalist shoes) can aid stability and, in some cases, facilitate depth.
• Listen to Your Body: Pain is a signal to stop and reassess. Never push through sharp or persistent pain.

The Verdict: It Depends on You

The question of whether to squat past 90 degrees isn't a simple "yes" or "no." For the vast majority of healthy individuals, deep squats are a highly effective and safe exercise, offering superior benefits for strength, muscle growth, and mobility. However, individual anatomy, current mobility, injury history, and specific goals must all be taken into account.

Ultimately, the "best" squat depth is the deepest you can achieve while maintaining excellent form, without pain, and in alignment with your personal fitness objectives. Prioritize movement quality and listen to your body's feedback.

Conclusion

Squatting below parallel is a fundamental human movement pattern and a cornerstone of effective strength training. Far from being inherently dangerous, deep squats, when performed correctly, can unlock greater muscular development, improve joint health, and enhance overall functional capacity. By addressing mobility limitations, focusing on meticulous form, and progressing gradually, most individuals can safely and beneficially incorporate deep squats into their training regimen.