Squatting: The 'Knees Over Toes' Myth, Biomechanics, and Safe Technique

Are your knees supposed to go over your toes when squatting?

The long-standing advice to keep your knees from going over your toes when squatting is largely a myth; for most individuals, allowing the knees to track forward over the toes is not only normal and safe, but often essential for achieving optimal squat depth, balance, and muscle activation.

The Myth Debunked: Understanding Squat Biomechanics

For decades, the instruction to prevent knees from tracking past the toes has been a cornerstone of squatting advice, rooted in concerns about knee safety. While well-intentioned, this blanket statement oversimplifies the complex biomechanics of the squat and can lead to suboptimal movement patterns, limiting performance and potentially shifting stress to other joints.

The Biomechanics of the Squat

A well-executed squat involves coordinated movement across the ankle, knee, and hip joints. Understanding these interactions is key to dispelling the "knees over toes" myth.

• Knee Joint Considerations: The knee is a hinge joint designed for flexion and extension. When the knee tracks forward over the toes, it's primarily undergoing greater flexion.
  • Tibial Translation: The tibia (shin bone) naturally moves forward relative to the femur (thigh bone) during squat descent. This anterior tibial translation is a normal part of knee flexion.
  • Shear Forces: While some argue that forward knee travel increases shear forces, research indicates that compressive forces (which the knee is well-designed to handle) are the predominant forces during squatting. Excessive restriction of forward knee movement can actually increase hip flexion, causing a more horizontal torso angle and shifting the stress to the lower back and hips, potentially increasing shear forces there.
• Hip Joint Engagement: The squat is fundamentally a hip-dominant movement. To achieve depth, the hips must hinge backward, allowing the torso to lean forward to maintain balance.
  • Posterior Weight Shift: Initiating the squat by pushing the hips back helps distribute the load and engage the powerful gluteal muscles. However, relying solely on a hip hinge without allowing adequate knee flexion can cause the lifter to fall backward or significantly limit squat depth.
• Ankle Mobility: Ankle dorsiflexion (the ability to move your shin forward over your foot) is crucial for squat depth and allowing the knees to track forward naturally.
  • Limited Dorsiflexion: If ankle mobility is restricted, the body will compensate. This often results in the heels lifting off the ground, an excessive forward lean of the torso, or an inability to reach full depth, all of which can compromise form and increase the risk of injury.

Why "Knees Over Toes" Is Often Necessary and Safe

For most individuals performing a full-range-of-motion squat, allowing the knees to travel beyond the toes is not just acceptable but often beneficial.

• Natural Human Movement: Observe children squatting or athletes performing various movements – their knees naturally track over their toes. This is a fundamental, innate human movement pattern.
• Optimizing Depth and Muscle Activation:
  • Increased Quadriceps Activation: Allowing the knees to track forward during a deep squat significantly increases the range of motion at the knee joint, which directly translates to greater activation and development of the quadriceps muscles.
  • Improved Balance: Restricting forward knee travel can force an excessive posterior weight shift, making it harder to maintain balance, especially with heavier loads.
  • Full Range of Motion: Achieving a deep, ass-to-grass squat without allowing some forward knee travel is practically impossible for most people without significant compensatory movements.
• Individual Anatomy and Proportions: People have different limb lengths and torso proportions. Individuals with longer femurs (thigh bones) relative to their tibias (shin bones) or torso will naturally exhibit more forward knee travel to maintain balance and achieve depth. This is a biomechanical necessity, not a flaw.

When "Knees Over Toes" Might Be Problematic (and why the myth persists)

While "knees over toes" is generally safe, the manner in which it occurs can sometimes be an issue, giving rise to the persistent myth.

• Excessive Forward Lean and Heel Lift: If the knees shoot excessively far forward, causing the heels to lift off the ground, this indicates a lack of ankle mobility or a poor squatting pattern. This can put undue stress on the knees and lower back. The issue here isn't the knees going over the toes, but rather the cause of that excessive movement (e.g., trying to stay too upright with poor ankle mobility).
• Pre-existing Knee Conditions: Individuals with specific knee pathologies (e.g., patellar tendonitis, severe osteoarthritis) may need to limit extreme knee flexion or forward knee travel under load, depending on their condition and a healthcare professional's advice. This is a specific adaptation, not a universal rule.
• Lack of Ankle Mobility: As mentioned, poor ankle dorsiflexion can force compensatory patterns. The body will find the path of least resistance, which might involve an excessive forward lean or heel lift, putting the knees in a vulnerable position.

How to Squat Safely and Effectively

Instead of focusing on an arbitrary "knees over toes" rule, prioritize fundamental squat mechanics.

• Prioritize Full Range of Motion (ROM): Aim for a depth where your hip crease drops below the top of your knees, provided you can maintain a neutral spine and stable heels.
• Maintain a Neutral Spine: Keep your back straight, avoiding excessive rounding or arching, throughout the entire movement. Engage your core.
• Focus on Hip Hinge First: Initiate the squat by pushing your hips back slightly, but allow your knees to bend and track forward naturally as you descend. Think about lowering your hips between your feet, not just straight down.
• Address Mobility Limitations: If you struggle with squat depth or maintaining good form, work on improving ankle dorsiflexion and hip mobility.
• Listen to Your Body: Pain is a signal. If you experience knee pain during squats, consult with a qualified coach or healthcare professional to assess your technique and identify any underlying issues.

Conclusion

The notion that your knees should never go over your toes when squatting is an outdated and largely inaccurate piece of advice. For most people, allowing natural forward knee tracking is essential for a deep, balanced, and effective squat that optimally targets the quadriceps and glutes. Focus instead on mastering proper form, maintaining a neutral spine, and ensuring adequate mobility to perform this fundamental human movement safely and efficiently.