Knee pain is one of the most common complaints among active individuals—but what if your knee isn’t actually the problem?
The truth is, the knee often becomes the victim rather than the culprit. If you’ve been battling knee pain without lasting relief, it may be time to look beyond the knee joint itself. Understanding key biomechanical principles—like the joint-by-joint approach, the screw-home mechanism, and the roles of foot stability, ankle mobility, and hip mobility—can unlock the real solution to your knee discomfort.
Joint-by-Joint Theory and Knee Pain
The joint-by-joint theory, developed by Gray Cook and Michael Boyle, suggests that the body operates as an alternating series of mobile and stable joints:
- Foot – Stability
- Ankle – Mobility
- Knee – Stability
- Hip – Mobility
- Lower back – Stability
When a joint doesn’t function as it should, neighboring joints compensate—leading to pain and dysfunction. The knee, designed primarily for stability, sits between the mobile ankle and hip. If either of those becomes restricted, the knee ends up taking the hit, often leading to pain and overuse injuries.
Screw-Home Mechanism: How Misalignment Causes Knee Pain
The screw-home mechanism is a critical part of knee function. As the knee fully extends, the tibia (shin bone) externally rotates relative to the femur (thigh bone)—locking the joint in a stable position.
If the hip lacks mobility or the foot/ankle aren’t functioning properly, this rotation can be compromised. Poor hip rotation or limited ankle dorsiflexion can force the knee into unnatural movement patterns—causing pain or injury over time.
How Foot, Ankle, and Hip Function Affect Knee Pain
To relieve knee pain and restore natural mechanics, we must address the joints above and below:
✅ 1. Foot Stability
Your foot is the foundation of movement. An unstable foot collapses into overpronation, forcing the knee to cave inward (valgus collapse)—increasing strain on ligaments and cartilage.
🔹 Improve foot stability with:
- Short foot exercises (for arch control)
- Toe yoga (isolating toe movement)
- Single-leg balance drills
✅ 2. Ankle Mobility
Limited ankle dorsiflexion (bringing your toes toward your shin) causes compensatory movement at the knee. This often leads to forward knee translation during squats and lunges—putting pressure on the patella.
🔹 Improve ankle mobility with:
- Banded dorsiflexion mobilizations
- Calf stretching (focus on both gastroc and soleus)
- Foam rolling the lower leg
✅ 3. Hip Mobility
Lack of hip external rotation or flexion forces the knee to compensate during movement. This disrupts alignment and adds stress to the joint.
🔹 Improve hip mobility with:
- 90/90 hip rotations
- Hip flexor and adductor stretches
- Glute activation drills (clamshells, monster walks)
How to Fix Knee Pain Without Focusing on the Knee
Here’s a step-by-step strategy you can follow today:
Strengthen Foot Stability
→ Arch control, toe movement, and balance
Improve Ankle Mobility
→ Mobilizations, stretching, and soft tissue release
Enhance Hip Mobility
→ Rotation drills, dynamic stretching, and glute activation
Reinforce Movement Patterns
→ Practice:
- Squats with external rotation torque at the hips
- Proper landing mechanics
- Strength training with aligned knees
Conclusion: Treat the Source, Not the Symptom
If knee pain has been holding you back, it’s time to stop chasing symptoms and start addressing the root cause.
By improving foot stability, ankle mobility, and hip mobility, you create a stable and resilient foundation for your knees. Instead of relying on temporary fixes, this holistic approach ensures long-term relief and better performance.
🔗 Want Help Identifying the Root Cause?
Ready to stop chasing knee pain and fix the real issue?
Book a free call with our expert physical therapy team today.
