from Dr. Squat:
COMMON PROBLEMS OF THE KNEE
- Chondromalacia patellae: Softening of the articular cartilage of the patella that is produced by osteoarthritic degeneration. Such cartilage is unsuited for the high compressive loads and frictional forces involved in squatting, and roughening of the underside of the kneecap is common. Tight quads are responsible for 80% of chondromalacia. Other causes include aging, repetitive overuse, and faulty biomechanics due to genetics.
- Patellofemoral Pain Syndrome (PFPS): Exemplified by pain in front of patella, which intensifies during activity. Also, pain during extended sitting, and/or walking up stairs. PFPS is further characterized by crepitus (noise), without instability. PFPS is considered to be a tracking problem ofthe patella, caused by an imbalance between the medial and lateral quadriceps. The damage to the underside of the patella is not unlike uneven tread wear in a car that needs the tires rotated.
- Unstable Knee Joint: Knee suddenly gives out. This is often caused by old injuries which have overstretched the knee ligaments.
- Locked Knee: The usual cause of locked knees is a torn meniscus or a loose body within the joint capsule.
- Swelling/Tightness: Nearly always indicates an internal injury. See physician immediately.
- Crepitus: Noisy knees are no reason for concern, UNLESS accompanied by pain and/or swelling.