Knee Pain During Running & Jumping: Causes, Biomechanics, and Prevention

Why does my knee hurt when I run and jump?

Knee pain during running and jumping is a common complaint, often stemming from a combination of overuse, improper biomechanics, muscle imbalances, and inadequate recovery that place excessive stress on the knee joint and surrounding structures.

Understanding Impact-Related Knee Pain

The knee joint, a complex hinge joint, is remarkably resilient but also highly susceptible to injury, especially during high-impact activities like running and jumping. These actions place significant stress on the patellofemoral joint (where your kneecap meets your thigh bone), the tibiofemoral joint (between your thigh and shin bones), and the surrounding tendons, ligaments, and cartilage. Pain typically arises when these structures are overloaded beyond their capacity to adapt, leading to irritation, inflammation, or damage.

Common Causes of Knee Pain During Running and Jumping

Understanding the specific structures involved can help pinpoint the likely cause of your pain:

• Patellofemoral Pain Syndrome (PFPS) - "Runner's Knee": This is the most prevalent cause of anterior (front) knee pain. It results from irritation of the cartilage underneath the kneecap or the surrounding soft tissues. Running and jumping increase the compressive forces on the patellofemoral joint, especially during knee flexion.
• Patellar Tendinopathy - "Jumper's Knee": Characterized by pain just below the kneecap, this is an overuse injury of the patellar tendon, which connects the kneecap to the shin bone. Repetitive explosive movements like jumping (especially landing) and sprinting can lead to microscopic tears and degeneration within the tendon structure.
• Iliotibial Band (ITB) Syndrome - "IT Band Friction Syndrome": Pain typically felt on the outside of the knee. The IT band is a thick band of fascia that runs from the hip to just below the knee. Repetitive knee flexion and extension, common in running, can cause the IT band to rub over the bony prominence on the outside of the thigh bone (lateral epicondyle), leading to inflammation.
• Quadriceps Tendinopathy: Similar to patellar tendinopathy, but the pain is located above the kneecap, affecting the quadriceps tendon. This is also an overuse injury from repetitive knee extension activities.
• Meniscus Injuries: The menisci are C-shaped cartilage pads that cushion the knee joint. While acute tears can occur from twisting motions, repetitive impact from running and jumping can contribute to degenerative tears over time, leading to pain, swelling, and sometimes clicking or locking sensations.
• Osteoarthritis (OA): Degenerative joint disease where the articular cartilage wears down. While more common with age, high-impact activities can accelerate its progression or exacerbate symptoms in individuals with pre-existing OA.
• Bursitis: Inflammation of the bursae, small fluid-filled sacs that reduce friction around the knee joint. Overuse or direct impact can cause bursitis, leading to localized pain and swelling.
• Stress Fractures: Less common but possible, especially in individuals who rapidly increase their training load. These are tiny cracks in the bone, often the tibia or femur, caused by repetitive stress.

Biomechanical Factors Contributing to Knee Pain

Your body's movement patterns and inherent structure play a critical role in how forces are distributed through your kinetic chain (the interconnected system of joints and muscles).

• Foot Mechanics:
  • Excessive Pronation (flat feet): Can cause internal rotation of the tibia and femur, increasing stress on the patellofemoral joint and IT band.
  • Excessive Supination (high arches): Can lead to poor shock absorption, transmitting more impact forces directly to the knee.
• Hip Weakness or Imbalance:
  • Weak Gluteus Medius: Can lead to "knee valgus" (knees collapsing inward) during running and landing, placing excessive stress on the medial (inner) knee structures and the patellofemoral joint.
  • Weak Gluteus Maximus: Reduces the hip's ability to absorb ground reaction forces, shunting more load to the knees.
• Core Instability: A weak core compromises proximal stability, meaning the hips and pelvis may not provide a stable base for lower limb movement, leading to compensatory movements at the knee.
• Muscle Imbalances and Tightness:
  • Tight Hamstrings: Can alter knee mechanics and increase patellofemoral joint compression.
  • Tight Quadriceps: Can pull the kneecap upwards, increasing pressure on the joint.
  • Tight Calves (Gastrocnemius/Soleus): Limits ankle dorsiflexion, forcing the knee to absorb more impact.
• Poor Landing Mechanics: Landing with stiff, locked knees or with excessive knee valgus can significantly increase peak forces on the knee joint structures.

Training Errors and Practices that Lead to Pain

Often, the way you train is a primary contributor to knee pain:

• Overuse / Too Much, Too Soon: Rapidly increasing mileage, intensity, or frequency of running or jumping without allowing the body sufficient time to adapt is a common culprit. Tissues need time to remodel and strengthen in response to stress.
• Inadequate Recovery: Insufficient rest between training sessions prevents tissues from repairing and rebuilding, leading to cumulative fatigue and breakdown.
• Improper or Worn-Out Footwear: Shoes that don't provide adequate support, cushioning, or are past their effective lifespan can alter gait mechanics and reduce shock absorption, increasing stress on the knees.
• Running Surface: Consistently running on hard, unforgiving surfaces (e.g., concrete) transmits more impact force through the joints compared to softer surfaces like tracks or trails.
• Lack of Warm-up/Cool-down: Skipping these crucial phases can leave muscles unprepared for activity or hinder recovery.

When to Seek Professional Help

While many cases of knee pain can be managed with rest and self-care, it's important to consult a healthcare professional (e.g., doctor, physical therapist, sports medicine specialist) if you experience:

• Acute, sharp pain that limits your ability to bear weight.
• Significant swelling or bruising around the knee.
• A "pop" or "snap" sensation at the time of injury.
• Knee instability, buckling, or giving way.
• Pain that persists or worsens despite rest and conservative measures.
• Inability to bend or straighten your knee fully.

Preventative Strategies and Management

Addressing knee pain from running and jumping requires a holistic approach focused on load management, strength, mobility, and proper technique.

• Gradual Load Progression: Follow the "10% rule" – do not increase your weekly training volume (mileage, jump reps) by more than 10%. Allow your body time to adapt.
• Strength Training:
  • Glutes: Focus on exercises like squats, deadlifts, hip thrusts, and glute bridges to strengthen gluteus maximus and medius.
  • Quadriceps and Hamstrings: Incorporate exercises like lunges, step-ups, and leg presses. Eccentric training (focusing on the lowering phase of movements) can be particularly beneficial for tendinopathies.
  • Calves: Calf raises to improve ankle stability and shock absorption.
  • Core: Planks, bird-dogs, and anti-rotation exercises to improve trunk stability.
• Mobility and Flexibility: Regularly stretch tight muscles (quads, hamstrings, hip flexors, calves, IT band) and use foam rolling to release tension.
• Optimize Running and Landing Mechanics:
  • Increase Cadence: Aim for a higher step rate (around 170-180 steps per minute for running) to reduce overstriding and impact forces.
  • Soft Landings: Practice landing softly and quietly during jumping, absorbing impact through bent knees and hips. Avoid "locking out" your knees.
  • Avoid Knee Valgus: Focus on keeping your knees aligned with your toes during squats, lunges, and landings.
• Appropriate Footwear: Wear running shoes that are suitable for your foot type and gait, and replace them every 300-500 miles or when they show signs of wear. Consider consulting a running shoe specialist.
• Cross-Training: Incorporate low-impact activities like cycling, swimming, or elliptical training to maintain cardiovascular fitness without constantly stressing the knees.
• Listen to Your Body: Pay attention to early signs of pain or discomfort. It's better to take a few days off or reduce intensity than to push through pain and risk a more severe injury.
• Nutrition and Recovery: Ensure adequate sleep, hydration, and a balanced diet to support tissue repair and overall health.

Conclusion

Knee pain experienced during running and jumping is a clear signal from your body that something in your training or biomechanics needs attention. By systematically addressing factors such as training load, muscle imbalances, movement patterns, and recovery, you can significantly reduce your risk of injury, alleviate existing pain, and continue to enjoy high-impact activities safely and effectively. Remember, consistent effort in prevention and management is key to long-term knee health.