Restricted Knee Movement: Causes, Diagnosis, and Treatment

Why can't I move my knee?

Restricted knee movement, whether due to pain, stiffness, or mechanical blockage, is a common and often debilitating issue that can arise from a wide range of acute injuries, chronic conditions, or overuse syndromes affecting the complex joint structures.

Understanding Knee Anatomy: A Quick Review

The knee is a marvel of biomechanical engineering, a hinge joint primarily responsible for flexion and extension, with a small degree of rotation. Its intricate design, however, also makes it susceptible to a variety of issues that can impede movement. Key components include:

• Bones: The femur (thigh bone), tibia (shin bone), and patella (kneecap).
• Ligaments: Strong, fibrous bands connecting bones, providing stability. Crucial ones include the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL).
• Menisci: Two C-shaped pieces of cartilage (medial and lateral) that act as shock absorbers and help distribute weight evenly across the joint.
• Articular Cartilage: Smooth, slippery tissue covering the ends of the bones, allowing them to glide effortlessly against each other.
• Tendons: Connect muscles to bones, facilitating movement. The quadriceps tendon connects the thigh muscles to the patella, and the patellar tendon connects the patella to the tibia.
• Bursae: Small, fluid-filled sacs that reduce friction between bones, tendons, and muscles.

Any disruption to these components can lead to pain, swelling, and a subsequent inability to move the knee through its full range of motion.

Common Causes of Restricted Knee Movement

The reasons for an inability to move the knee are diverse, ranging from sudden traumatic injuries to gradual degenerative processes.

• Acute Injuries: These often result from direct trauma, twisting, or hyperextension.

  • Ligament Tears (ACL, PCL, MCL, LCL): Tears in these stabilizing ligaments can lead to instability, swelling, and pain, making movement difficult or impossible. An ACL tear, for instance, often results in immediate swelling and a feeling of the knee "giving out."
  • Meniscus Tears: A torn meniscus can cause a "locking" or "catching" sensation, where a fragment of cartilage physically blocks the joint's movement. Swelling and pain are also common.
  • Fractures: Breaks in the patella, tibia, or femur can cause severe pain, deformity, and an inability to bear weight or move the joint.
  • Patellar Dislocation: When the kneecap slips out of its groove, it causes intense pain and an obvious deformity, rendering the knee immobile until reduced.
  • Quadriceps or Patellar Tendon Rupture: A complete tear of these tendons prevents the leg from being straightened or bent actively.

• Inflammatory and Degenerative Conditions: These conditions often develop over time, causing progressive pain and stiffness.

  • Osteoarthritis (OA): The most common form of arthritis, OA involves the breakdown of articular cartilage. This leads to bone-on-bone friction, pain, stiffness, and reduced range of motion, especially after periods of rest.
  • Rheumatoid Arthritis (RA): An autoimmune disease causing chronic inflammation of the joint lining (synovium), leading to pain, swelling, warmth, and significant stiffness, particularly in the morning.
  • Gout: A form of inflammatory arthritis caused by uric acid crystal deposits in the joint, leading to sudden, severe attacks of pain, swelling, redness, and warmth, making movement excruciating.
  • Bursitis: Inflammation of one of the bursae around the knee (e.g., prepatellar bursitis, pes anserine bursitis) causes localized pain and swelling that can limit movement, especially when pressure is applied.
  • Tendonitis/Tendinopathy: Inflammation or degeneration of the tendons (e.g., patellar tendonitis, quadriceps tendonitis) causes pain with movement and can lead to stiffness, particularly after activity.

• Mechanical Obstructions: Physical blockages within the joint can directly impede movement.

  • Loose Bodies: Fragments of cartilage or bone that break off and float within the joint can get caught between the joint surfaces, causing sudden locking, catching, or pain during movement.
  • Baker's Cyst (Popliteal Cyst): A fluid-filled sac that forms behind the knee, often associated with other knee conditions like arthritis or meniscus tears. If large, it can cause a feeling of fullness, tightness, and restrict full knee flexion.
  • Plica Syndrome: A condition where a fold in the joint lining (plica) becomes irritated or inflamed, causing pain, clicking, and a feeling of catching or limited movement.

• Overuse Syndromes and Other Factors:

  • Patellofemoral Pain Syndrome (PFPS): Often called "runner's knee," this condition involves pain around or behind the kneecap, especially with activities like climbing stairs, squatting, or prolonged sitting. While not typically causing full immobility, the pain can significantly limit the desire and ability to move the knee fully.
  • Swelling (Effusion): Any significant swelling within the knee joint capsule (hemarthrosis from blood, or joint effusion from synovial fluid) increases pressure and can mechanically restrict range of motion and cause pain. The body's natural response to joint injury is often to limit movement through swelling and muscle guarding.
  • Muscle Spasm/Guarding: In response to injury or pain, the muscles surrounding the knee may involuntarily tighten or spasm, preventing movement to protect the joint.
  • Post-Surgical Stiffness: Following knee surgery (e.g., ACL reconstruction, total knee replacement), scar tissue formation and lack of early mobilization can lead to significant stiffness and limited range of motion.

When to Seek Professional Medical Attention

If you experience an inability to move your knee, it's crucial to seek medical evaluation, especially if accompanied by:

• Severe pain
• Inability to bear weight on the affected leg
• Significant swelling or bruising
• Deformity of the knee or leg
• Numbness or tingling below the knee
• A "popping" sound at the time of injury
• Signs of infection (fever, redness, warmth around the joint)
• Symptoms that do not improve with rest and basic self-care within a day or two

Diagnostic Approaches

A healthcare professional will typically perform a thorough physical examination, assessing your range of motion, stability, and tenderness. Diagnostic tools may include:

• X-rays: To check for fractures or signs of advanced arthritis.
• Magnetic Resonance Imaging (MRI): Provides detailed images of soft tissues like ligaments, tendons, cartilage, and menisci.
• Ultrasound: Useful for visualizing soft tissue inflammation, fluid collections (e.g., bursitis, Baker's cyst), and tendon issues.
• Blood Tests: To rule out systemic inflammatory conditions like rheumatoid arthritis or gout.
• Joint Aspiration (Arthrocentesis): Removal of fluid from the joint for analysis, especially if infection or crystal-induced arthritis is suspected.

General Management Strategies

Treatment for restricted knee movement depends entirely on the underlying cause. However, common principles often include:

• RICE Protocol (for acute injuries): Rest, Ice, Compression, and Elevation to reduce swelling and pain.
• Pain Management: Over-the-counter or prescription anti-inflammatory medications (NSAIDs) to manage pain and inflammation.
• Physical Therapy: A cornerstone of recovery, focusing on restoring range of motion, strengthening surrounding muscles (quadriceps, hamstrings, glutes), improving balance, and correcting biomechanical imbalances.
• Activity Modification: Adjusting or temporarily avoiding activities that exacerbate symptoms.
• Injections: Corticosteroid injections for inflammation, hyaluronic acid for osteoarthritis, or platelet-rich plasma (PRP) in some cases.
• Surgical Intervention: For severe injuries (e.g., complete ligament tears, large meniscus tears, complex fractures) or advanced degenerative conditions that haven't responded to conservative measures.

The Kinesiology Perspective: Restoring Function

From a kinesiological standpoint, restoring knee movement goes beyond just treating the immediate pathology. It involves a holistic approach to re-educating the body's movement patterns and enhancing joint resilience.

• Neuromuscular Control: Focusing on exercises that improve the brain's ability to communicate with and control the muscles around the knee is crucial. This helps stabilize the joint and prevent re-injury.
• Progressive Loading: Gradually increasing the stress on the knee joint through controlled exercises helps tissues adapt, strengthen, and regain tolerance for activity.
• Biomechanical Assessment: Identifying and correcting underlying imbalances in strength, flexibility, or movement patterns (e.g., weak hip abductors, poor ankle mobility) that may contribute to knee dysfunction.
• Functional Movement: Integrating exercises that mimic daily activities and sports-specific movements to ensure the knee can perform optimally in real-world scenarios.

Prevention Strategies

While not all knee issues are preventable, many can be mitigated through proactive measures:

• Maintain a Healthy Weight: Reduces stress on the knee joints.
• Regular, Balanced Exercise: Include strength training for the quadriceps, hamstrings, and glutes, along with flexibility and balance exercises.
• Proper Warm-up and Cool-down: Prepare muscles and joints for activity and aid recovery.
• Correct Technique: In sports and daily activities, ensure proper biomechanics to avoid undue stress on the knee.
• Appropriate Footwear: Wear shoes that provide adequate support and cushioning.
• Listen to Your Body: Avoid pushing through pain, and allow for adequate rest and recovery.
• Gradual Progression: When starting new activities or increasing intensity, do so gradually to allow your body to adapt.

An inability to move your knee is a signal that demands attention. Understanding the potential causes, seeking timely professional assessment, and committing to a structured rehabilitation plan are paramount to restoring function and maintaining long-term knee health.