Health blog

Struggling to bend your knee can feel frustrating and even alarming. Whether your knee suddenly won’t move or its stiffness has crept up over time, the discomfort and limitations in mobility can make your daily life that much more difficult. For many people, bending an uncooperative knee can range from mildly painful to outright impossible, and knowing where to start for help can be overwhelming.

If you’ve found yourself Googling “why can’t I bend my knee” or “what to do when my knee locks up,” you’re not alone. We hope this information can provide some relief, or at least a better understanding of your symptoms and how you might pursue treatment.

What does your knee feel like when you try to bend it?

For some, knee movement may feel restricted due to sharp pain, swelling, or discomfort when applying weight. You might feel like your knee is “stuck” or “locking up,” preventing it from moving freely.

When this inability to bend occurs suddenly, it can lead to a condition known as a locked knee, where it feels as though your knee physically won’t move past a certain point. Even bending it slightly might trigger pain or abnormal resistance.

For others, knee stiffness might not involve complete locking but rather increased discomfort or tightness when trying to move through your whole range of motion. This type of restriction is often referred to as pseudo knee locking, which can occur due to conditions like inflammation or arthritis.

Symptoms of a locked knee

A locked knee occurs when your knee joint feels frozen or physically stuck, making movement difficult or impossible. This can be accompanied by some or several of the following symptoms:

• Sharp pain: Attempting to move your knee triggers sudden, severe pain that halts any further motion.
• Immobility: The knee won’t bend or straighten from its current position.
• Clicking or popping sensations: You may feel a noticeable click or hear a sound when trying to move the knee.
• Swelling or stiffness: Swollen tissue inside or around the joint may limit its range of motion.

Locked knee joints can stem from issues like a torn meniscus, fragmented cartilage, or other structural damage in the knee that gets in the way of smooth movement.

Symptoms of knee pain that impacts movement (pseudo knee locking)

If you can’t fully bend your knee but it’s not totally locked up or frozen, you may be experiencing pseudo knee locking, which is characterized by general stiffness caused by pain. Symptoms of a pseudo locked knee may include:

• Achy, throbbing pain: A persistent, dull ache that increases with movement or physical activity.
• Inflammation and swelling: Visible swelling around the kneecap or joint that limits flexibility.
• Weakness or instability: The knee may feel weak, like it might give out when you try to put weight on it.
• Warmth or redness: Signs of inflammation, often signaling an overuse injury or localized irritation.
• Popping sensations without locking: Clicking or popping that accompany discomfort but doesn’t prevent movement entirely.

Because knee locking and knee pain in general can result from various factors, like arthritis, ligament sprains, or overuse, figuring out how to describe your symptoms is key to identifying the underlying cause and therefore how to treat it.

What causes a locked knee?

Common conditions that cause locked knees include:

• Meniscus tear: A torn meniscus, which normally acts as a cushion between the bones in your knee, can cause fragments to block movement.
• Patellofemoral pain syndrome: The medical term for runner’s knee is usually triggered by overuse of the knee or weak muscles surrounding the knee.
• Ligament injuries: Damage to major ligaments, such as the ACL, can lead to severely restricted motion.
• Osteoarthritis: Worn cartilage can cause stiffness, swelling, and discomfort during movement.
• Knee bursitis: Inflamed bursae in the joint can result in painful restrictions.

Whether your knee is physically locked or painfully stiff, understanding these conditions can guide you toward the right treatment.

Treatments for a locked or stiff knee

If you’re dealing with a locked knee or can’t fully bend it, there are steps you can take to alleviate discomfort, restore mobility, and address the underlying cause. At home, you can rest, ice, compress, or elevate (RICE) the joint to see if your symptoms improve on their own. If you’ve already been dealing with a locked knee for a while, though, it’s probably more effective to seek specialist treatment.

Physical therapy is one of the most effective treatments for restoring knee mobility across a wide variety of underlying causes. Whether you’re dealing with a locked knee joint or pseudo knee locking, our skilled physical therapists can design exercises to improve strength, flexibility, and overall function. Professional treatments may also include:

• Manual therapy
• Aquatic therapy
• Personalized exercises or stretches
• Diagnosis and referral for meniscus tears or ligament injuries

Find a physical therapist in New Orleans

Your knee pain doesn’t have to control your life. Whether you’ve been experiencing sharp pain, pseudo knee locking, or swelling that just won’t go away, connecting with a trusted physical therapist can make all the difference.

Located right here in New Orleans, our physical therapy professionals specialize in treating locked knees, knee pain, and related conditions. Together, we’ll create a personalized plan to get your knee moving freely again. Start a conversation with our team by calling one of our clinic locations or by requesting your first appointment online today.