Knee locking up with no known injury

Knee locking can be caused by several factors, even in the absence of a known injury. Here are some potential causes:

1. **Meniscus Tear**: A tear in the cartilage of the knee can cause locking, especially if a fragment is caught in the joint.
2. **Patellar Issues**: Conditions related to the kneecap, such as patellar subluxation, can lead to locking sensations.
3. **Ligament Issues**: Although you mentioned no injuries, ligament injuries can occur without a specific traumatic event and may lead to instability or locking.
4. **Arthritis**: Osteoarthritis or other forms of arthritis can cause swelling and mechanical issues in the joint.
5. **Plica Syndrome**: This occurs when a fold in the lining of the knee joint becomes irritated or inflamed, potentially leading to locking.

Until your doctor's visit, consider these tips:

- **Rest**: Avoid activities that cause pain or further strain on your knee.
- **Ice**: Apply ice to reduce swelling and discomfort.
- **Compression**: Use a knee brace or wrap for support.
- **Elevation**: Elevate your knee to help reduce swelling.
- **Gentle Movement**: Engage in gentle range-of-motion exercises if they don’t cause pain.

Be sure to share all your symptoms with your doctor for a comprehensive evaluation and appropriate treatment.

Loose bodies floating around in your knee. I have them as well. Locks up when I sprint.

I’ve been having knee issues since high school, so I have been functioning with “rocks” in my knees since 99 or so. You might just need a small scope, if anything. It is worse for me sometimes than others. I have one about the size of a marble.