Ligament injuries: The knee has four main ligaments that can be injured, including the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL). Ligament injuries can cause pain, swelling, and/or instability in the knee joint.

Meniscus tears: The meniscus is a piece of cartilage in the knee joint that helps to cushion and stabilize the joint. Tears can occur due to sudden twisting or rotating movements, and can cause pain, swelling, and/or limited mobility in the knee.

Patellofemoral pain syndrome: This is a condition that involves pain in the front of the knee, often due to overuse or improper alignment of the kneecap.

Osteoarthritis: This is a degenerative joint disease that can affect the knee joint, causing pain, stiffness, and/or limited mobility.

Tendinitis: This is inflammation of the tendons around the knee joint, often due to overuse or repetitive strain. It can cause pain and/or swelling in the knee area.