Knee injuries often damage the ligaments and cartilage. Anterior cruciate ligament injury is common in athletes who are involved in sports like skiing football, basketball etc. It occurs when pivoting or landing from a jump. Median collateral ligament injury is common among people involved in contact sports like rugby, football etc.

Posterior cruciate ligament injury occurs when a person receives a blow to the knee or makes a mistake while running or playing. It is also common among people involved in car accidents. Torn or worn out cartilage is another common knee injury. The meniscus of the knee is a cartilage which maintains knee joint stability. This cartilage tends to tear when the knee is bent or twisted in an awkward manner. Patella dislocation or knee cap dislocation can cause extreme pain and difficulty in walking. It can be caused by impact, accidents etc. A common overuse knee injury is bursitis. Inflammation of the bursa is common in people who spend a lot of time on their knees like housemaids, gardeners etc.

Tendonitis is a knee injury caused by overuse of the knee muscles. Patellar and quadriceps tendonitis is common among athletes, and people engaged in strenuous activities. Pulled and torn muscles are a type of knee injury. The hamstring and quadriceps muscles are often affected.