Disclaimer

Suddenly slowing down or changing direction, pivoting or landing awkwardly from a jump. Other causes can be a blow to the knee or a sudden stop that would put a high amount of pressure on the knees. 

You can get an ACL tear from poor conditioning, wearing footwear that doesn't fit correctly, hormonal and muscle strength also come into play, as well as running on a hard surface such as astroturf. 

How you can prevent an ACL injury, core strength exercises, hamstring strengthening and jumping and landing training to have proper knee positioning. Apply RICE and see a physical therapist, you might have to wear a knee brace or use crutches to avoid putting weight on the knee. In most cases, the recovery time is 8 to 9 months.

A meniscus tear happens when you put weight onto your knee and then quickly rotate it. The meniscus is a shock absorber in your knee that is located between the shin bone and the thigh bone. Treatment includes RICE, medication (creams or painkillers, consult a doctor before buying).

In some cases, a torn meniscus requires surgery. Symptoms can include a popping sensation in the knee, swelling or stiffness, pain when rotating or turning the knee, your knee being locked in place when you want to move it and your knee giving way. 

Athletes in contact sports such as football and basketball, where a lot of fast paced pivoting is required have an increased risk at a meniscus tear and can develop osteoarthritis( when the protective cartilage between bones wears down, causing pain and swelling).

The PCL or Posterior Cruciate Ligament tear is less common than its counterpart the ACL(Anterior Cruciate Ligament). It has similar causes to an ACL pull, being falling onto a bent knee, a large hit to the knee, bending your knee too far backward or dislocation of the knee. 

Symptoms can be pain, swelling, instability, stiffness, difficulty walking and difficulty going down the stairs. Treatment includes a knee brace or bandage, crutches, physical therapy and sometimes surgery. 

You can apply RICE and stop the majority of physical activity. For a light or mild strain, healing time can be around 10 days, depending on the person. But if surgery was needed, it can take up to 10 months to heal completely. 

Swollen knee is when there is a buildup of fluid in your knee joint, causing it to swell. This can result in losing to the ability to put weight on your leg and pain.

It can be caused by overuse, a meniscus tear, ACL injury or tear and a broken bone. Treatment includes RICE, usage of painkillers and physical therapy.

A knee brace might also prove beneficial. Healing could take a day or more, any more than a few days and you should see a doctor, for risk of an infection.

Patellar tendonitis is commonly called jumper's knee and mostly affects athletes in volleyball or basketball. Tendonitis is caused when too many tears in the tendon occur at the same time, weakening it.

 Tears are a normal thing in sports, for during the exercise your creating microtears in your muscle, allowing you to grow back stronger and better than before. Tendonitis happens when you overuse the tendon, creating a bigger tear than usual. 

Patellar tendonitis can start as just swelling and pain in the muscle but it can get worse over time and eventually, can prohibit some things in your daily life such as standing up and going up stairs. Prevention methods include, strengthening the muscle (visit a physiologist for advice), improve technique and stop when you feel pain. 

Treatment is varied between surgical and injection based medicine, you may also do some strengthening or stretching exercises and can use painkillers and RICE.