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The scramble is on: steep inclines, hairpin turns, mud, striving for the holeshot and the grueling pressure on your knees. The best defense against injury is to be well educated about your knees: their purpose and common injuries – prevention and treatment.

The Function of a Knee

The knees are made up of bones, cartilage, ligaments, tendons and muscles and their main function is to provide stability and support to the body. They also help the leg bend and straighten, which allow you to stand, sit, walk, run, jump, and squat.

Knee function can be severely hindered if one or more parts of the knee are injured, causing swelling or pain. Injury can occur from a direct blow or sudden movement that puts pressure on the knee or from basic wear and tear on it’s parts, caused by a repetitive movement or motion.

Injuries to Cartilage

Cartilage is a dense connective tissue that is present in many parts of the body and it cannot be seen alone by x-ray. There are three main types of cartilage and all differ in their structure and function:

• Hyaline (Articular) Cartilage – made up of collagen fibers and a proteoglycan matrix

• Fibrocartilage – menisci are made of this

• Elastic Cartilage (not found in the knee)

Hyaline cartilage, in the knee, serves two main functions: to give a smooth articulating surface and to provide shock absorption that can hold up against compression and tension. Most injuries to this type of cartilage are caused either by a one-time trauma or impact or a repeated trauma such as overuse, and are first noticed by pain, swelling, or limited range of motion. These cartilage injuries may also include some detached bone, in which case an x-ray will pick up the bone fragments and may aid in quicker diagnosis.

Fibrocartilage is what menisci are made up of. Meniscus is a C-shaped piece of cartilage that offers padding between the femur and tibia. If the knee is twisted while bearing weight, the meniscus is easily injured. The injuries may be small to large and in turn can leave the cartilage connected or hanging depending on the location and severity of the damage.

Cartilage damage can be diagnosed in two ways:

• MRI ? scanning that shows the cartilage lesion clearly and also provides information about the surrounding bone and ACL

• Arthroscopy ? operation where the inside of the knee is closely viewed with a camera (needed procedures can also be done with this operation)

The main ways to treat cartilage injuries are:

• Exercises to strengthen muscles including physical therapy

• Electrical stimulation for strengthening

• Surgery including arthroscopy (there are many different treatments that can be offered surgically)

Injuries to Ligaments

Ligaments are short bands of tough fibrous connective tissue that is made up of long, stringy collagen fibers. They connect bone to bone and form a joint. There are four types of ligaments:

• Anterior cruciate ligament (ACL) ? connects your femur to your tibia at the center of the knee

• Lateral collateral ligament (LCL) – connects your femur to your tibia along the outside of your knee

• Posterior cruciate ligament (PCL) ? connects your femur to your tibia at the back of the knee

• Medial collateral ligament (MCL) ? connects your femur to your tibia along the inside of your knee

The ACL and PCL attach on one side of the knee to the femur (thigh bone) and on the other side to the tibia (shin bone), and cross each other.

In motocross, there is a high occurrence of ligament injuries due to the strain put on a rider’s knees. They are often referred to as ?sprains’. The ACL is injured most by a sudden twisting motion and is either stretched or torn. A blow to the ACL is often referred to as a ?blown knee’. Some sort of a direct impact to the knee often causes damage to the PCL. The LCL and MCL are most often hurt by some sort of direct hit to the outer knee. All of these ligaments can also be injured by repeated wear and tear and can be easily re-wounded after the initial damage is done.

Some symptoms of ligament injuries are:

• A snap or pop sound or feeling

• Pain surrounding the area

• Immediate swelling around the injured area

• Possible temporary relief from the injury a few minutes after it occurs, giving a false sense of wellness

• A giving way feeling if activity is attempted to be resumed

Ligament injuries are generally treated by:

• Ice packs to control swelling directly after the injury occurs

• Exercises, either alone or with a physical therapist or a doctor

• A knee brace for stability or correction

• Surgery (for more severe injuries)

Injuries to Tendons

Tendons are strong tissues that connect bone to muscle. The tendons in the knee are the patellar tendon, which connects to the bottom of your kneecap and attaches to the top of the tibia and the quadriceps tendon, which connects to the top of the patella and lets your leg to extend.

The two injuries most often associated with tendons of the knee and motocross are a strain and tendonitis. A strain occurs when a tendon has been either partially or completely torn. The symptoms are similar to those of a sprain and there may be some bruising around the affected area. Tendonitis is an inflammation of the tendon and pain may be felt when walking or extending a leg or when bending.

Tendon injuries are generally caused by one of two reasons:

• Trying to break a fall ? when the thigh muscle contracts the tendon can become damaged or tear

• Overuse ? the tendon stretches and gets worn out like and old rubber band and the knee will become inflamed

There are a few ways to treat a damaged tendon:

• Ice on the affected area

• Pain relievers to reduce pain and swelling

• Keep the leg elevated

• Stretching and strengthening exercises

• Rest the knee and limit activity

• A brace or cast to limit movement and further injury

• Surgery for extensive damage and tears

Bone and Muscle

Watch for a follow-up to this article about the bones and muscles in the knee and the injuries that can occur to those. Remember, healthy knees are the best way to go?keep them stretched and warmed up at all times and wear protective gear whenever possible to help prevent injury.

“EVS ? Winning with Safety”