Why does my child have knee pain?

As children grow and play sports, there are always going to be little bumps and bruises along the way. As they grow they will also go through several growth spurts which often cause pain in their young joints. One of the more common injuries in young athletes is pain located under the kneecap or medically known as, chondromalacia (con-dro-ma-la-chia). This condition occurs when the surface underneath the kneecap is roughened and irritated. The pain associated with this disorder will usually consist of a dull-achy pain, which gets worse with stair climbing and deep-knee bends. The following will describe how to decrease the associated pain and prevent this injury from occurring.

ANATOMY

The top of the patella is connected to the quadricep (upper thigh) muscles group via a tendon. The lower part of the kneecap is then connected to the shinbone via a tendon. When the knee is bent, the kneecap will glide up and through a groove along the femur (upper thighbone). As we will see, the quadriceps are vitally important in preventing and treating this condition. Chondromalacia is presented when there is a roughening of the cartilage on the backside of the patella. Several experts will sometime refer to this as the “sandpaper” effect. This roughening will subsequently cause an inflammatory response. The pain associated with this disorder is from the inflammation of the kneecap cartilage, as it presses against the femur during bending of the knee.

CAUSES

These are just four of the main reasons why people may be predisposed to this problem.

Tight quadricep muscles
This condition is very common during growing spurts. It is common in children because of the growth of the quadricep muscles in relation to the bone growth. The bones in children tend to grow quicker than the muscles, therefore causing tightness within the quadriceps. This puts excessive pressure upon the patella, possibly causing chondromalacia.
Poor tracking of the kneecap
If the kneecap does not track perfectly through the groove in the femur, it will cause too much pressure on the patella. This is a common cause in the majority of cases. People who are susceptible usually have uneven knees (knock-kneed), wider hips, or rotation of the tibia (lower leg bone).
Flat Feet
People with flat feet will cause the knees to buckle inwards and put unnecessary pressure upon the kneecap.
Muscle imbalance
Four separate muscles make up the quadriceps. When one of those muscles is stronger than another one, the muscles are said to be imbalanced. The inner quadriceps muscle (VMO) is usually the weakest on people with this condition.

EXERCISES

There are unfortunately no quick fixes for this problem. Many may try a neoprene knee brace that could help, but it is not always guaranteed. When the athlete is in pain, try treating the area as you would with any other injury, R.I.C.E. (Rest, Ice, Compression, and Elevation). The long-term treatment however will usually consist of properly instructed exercises. Proper exercises will help the patella slide in that groove easier, therefore decreasing the pain. These exercises should be done daily instructed by an athletic therapist to create good results.

Stretching Instructions: Hold each stretch for 20-40 seconds and repeat 3 times.
Note: Make sure the stretch is done slow and statically, do NOT bounce.

Hamstring Stretch
Sitting with one leg straight while on a bench or bed, with other leg hanging by the side. Reach forward bringing your chest to your knee. (Note: Keep the back straight!). If this causes any knee pain, place a small towel under the knee to avoid fully straightening the knee.
Quadriceps Stretch
The quadriceps muscles as already stated are the most important group in relation to chondromalacia. To stretch the quadriceps, stand on one foot while balancing against a wall. Pull the other foot up and to behind your buttock. Keep your back straight and the knees close.

Strengthening Instructions: Hold each exercise for 5 seconds, and repeat 10 times. It is very important to work in the first few degrees of knee bending, because this is when the least amount of pressure is placed upon the knee cap.

Straight Leg Raise Strengthening
The inner quadriceps needs to be focused on during strengthening for this condition. Lying on the floor up on your back. Turn the foot out slightly with the big toe up (This will ideally isolate the V.M.O. muscle). Then tighten the quadriceps muscles, and raise the foot off the ground 6-12″.
Wall squat strengthening with pillow
Stand with your back against a wall, your feet 2-3 ft. out from the wall and shoulder width apart. Place a pillow between your knees and squeeze together. Slowly lower your body down against the wall until your knees are at 30-60 degrees flexion (knees bending), or you can no longer see your toes with your head pressed up the wall. If you have any discomfort or pain with this exercise, do not bend down to much.

Although there are several types of knee problems in children, this is just one of the more popular ones. Children will often suffer ligament damage or fractures while playing sports and these exercises are therefore not always appropriate. As with any exercise program, one should first consult their family doctor or athletic therapist for further instructions or warnings.