Motion Exercises ....Strengthening Exercises .

To keep your joints healthy, physical therapists urge you to strengthen the surrounding muscles and increase their range of motion. This you can do through regular exercise.

The knee is the most susceptible to injury in people with and without haemophilia. It's truly an irony of our physiology that the knee joint, which enables us to participate in such vigorous activities as football and rollerblading, is so delicate and so easily injured. Considering that when you simply walk up a few stairs you are putting pressure across your knee joints that is approximately four times your body weight, it isn't surprising that nearly 50 million Americans have knee problems, either from athletic injuries or simple everyday wear and tear.

To further understand the knee, let's take a closer look at its anatomy: The knee is a relatively straightforward hinge joint which connects the thigh bone (femur) with the leg bone (tibia). Where the bones meet, they are padded with a tough substance called cartilage. In addition, between the bones and around the joint are the synovial cells, which produce synovial fluid, a thick liquid that protects and lubricates the joint. Surrounding the entire joint is a tough, stretchy coating referred to as the capsule.

The knee relies on several muscle groups to work effectively. The quadriceps extend the knee; the hamstrings and calf muscles flex the knee. There are also the hip abductors, located on the outside of the leg, and the hip adductors located on the inside of the thigh. These muscles provide strength and stability to the knee.

Bleeds and the Knee

When PWHs bleed into the knee either spontaneously or as a result of an injury, blood leaks into the joint space. If the area isn't treated with factor immediately, the joint continuous to fill up with blood like a reservoir behind a dam. This infusion of blood stretches and swells the capsule around the joint far beyond its original size. The swelling creates so much pressure that bleeding may stop by itself. But the swelling also leaves the joint severely traumatised and painful.

How significant is the damage? After several bleeding episodes in the knee, degenerative changes may occur. Scar tissue may form which shrinks the space inside the joint, making it harder to bend. Cartilage may also get destroyed, leaving less padding between the bones. This can happen because the synovial cells release enzymes to digest the extra blood and these enzymes may also digest some cartilage. The result is haemophilic arthropathy.

Hinge joints such as the knee, elbow and ankle are especially susceptible to bleeding, trauma and development of arthropathy because they have a relatively large amount of synovium and they are less able to withstand rotary and angular stress. Socket-type joints like the hip and shoulder are less susceptible to trauma.

Many PWHs get caught up in a debilitating cycle of knee problems. Frequent injuries and bleeds into the joint cause pain and decrease in mobility. With a decrease in mobility, muscles grow weaker and can no longer protect the joint - and you need strong muscles to support your joints! The greater the muscle strength, the greater the stability of the joint. For example, if you jump down a step and your muscles are strong, they actually absorb stress and minimise the compressive forces to your knees. Weak muscles cannot do this and the impact is on the joint itself.

Keeping Muscles Strong

So it is particularly important for PWHs to participate in an exercise program that will help strengthen the muscles around the knees, increase the joints' range of motion and build up endurance. The goal of these exercises are both reparative and preventative. As a PWH with joint damage, you'll find that both range of motion and strengthening exercises help increase joint mobility. These same exercises can also help prevent further joint destruction.

To keep joints strong, you also need exercise for endurance which increases your overall strength and improves your stamina. This allows your muscles to handle more stress. Swimming, cycling, rowing are some of the activities that can help you build up your endurance without putting too much pressure on your knees.

The exercises on these pages improve joint range of motion and strengthen muscles. Beginners should aim for sets of six repetitions ("reps"), then increase reps over time. If you feel any pain during an exercise stop immediately. A PWH should never work toward the pain (as in "no pain, no gain") that is a popular credo in some gyms. For exercises that call for weights, begin with one or two pounds and slowly progress from there.

Avoiding Injury

For many PWHs, the fear of injury is perhaps the greatest obstacle to exercise. Don't start your exercise on an overzealous note. PWHs who are sensible and careful about working out usually avoid injury. This means that you have to perform these exercises slowly, steadily and regularly. It's best to exercise your joints twice a day regularly for five days a week. If you are just beginning to exercise you may experience some bleeds at first. Most likely, as you build your strength up, these bleeding episodes will decrease or stop. Be sure to discuss this exercise program, and any other you are considering, with your doctor before you start. Or work out under the guidance of a physical therapist who can monitor the intensity of the exercise and then help you progress.

The following exercises are geared to teenagers and adults. Since young children don't generally like regular exercises programs, we suggest that parents (under direction of a physical therapist) encourage children in more playful forms of exercise such as kicking a ball, safe and supervised jumping and bicycling with an elevated seat which puts less pressure on the knee.

Once you begin working out, you'll find that regular exercise reaps great psychological benefits too. Not only will you have the satisfaction of knowing you are doing something positive for your body you'll have far more energy and strength for other activities as well.

Theresa Kelly is the assistant chief physical therapist in the Department of Rehabilitation Medicine at the New York Hospital/Cornell Medical Centre.

June Zimmerman is a writer and specialises in medicine and healthcare.