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Osteoarthritis of the Knee
Exercise can help

If you have osteoarthritis (OA), you know how this chronic disorder can alter your daily life. It can affect many joints, especially the knee. Running, walking, squatting, kneeling and climbing stairs can all be challenging. Bearing weight is difficult, making work and other activities hard. OA in the knee may affect as many as one in 10 Canadians over age 65. The effects cannot be undone.

OA can damage all parts of the knee joint, especially surface cartilage covering the ends of the bones. As the cartilage breaks down, the joint gets worse over time. The knee becomes painful, swollen and loses range of motion. The bones of the joint deform, developing bumps on their ends, while muscles atrophy (shrink).

There is no known cure for OA. For some, knee OA can be managed without surgery. This involves learning about the condition, controlling pain, improving function and slowing down the disease.

Exercise is one effective way to cope. Research shows that various kinds of exercise can ease pain in knee OA patients. As exercise makes muscles stronger and reduces body weight, less stress is placed on the joint. It begins to work better. Other areas of health and wellbeing improve as well.

Developing an exercise program

An effective exercise program has four basic parts: type, frequency, intensity and duration of exercise.

Type of exercise - Non-weight bearing activities are probably the best choice for those with knee OA. They allow the knee to move through its greatest range of motion, with the least load and stress through the joint.

Frequency - To truly improve knee OA symptoms, some type of exercise at least three times a week is necessary. However, to gain other health benefits, exercising three to five days a week is best.

Intensity - This measures how strenuous you find the workout. It can be difficult to measure as it depends both on you and the type of exercise you choose. However, it can be measured by:

• the number of sets and repetitions (reps) of the exercise involved, or
• by the heart rate you achieve, or
• by how hard you work while doing the exercise.

Duration - Exercise sessions should last between 30 to 90 minutes, depending on the type. At least four weeks of exercise are required to improve symptoms. Ideally, exercising is not just a temporary way to treat knee OA. The best benefits come from a lasting lifestyle change.

Choosing an exercise

Many different kinds of exercise programs are possible. To treat knee OA, you might consider the following options.

Aerobic exercise

Frequency: three to five days a week

Intensity: 40 to 80 per cent of maximum heart rate (maximum heart rate is the number 220 minus your age), or 12 to 16 on a scale out of 20 in the level of exertion you feel.

Duration: 30 to 60 minutes

Type: non-weight bearing
Non-weight bearing aerobic exercises include:

• cycling
• elliptical machine
• rowing machine
• exercise in water (swimming and water aerobics)
• skating and cross-country skiing.

For aerobic exercise, stay within a range of 40 to 80 per cent of your maximum heart rate, or 12 to 16 out of 20 in the level of exertion you feel. Begin by exercising at a lower intensity. Aim to gradually increase intensity as you become more fit and get used to the exercise.

Range of motion

Frequency: three to five days a week
Intensity: two sets, hold for 30 seconds per stretch
Duration: 5 to 10 minutes
Type: stretching
Non-weight bearing stretching exercises include:

• seated quadriceps stretch
• seated hamstring stretch
• standing calf stretch.

Do two sets of stretching exercises. Each stretch should be held for a minimum of 30 seconds. With knee OA, it is important to stretch the quadriceps, hamstrings and calves as they are directly linked to the knee joint. Stretching the muscles of the hips and iliotibial band is also recommended, since they also affect the function of the knee.

Strengthening

Frequency: three to five days a week
Intensity: two to three sets, 10 to 15 reps
Duration: 30 to 60 minutes
Type: lower extremity strengthening
Appropriate strength training exercises include:

• knee extension (quadriceps)
• knee flexion (hamstrings)
• calf raises
• mini squat
• leg press.

Strength training is the hardest of the exercise programs for knee OA. There are many different, effective ways to do strength training. However, using elastic tubing for resistance may be best for those with knee OA beginning strength training.

In general, strength training for knee OA should include exercises for the calves, quadriceps, hamstrings, pelvis and body core. The exercise program should include at least two sets of 10 to 15 repetitions of these exercises. Rest time between exercises should be 60 to 90 seconds.

Proper technique is essential for success in strength training, regardless of the program. Since technique is so important, anyone interested in strength training should get professional guidance. A physiotherapist or personal trainer familiar with rehabilitation exercises can help.

Exercise is a proven effective and safe therapy to improve knee OA pain and joint function. It is not difficult to include regular physical activity in your lifestyle. Find activities that you can do without making symptoms worse. Above all, enjoy yourself and have fun!

Leg Exercise Program

This program will help make the muscles of your legs stronger. Strengthening the leg muscles is proven to increase function and reduce pain for knee osteoarthritis patients. Here, Thera-Band elastic band dynamic resistance exercises are used.
The program requires three 45-minute sessions per week for twelve weeks, and involves two stages. Each stage lasts six weeks. The first stage is done with light resistance Thera-Bands, the second with the heavier resistance version. For information on how to purchase Thera-bands, visit www.thera-band.com or talk to your physiotherapist.

Stage 1 - Initial Strengthening

Perform these exercises on both your affected and unaffected knees three times a week for the first six weeks. Technique is very important. You may want to ask your physiotherapist for guidance on doing these exercises correctly.

Weeks 1 - 3

• Five minutes of warm-up
  
• Three sets of 10 repetitions of the Thera-Band exercises:
  
• Knee extension (figure 1)
  
• Knee flexion (figure 2)
  
• Calf raises (figure 3)
  
• Leg press (figure 6)
  
• Five minutes of light stretching – repeat each stretch once or twice, holding it for 15 seconds:
  
• Hip flexor (figure 7)
  
• Lateral hip
  
• Quadricep (figure 9)
  
• Hamstring (figure 10)

Weeks 4 – 6

• Five minutes of warm-up
  
• Three sets of 20 repetitions of the knee flexion, extension and leg press exercises. Build up gradually. First perform 15 repetitions, then go up to 20. or build by increments of two – 12, 14, 16, 18 - until you can comfortably do 20 repetitions.
  
• Three sets of 12 repetitions of the calf exercise
  
• Five minutes of light stretching

Stage 2 - Further Progress

After the first six weeks, with the approval of your physiotherapist, you can begin using a heavier resistance Thera-band. Use this band to do the same exercises.

Weeks 7 – 9

• Five minutes of warm-up
  Three sets of 10 repetitions of the knee flexion, extension and leg press exercises.
  
• Three sets of 15 repetitions of the calf exercise
  
• Five minutes of light stretching

You may wish to check technique with your physiotherapist before proceeding to the next level.

Weeks 10 - 12

• Five minutes of warm-up
  
• Gradually increase the repetitions, until you are doing three sets of 20 knee flexion, extension and leg press exercises. As before, build until you are comfortably able to perform all of the repetitions.
  
• Three sets of 15 repetitions of the calf exercise
  
• Five minutes of light stretching

Leg Exercises

Figure 1.
KNEE EXTENSION: Targets your quadricep muscle

Secure one end of the elastic band behind the chair, attaching the other end of the band to your ankle. Sit tall (chin up, abdominals tight and without letting your pelvis or trunk move). Hold onto the side of the chair, and slowly extend your leg against the resistance of the band until the leg is straight. Hold briefly at this position, then allow your leg to return to the start position. Do three sets of 10 repetitions gradually progressing to 20 repetitions.

Figure 2.
KNEE FLEXION: Targets your hamstring muscle

Tie the ends of the band together creating a loop. Securely attach one end of the loop close to the floor. Wrap the other end around the heel of your foot. Sit tall in a chair - chin up, abdominals tight without letting your pelvis or trunk move. Slowly bend your knee bringing your foot closer to the base of the chair. Hold briefly at this position, then allow your leg to return to the start position. Do three sets of 10 repetitions gradually progressing to 20 repetitions.

Alternate version: Tie the ends of the band together creating a loop. Securely attach one end of the loop close to the floor. Lie flat on your stomach. Place the other end of the loop around your ankle. Begin with your knee straight and bend your leg against the resistance of the band. Hold briefly at this position then allow your leg to return to the start position. Do three sets of 10 repetitions gradually progressing to 20 repetitions.

Figure 4.
MINISQUAT:
Targets your quadricep muscle

Hold the ends of the band in your hands at hip level. Stand on the middle of the band with both feet. Keep your back and arms straight. Slowly bend both knees slightly to the minisquat position. Do not allow your knees to rotate either inward or outward. Hold this position briefly. Allow your leg to return to the start position. Do three sets of 10 repetitions, gradually progressing to 20.

Figure 3.
CALF RAISES:
(without Thera-Band) – Targets your calf muscle

Stand tall, ideally on a stair. Hold on to a chair or railing if needed. Keep your legs straight. Slowly raise your heels so that you are standing on your toes. Hold this position briefly. Allow your legs to return to the start position. Do three sets of 10 repetitions, gradually progressing to 20.

Figure 4.
TERMINAL KNEE EXTENSION:
Targets your hamstring muscle

Make a loop in the band and securely attach one end at knee height. Place your knee inside the loop, keeping the band above the knee joint. Take up the slack. Slowly bend and straighten your knee stretching the band as you extend your knee. Do three sets of 10 repetitions. Gradually progress to
20 repetitions.

Figure 6.
LEG PRESS: Targets the quadricep muscle

Lie flat on your back with your knee slightly bent. Loop the middle of the band around the bottom of your foot. Grasp the ends of the band and pull them close to your shoulders. Slowly extend your leg against the resistance of the band until your leg is straight. Hold briefly, then allow your leg to return to the first position. Do three sets of 10 repetitions gradually progressing to 20.
Alternate version: Sitting tall in a chair, wrap the middle of the band around the bottom of your foot. Pull the ends of the bands to chest level. With your knee slightly bent, slowly extend your leg against the resistance of the band until your leg is straight. Hold briefly at this position. Allow your leg to return to the first position. Do three sets of 10 repetitions, gradually progressing to 20.

Figure 7.
HIP FLEXOR STRETCH:

Stand two to three feet away from a chair or desk and place your left foot on the front edge of the chair/desk. Point both feet straight ahead. Draw in your belly button using your abdominal muscles. Tighten your right buttock to push your right hip forward until you feel a stretch at the front of the right hip. Keep your back vertical the whole time. Maintain the stretch for 15 seconds. Progress to keeping your foot flat on the floor.

Figure 8.
OUTER HIP STRETCH:

Sit on the front part of a chair. Cross your legs, placing the outside of one ankle on top of the other knee. Slowly let the knee fall out to the side as far as is comfortable. Bend forward at the waist slightly until you feel a stretch on the outside of this hip. Gently pushing the knee down further with your hand will increase the stretch.
Do not force – you should not feel pain. Hold the stretch for 15 seconds.

Figure 9.
QUADRICEP STRETCH:

Figure 10.
HAMSTRING STRETCH

Steady yourself, using a wall for support. Step forward with your right foot two to three feet. Keep your right knee straight. Pull your right foot and toes back, then slowly bend forward at the waist until you feel a stretch in the back of your right thigh and knee. Push your backside out and let your left knee bend slightly to increase the stretch. Hold for 15 seconds.

* Images courtesy of David Lindsay, University of Calgary Sport Medicine Centre.