Strength and flexibility for older patients, part 3: knees.(EXERCISE RX)

The looseness or tightness of the leg and hip muscles can have an enormous impact on knee pain.

The quadriceps and hamstrings maintain about 30% of the knee joint's stability. If a patient complains of knee pain and avoids moving the knee at all, those muscles will atrophy and eventually make the pain worse. There is evidence that people with knee problems who keep the hips loose and maintain strength in the leg muscles--especially the quadriceps--function quite well despite mild knee pain.

In addition, patients who might be candidates for knee replacement surgery can delay it for many years simply by keeping the leg muscles strong and loose. As the population ages, this stands out as an important consideration.

Most people aged 60 years and older have some osteoarthritis in their knees, but limber muscles can relieve pain over the long term. These patients should not avoid exercise, but should ease gradually into new activities.

The knee, though primarily a joint with a hingelike action, has the ability to rotate slightly inward, which makes it remarkably versatile but also susceptible to injury. Strong quadriceps muscles help keep the joint in place from the front, while hamstrings do the same from the rear, so it's important to strengthen both sets of muscles using similar amounts of weight.

In this month's column, we'll look at some exercises to help older patients prevent or relieve knee pain. (See illustrations and instructions for patients below.)

Patients who are very sedentary should start without any weights, but if it feels easy, they should begin with very light weights and build up gradually until the last few repetitions of the last set are a bit difficult.