Five exercises for knee osteoarthritis that are worth the time

Exercise for arthritis sounds like advice people give when they have nothing better to offer. It is not. In knee osteoarthritis, structured strengthening produces pain reductions comparable to anti-inflammatory medication in trials, without the stomach, kidney or cardiac risk, and it is the only intervention that also improves function over the long term.

The catch is that it has to be done regularly and it has to be loaded enough to count.

Why the quadriceps matters so much

The muscle on the front of the thigh acts as the knee's shock absorber. It decelerates the leg before the joint surfaces meet. When it is strong, load passes through muscle. When it is weak, load passes through cartilage.

A painful knee shuts this muscle down within days, which is why people lose thigh bulk quickly after an injury or a flare. That weakness then increases joint load and the pain worsens. Most of what follows is aimed at reversing that loop.

The five

1. Static quadriceps hold

Sit with the leg straight out. Press the back of the knee down towards the floor, tightening the thigh, and hold for five seconds. Ten repetitions. This is the starting point when the knee is too sore for anything else, because the joint does not move at all.

2. Straight leg raise

Lying down, one knee bent, the other straight. Tighten the thigh of the straight leg and lift it about twenty centimetres. Hold three seconds, lower slowly. Ten to fifteen repetitions each side. The slow lowering is the part that builds strength, so do not let the leg drop.

3. Sit-to-stand

From a dining chair, stand up without using your hands, then sit down under control taking three seconds. Start with five, build to fifteen. This is the single most functional movement on the list, because it is the one you do dozens of times a day.

4. Step-down

Stand on the bottom step. Lower the opposite foot slowly towards the floor, touch lightly, return. Five to ten each side, holding the rail. This trains the eccentric control that descending stairs demands, which is exactly where most people hurt.

5. Stationary cycling

Ten to twenty minutes with the saddle high enough that the knee does not bend past about ninety degrees, and light resistance. Cycling loads the joint through range without impact, and it is the easiest way to get the aerobic component that trials also show benefit from.

The mistakes that waste the effort

• Stopping when it feels better. The strength fades in weeks. This is maintenance, not a course of treatment.
• Going too light. If fifteen repetitions feel easy, add a second set or slow the lowering phase. Muscle only responds to being challenged.
• Deep squats and lunges during a flare. Loading a knee past ninety degrees under load is the fastest way to set yourself back.
• Resting a sore knee completely. Cartilage has no blood supply and depends on movement to exchange nutrients. Total rest makes stiffness and weakness worse.

Where injections fit alongside this

If pain is severe enough that you cannot do the exercises at all, you are in a loop that exercise alone will not break. That is the clearest indication for an injection: not as a replacement for the strength work, but to create the window in which the strength work becomes possible.

Patients who use a hyaluronic acid injection and then do nothing else usually come back when it wears off. Patients who use the comfortable months to build the thigh muscle often need the next injection later, or not at all.