How do I do quad sets properly for a weak knee?

Step by step

Do this sitting on a bed or the floor with your back supported.

• 1. Sit with the injured leg straight out in front of you and the other knee bent or straight, whichever is comfortable
• 2. Place a small rolled towel under the ankle, not under the knee, so the knee can sink towards straight
• 3. Tighten the muscle on the front of the thigh so the kneecap slides up slightly and the back of the knee presses down
• 4. Pull your toes towards you at the same time if it helps you feel the muscle work
• 5. Hold for five seconds while breathing normally, then relax fully for a few seconds
• 6. Repeat ten times, three or four times a day

How to tell it is working

Put your fingertips on the inner part of the thigh just above the kneecap. You should feel the muscle firm up under your fingers when you tighten. Compare it with the other leg. After surgery or a significant injury it is common for the muscle to feel weak or slow to respond for days or weeks; this is called quadriceps inhibition and is often linked to swelling.

If you cannot feel a contraction, try the good leg first so your brain remembers the movement, then do both legs together. Reducing swelling with ice and elevation often makes the muscle easier to switch on.

Common mistakes

• Holding your breath, which raises blood pressure and makes you tense
• Squeezing the buttocks instead of the thigh
• Putting a pillow under the knee, which trains the knee to stay bent
• Doing a few rushed repetitions instead of slow, full holds

When to stop and get checked

Quad sets should feel like effort, not sharp pain. Stop and contact your surgeon or physiotherapist if the knee becomes much more swollen, if you cannot get the knee straight at all, or if after surgery you notice increasing redness, wound leakage, fever or calf pain and swelling. Persistent inability to tighten the quadriceps weeks after an injury is worth an examination at Aman Hospital in Doha.