What is quad set?

Quad sets

1. Sit with your leg straight and supported on the floor or a firm bed. (If you feel discomfort in the front or back of your knee, place a small towel roll under your knee.)
2. Tighten the muscles on top of your thigh by pressing the back of your knee flat down to the floor. (If you feel discomfort under your kneecap, place a small towel roll under your knee.)
3. Hold for about 6 seconds, then rest for up to 10 seconds.
4. Do 8 to 12 repetitions several times a day.