How many Quads are there?
You'd be surprised to know how many people have never thought of it - that the name "Quad" is a number four.
Without our Quads we would not be able to stand - we would buckle at the knees. Some people do, because the Quads have issues.
The four Quadricep muscles work together to straighten (extend) the knee joint. If they don't work, the knee cannot straighten.
One of them, Rectus Femoris, is also a hip flexor. The other three, Vastus L., Vastus I., and Vastus M. (see image) attach on the femur (thigh bone) and at the patella tendon (below knee cap).
These muscles also support and stabilize the knee ligaments so the knee does not torque - that's critical. Any knee joint that is too loose or wobbly (due to weak Quads) has a higher chance of wearing out the Meniscus, the knee cartilage. That is why it's so important for knee health to strengthen your Quads.
Most of the time, we see weakness in the Quads, however occasionally (especially in inconsistent athletes and weekend warriors), we deal with tightness and tension. Runner's knee is one such injury caused by Quads getting too tight.
In that case, massage is a great tool to prevent chronic tension. It's also important to stretch the Quads on a regular basis.
To Prevent Weakness/Wobbly-ness - Strengthen the Quads with Squats, Lunges, and other strengthening exercises every day.
To Treat Tightness/Tension:
1. Stretch. Make sure not to stretch to the point of tearing. Easy and comfortable stretches held for 1 minute or longer are more effective (and safer) than intense stretches.
2. Get a massage to release chronic cramps and lengthen the tissue along the thigh and around the knee.
3. Foam roll the Quads. Foam rolling is very effective to roll out basic tension.