The VMO - The Key to Patella Tracking, Knee Pain Relief and Knee Joint Stability

The VMO, or vastus medialis obliquus, is the largecontracting the quadriceps, as hard as you can, for
tear drop shaped thigh muscle, that lies just abovesix seconds. This is particularly important when you
and on the inner side of the kneecap, or patella. It ishave a fresh injury, or in the first few days after
one of the four quadriceps muscles in the front ofknee surgery. It adds strength, but without any
the thigh, but it is the only one that attaches directlymovement of the joint.
to the inner (medial), upper margin of the patella.Similar in effect is straight leg raising. Lying on your
For this reason, it pulls inward on the kneecap andback, with the opposite leg bent up (to straighten
opposes the slightly outer (lateral) pull of the otheryour spine, and relieve stress across the lower back),
three muscles. The VMO is most active in the last 30you tense your quads, and, while maintaining the
degrees of extension, meaning that it helps to lockcontraction, then slowly raise the straight leg up, to
the knee out, fully straight. So, you can see that thisabout 45 degrees. Then, slowly lower it again. To
one muscle has a strong influence on both thestart with, try for 3 sets of 15-20 repetitions. This,
kneecap and knee stability, as a consequence of itstoo, is an exercise that is very useful in the
anatomy.immediate aftermath of an injury, or surgery.
Pain behind the kneecap usually results from a directIsotonic exercise is muscle contraction with
blow or a fall, or it may result from maltracking,shortening and what we normally think of as
meaning that the kneecap is pulled off its normalexercise, with overt movement of the joint. This
path, usually to the outside (lateral side), and oftentype of exercise can utilize the resistance of
because the VMO is weak and can't counteract thebodyweight only, or additional external resistance, like
pull of the other three quadriceps. Usually, this isfree weights, or an exercise machine.
accompanied by tightening or contracture of the softThe simplest exercise is a quarter squat. With or
tissues on the outer side (lateral side) of thewithout weights, with your back against the wall,
kneecap, which makes it much harder to treat andsimply squat down just a quarter of the way,
correct the problem.approximating about 30 degrees of knee flexion,
Some combination of these factors is usually involvedthen stand straight and tense the quads strongly.
in kneecap pain, which can also be accompanied byEven full range movements, like Full Squats or Hindu
instability, or giving way of the knee. Over time,Squats, can be converted to VMO strengthening
these factors can result in degenerative softening ofexercises by that isometric tensing of the quads,
the cartilage under the kneecap, a disease calledwith the knee fully straight, with each repetition.
chondromalacia patellae.My personal favorite for working the VMO is the
The other major source of pain in the knee comesHack Squat. In this exercise, you hold a barbell or
from within the joint, either from a twisting injurytwo dumbbells behind your knees and leaning
that may injure a meniscus, one of the cushionsbackward to put maximal stress on the VMO, do
within the joint, or a sprain of one of the ligaments,quarter squats. It's helpful to have a wooden block
or an effusion, or "water on the knee," which resultsunder your heels to help with balance.
from inflammation of the lining membrane of theMachine exercises are also useful, but leg press
joint, the synovium. And, in the older population,machines are probably better for your knee than leg
degenerative arthritis within the joint is also a sourceextension machines, because the leg press loads your
of knee pain and instability.knee from above, and is more physiological (a "closed
In every case, strengthening the VMO is critical tochain" exercise). This is especially true if you have
relieving knee pain and restoring knee joint stability.kneecap disease, like chondromalacia patella, or
So, what exercises are best for doing that? Herepatellofemoral arthritis. Here again, you can handle
again, we take our lead from the functional anatomy.very heavy weight eventually, because you're using it
Since the VMO muscle fully straightens the knee, andfor a very short arc, just 30 degrees.
is most active in the last 30 degrees of extension,Whatever exercises you choose, you will begin to
we want to load the muscle within that range ofnotice an improvement in your pain and your stability
motion, to strengthen it.within about 10 days, and real improvement within 30
Isometric exercises, technically defined as muscledays. As the VMO becomes stronger, your patella
contraction without shortening, those done with thetracking will improve and your knee will subjectively
knee fully straight, can increase VMO tone andfeel more stable. Although this regimen can't cure
strengthen its tendinous attachments. For example,everything, it can go a long way toward making your
quad setting is done by tensing the straight leg,knees feel better and stronger. Give it a try.