VMO – the Quad leader


VMO is short for Vastus Medalis Oblique and makes up one of the four components of the quadriceps. Its fibres are more obliquley aligned in comparison to the other fibres of vastus medialis, and are arguably the most important to stabilise the knee actively and dynamically.
Due to its attachment point via the patella tendon to the tibia head, its key role is to keep it within the patella groove and stop the knee cap moving left or right. The unwelcomed movement often occurs when there is an imbalance between the different quadricep muscles. In most cases this means, weakness in the medial structures (vmo) and tightness through lateral structures (vastus lateralis/ITB). This imbalance can occur from structural problems, bad training habits or an underlying injury to the knee joint itself.
Physiologically, in an individual who has a normal functioning vmo, the fibers would contract efficiently through their full range of movement. Weakness therefore has the opposite effect, the fibres contract intermittently causing premature fatigue. In this situation, the patella becomes unstable when bending and straightening the knee. It can lead to joint pain, dull aches, tendon issues such as patellofemoral syndrome, chondromalacia and it certainly has a negative effect on long term injuries such as arthritis. Maintaining vmo activation and strength will inevitably reduce risk of acute or chronic injury and also help recovery from knee surgery and injury.

So to make sure your vmo is activating complete the following simple exercise…

1) Place a rolled up towel under your knee. Put your hand on your vmo (inside of your thigh). Extend your knee by straightening your leg and pushing down onto the towel. Hold this position for 10 seconds. You’re not aiming to isolate the vmo contraction due to the femoral nerve being its supply, just simply ensure your vmo is contracted throughout. Repeat 5 times. Do the same with the outside of your quad (Vastus lateralis).

Once you get the hang of the above try completing with more functional movements…

2) The proximal tendon attachment arises from adductor Magnus. Squeezing a small swiss ball between your knees whilst completing a wall squat, will contract the muscle throughout the movement – a two in one exercise, what more could you want!
If you are interested in finding out more please come and see me at the center.