The Vastus Medialis Oblique (VMO)

Despite the emphasis placed upon the importance of VMO training to re-balance the quadriceps in patellofemoral pain syndrome, it's still relatively unknown whether the timing of Vastus Medialis Oblique (VMO) & Vastus Lateralis (VL) contraction is a risk factor for patellofemoral pain syndrome (knee cap pain).
 To add to this issue, debate exists as to whether the Vastus Medialis oblique (VMO) can be activated to a greater degree than the Vastus Lateralis to produce preferential strengthening.

What does the evidence say?

For:

In closed kinetic chain exercises, more selective VMO activation can be obtained at 60° knee flexion (Tang et al 2001).

Performing quads exercises with EMG biofeedback improved the muscle activity balance between VMO & VL (Ng et al 2008).

Lunges produced the VMO:VL ratio (1.18:1), which is the closest to the idealized ratio of 1:1 (Irish et al 2010).

Corrective taping is effective in reducing pain in patellofemoral pain (Herrington & Payton 1997).

Against:

Performing semi squats with maximum isometric hip adduction doesn't bias the Vastus Medialis Oblique (VMO) (Coqueiro et al 2005).

Open kinetic chain knee extension exercises produced significantly greater activation of VL (Irish et al 2010).

Taping did not reduce pain in the patellofemoral pain group but it did enhance the efficiency of Vastus Medialis Oblique (Keet et al 2007).

So what should we do then?

Patellar taping: This appears to increase VMO activity but it is uncertain if this reduces pain.

Progressive functional retraining of VMO using EMG biofeedback seems to be the most effective way of biasing the VMO but not everyone has access to biofeedback making this difficult to relate to the average patient!

Open chain exercises are not effective but closed chain can be.

Amongst the closed kinetic chain exercises, the squat is considered safe and effective, due to the stabilizing effect of co-contraction quadriceps and hamstrings. This exercise should be performed to near 50 degrees, not to generate as much force and pressure in the patellofemoral joint.

Despite this if the VMO isn’t working correctly due to other causes then no amount of VMO exercise will cure the pain.

So….

Think above and below the knee:

It appears the glutes can be important in patellofemoral pain syndrome along with the tightness in certain soft tissues so even though we are discussing the VMO it is important that gluteal strengthening exercises and stretching of soft tissue structures are performed (Sallie et al 2002).

Whatever we choose to do it seems that high dose & repetition appears to be the most benefit in patellofemoral pain (Osteras et al 2013).

So as you can see the benefits for implementing these VMO protocols are not well documented; scientific evidences are insufficient to prove the real effectiveness of these exercises in improving the performance of quadriceps muscle or assist in muscle balance of patellofemoral stabilizers and therefore pain (Nobre 2012).

Overall then, rather than focus all of our attention to VMO strengthening, we need to look for issues in movement dysfunction through the body. Problems in the ankle, foot, knee, hip, sacroiliac joint, and lumbar spine can all influence the positioning of the knee during dynamic activities, which in turn affects the amount of stress in the patellofemoral joint. This means treat everyone as an individual when working out the cause and therefore treatment of their patellofemoral pain and not just give them all VMO exercises!

If you need any further information or would like to book an appointment then call Hawkes Physiotherapy on 01782 771861 or 07866195914

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