A lot of patients I see with patellofemoral pain who have failed to improve following exercise rehabilitation have spent substantial time trying to activate their VMO (Vastus Medialis Oblique) muscle. The questions we need to ask are:
1. Why have they focussed so much on exercising this little muscle?
2. Why hasn’t it worked?
So why the focus?
1. There is consistent evidence that VMO activation is delated in people with patellofemoral pain. This means the muscle turns on later than it should during activities like squatting and walking down stairs
2. Studies of combined interventions (including exercise, taping and manual therapy) often include a focus on retraining of the VMO. Nb: Because multiple interventions are used in this study, it is unclear which are most important.
3. It seems that almost all undergraduate physiotherapy university courses spend time teaching future physiotherapists how to retrain VMO
Why is it often ineffective?
1. Practically, it can take a lot of time, and can require additional equipment to complete exercises targeted at VMO retraining. Therefore, compliance can be poor
2.Many of the exercises prescribed to retrain the VMO are in a non-weight-bearing position (e.g. in sitting) and therefore have very little carryover to functional tasks such as squatting and stairs where people report pain.
3. The evidence actually tells us that combining VMO retraining with other exercise does not actually improve outcomes. That’s right, the evidence says it doesn’t work. A disclaimer here is that it may still be helpful for some and clinical trials often miss this point. However, if applied with a blanket approach, it will not be that useful.
So what should we do?
Successfully managing patellofemoral pain is far more complex than focussing on one small muscle. For more information on successful treatments for patellofemoral pain click here.