Patellofemoral pain syndrome

hi everyone,


Pls. help me with my report.
Do you know the cause of VMO weakness in pt's with PFPS??
And is it possible that a person can get PFPS without any other predisposing factors just a repetitive running?

THanks

What texts or literature have you looked at so far?

I've already read Brotzman's orthopoedic Rehab and Kisner's Therapeutic Exercise and it was telling that one of the cause of having PFPS is VMO weakness.. How does a runner will have weak VMO if he is using his Quads during running.
and correct me if i'm wrong..the type of gait they have is antalgic gait.

Thanks for the response.

Here is a fairly recent review which in the background covers the causative aspects of PFS

PEDro - Detailed Search Results

One of the sports physios on this site may explain this more eloquently but I will do my best. Certain muscles that cross one joint in the body have a very important stabilizing role for the joint. The VMO plays a crucial role in ensuring the patella tracks in the groove between the two femoral condyles while the quadriceps is working during knee movement and when the VMO is weak the patella tends to be pulled laterally due to the knee angle, and structures such as the ilio tibial band. These muscles like the VMO tend to be vulnerable to dysfunction. For example even quite low levels and swelling at the knee is accompanied by reduced and abnormal firing of VMO. Therefore minor trauma or injury can induce this type of weakness and it appears to be neurologically mediated. Biomechanical factors such as tight lateral structures (eg the ilio tibial band) increased Q angle (this is to do with the line of pull of the quadriceps) and small or misshapen patellae can also predispose this problem.

So in the case of runners, even though they may hqve muscles with good srength and endurance generally, the small VMO could become dysfunctional quite readily through factors listed above. presumably this is often a case of a vicious cycle: once the muslce is "switched off by trauma the abnormal tracking producers trauma resulting in pain, inflammation to the anterior structures of the knee which in turn switch off the VMO more and so the syndrome arises. Muscles like the VMO readily atrophy following the neurogenically mediated weakness.

Hope this is of help and good luck with your report

The information you've given helped me a lot. Thanks for your time. ^_^

I agree with gcoe. however you may also want to look at pelvic stability such as glut med, its ability to stabilise the pelvis with movts.

Supinated foot may also give PFPS as well and it will be worth looking at the foot as well.

hope this helps.

Dear Shantal, it seems that your post in not new but I hope this will help:
yes a person can get PFPS if he is practicing
repetitive running and the reason is that the repetitive running without warming the muscle by preparing it for actvities by streching can cause a microtrauma to the muscle fibre, tendon and joint and the joint react by hypersecretion of the synovial fluid as normal reaction to protect the joint and after the synovial fluid increased (even a little 10 to 15 ml) this can make the knee unable to extend to the last degree (invisible flexion) causing a rest of the VMO who is responsible of the extension of the knee on these degrees also is responsible of the stabilisation of the patella on it is place, after time the VMO become weak and cause the patello femoral syndrom.
I hope this help you
Juliette Moussa
S. Physiotherapist