PT on the Net Research

VMO - Strengthening the Quads


Question:

A young women in our gym was told she needed to strengthen her vastus medialis. Her attachment point seems to generate a bit of pain. How do you isolate a single quadriceps muscle?

Answer:

I am unaware of any research to support the idea that one can isolate a single head of the quadriceps. I would first recommend finding out who is giving her the advice (PT, MD, DC, a "friend," etc.), and why she was told to do this (i.e., was there an injury or some sort of diagnosis?).

Research has shown if there is a lower extremity/knee injury history, it may be possible that the VMO (vastus medialis) has weakened/atrophied for the two main reasons:

  1. The VMO may only attain maximal concentric contraction in the last 10 degrees of extension, a ROM rarely achieved/visited due to injury.
  2. The VMO has also been found to contain a large quantity of TYPE II muscle fibers. These fiber types are activated primarily during higher intensity activities, which once again may be impossible to perform due to injury.

If the individual does have an injury history, and since you mentioned she is now experiencing pain, than I would recommend referring her to the appropriate medical professional. Once you've done so, consider the following.

Begin by assessing her static and transitional flexibility. A postural distortion pattern known as PRONATION DISTORTION can be characterized by EXCESSIVE KNEE FLEXION (preventing that final 10 degrees of knee extension we mentioned above), as well as internal knee rotation and ankle/foot pronation (flat feet), while standing and/or performing functional movements (i.e., overhead squat, lunging, etc.). The muscular imbalances that cause such faulty movement patterns are as follows: