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Second opinion – what might be the best exercise to activate vastus medialis?

By January 14, 2020No Comments

Today I got a guest client who wanted to have a second opinion with her knee problem.

Shortly, fall with downhill March 2019. Operation – rehab with a couple of different physiotherapists at her homeplace. Somehow pain-free, but still feel strange at her left knee. She asked her physio if there is any side difference at the muscles. She didn’t get any reasonable answer.

I notice at once that there are side difference – left side vastus medialis muscle is not so prominent than the right side. But how to measure muscle activity, and how to find effective exercise to strengthen vastus medialis? And can it be done objectively?


I measured circumstance with the measuring tape ten centimeters above the kneecap – side difference was six centimeters. I used the MPower EMG (Electromyography) to see real muscle activity with different exercises. MPower shows immediately if the desired muscle is activated or not and how much.

I connected pods in both vastus medialis muscles (approximately at the same position). The exercises performed was:

* seated leg stretch

* bodyweight squat

* one leg squat

* forward lunges


* Seated leg stretch: As expected, we saw at once side difference with muscle activity. The most significant difference was with a seated leg stretch, where the right side was dominant.

* Bodyweight squat: vastus medialis activates later, despite balanced squat (seen with my eyes)

* One leg squat: left side vastus medialis was less active than right side vastus medialis

* Forward lunges: Good activity with both sides.


How to measure muscle activity: I used MPower EMG: two pods and an app to find out how vastus medialis react to exercises and movements. That was an excellent way to see real-time activity.

What exercise to use: we found out that forward lunges got the most activity to vastus medialis. She starts now to work with this daily for a couple of weeks. Then we will retest all the movements again and see what has happened.

Objective measurement: MPower EMG measurement pods with the app gives accurate results from muscle activity.