I’ve only dabbled with glucosamine myself, never got into it, but what I’ve read points to the following:
One, it works well in some people and not at all in others.
Two, you have to take it regularly for a while to build a level in your system to see results.
Three, it is often combined with the supplement Chondroitin.
I have seen it work miracles in dogs (no placebo effect there.)
Different therapists will have differing opinions as to whether the vmo can be isolated and strengthened on its own. I have seen good results from a “closed chain” exercise which can be done (ideally) on a Pilates Reformer, or on an inclined leg press machine at the gym.
Warning: The big boys in the gym will have a laugh when they see this.
Set the weight light enough that you can press the carriage away while standing on your toes, as if wearing high heels. Depending on the machine, the carriage alone may be enough.
Place your feet parallel, squeezing a 6-8” ball between your ankles. On your toes do sets of 8 – 10 reps. The squeezing action should engage your inner thighs with an accent on the vmo. With a little practice you will find a weight which tires you in 8-10 reps but you are still comfortably on your toes. Avoid any rotation in the legs, concentrate on stability from the center of your body through your hips, inner thighs, knees and feet.
Discuss this with your knee doc and or P/T before going crazy with it to be sure it is right for your specific condition.