I'd been to see a physio about my knee pain (Patello-femoral Pain Syndrome) months ago and he set me up with a load of rehab exercises to to strengthen the VMO of both legs as he said they were weak. After trying these the exercises for a few months there was no improvement.
I thought fuck it then, and started squating, using the empty bar and have now worked up to 110kg and the pain is gone for most of the time so happy days.
Now, as other people may know, the gym where I work is crap, and I can't squat there as there is the facility, so I've been doing RLESS/lunges/walking lunges and have worked up to 2x 25 kg dumbells (the max weight they have) - again with little or no pain.
SO today, to make things a little more difficult, I thought I'd try pre-exhaust my quads with leg press followed by leg extensions. Leg press went fine. Leg extensions. I set it to a light weight for the first warm up set - 10 reps - my VMO on both legs fired like crazy and I struggled to finish the set. I done 2 more sets at this "warm up" weight and had the same thing.
This has obvioulsy demonstrated how weak the VMO is compared to the rest of the leg. I have had no after effect on my knees (as of yet - time will tell).
The question is:
Is it wise to use this exercise to strengthen the VMO, as all other exercises given to me, I haven't felt it work at all and this I could feel firing like mad through the full ROM.
Is the leg extension a safe and/or knee friendly exercise, or will I do myself more damage in the long run if I stick with it.