SLS/PE1, mobility and knee pain

Hi there.

I used to do bodyweight regular squat exercise for more than a year, it came to my attention earlier that I would have left knee pain when I do more than 20reps of regular squat per set.

Now that I'm doing foundation and working to achieve single leg squat, I'm now at step4 which is 4sets 6reps. My problem when I do mobility work I noticed the aforementioned pain in the second rep if not the first. I'm not sure if this is only poor conditioning of my left knee and week connective tissue or it is more than that.. I've never had knee injury or trauma before.

Thanks in advance for your input and advice. 

A good place to start would be posting a video of your SLS PE1 and iM. You definitely want to take care of this now and avoid irritating it anymore, so reduce the reps/sets to the point where there is no irritation or pain in the joint.

I'm with Everett Ahmed I'd like to see a video.