This marks the second time in my life that I have started training single leg movements. The first time was back in 2008 when I was in reasonably good shape. I had been doing some barbell squatting and had been breakdancing for several years, and I was bicycling every now and then. I was unaware of any of the progressions leading up to it, so I stated training the SLS. It seemed to be going fine as I could perform the movement, but months later I ended up with chronic pain in my right knee, diagnosed as damaged cartilage, which led to surgery. Since there was no acute trauma I can't be certain of the cause but I know that the only additions I had made were the single leg movements, so my best guess is that they were more than my knees could handle. Years later and my knee isn't perfect, but the pain is gone and I only feel it again if I stop exercising for a couple of weeks or more. Between the recovery period and now I have dabbled in barbell squatting and deadlifting, as well as having done a lot of carrrying of heavy objects up and down stairs when moving and helping friends move on several occasions, some heavy lifting at work, and have not had any issues with the knee.
I got through mastery of SLS PE1 and the iM without any issues, working the 3 day per week plan. I moved on to PE2 and was pleasantly surprised to find that I could perform the exercise without issue. The iM here seemed especially easy since I have been standing up this way (usually without the twist) since I discovered the movement on my own about 15 years ago. I normally do all the work at home, in bare feet and on carpet. It was week seven when I was out of town and doing the workouts in a hotel gym, which of course required me to wear shoes. The bracing for the movement seemd a bit different due to the variance in friction, and on the third training day of the week I started to get pain in my left knee (not the one for which I had surgery). The pain persisted through week 8, so I backed off of all squatting motions and started doing a series of leg lifts as a substitue for leg work. So now I don't know if wearing the shoes caused the problem or if it was going to happen regardless because SLS PE2 is still more than what my knees can handle. I am now at week 11, and since laying off the other leg work the knee has been feeling better. So, I went to the gym with my friend yesterday and tried some front squats, back squats, and deadlifts all with just the barbell and then with light weight to see how they would feel. Even though walking up and down stairs is a bit painful, I had no issues whatsoever with the barbell movements. I am a bit perplexed with this siuation.
Is it normal for some people to have difficulty transitioning to sigle leg work?
Are there any progressions between PE1 and PE2 that can help me better prepare?
I'm thinking I might go the route of barbell work until I have built a good degree of leg strength before I move to single leg work.
Edit 16th December 2014:
A day or so after posting this I realized that I might find some clues in BtGB. I'm glad I did because it outlines several deck squat variations with increases in difficulty beyond the basic movement. It also states specificaly that if single leg work is too difficult then the deck squat variations can be used to work up to it. I have to admit I all but forgot about the book once Foundation was released. Going to have to give it another read through as it is an excellent companion for Foundation.
Still, I'm a bit surprised that any topic on this board would go six days with 0 views, let alone 0 responses. Oh well. Hopefully this will benefit someone at some point.