I re-watched this video and I’m still not sure what you’re referring to. My knees stay centered over a mid-foot balance in almost all of the exercises, and a couple of them even looked more like a rear-foot balance (on heels), but it’s hard to tell with 100% certainty from the rough-cut video.

There is a little forward lean with the shins on some of the variations, but this is normal for some exercises (e.g. forward lunges, walking lunges, etc.), and the angle of the shin (and the resulting knee positioning) is exercise-specific – not absolute for ALL lower-body strength training exercises.

I’ve heard the recommendation to not allow the knee to protrude beyond the toes in lunge-type strength training exercises – including from personal training organizations like the NSCA. I was certified as a NSCA-CPT in 2006. I think this is a narrow-minded and outdated training recommendation, and now a myth that was perpetuated from vague exercise technique instructions – even in the very handbooks used to test for well-known CPT certifications.

There is nothing inherently damaging about allowing the knee to protrude beyond the toes in an exercise like this. If it was dangerous, then anyone who climbs stairs on a regular basis would be injured. What IS problematic is when one allows this to happen with a forefoot balance (ie ball of foot), which drastically changes the movements force production and structure and bottle-necks unnecessary strain and tension right into the patella. This is especially risky when there are pre-existing conditions that affect the knee, which many people have. If you add extra resistance, high volume training, more intensity, etc., then, of course, you have a recipe for injury.

What’s most important in an exercise like the forward lunge is maintaining a mid-foot balance throughout the landing, absorption, descent, and ascent. Assuming one does not have any structural injuries, if you do this, then knee positioning takes care of itself. If there ARE structural problems, then the trainer or coach should be able to address them specifically or recommend another exercise entirely.

Ironically, several years ago, I was an orthopedic surgeon’s dream come true, Instead of a recommended surgery, I spent 3 years in physical therapy, and since then I have remained 100% injury-free – despite my rigorous training demands – including regularly using the exercises demonstrated in the above video. With my extensive injury history, and being told by two different doctors (one an orthopedist) that I would be permanently disabled, it’s a miracle that I can train at all – let alone with the frequency and intensity that I do.

I appreciate your comment, though I find it completely unfounded and peculiar.