Sitting on the rower, feet strapped in, legs fully extended: if I lean forward with my torse (without bending it) at some point I feel stuff pulling, essentially the back of the knees and right above & below it (i.e. lower hamstring, back of the knee, upper calf). Guess that's kind of normal.
Now on thing I think may explain my difficulty to lean forward during recovery&catch: I have hyperextended knees. Nothing spectacular, but it's visible.
Actually it's more visible on my left leg than on my right one (right knee is a bit of a mess, anterior cruciate ligament almost completely gone + meniscus lesion, all this like 30yrs ago). Generally speaking, none of this affects my rowing, except what I describe here below.
I noticed that when I row, if I try to fully extend the legs at the end of the drive (as is good practice, I'm told) I can go into hyperextension (especially left leg). When this happens, two things happen:
- leaning "a lot" forward is a bit harder
- once leant forward, bending the legs during the start of the recovery is harder: the movement is not really smooth, it's like if the legs "pops up" (from hyperextended to flat to slightly bent). It's nothing scary, there's no snap or something, but I can feel it. It's like a bent flexible beam that snaps from bent one way to bent the opposite way.

Don't know if there's anything that I can do to avoid hyperextending.