Single leg squat

In 1999 (and on a few other occasions) I published and claimed copyright on this exercise description (bolding added now):

Single leg squat

You know that I wouldn't want you to miss out on doing these delightful unilateral movements, so here we go - stand on 1 leg beside the squat rack or similar. Place the other leg out so that the heel stays just off the ground at all times. Bend the support knee and go down as far as you can whilst keeping your foot flat on the ground. 3 seconds down, no pause, controlled explosive up. Initially I suspect your range will be limited but as you get better at it over time, aim to increase range as well (and maybe even more importantly) as reps. Using your bodyweight only, I expect somewhere between 5-10 reps on day one, and look to use DB’s in one hand if you exceed 15 reps. If this is the case, I have to wonder what you were doing during the earlier part of the workout?! Use the squat rack to hold on to for balance if needed (and you probably will need to) but don’t get sucked into the temptation of using it to pull yourself up. Remember this is a leg day!

I was conducting research and I came upon the following exercise in a publication copyright claimed by another 'author' at a subsequent date (bolding added):

One leg squat :

Stand on 1 leg beside the squat rack or similar. Place the other leg out so that the heel stays just off the ground at all times. Bent the support knee and go down as far as you can whilst keeping your foot flat on the ground. 3 seconds down, no pause, controlled explosive up. Initially I suspect your range will be limited but as you get better at it over time, aim to increase range as well (and maybe even more importantly) as reps. Using your bodyweight only, expect somewhere between 5-10 reps on day one, and look to use DB’s in one hand if you exceed 15 reps. Use the squat rack to hold on to for balance if needed (and you probably will need to) but don’t get sucked into the temptation of using it to pull yourself up.

And I said to myself: “That looks familiar!” So I cross-referenced it and I said to myself: “Wow! No wonder that looked familiar!”

And I came upon this description another 5 or so more times by the same 'author' in different publications.

I noted that the use of this description was in the absence of credits or references to the origin or permission to use from the original author (myself), and that the 'author' claimed copyright....