I modified my brother-in-laws leg exercise (too much on my knees) which has jumping.
It's almost like this position but your back is straight as possible. I don't think it will ever be fully straight because of the balance requirements. The lead leg never bends below a 90 degree angle and you are only allowed to go 20-30 degrees more than the 90 degree angle, the smaller the raise the more difficult. From here you walk in this position with your back straight and not bent over. (I'll share a video once my legs return ) Here is how it works.
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The lead leg pushes up no more than 30 more degrees than the 90 degree. Then you walk forward and lower yourself down to the 90 degree angle, then push up, walk forward (while in this position). So each step is like a mini-squat for the lead leg, while in in this position. You never fully stand up. I think my son and I must have done 50 yards of this on a slight incline and we broke it into pieces. Rest in between was self managed. No set time, but no more than 15 seconds. Just long enough to shake off some pain from the thighs and keep going. Each round covers the total distance then walk back to the beginning and do it again. So you walk 8ft rest - 9ft rest- 10ft rest and continue until you are done with all the rounds you commit yourself to.
Round 1: 8ft -> 9ft ->10ft - >10ft -> 10ft -> 7ft -> 5ft.
Round 2: 8ft -> 9ft ->10ft - >10ft -> 10ft -> 7ft -> 5ft.
Round 3: 8ft -> 9ft ->10ft - >10ft -> 10ft -> 7ft -> 5ft.
Round 4: 8ft -> 9ft ->10ft - >10ft -> 10ft -> 7ft -> 5ft.
Round 5: 8ft -> 9ft ->10ft - >10ft -> 10ft -> 7ft -> 5ft.
This is not a fast exercise, Go slow but not too slow. Like slow casual walk speed. You want to keep the leg muscles engaged. Which is why you don't rise too high. Going to low is no good for the knees. Keep the correct angle and you'll feel it in your thighs..
The Ultimate goal is to go the distance without the short breaks. When my legs get stronger, I'll do 8f + 9ft and then the smaller sections.. As my legs get stronger then I'll add another sections. It's better not to lean forward like a wrestler on this one. It's will strengthen thighs and lower back. If you feel weight on your knees then you have to shift the weight more towards the heels.
Not sure if I described a clear picture of it.