i want to share with all my experience with the single leg squat progression.
i got an injury to my right knee and cause 14 years of agonist football my hips are very very tight.
but this cannot stop me! so i restart from zero for the SLS.
for the first 3 weeks i did , for what my knee allowed, the progression, but really very low improvement.
consider that in my cossack my ass wasn't able to go down more then knee height, and after 3 no improvements in the depth.
so just for a chance i did 2 position where , in one of them my calves where stretched (damn very super tight calves) and in the other there was a deep stretch of the quads.
i introduced in my training a calves stretching series and a quads stretch after the mobility element for the current PE for SLS and the depth of my squat increased. now my ass is a bout at the half of the shinbone.
i know this is strange but seems that this approach solved the same problem in my brother.
does anyone of you experienced my same situation?