Once the athlete can straighten that leg and is now receiving the stretch on the ham, should that position be held for a number of seconds?
I actually had one of the two guys hold that position for about 6-10 seconds and then had him try to pull the straight leg down to the ground under mild resistance. Is the last part advisable or even necessary or should I, after they can straighten and hold(?), have them re-bend the leg to push the knee back a bit further before attempting to re-straighten it for rep 2 and so on?