Anchor a band low and curl your heel straight to your butt.
Keep the working thigh vertical and still. All the motion happens at the knee.
Curling your heel towards your glute against a band trains the hamstrings in their knee-flexion role, one leg at a time, with the band pulling hardest right where you are strongest at the top of the curl. Because your thigh stays vertical and still, the work stays isolated at the knee instead of leaking into the hips. It is a handy way to hit the hamstrings directly when you have no machine, and a good tool for evening out a weaker side.
For home training or travel, yes, it covers the same knee-flexion job. The band resistance ramps up towards the top rather than staying even, so squeeze hard at peak contraction and control the lower back down.
That is your hip flexors and momentum stealing the rep. Keep the working thigh vertical and frozen so the only thing moving is your heel travelling towards your glute.
Low and behind you is wrong, low and in front is right. Face the anchor with the band at ankle height so the tension pulls your heel forwards and your hamstring has to drag it back.
