Lensers with hyper extension, you want to control your range of motion. This first exercise makes you feel your pointy, separately from your knee stretch. So grab a towel and place it under your knee. Your knee is not actively bent, not stretched, the leg is relaxed. You flex your ankle and you resist your knee lifting up. Now point and resist your knee pushing down. Keep going with ten sets of flex and point. The challenge is to dissociate your knee from your ankle work. You can try a bigger, smaller towel until you find the size that works best for you. Feel that you can point your ankle without any knee movement. Think your attitude or pretty bad more. Notice this feeling in your neck's development as well. Here it was manuals first try and there's still a little bit of knee movement. That's fine. Remove the towel and wear the other leg. So this second exercise is to feel what a straight leg is. The straight leg as the hip, knee and ankle are fairly aligned. A hyper extended knee is behind the hip and ankle line. If seated your ankle would rise above the floor. That's not a straight leg and it stresses out your knees. So let's learn a beautiful line that preserves your knees. You need to pull up your knee cap towards the top of your thigh and notice that your quadriceps muscle will activate. Release your knee cap and complete a set of 10. It can be challenging at first to isolate the knee cap because as any knee you have it, it takes time so don't give up. You quite won't bulk up if you have a core extended posture. But make sure your ankle remain on the floor. Resist pushing your knee down as you learn prior. Hyper extension might look nicer but avoid it in weight bearing positions. Preserve your knees for a longer carrier.