I researched this injury and found this exercise on this board but need some clarification.
The popliteus muscle is slightly stretched when the hamstrings are stretched. To strengthen the muscle, sit on a high chair with your legs dangling off the ground. Using elastic tubing anchored at one end, wrap the other end around the inside of your foot and rotate your foot and lower leg inward. Use low resistance and high repetition, remembering that this is not a powerful muscle.
What exactly am I attaching it to? Thanks