Lunges could be done in every direction and they increase not only the strength of the thighs and the gluteal muscles, but stretch also the back leg when it’s straight like today during some diagonal lunges.
I stand straight with closed legs and my hands on the hips and do a big diagonal lunge to the right (about 45°). The thigh and the lower leg of my left leg are in a 90° angle. Thereby both feet look still in the same direction like when I started. Afterwards I push back by extending my right leg and go on with a lunge on the left side.