Yoga term: none
This is a stretch I developed to reach the area of the hip joint towards the sacrum and up to the lower back. The variation with the hand on the back is a lighter one. The hand on the back is in the area where a lot of tension can be. The hand aids in the healing and release of that tension. The variation with the arm up is good for strengthening and working for more rotation. This pose can advance to a lock.
Use the forward bend as a template. Once there bend one knee and shift your weight to that leg. ratio is about 70% of the weight. Take the arm of the same side of the bent leg and reach to the opposite leg grabbing the outside of that ankle. Try to keep the hips over the heels. As you can see I am slightly off. The bent leg has the knee rotating slightly inward and over the two largest toes. weight is distributed evenly on that foot. Basically just maintain proper alignment of that leg. That straight leg is locked but relaxed just make sure to keep the whole leg rotating inward slightly. Focus on the stretch and pull in from the lower abdomen.