Work in Pigeon pose here, rather than Full Locust pose.
Right side pigeon pose:
Slide the right knee forward, line it up just outside of the right hip and rest the right outer shin on the floor in front of you. Line the right heel in front of the left hip and stretch the left leg straight back.
Place the hands on the floor beside both hips to square the hips forward, and if you can balance here, stretch the arms up by the ears. For an increased stretch, move the right shin away from the body, but be careful not to compress the belly. Keep the hands on the floor to support the upper body if needed.