Steps you need to follow for doing Leg Extension Sideways Stretch:-
Lie down sideways on your left, with elbow bent on the ground, supporting the head with the palm.
Inhale and lift your right leg, keeping the knee straight and toes pointing diagonally. Exhale and bring it down. Repeat five times at a medium speed. Do not use jerky movements, and do not do it too slowly.
Turn to the opposite side on your right.
Inhale and light the left leg up, exhale down. Repeat the same exercise five times.
Make sure that the core is engaged for better results.