Lunge pose builds strength, flexibility and balance. It opens the chest, relieves low back pain and can help with sciatica by releasing tension in the hips and groin.
If stability is a challenge, or if the yogi does not yet have enough strength to keep the back leg straight, the back knee can bend and lower to the floor. A yoga mat or blanket may be placed under the lowered knee so as to avoid compressing the knee cap unnecessarily.
Additional ways to entering the pose include standing forward bend or downward-facing dog pose.