Modify Paschimottanasana as necessary to find safe alignment in your body.
If your hamstrings are tight or you find it difficult to focus on your breathing …
TRY bending your knees. With your feet flexed, press your knees together and bend them just until you’re able to grasp your feet. (If this connection is not possible yet, simply rest your hands on your ankles or shins.) Relax your neck, and bow your head toward your knees. Gaze at a place below the tip of your nose, and focus on the even length, sound, and movement of your breath as it moves in and out of your lungs and rib cage.
If you suffer from chronic back pain or disc issues …
TRY moving into the pose with a more neutral spine, allowing an anterior (forward) tilt in your pelvis. Establish this type of seat by relaxing your groins, moving your pubic bones toward the floor, and widening your sitting bones. Gently draw in and upward from your pelvic floor and low belly, which will create internal support to soften gripping in your back muscles. If you still feel discomfort, add a slight bend in your knees. Only go as far forward and down as you can without creating pressure in your back. Gradually reach for your ankles or feet (if it feels comfortable), maintaining length in your spine.
If your abdomen feels compressed and you find it difficult to take full, deep breaths …
TRY separating your legs slightly (no wider than the width of your hips), and bend your knees, which will put less pressure on your abdomen and diaphragm. Maintain the integrity of the posture by keeping your feet flexed with your knees pointing straight up in the same direction as your toes. Try to hold the outer edges of your feet, and relax your upper back. Draw in your inhales gradually, allowing your whole rib cage to expand.