This is #1 reason why you must look after the health of your spine. Stop doing crunches and sit ups ASAP! Use proper lifting techniques at work. Keep in shape and ensure your hamstrings are stretched. Ice and Advil after injury or hard workout. Stenosis can be prevented. Read more in Carswell.com JESleeth Preventing Back and Neck Pain.
Good advice! Heartened to hear about therapists who follow the maxim - "first, do no harm." I really like the posts and comments between this physical therapist and other therapists. Helps me understand more about sciatic nerve pain causes and treatment.