If you want to know how to relax tight muscles in the lower back and how to stretch lower back pain, you’ve come to the right place. “Stretching the lower back counteracts some of the [postural] changes that come with age and gives your back muscles more breathing room,” he says. He also recommends spending a few minutes stretching the lower back any time your back feels stiff or you’ve just spent a prolonged time sitting, like at your desk or after a long flight.