Incorporating a foam roller into your pre-workout stretch is a great way to release tension in tight areas, especially in your calves and glutes. But if you're warming up, particularly before a weightlifting session, you should avoid rolling out your lower back. Foam rolling increases mobility — which makes unknotting your lower body helpful for getting deep into those squats — but loosening your lower back can increase your risk for injury.
According to Equinox personal trainer Erika Bonifacio, it's fine to roll out your thoracic spine (located in the upper half of your body), as it should be mobile. However, she advises against going any lower than the chest area.
"Having your low back too mobile can cause a lot of injury with lifting, but also just in daily motions," Erika told POPSUGAR. "For example, even sitting on a chair over time with too much flexion in the low back can eventually become a chronic injury, like a herniated disc."
Now let's say you're performing a deadlift with a flexed low back. This will cause you to put a load on your spine in a similar fashion, which may result in a herniated disc or a slip or ruptured spinal disc.
In addition to this tip, always keep proper form top of mind, and don't lift heavier than you can handle.