Im in a lot of pain in my lower back and with every step i take my back pops. what could cause this?

Exam: Multiple issues and conditions can cause lower back pain. It is time to get examined, xrays, medical and PT evaluation. What do you mean ":Back pops"????? Call for an appointment.You must be examined.

Muscle spasm: Looks like you sprained your back. If the problem began within the last 24 hours, you can apply local cold. Otherwise, apply heat. You can also apply a topical over-the-counter methylsalicylate-type preparation, or take an oral nonsteroidal medication like ibuprofen if safe for you. You should avoid immobility and back braces unless directed by your physician. Hope that helps.