Had one in my lower back many years ago after persistent back pain/movement.
Slight discomfort for a few days afterwards but nothing compared to the pain I was in. Back kinda sorted itself over next month or two with rest/exercise so no need for further treament.
Would recommend.
Likely just a pull/strain if rest fixed it for you...know two with chronic back pain; you don't want it. Ones got worse after surgery,..using a cane at 38, in a 'kin wheel chair at 49... it's no life but I'm not gonna' tell him what he already knows.