Employee bent over to open a bag of mansand to empty it out. When EE straightened their back they felt a pop. Injury is a result of ergonomic nature. Employee initially injured back on 10/08/2024 and has been trying to care for injury at home. Activities completed on 11/22/2024 aggravated the injury. Employee went in to ER on 11/24/2024 & was kept overnight for treatment to back.