Employee was using a torque multiplier to remove a bolt from a front end loader axle when the multiplier gear slipped causing EE to jerk forward, injuring EE's L pectoral. Employee was seen at the ER on 8/06/24 and given a return to work with restrictions, pending an MRI. EE stated it did not bother EE until then. An MRI was scheduled for 8/20/24 where EE was told to stay off work