Indicates the employee was uncovering the ""muela"" (quarry mill) using the sling (eslinga) that adapts to the patella, the sling was stripped. EE tried to unlock it with a rope and a stone fell, hitting EE in the left arm. The employee reported to work the next day and EE's arm was swollen and in pain. The employee was absent on April 7 and goes to the private doctor.