Soreness, pain, hurt-nonspecified injury

The first employee was using a backhoe to dig a 12" to 18" trench for the drill slurry, so the slurry water could be pumped away while concrete was being poured. The second employee instructed the first to pull forward so he could dig the pit for the pump head. The first employee put the backhoe in drive, but it lurched forward because it was still throttled up. The first employee tried to pull the shifter down into neutral, but it went all the way down into reverse. It backed up quickly, striking the second employee in the knee.