EE WAS CLIMBING DOWN LADDER FROM CAB ON 966 LOADER. HIS RIGHT FOOT GOT TANGLED ON 2ND RUNG AND HE LOST BALANCE CAUSING HIM TO FALL APPROX 3 FEET TO THE GROUND. HE FELL HITTING HIS HEAD ON THE GROUND CAUSING A MILD CONCUSSION. EE LOST CONCIOUSNESS FOR A VERY SHORT TIME.