EE WAS INSTALLING PIPE FROM THE WORKDECK OF A SCISSORLIFT WHEN A STABILIZER JACK SANK INTO SOFT MUCK CAUSING SCISSORLIFT TO TIP OVER AGAINST THERIB AND THROW HIM ONTO THE GROUND FROM A HEIGHT OF 8'. HE DID NOT REPORT THE INCIDENT UNTIL HE WAS ASKED AND DID NOT VISIT THE DOCTOR UNTIL 2/1/02. HE RECEIVED A CORTISONE INJECTION INTO AN INJURED SHOULDER. WAS NOT A FAILURE OF EQUIPMENT.