A NEARBY EMPLOYEE WAS USING AN 8 LB SLEDGEHAMMER TO REMOVE A SHAFT. THE INJURED EMPLOYEE WALKED BEHIND THE EMPLOYEE USING THE SLEDGEHAMMER AT THE MOMENT HE PUT THE SLEDGEHAMMER TO REST ON HIS SHOULDER. THE INJURED EMPLOYEE WAS HIT ON TOP OF SHOULDER WITH THE HAMMER. THE BLOW WAS WITH MINIMAL IMPACT, BUT CAUSED SLIGHT BRUISING.