An employee was in the in the rear of a bucket truck making up material when another employee aloft in the bucket began to lower the basket to its cradled position. The employee in the back of the truck was struck on the right shoulder by the bottom of the basket, which caused forward momentum and positioned him between the basket rest and the basket as it came to its resting position. He suffered five broken ribs on the right side of his abdomen and a hemopneumothorax.