An employee was collecting carts in the parking lot using a cart pusher. The employee then used a remote control to move the line of carts through the front entrance door and into the vestibule. As the employee neared the rows of carts that were already in the vestibule, he attempted to move a misaligned cart out of the way of the carts he was bringing in and became pinned between the carts that were already in the vestibule and the carts he was bringing into the store. The employee sustained two broken knees.